Adjuvant Radiotherapy for Extrahepatic Cholangiocarcinoma: A Quality Assessment-Based Meta-Analysis

Risk Factors for Distant Metastasis in Extrahepatic Bile Duct Cancer after Curative Resection (KROG 1814)

PURPOSE

Risk factors predicting distant metastasis (DM) in extrahepatic bile duct cancer (EHBDC) patients treated with curative resection were investigated.

MATERIALS AND METHODS

Medical records of 1,418 EHBDC patients undergoing curative resection between Jan 2000 and Dec 2015 from 14 institutions were reviewed. After resection, 924 patients (67.6%) were surveilled without adjuvant therapy, 297 (21.7%) were treated with concurrent chemoradiotherapy (CCRT) and 148 (10.8%) with CCRT followed by chemotherapy. To exclude the treatment effect from innate confounders, patients not treated with adjuvant therapy were evaluated.

RESULTS

After a median follow-up of 36.7 months (range, 2.7 to 213.2 months), the 5-year distant metastasis-free survival (DMFS) rate was 57.7%. On multivariate analysis, perihilar or diffuse tumor (hazard ratio [HR], 1.391; p=0.004), poorly differentiated histology (HR, 2.014; p < 0.001), presence of perineural invasion (HR, 1.768; p < 0.001), positive nodal metastasis (HR, 2.670; p < 0.001) and preoperative carbohydrate antigen (CA) 19-9 ≥ 37 U/mL (HR, 1.353; p < 0.001) were significantly associated with inferior DMFS. The DMFS rates significantly differed according to the number of these risk factors. For validation, patients who underwent adjuvant therapy were evaluated. In patients with ≥ 3 factors, additional chemotherapy after CCRT resulted in a superior DMFS compared with CCRT alone (5-year rate, 47.6% vs. 27.7%; p=0.001), but the benefit of additional chemotherapy was not observed in patients with 0-2 risk factors.

CONCLUSION

Tumor location, histologic differentiation, perineural invasion, lymph node metastasis, and preoperative CA 19-9 level predicted DM risk in resected EHBDC. These risk factors might help identifying a subset of patients who could benefit from additional chemotherapy after resection.

Analysis of the efficacy and factors influencing survival of adjuvant radiotherapy for stage II-III biliary tract carcinoma

BACKGROUND

To determine the efficacy of adjuvant radiotherapy for stage II-III biliary tract carcinoma.

METHODS

We retrospectively analyzed the data of 37 patients who underwent radical resection of biliary tract carcinomas at the Affiliated Hospital of Inner Mongolia Medical University between 2016 and 2020. We analyzed survival differences between patients who did (n = 17) and did not (n = 20) receive postoperative adjuvant radiotherapy by using Kaplan-Meier analysis. The log-rank test and Cox univariate analysis were used. The Cox proportional risk regression model was used for the multifactorial analysis of factors influencing prognosis.

RESULTS

The median survival time (28.9 vs. 14.5 months) and the 1-year (82.40% vs. 55.0%) and 2-year survival rates (58.8% vs. 25.0%) were significantly higher among patients who received adjuvant radiotherapy than among those who did not (χ2 = 6.381, p = 0.012). Multifactorial analysis showed that pathological tumor type (p = 0.004), disease stage (p = 0.021), and adjuvant radiotherapy (p = 0.001) were independent prognostic factors in biliary tract carcinoma. Subgroup analyses showed that compared to no radiotherapy, adjuvant radiotherapy significantly improved median survival time in patients with stage III disease (21.6 vs. 12.7 months; p = 0.017), positive margins (28.9 vs. 10.5 months; p = 0.012), and T3 or T4 tumors (26.8 vs. 16.8 months; p = 0.037).

CONCLUSION

Adjuvant radiotherapy significantly improved the survival of patients with biliary tract carcinoma, and is recommended especially for patients with stage III disease, positive surgical margins, or ≥ T3.

Adjuvant Chemoradiation in Patients with Lymph Node-Positive Biliary Tract Cancers: Secondary Analysis of a Single-Arm Clinical Trial (SWOG 0809)

BACKGROUND

SWOG 0809 is the only prospective study of adjuvant chemotherapy followed by chemoradiation focusing on margin status in patients with extrahepatic cholangiocarcinoma (EHCC) and gallbladder cancer (GBCA); however, the effects of adjuvant therapy by nodal status have never been reported in this population.

METHODS

Patients with resected EHCC and GBCA, stage pT2-4, node-positive (N+) or margin-positive (R1) who completed four cycles of chemotherapy followed by radiotherapy were included. Cox regression was used to compare overall survival (OS), disease-free survival (DFS), local recurrence, and distant metastasis by nodal status. DFS rates were compared with historical data via a one-sample t-test.

RESULTS

Sixty-nine patients [EHCC, n = 46 (66%); GBCA, n = 23 (33%)] were evaluated, with a median age of 61.7 years and an R0 rate of 66.7% and R1 rate of 33.3%. EHCC versus GBCA was more likely to be N+ (73.9% vs. 47.8%, p = 0.03). Nodal status did not significantly impact OS (hazard ratio [HR] 1.98, 95% confidence interval [CI] 0.86-4.54, p = 0.11) or DFS (HR 1.63, 95% CI 0.77-3.44, p = 0.20). Two-year OS was 70.6% for node-negative (N0) disease and 60.9% for N+ disease, while 2-year DFS was 62.5% for N0 tumors and 49.8% for N+ tumors. N+ versus N0 tumors showed higher rates of distant failure (42.2% vs. 25.0%, p = 0.04). The 2-year DFS rate in N+ tumors was significantly higher than in historical controls (49.8% vs. 29.7%, p = 0.004).

CONCLUSIONS

Adjuvant therapy is associated with favorable outcome independent of nodal status and may impact local control in N+ patients. These data could serve as a benchmark for future adjuvant trials, including molecular-targeted agents.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.