Skip to main content
Erschienen in: World Journal of Surgical Oncology 1/2023

Open Access 01.12.2023 | Research

Prognosis and local treatment strategies of breast cancer patients with different numbers of micrometastatic lymph nodes

verfasst von: Shiping Luo, Wenfen Fu, Jingyi Lin, Jie Zhang, Chuangui Song

Erschienen in: World Journal of Surgical Oncology | Ausgabe 1/2023

Abstract

Background

Lymph node micrometastasis is an important prognostic factor in breast cancer, but patients with different numbers of involved lymph nodes are all divided into the same N1mi stage without distinction. We designed this study to compare the prognosis and local treatment recommendations of N1mi breast cancer patients with different numbers of micrometastatic lymph nodes.

Patients and methods

A total of 27,032 breast cancer patients with T1-2N1miM0 stage from the Surveillance, Epidemiology, and End Results (SEER) database (2004–2019) who underwent breast surgery were included in this retrospective study. Patients were divided into three groups for prognosis comparison according to the number of micrometastatic lymph nodes: N1mi with 1 (Nmi = 1), 2 (Nmi = 2), or more (Nmi ≥ 3) involved lymph nodes. We explored the characteristics and survival outcomes of the population receiving different local treatments, including different axillary surgery types and whether receiving radiotherapy or not. Univariate and multivariate Cox proportional hazards regression analysis were used to compare the overall survival (OS) and breast cancer-specific survival (BCSS) in different groups. Stratified analyses and interaction analyses were also applied to explore the predictive significance of different involved lymph nodes numbers. Propensity score matching (PSM) method was utilized to balance the differences between groups.

Results

Univariate and multivariate Cox regression analysis indicated that nodal status was an independent prognostic factor. After adjustment for other prognostic factors, there was a significant difference in prognosis between Nmi = 1 group and Nmi = 2 group [adjusted hazard ratio (HR) 1.145, 95% confidence interval (CI): 1.047–1.251, P = 0.003], and patients with Nmi ≥ 3 group had a significantly poorer prognosis (adjusted HR 1.679, 95% CI 1.589–2.407; P < 0.001). The proportion of N1mi patients only underwent sentinel lymph nodes biopsy (SLNB) gradually increased from 2010 (Ptrend < 0.001). After adjusting for other factors, N1mi patients who underwent axillary lymph nodes dissection (ALND) was associated with significant survival benefit than SLNB (adjusted HR 0.932, 95%CI 0.874–0.994; P = 0.033), the same goes for receiving radiotherapy (adjusted HR 1.107, 95%CI 1.030–1.190; P = 0.006). Further stratified analysis showed that in the SLNB subgroup, radiotherapy was associated with a significant survival benefit (HR 1.695, 95%CI 1.534–1.874; P < 0.001), whereas in the ALND subgroup, there was no significant prognostic difference with or without radiotherapy (HR 1.029, 95%CI 0.933–1.136; P = 0.564).

Conclusion

Our study indicates that the increasing number of lymph node micrometastases was associated a worse prognosis of N1mi breast cancer patients. In addition, ALND does provide a significant survival benefit for these patients, while the benefit from local radiotherapy may be of even greater importance.
Hinweise

Supplementary Information

The online version contains supplementary material available at https://​doi.​org/​10.​1186/​s12957-023-03082-x.
Shiping Luo and Wenfen Fu contributed equally to this work.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Abkürzungen
OS
Overall survival
BCSS
Breast cancer-specific survival
PSM
Propensity score matching
LNMM
Lymph node micrometastases
SLNB
Sentinel lymph node biopsy
ALND
Axillary lymph node dissection
BCS
Breast-conserving surgery
ER
Estrogen receptor
PR
Progesterone receptor
HER2
Human epidermal growth factor receptor 2
IDC
Invasive ductal carcinoma
ILC
Invasive lobular carcinoma
WBRT
Whole breast radiation therapy
ART
Axillary radiotherapy
HR
Hazard ratio
CI
Confidence interval
DFS
Disease-free survival
LRR
Local recurrence rate
NAC
Neoadjuvant chemotherapy

