Abstract 141P
Background
Curative surgery is a mainstay treatment for resectable cholangiocarcinoma (CCA). The role of adjuvant chemotherapy (AC) in such patients remains controversial. This retrospective study aimed to identify patients who would benefit from AC.
Methods
Resected CCA patients undergoing curative surgery, with or without AC, were identified from 3 cancer centers in Thailand. R2 resection were excluded. Using the largest center as the discovery cohort, we generated propensity scores matching (PSM). Uni/multivariate Cox regression analyses for overall survival (OS) were conducted in the PSM discovery cohort to identify factors and develop a predictive risk score, which classified patients into high and low-risk groups. The proposed risk score was validated in the other 2 centers.
Results
In the discovery cohort, 493 patients were identified. After PSM, 328 patients were categorized into surgery (N=164) and surgery + AC (N=164) groups. The baseline characteristics in the PSM discovery cohort were well balanced. In the validation cohort, patients with a positive pathological lymph node received AC more frequently than those under observation (47% vs 18%; p=0.02). A MINT pathological risk score was developed from multivariate analysis for OS. In PSM discovery cohort, for low-risk score, the surgery group has significantly longer OS compared to the surgery + AC group (49.4 vs 31.5 months, HR 1.78 [1.11-2.86]; p 0.016). Conversely, for high-risk score, the surgery + AC group has better OS than the surgery group [18.8 vs 8.0 months, HR 0.60 (0.46-0.79); p < 0.001]. The results were comparable in the validation cohort. Table: 141P
| MINT Risk Factor (Score) | Cohort | HR (95% CI) | p-value |
| Surgical Margin (1) | Discovery (n=328) | 1.31 (1.02 - 1.70) | 0.04 |
| Perineural Invasion (1) | 1.36 (1.03 - 1.79) | 0.03 | |
| Lymph Node – pN1 (2) pNx (1) | 1.87 (1.40 - 2.50) 1.42 (1.02 - 1.98) | <0.01 <0.01 | |
| Tumor size (≥ 5 cm) (1) | 1.39 (1.09 - 1.78) | <0.01 | |
| Low risk (0-1) | Validation (n=83) | 3.11 (1.06 – 9.17) | 0.04 |
| High risk (≥ 2) | 0.70 (0.35 – 1.39) | 0.31 |
Conclusions
Resected CCA patients with high-risk MINT pathological risk score were likely to benefit from AC, while those with a low-risk score were not. Further validation in a larger prospective cohort is warranted.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.