Background
Methods
Patients
Neoadjuvant chemotherapy
Assessment of the response to neoadjuvant chemotherapy
CT images acquisition
Radiomics feature extraction
Feature reduction and model building
Model evaluation and comparison
Survival analysis
Statistical analyses
Results
Baseline characteristics
Factors | Training cohort (n = 74) | Validation cohort (n = 32) | P value |
---|---|---|---|
Age (years, mean ± SD) | 55.15 ± 11.43 | 54.13 ± 12.68 | 0.68 |
Gender | 0.53 | ||
Male | 48 | 18 | |
Female | 26 | 14 | |
BMI (kg/m2) | 21 ± 3 | 22 ± 3 | 0.12 |
Preoperative T stage | 0.39 | ||
2 | 1 | 0 | |
3 | 11 | 2 | |
4 | 62 | 29 | |
Preoperative N status | 0.99 | ||
0 | 2 | 1 | |
1–3 | 72 | 31 | |
Preoperative M status | 0.85 | ||
0 | 47 | 19 | |
1 | 27 | 13 | |
Postoperative T stage | 0.83 | ||
1–2 | 11 | 6 | |
3–4 | 63 | 26 | |
Postoperative N status | 0.06 | ||
0 | 35 | 8 | |
1–3 | 39 | 24 | |
Postoperative M status | 0.90 | ||
0 | 53 | 24 | |
1 | 21 | 8 | |
Postoperative TNM stage | 0.23 | ||
0 | 3 | 3 | |
1 | 6 | 1 | |
2 | 22 | 5 | |
3 | 22 | 15 | |
4 | 21 | 8 | |
AFP (ng/mL) | 9.25 ± 17.79 | 6.48 ± 8.33 | 0.40 |
CEA (IU/L) | 0.23 | ||
Normal | 50 | 26 | |
Elevated | 24 | 6 | |
CA125 (IU/L) | 0.08 | ||
Normal | 73 | 29 | |
Elevated | 1 | 3 | |
CA199 (IU/L) | 1.00 | ||
Normal | 64 | 27 | |
Elevated | 10 | 5 | |
Operative duration (min) | 349.46 ± 116.47 | 359.22 ± 111.98 | 0.69 |
Blood transfusion (ml) | 347.92 ± 506.39 | 362.50 ± 458.43 | 0.89 |
Total number of dissected lymph node | 40.81 ± 18.67 | 44.09 ± 17.77 | 0.40 |
Number of positive lymph node | 5.27 ± 9.01 | 7.34 ± 10.42 | 0.30 |
Treatment response | 0.25 | ||
TRG 1 | 3 | 3 | |
TRG 2 | 34 | 14 | |
TRG 3 | 24 | 10 | |
TRG 4 | 10 | 4 | |
TRG 5 | 3 | 1 |
Model construction
Factors | Responding group | Non-responding group | P value |
---|---|---|---|
Age (years, mean ± SD) | 56.76 ± 11.42 | 52.85 ± 11.91 | 0.02 |
Gender | 1.00 | ||
Male | 24 | 24 | |
Female | 13 | 13 | |
BMI (kg/m2) | 21 ± 3 | 21 ± 4 | 0.42 |
AFP (ng/mL) | 8.95 ± 13.51 | 7.86 ± 17.55 | 0.56 |
CEA (IU/L) | 0.80 | ||
Normal | 26 | 24 | |
Elevated | 11 | 13 | |
CA199 (IU/L) | 1.00 | ||
Normal | 32 | 32 | |
Elevated | 5 | 5 | |
CA125 (IU/L) | 1.00 | ||
Normal | 36 | 37 | |
Elevated | 1 | 0 | |
Preoperative T stage | 0.17 | ||
2 | 0 | 1 | |
3 | 8 | 3 | |
4 | 29 | 33 | |
Preoperative N status | 0.19 | ||
0 | 2 | 0 | |
1 | 13 | 8 | |
2 | 18 | 21 | |
3 | 4 | 8 | |
Preoperative M status | 0.05 | ||
0 | 28 | 19 | |
1 | 9 | 18 | |
Radiomics score | 0.54 ± 0.22 | 0.41 ± 0.22 | < 0.01 |
Cohorts | Models | Responding group | Non-responding group | OR (95% CI) | P value |
---|---|---|---|---|---|
Training cohort | rad_score | 0.56 ± 0.26 | 0.38 ± 0.25 | 14.51 (2.40, 98.35) | < 0.01 |
clinical_score | 0.56 ± 0.11 | 0.47 ± 0.13 | 355.62 (7.98, 2.41*104) | < 0.01 | |
rad_clinical score | −0.61 ± 0.29 | −0.88 ± 0.34 | 12.22 (2.79, 64.65) | < 0.01 | |
Validation cohort | rad_score | 0.54 ± 0.12 | 0.42 ± 0.08 | 1.21*105 (52.25, 3.07*109) | < 0.01 |
clinical_score | 0.52 ± 0.12 | 0.48 ± 0.11 | 33.46 (0.07, 2.98*104) | 0.28 | |
rad_clinical score | −0.38 ± 0.23 | −0.56 ± 0.27 | 16.90 (1.04, 422.82) | 0.06 |
Model performance in response prediction and validation
Cut-off | ACC | SEN | SPE | PPV | NPV | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
– | ACC | P | SEN | P | SPE | P | PPV | P | NPV | P | |
rad_score | 0.516 | 0.81 | – | 0.75 | – | 0.88 | – | 0.86 | – | 0.78 | – |
clinical_score | 0.462 | 0.63 | 0.11 | 0.75 | 1.00 | 0.50 | < 0.01 | 0.60 | 0.02 | 0.67 | 0.32 |
rad_clinical score | −0.651 | 0.69 | 0.26 | 0.88 | 0.18 | 0.50 | < 0.01 | 0.64 | 0.04 | 0.80 | 0.84 |
Survival stratification by the models
Factors | HR | 95% CI | P value |
---|---|---|---|
Preoperative T stage | 2.59 | 1.03–6.53 | 0.04 |
Total number of dissected lymph node | 1.03 | 1.00–1.06 | 0.04 |
Postoperative N status | 2.09 | 1.48–3.98 | < 0.01 |
TNM stage | 2.67 | 1.15–6.23 | 0.02 |
rad_score | 0.22 | 0.11–0.42 | < 0.01 |
clinical_score | 2.65 | 1.07–6.54 | 0.03 |
rad_clinical_score | 4.27 | 1.18–15.39 | 0.03 |