Introduction

Lymph node micrometastases (LNMM) was defined as the presence of metastases no larger than 2 mm in the lymph nodes, which was firstly proposed by Huvos et al. in 1971 [1]. In 2002, the 6th edition of the American Joint Committee on Cancer (AJCC) Manual for Staging of Cancer based on lymph node involvement status, classified N staging into macrometastases (metastases lager than 2 mm), micrometastases (N1mi, metastases 0.2–2 mm in size), and isolated tumor cells (ITC, single tumor cells or small clusters of cells not larger than 0.2 mm, pN0(i +)) [2, 3]. After that, Patani et al. [4, 5] analyzed relevant literature on breast cancer LNMM, found that 12 of them (2000–2006) supported LNMM with independent prognostic significance and the prognosis is worse than that of lymph nodes without metastasis. While a recent multi-center cohort study from Sweden [6] showed that lymph node micrometastases were associated with significantly lower 10-year breast cancer-specific survival (BCSS) and overall survival (OS) rates compared with lymph node-negative cases, while outcomes were similar to those of lymph node macrometastases, which may be associated with inadequate systemic treatment. Although the conclusions of different studies are inconsistent, LNMM is still considered to be an important prognostic factor of breast cancer.
With the progress of comprehensive treatments of breast cancer, surgical treatment has gradually become more precise and less invasive. Hence, the local treatments of patients with LNMM have attracted more attention to further improve. Previous large clinical studies [711] have attempted to address the question of whether axillary lymph node dissection (ALND) can be safely omitted when micrometastases are found in sentinel lymph nodes (SLN). Although the 10-year follow-up results of IBCSG 23–01 [8] and the American College of Surgeons Oncology Group(ACOSOG) Z0011 trial [9] both support the avoidance of ALND in breast cancer patients with LNMM, most of these patients underwent breast-conserving surgery (BCS) plus whole breast radiation therapy (WBRT). Therefore, the conclusions of these two studies can only be applied to the clinical practice of relevant populations that meet the inclusion criteria and cannot be extrapolated to all pN1mi patients. In addition, the AMAROS trial [10] showed that axillary radiotherapy (ART) is the best alternative to ALND in patients with 1–2 sentinel lymph node (SLN) metastases.
Accordingly, National Comprehensive Cancer Network(NCCN) guideline [12] and American Society of Clinical Oncology(ASCO) guideline [13] recommend radiotherapy of the axilla in lieu of ALND in patients with pathological SLN-positive and low tumor burden. Patients with LNMM are also treated in the light of the guidelines’ recommendation for patients with positive lymph nodes. However, different numbers of involved lymph nodes are all divided into the same N1mi stage without categorization. We designed this study to compare the prognosis and local treatment recommendations of N1mi breast cancer patients with different numbers of micrometastatic lymph nodes.

Patients and methods

Data source and study population

We screened the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute to identify eligible breast cancer patients in this retrospective study. The SEER database is an open-access resource for cancer-based epidemiology and survival analyses (See Website “https://​seer.​cancer.​gov/​data/​” for detailed information). Data access for present study was authorized by SEER Program. As all patient information in the SEER database is de-identified, this study was exempt from Institutional Review Board evaluation.
The SEER*Stat version 8.4.0 was utilized to extract 32,032 pN1mi breast cancer patients’ information, diagnosed between January 2004 and December 2019 (Nov 2021 Submission). We excluded patients identified by death certificate or autopsy and with incomplete survival data. Female patients with T1-2 invasive breast cancer without distant metastasis and underwent breast surgery were included in this study. Patients who did not undergo surgery or whose type of surgery was unknown, had distant metastases, or had an unclear number of axillary lymph nodes examined were excluded (Supplemental Figure S1). The data elements include patient basic demographic characteristics, cancer pathological types, staging and molecular biomarkers status, the treatment received for the cancer, and survival outcomes information. It is worth noting that the information of epidermal growth factor receptor-2 (HER2) status in the SEER database has been registered from 2010, so the correlation analysis of HER2 status and molecular types only included case data since then.
Finally, a total of 27,032 female breast cancer patients, with a stage of T1-2N1miM0, were included in our retrospective study. Patients were divided into three groups for prognosis comparison according to the number of LNMM: N1mi with 1 (Nmi = 1), 2 (Nmi = 2), or more (Nmi ≥ 3) involved lymph nodes. Furthermore, survival outcomes of different local treatments, including axillary surgery types and radiotherapy, are required for these three groups. The number of lymph nodes removed was used as a surrogate for the type of axillary surgery which was defined as in previous similar studies [1417], that is, patients with 5 or less lymph nodes resected were categorized as receiving sentinel lymph node biopsy (SLNB) while 6 or more as undergoing ALND.

