Background
Ampullary cancer was the second common peri-ampullary malignancy. Recent literatures reported a 5-year survival rate ranging from 32% to 65%.[
1-
5] Pancreatoduodenectomy (PD), the standard surgical strategy for ampullary cancer, was still associated with high rate of postoperative complications, reaching to 33%-52%.[
5,
6] Therefore, local ampullectomy had been attempted to be an alternative to PD for early cancer .
Local ampullectomy, first described by Halsted in 1899, was generally accepted in treatment of small benign tumors; but controversy still remained about expanding the indications to early ampullary cancers (mainly focusing on pT1) because of the high rate of recurrence.[
6-
10] Furthermore, because of the limited number of ampullary cancer patients, as regards to the surgical mode of early ampullary cancers, indications for performing local ampullectomy were not very clear and well-accepted.
In this study, we collected patients with pT1 ampullary cancers who underwent a surgical treatment, including PD and local ampullectomy; and further analysis were done to determine the feasibility of local ampullectomy.
Methods
Patients
There were 89 patients with a pT1 ampullary adenocarcinoma who underwent surgical resection at the First Affiliated Hospital of Zhengzhou University between January, 1978 and December, 2010. Carcinomas of the distal bile duct, pancreas, or duodenum, as well as carcinoid tumors of the ampulla, were excluded. The pT1 stage meant that according to the seventh edition of the American Joint Committee on Cancer (AJCC), the tumor was confined to ampulla of Vater, As present study sought to examine the outcomes following surgical management of ampullary cancers, patients who had endoscopic excision of ampullary neoplasm were also excluded from this study. All the patients did not receive adjuvant therapy. The following data were collected: demographics, operation details, postoperative complications, tumor size, lymph node metastasis, lymphovascular invasion. Specific complications such as pancreatic fistula and delayed gastric emptying were defined according to the International Study Group of Pancreatic Surgery definition.[
11,
12] This research was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University.
Pre-operative staging
All the patients had a magnetic resonance (MR) examination before operation. Endoscopic ultrasound (EUS) was used to determine the stage of 82 patients after 1990.
Operative approach
Following were rules for choosing operation approach: 1. If the tumor size was >4 cm, PD would be performed. 2. For patients with enlarged abdominal lymph node identified by pre-operative imaging examination, PD would be performed. 3. For patients who were older than 70 years and refused to receive PD, local ampullectomy was performed.
The technique of pancreaticoduodenectomy was performed as previously described.[
2,
11] Drains were routinely placed intraoperatively near the pancreatic and biliary anastomoses. Local ampullectomy consisted of local resection of the ampulla through a transduodenal approach followed by a pancreaticobiliary sphincteroplasty.[
9] Lymphadenectomy was not conducted.
Statistical analysis
Categorical variables were compared using Fisher’s exact test. Continuous variables were compared using the Mann–Whitney sum test. Actuarial survival was estimated using the non-parametric product limit method (e.g. Kaplan–Meier) and differences in survival were examined by the log-rank test. Multivariate Cox proportional hazard models were employed to determine clinicopathological factors which were associated with long-term survival. The most parsimonious model was created using a step-wise approach, which included factors with statistically significance (e.g.P ≤ 0.10) in univariate analysis. Averages were provided as median values and statistical significance was designated as P < 0.05. All statistical analysis were performed using SPSS 17.0 software (SPSS Inc. Chicago, IL, USA).
Discussion
Early ampullary cancers limited to the ampulla of Vater (pT1) showed a fairly good prognosis. These tumors could be radically removed in all cases and showed a 5-year survival rate of 60% to 90% according to the previous reports.[
5,
13,
14] In order to achieve such a good outcome, complete resection of the tumor was mandatory.[
15,
16].
There was no doubt that the standard operation for ampullary cancer should be PD. But PD showed high rate of postoperative complications, so local ampullectomy had been an alternative for early ampullary cancer and showed comparable survival as PD [
17-
20]. In this study, we identified patients with pT1 ampullary cancer treated with local ampullectomy and standard PD, and analysed the clinical data of these patients. The results showed that patients treated with local ampullectomy showed overall survival equal to those patients treated with PD; but the disease-free survival time turned to be shorter in patients treated with local ampullectomy than that in patients treated with PD. Among the clinicopathological factors, lymph node metastasis was the main one which caused ampullectomy fail.
Therefore, the indications for local ampullectomy treatment should and must be fully explained and strictly executed. Botsios [
18] et al. recommended ampullectomy for T1 cancer and Yoon et al. [
5] recommended it for pTis cancers or pT1 cancers with size≦ 1.0 cm in patients with a high operative risk. However, because of lack of a large multi-center clinical studies, a generally accepted standard was still lacking.
Various of investigations were available for staging ampullary tumors, including CT scanning, magnetic resonance (MR) imaging, endoscopic ultrasound (EUS) and transpapillary intraductal ultrasound. Although EUS could accurately define the depth of invasion in 75% to 83% of cases, the reported accuracy of EUS for detecting lymph node metastasis ranged from 54% to 68%. [
21-
23] CT scanning had been compared with EUS in staging utility in a number of studies and shown a lower agreement for T and N staging with the histopathology when compared with EUS.[
23-
25] MR imaging had been reported that it harbored a sensitivity of 46% to 93.3% [
26-
28] in T staging; and one study presented a sensitivity of 77% for nodal detection [
26]. In these patients included in this study, EUS was superior to MR in T staging, and achieved an accuracy of 87.8%; and only 2.4% patients were under-staged. So, EUS was strongly recommended before operation.
Previous studies showed that lymph nodes metastasis was associated with tumor size and tumor grade. Bottger and Junginger [
29] reported that lymph node metastases was not found in tumors smaller than 0.6 cm, or in well-differentiated tumors; so local ampullectomy for ampullary cancer might be used in such cases. Brown [
30] reported 10 cases of pT1 ampullary cancers with no lymph node metastasis. Winter et al. [
6] also reported that tumor size ≥ 1 c m, poor histological grade, perineural invasion, microscopic vessel invasion and T stage were significantly associated with lymph node metastasis. Lymph node metastases were present in nearly 30% of patients with T1 diseases. In present study, we explored the relationship between lymph node metastasis and the clinicalpathological factors. The result showed that patients with pT1 cancers had a 34.92% (22/63) rate of lymph node metastasis. Rate of lymph node metastasis in patients with well-differentiated tumors was 8%,; In patients with tumor size ≤1 cm it was 15% and in patients with ulcerative tumor morphology it was 40.74%. This meant that well-differentiated tumors with polypoid gross morphology and size≦1 cm might be the indications of local ampullectomy in high operative risk patients.
However, there were some disadvantages in our study. Firstly, this study was retrospectively conducted, resulting in less strong evidence. Secondly, this was a single center study, the number of patients were limited. Therefore, a large scale, multi-center RCT study should be performed in the future to verify the feasibility of local ampullectomy in high risk patients.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
JS, ZL and HL were the key authors for the conception, design, coordination, and drafting of the manuscript, as well as the analysis and interpretation of the data. CY, YS and CW participated in the design and interpretation of the data and helped in drafting the manuscript. YS and CW contributed substantively by revising the manuscript critically for intellectual content and participating in the interpretation of data and the revision of the manuscript. All authors read and approved the final manuscript.