Statistical analysis

Patients-, tumor-, and treatment- level characteristics are presented as frequencies (N) and percentages, and compared using chi-square tests as appropriate. Kaplan–Meier method and log-rank test were used to draw survival curves and compare differences among different subgroups without adjustment for other factors. Univariate and multivariate cox regression analyses were used to identify independent prognostic factors and to calculate hazard ratios (HR) toward target subgroups after adjustment for other prognostic factors. Stratified analyses and interaction analyses were also applied to explore the predictive significance of different LNMM involved numbers.
In the analysis of axillary surgery and radiotherapy, we adopted the method of 1:1 nearest propensity score matching (PSM) with matching tolerance 0.02, in order to balance the characteristic differences between the two compared axillary surgery groups, covariables included in propensity score matching were age, race, marital status, grade, T stage, nodal status, estrogen receptor (ER) status, progesterone receptor (PR) status, HER2 status, type of breast surgery, radiation and chemotherapy. All tests were two-sided, and a P value < 0.05 was considered to be statistically significant. All statistical analyses were performed using IBM SPSS software version 24.0 (IBM Corp., Armonk, USA) and R version 4.1.3 (The R Project for Statistical Computing, Vienna, Austria).

Results

Basic characteristics and survival analyses of the overall population

A total of 27,032 patients with T1-2N1miM0 breast cancer were included in this study, of which 22,463 (83.1%) were involved in one LNMM, 3,089 (11.4%) in two, and 1,480 (5.5%) in three or more lymph nodes. The patient’s basic characteristics are shown in Table 1. There were 21,466 (77.9%) patients with pathological type of invasive ductal carcinoma (IDC) and 2123 (7.9%) of invasive lobular carcinoma (ILC). Among all the patients, 59.1% had tumors no larger than 2 cm in size, and the remaining 40.9% had tumors between 2 and 5 cm. Most patients were hormone receptor positive (ER positive 85.9%, progesterone receptor (PR) positive 76.3%) and HER2 negative (84.1%, after 2010). A total of 15,622(57.8%) patients underwent SLNB, of which 14,293(91.5%) were patients with one LNMM, accounting for 63.6% of the Nmi = 1 subgroup. While in the Nmi = 2 subgroup, the proportion of receiving SLNB decreased to 38.1%, and the remaining 61.9% of patients received ALND.
Table 1
Demographic and clinical characteristics of patients, stratified by the number of micrometastatic lymph nodes
Characteristics
Total
N1mi = 1
N1mi = 2
N1mi ≥ 3
P value
N
27,032
22,463
3089
1480
 
Age, years
    
 < 0.001
  < 40
1838 (6.8)
1463 (6.5)
250 (8.1)
125 (8.4)
 
 40–59
13,141 (48.6)
10,813 (48.1)
1567 (50.7)
761 (51.4)
 
  ≥ 60
12,053 (44.6)
10,187 (45.4)
1272 (41.2)
594 (40.1)
 
Race
    
 < 0.001
 White
21,466 (79.4)
17,954 (79.9)
2398 (77.6)
1114 (75.3)
 
 Black
2793 (10.3)
2198 (9.8)
379 (12.3)
216 (14.6)
 
 Other a
2773 (10.3)
2311 (10.3)
312 (10.1)
150 (10.1)
 
Marital
    
0.003
 Married
16,130 (59.7)
13,501 (60.1)
1793 (58.0)
836 (56.5)
 
 Single b
9822 (36.3)
8094 (36.0)
1147 (37.1)
581 (39.3)
 
 Unknown
1080 (4.0)
868 (3.9)
149 (4.8)
63 (4.3)
 
Histological types
    
0.038
 IDC
21,070 (77.9)
17,565 (78.2)
2377 (77.0)
1128 (76.2)
 
 ILC
2123 (7.9)
1725 (7.7)
254 (8.2)
144 (9.7)
 
 Other
3839 (14.2)
3173 (14.1)
458 (14.8)
208 (14.1)
 
Grade
    
 < 0.001
 I
5252 (19.4)
4596 (20.5)
496 (16.1)
160 (10.8)
 
 II
12,950 (47.9)
10,786 (48.0)
1483 (48.0)
681 (46.0)
 
 III
8167 (30.2)
6578 (29.3)
1013 (32.8)
576 (38.9)
 
 Unknown
663 (2.5)
503 (2.2)
97 (3.1)
63 (4.3)
 
T stage
    
 < 0.001
 T1
15,986 (59.1)
13,758 (61.2)
1613 (52.2)
615 (41.6)
 
 T2
11,046 (40.9)
8705 (38.8)
1476 (47.8)
865 (58.4)
 
Type of surgery
    
 < 0.001
 BCS
14,826 (54.8)
12,768 (56.8)
1522 (49.3)
536 (36.2)
 
 Mastectomy
12,206 (45.2)
9695 (43.2)
1567 (50.7)
944 (63.8)
 
Type of axillary surgery
    
 < 0.001
 SLNB
15,622 (57.8)
14,293 (63.6)
1176 (38.1)
153 (10.3)
 
 ALND
11,410 (42.2)
8170 (36.4)
1913 (61.9)
1327 (89.7)
 
Radiation
    
0.181
 Yes
14,368 (53.2)
11,995 (53.4)
1598 (51.7)
775 (52.4)
 
 No/refused
12,664 (46.8)
10,468 (46.6)
1491 (48.3)
705 (47.6)
 
Chemotherapy
    
 < 0.001
 Yes
14,039 (51.9)
11,021 (49.1)
1913 (61.9)
1105 (74.7)
 
 No/unknown
12,993 (48.1)
11,442 (50.9)
1176 (38.1)
375 (25.3)
 
ER status
    
 < 0.001
 Positive
23,208 (85.9)
19,446 (86.6)
2593 (83.9)
1169 (79.0)
 
 Negative
3271 (12.1)
2586 (11.5)
421 (13.6)
264 (17.8)
 
 Borderline
553 (2.0)
431 (1.9)
75 (2.4)
47 (3.2)
 
PR status
    
 < 0.001
 Positive
20,631 (76.3)
17,285 (76.9)
2315 (74.9)
1031 (69.7)
 
 Negative
5649 (20.9)
4584 (20.4)
675 (21.9)
390 (26.4)
 
 Borderline
752 (2.8)
594 (2.6)
99 (3.2)
59 (4.0)
 
HER2 status
    
 < 0.001
 Positive
2048 (7.6)
1690 (7.5)
243 (7.9)
115 (7.8)
 
 Negative
13,957 (51.6)
12,044 (53.6)
1409 (45.6)
504 (34.1)
 
 Borderline
600 (2.2)
488 (2.2)
64 (2.1)
48 (3.2)
 
 Not 2010 + 
10,427 (38.6)
8241 (36.7)
1373 (44.4)
813 (54.9)
 
IDC invasive ductal carcinoma, ILC invasive lobular carcinoma, SLNB sentinel lymph node biopsy, ALND axillary lymph node dissection, BCS breast-conserving surgery, ER estrogen receptor, PR progesterone receptor; HER2 human epidermal growth factor receptor 2
aOther includes American Indian/Alaskan native, and Asian/Pacific Islander
bSingle includes divorced, separated, single (never married), unmarried or domestic partner and widowed
The univariate and multivariate cox regression analysis (Supplemental Table S1) indicated that age, race, marital status, histologic type, grade, T stage, number of LNMM, ER, PR, HER2 status, and different type of adjuvant treatments were independent prognostic factors in the T1-2N1miM0 breast cancer population. After adjustment for other prognostic factors, the overall death risk of Nmi = 2 increased by 1.145 times (95%CI 1.047–1.251, P = 0.003) compared with Nmi = 1, and the risk of Nmi ≥ 3 group increased by 1.697 times (95%CI 1.53–1.882, P < 0.001) (Fig. 1). Therefore, within the same pN1mi stage, the prognosis of different numbers of LNMM was significantly different.

Descriptive statistics and survival analyses of axillary surgery types

Baseline characteristics for different types of axillary surgery are presented in Supplemental Table S2. It is shown that in the T1-2N1miM0 population, patients older than 60 were more likely to receive SLNB, and patients younger than 40 were more likely to undergo ALND. In addition, patients underwent breast-conserving surgery (BCS) were more likely to receive SLNB, while ALND was more common in patients with mastectomy. In Fig. 2, it can be clearly seen that before 2010, most of the patients with pN1mi received ALND. And after 2011, the number of patients has gradually decreased. The number of different axillary surgery types reversed between 2010 and 2011. Overall, the proportion of pN1mi patients receiving SLNB is increasing year by year(P for trend < 0.001). Among them, the patients with one LNMM are the most significant (Supplemental Table S3).
However, in the overall population, ALND was associated with better overall survival than SLNB (adjusted HR 0.932, 95%CI 0.874–0.994; P = 0.033) (Supplemental Table S1), this trend was also the same in the Nmi = 1 subgroup (adjusted HR: 0.926, 95%CI 0.859–0.990; P = 0.026) and the Nmi = 2 subgroup(adjusted HR 0.828, 95%CI 0.691–0.993; P = 0.042) (Fig. 3A–C). To further verify this conclusion, we performed 1:1 PSM on SLNB and ALND cohorts, and there was ditto significant difference in survival between the two groups after matching (HR 0.875, 95%CI 0.813–0.940; P < 0.001). The same result was found in the Nmi = 1 subgroup (HR 0.881, 95%CI 0.814–0.953; P = 0.002), and the Nmi = 2 subgroup (HR 0.791, 95%CI 0.644–0.972; P = 0.026) (Fig. 3D–F).

Stratified analyses of radiation and interaction analyses

After adjustment for other factors, receiving radiotherapy resulted in some improvement in prognosis (HR 1.107, 95%CI 1.030–1.190; P = 0.006) (Fig. 4). Further stratification analyses showed that the benefit of radiation was significant for IDC patients (HR 1.116, 95%CI 1.028–1.211; P = 0.009), but not for ILC (HR: 0.948, 95%CI 0.742–1.210; P = 0.666) and other types of carcinoma. In the SLNB subgroup, radiotherapy was associated with a significant survival benefit (adjusted HR 1.197, 95%CI 1.076–1.331, P = 0.001), whereas in the ALND subgroup, there was no significant prognostic difference with or without radiotherapy (HR 1.029, 95%CI 0.933–1.136; P = 0.564) (Supplemental Figure S2).
We performed an interaction analysis between axillary surgery type with radiotherapy and obtained significant results. This means that the radiotherapy benefit difference between the with and without radiotherapy in the SLNB and ALND subgroups is distinct. According to the survival analysis (Fig. 5) of different local treatments combinations, it appears that receiving SLNB plus radiation has the best prognosis, while SLNB without radiotherapy gain the worst prognosis. There was no significant difference in survival outcomes between SLNB and ALND with radiotherapy (P = 0.121), nor between the two groups without radiotherapy (P = 0.113). However, the difference in survival between radiotherapy and no radiotherapy was prominent. When the number of LNMM was only one, the conclusion was consistent with the above. However, when two lymph nodes were involved, the combination of ALND plus radiotherapy transformed the best prognosis.

Discussion

From the 6th edition of AJCC manual [2] for staging to the latest 8th edition [14], no matter how many number of micrometastasis lymph nodes were detected, they were all divided into the same pN1mi staging, and the difference in prognosis caused by the inconsistent number was not distinguished. Evidence that the number of macrometastatic lymph nodes negatively affects survival outcome [1820] prompted refinement of the staging system. We designed this study to distinguish the prognosis and local treatment recommendations of N1mi breast cancer patients with different numbers of micrometastatic lymph nodes involved. Our study demonstrated that for breast cancer patients with identical T1-2N1miM0 stage, the greater number of LNMM, the worse the prognosis (P < 0.001).
To investigate the prognostic significance of axillary lymph node micrometastases, the MIRROR trial [21] was the first retrospective cohort study of patients with LNMM and ITC, which confirmed that for patients who did not receive adjuvant therapy, both pN0(i +) and pN1mi stages are independent prognostic indicators. There is no significant survival difference in prognosis between pN0(i +) and pN1mi stage patients, and both pN0(i +) and pN1mi stage patients can benefit from adjuvant therapy. The NSABP B-32 trial [11, 22] enrolled 3795 breast cancer patients who underwent BCS and received postoperative whole-breast radiotherapy(WBRT) and systemic adjuvant therapy. After a median follow-up of 95 months, there was no significant difference in disease-free survival (DFS), OS and distant metastasis-free survival between pN1mi and pN0 stage patients. There are also discussions on the prognostic significance of the involved lymph node number in patients with pNmi stage. Roi Weiser et al. [15] used National Cancer Database (NCDB) data to analyze the prognosis of lymph nodes status, and concluded all nodal status had a positive effect on survival compared with Nmic > 1 status, with HRs of 0.68, 0.88, and 0.93 for N0, Nmi = 1, and N1.1 disease respectively, with only N0 reaching statistical significance.
Through the SEER database registration data, it can be observed that before 2010, more pNmi patients chose to receive ALND, but this situation changed in 2011, and SLNB only became a preferred option for more patients, and the proportion of undergoing SLNB has since increased year by year. Until the most recent follow-up in 2019, about 79.84% of patients only received SLNB, and the proportion of patients with only one LNMM was as high as 82.14%. The management of the axilla in patients with LNMM has a long history. In 2010, Yi et al. [23] reported a retrospective study on the choice of SLNB or ALND in patients with axillary lymph node-positive breast cancer. There were 6838 breast cancer patients with LNMM, of which 2240 received SLNB and 4598 received ALND, and post-surgery relevant systemic therapy and local radiation therapy. After 50 months of follow-up, there was no significant difference in the recurrence rate between patients who underwent SLNB only and those who underwent ALND. However, in our study, ALND does provide a significant survival benefit for N1mi breast cancer patients after a median follow-up of 95 months, whether in multivariate-adjusted cox regression analyses or survival analyses after PSM.
Both IBCSG 23–01 [8] and ACOSOG Z0011 [9] suggest that axillary dissection can be avoided in patients with early breast cancer and limited sentinel lymph node involvement. However, since more than 90% of the patients received BCS + whole breast radiotherapy in these two trials, the results are only applicable to the status of the enrolled population. AATRM trial [24] is a prospective and randomized clinical trial specifically targeting the early breast cancer patients with sentinel lymph node micrometastases, it randomized patients to ALND or clinical follow-up and showed no significant difference in DFS between two groups. Another multi-institutional prospective study of 260 pT1-2Nmi post-mastectomy patients reported from Lim SZ et al. [25] suggested that no statistically significant differences were found between patients with SLNB, ALND, or PMRT. Nonetheless, our study found discrepant results with different numbers of LNMM involved. SLNB with radiotherapy had the best prognosis when there was only one lymph node micrometastasis, while when the number of micrometastatic lymph nodes increased to two, ALND plus radiotherapy had the best survival outcome. Although only whether received radiotherapy or not achieved significant benefit, it still suggested that when the number of lymph node involved is different, the treatment mode should be focused and cannot be static.
The recently published prospective SENOMIC trial [26] omitting a completion ALND in breast cancer patients with sentinel LNMM, and found that patients who had mastectomy without adjuvant radiotherapy had a significantly higher risk of recurrence than those who underwent breast-conserving surgery. As with trials such as IBCSG23-01 and Z0011, radiotherapy after BCS plays an important role in improving outcomes. In our stratification analysis of different treatments, we found that there was no significant difference in survival between different axillary surgery types, with or without radiotherapy. While when patients have undergone different types of axillary surgery, whether they receive radiotherapy become important. When pNmi breast cancer patients only underwent SLNB, compared with those who received radiotherapy, the HR value of without radiotherapy was 1.695 (95%CI 1.534–1.874; P < 0.001).
Stratified analyses and interaction analysis in our study indicate that the benefit from local radiotherapy in pN1mi patients may be of even greater importance on the survival outcome. AMAROS trial [10] testified axillary radiotherapy is the best option to replace ALND when 1–2 SLNs have metastasized in T1-2 breast cancer patients, which can improve the quality of life without affecting DFS and OS. The OTOASOR trial [27] also have proved the equivalence of ALND and ART in patients with low lymph nodal burden. These two trials included 29% and 25% of patients with microscopic nodal disease respectively. In 2018, Wu SP et al. [28] reported a retrospective study that evaluated the survival impact of PMRT in patients with N1mi within the National Cancer Database, and found that no OS differences were associated with PMRT, whether in the SLNB group or the ALND group. Another two large, single-institution studies separately from Memorial Sloan Kettering Cancer Center and MD Anderson Cancer Center [29, 30] demonstrated no difference in local recurrence rates(LRR) for patients with N1mi disease post-mastectomy and SLNB, regardless of further radiation or ALND. However, a study from Merfeld EC et al. [31] indicated that pN1mi patients with grade 3 were observed to be at substantial risk for LRR, and radiotherapy was associated with a lower risk of LRR.
Inevitably, there are several limitations related to its design and data source in our study. Firstly, this is a retrospective study derived from a public database, although PSM-based analyses can reduce the effects of the observed confounders, it cannot address unobserved confounders nor the inevitable cases-loses. Secondly, locoregional recurrence cannot be captured in the SEER database. And it is also unfortunate that cases receiving neoadjuvant chemotherapy (NAC) could not be identified in the SEER database, so axillary management cannot be discussed in patients receiving NAC.

Conclusion

Our study indicates that the increasing number of LNMM was associated a worse prognosis of N1mi breast cancer patients. And ALND does provide a significant survival benefit for N1mi patients, while the benefit from local radiotherapy may be of even greater importance, avoidance of ALND can be considered in patients receiving radiotherapy. In addition, local treatment strategies for breast cancer patients with different numbers of micrometastatic lymph nodes should be individualized and cannot be generalized.

Declarations

Not applicable. SEER is a publically available anonymous data source, so this study was not reviewed by a Human Subjects Committee.

Competing interests

The authors declare no competing interests.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://​creativecommons.​org/​licenses/​by/​4.​0/​. The Creative Commons Public Domain Dedication waiver (http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Literatur
2.
Zurück zum Zitat Greene FL. In: American Joint Committee on Cancer, American Cancer Society, editor. AJCC cancer staging manual. 6th ed. New York: Springer; 2002.CrossRef Greene FL. In: American Joint Committee on Cancer, American Cancer Society, editor. AJCC cancer staging manual. 6th ed. New York: Springer; 2002.CrossRef
4.
Zurück zum Zitat Patani N, Mokbel K. The clinical significance of sentinel lymph node micrometastasis in breast cancer. Breast Cancer Res Treat. 2009;114(3):393–402.CrossRefPubMed Patani N, Mokbel K. The clinical significance of sentinel lymph node micrometastasis in breast cancer. Breast Cancer Res Treat. 2009;114(3):393–402.CrossRefPubMed
5.
Zurück zum Zitat Chen SL, Hochne FM, Giuliano AE. The prognostic significance of micrometastases in breast cancer: a SEER population-based analysis. Ann Surg Oncol. 2007;14(12):3378–84.CrossRefPubMed Chen SL, Hochne FM, Giuliano AE. The prognostic significance of micrometastases in breast cancer: a SEER population-based analysis. Ann Surg Oncol. 2007;14(12):3378–84.CrossRefPubMed
21.
Zurück zum Zitat de Boer M, van Deurzen CH, van Dijck JA, et al. Micrometastases or isolated tumor cells and the outcome of breast cancer. N Engl J Med. 2009;361(7):653–63.CrossRefPubMed de Boer M, van Deurzen CH, van Dijck JA, et al. Micrometastases or isolated tumor cells and the outcome of breast cancer. N Engl J Med. 2009;361(7):653–63.CrossRefPubMed
23.
Zurück zum Zitat Yi M, Giordano SH, Meric-Bernstam F, et al. Trends in and outcomes from sentinel lymph node biopsy (SLNB) alone vs. SLNB with axillary lymph node dissection for node-positive breast cancer patients: experience from the SEER database. Ann Surg Oncol. 2010;17 Suppl 3(0 3):343–351. https://doi.org/10.1245/s10434-010-1253-3. Yi M, Giordano SH, Meric-Bernstam F, et al. Trends in and outcomes from sentinel lymph node biopsy (SLNB) alone vs. SLNB with axillary lymph node dissection for node-positive breast cancer patients: experience from the SEER database. Ann Surg Oncol. 2010;17 Suppl 3(0 3):343–351. https://​doi.​org/​10.​1245/​s10434-010-1253-3.
27.
Zurück zum Zitat Sávolt Á, Péley G, Polgár C, et al. Eight-year follow up result of the OTOASOR trial: The Optimal Treatment Of the Axilla - Surgery Or Radiotherapy after positive sentinel lymph node biopsy in early-stage breast cancer: a randomized, single centre, phase III, non-inferiority trial. Eur J Surg Oncol. 2017;43(4):672–9. https://doi.org/10.1016/j.ejso.2016.12.011.CrossRefPubMed Sávolt Á, Péley G, Polgár C, et al. Eight-year follow up result of the OTOASOR trial: The Optimal Treatment Of the Axilla - Surgery Or Radiotherapy after positive sentinel lymph node biopsy in early-stage breast cancer: a randomized, single centre, phase III, non-inferiority trial. Eur J Surg Oncol. 2017;43(4):672–9. https://​doi.​org/​10.​1016/​j.​ejso.​2016.​12.​011.CrossRefPubMed
29.
Zurück zum Zitat Mamtani A, Patil S, Stempel M, Morrow M. Axillary micrometastases and isolated tumor cells are not an indication for post-mastectomy radiotherapy in stage 1 and 2 breast cancer [published correction appears in Ann Surg Oncol. 2017 Jul 17;:]. Ann Surg Oncol. 2017;24(8):2182–2188. https://doi.org/10.1245/s10434-017-5866-7. Mamtani A, Patil S, Stempel M, Morrow M. Axillary micrometastases and isolated tumor cells are not an indication for post-mastectomy radiotherapy in stage 1 and 2 breast cancer [published correction appears in Ann Surg Oncol. 2017 Jul 17;:]. Ann Surg Oncol. 2017;24(8):2182–2188. https://​doi.​org/​10.​1245/​s10434-017-5866-7.
31.
Zurück zum Zitat Merfeld EC, Burr AR, Brickson C, Neuman HB, Anderson BM. De-escalating locoregional therapy for axillary micrometastases in breast cancer: how much is too much? [published online ahead of print, 2022 Jan 12]. Clin Breast Cancer. 2022;S1526–8209(22)00016–7. https://doi.org/10.1016/j.clbc.2022.01.001. Merfeld EC, Burr AR, Brickson C, Neuman HB, Anderson BM. De-escalating locoregional therapy for axillary micrometastases in breast cancer: how much is too much? [published online ahead of print, 2022 Jan 12]. Clin Breast Cancer. 2022;S1526–8209(22)00016–7. https://​doi.​org/​10.​1016/​j.​clbc.​2022.​01.​001.
Metadaten
Titel
Prognosis and local treatment strategies of breast cancer patients with different numbers of micrometastatic lymph nodes
verfasst von
Shiping Luo
Wenfen Fu
Jingyi Lin
Jie Zhang
Chuangui Song
Publikationsdatum
01.12.2023
Verlag
BioMed Central
Erschienen in
World Journal of Surgical Oncology / Ausgabe 1/2023
Elektronische ISSN: 1477-7819
DOI
https://doi.org/10.1186/s12957-023-03082-x

Weitere Artikel der Ausgabe 1/2023

World Journal of Surgical Oncology 1/2023 Zur Ausgabe

Vorsicht, erhöhte Blutungsgefahr nach PCI!

10.05.2024 Koronare Herzerkrankung Nachrichten

Nach PCI besteht ein erhöhtes Blutungsrisiko, wenn die Behandelten eine verminderte linksventrikuläre Ejektionsfraktion aufweisen. Das Risiko ist umso höher, je stärker die Pumpfunktion eingeschränkt ist.

Darf man die Behandlung eines Neonazis ablehnen?

08.05.2024 Gesellschaft Nachrichten

In einer Leseranfrage in der Zeitschrift Journal of the American Academy of Dermatology möchte ein anonymer Dermatologe bzw. eine anonyme Dermatologin wissen, ob er oder sie einen Patienten behandeln muss, der eine rassistische Tätowierung trägt.

Deutlich weniger Infektionen: Wundprotektoren schützen!

08.05.2024 Postoperative Wundinfektion Nachrichten

Der Einsatz von Wundprotektoren bei offenen Eingriffen am unteren Gastrointestinaltrakt schützt vor Infektionen im Op.-Gebiet – und dient darüber hinaus der besseren Sicht. Das bestätigt mit großer Robustheit eine randomisierte Studie im Fachblatt JAMA Surgery.

Chirurginnen und Chirurgen sind stark suizidgefährdet

07.05.2024 Suizid Nachrichten

Der belastende Arbeitsalltag wirkt sich negativ auf die psychische Gesundheit der Angehörigen ärztlicher Berufsgruppen aus. Chirurginnen und Chirurgen bilden da keine Ausnahme, im Gegenteil.

Update Chirurgie

Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert.

S3-Leitlinie „Diagnostik und Therapie des Karpaltunnelsyndroms“

Karpaltunnelsyndrom BDC Leitlinien Webinare
CME: 2 Punkte

Das Karpaltunnelsyndrom ist die häufigste Kompressionsneuropathie peripherer Nerven. Obwohl die Anamnese mit dem nächtlichen Einschlafen der Hand (Brachialgia parästhetica nocturna) sehr typisch ist, ist eine klinisch-neurologische Untersuchung und Elektroneurografie in manchen Fällen auch eine Neurosonografie erforderlich. Im Anfangsstadium sind konservative Maßnahmen (Handgelenksschiene, Ergotherapie) empfehlenswert. Bei nicht Ansprechen der konservativen Therapie oder Auftreten von neurologischen Ausfällen ist eine Dekompression des N. medianus am Karpaltunnel indiziert.

Prof. Dr. med. Gregor Antoniadis
Berufsverband der Deutschen Chirurgie e.V.

S2e-Leitlinie „Distale Radiusfraktur“

Radiusfraktur BDC Leitlinien Webinare
CME: 2 Punkte

Das Webinar beschäftigt sich mit Fragen und Antworten zu Diagnostik und Klassifikation sowie Möglichkeiten des Ausschlusses von Zusatzverletzungen. Die Referenten erläutern, welche Frakturen konservativ behandelt werden können und wie. Das Webinar beantwortet die Frage nach aktuellen operativen Therapiekonzepten: Welcher Zugang, welches Osteosynthesematerial? Auf was muss bei der Nachbehandlung der distalen Radiusfraktur geachtet werden?

PD Dr. med. Oliver Pieske
Dr. med. Benjamin Meyknecht
Berufsverband der Deutschen Chirurgie e.V.

S1-Leitlinie „Empfehlungen zur Therapie der akuten Appendizitis bei Erwachsenen“

Appendizitis BDC Leitlinien Webinare
CME: 2 Punkte

Inhalte des Webinars zur S1-Leitlinie „Empfehlungen zur Therapie der akuten Appendizitis bei Erwachsenen“ sind die Darstellung des Projektes und des Erstellungswegs zur S1-Leitlinie, die Erläuterung der klinischen Relevanz der Klassifikation EAES 2015, die wissenschaftliche Begründung der wichtigsten Empfehlungen und die Darstellung stadiengerechter Therapieoptionen.

Dr. med. Mihailo Andric
Berufsverband der Deutschen Chirurgie e.V.