Adjuvant chemo confers no survival advantage following biliary tract cancer resection

In older patients with resected biliary tract cancer (BTC), adjuvant chemotherapy does not appear to yield significant survival gains when compared with observation, according to a study.

For the study, researchers accessed the National Cancer Database and looked at the medical records of 8,091 older adult patients with resected BTC (median age 77 years, 63.5 percent female). Of these patients, 2,632 (32.5 percent) received single-agent or multiagent adjuvant chemotherapy treatment following resection.

The use of adjuvant chemotherapy notably increased across the study period, from 20.7 percent (n=495) in 2004–2009 to 41.2 percent (n=856) in 2016–2019. Adjuvant chemotherapy was less likely to be given to older patients (≥80 years; odds ratio [OR], 0.29, 95 percent confidence interval [CI], 0.25–0.33; p<0.001) and those with gallbladder being the primary site of the resection (OR, 0.71, 95 percent CI, 0.61–0.83; p<0.001).

In an analysis that used inverse probability of treatment weighting, the primary outcome of overall survival (OS) did not significantly differ between the adjuvant chemotherapy and observation groups (median OS, 20.5 vs 19.0 months, respectively).

Looking at the subgroup of patients who underwent adjuvant chemotherapy, those who received single-agent treatment but not multiagent treatment was associated with a longer OS compared with observation (median, 21.5 and 19.1 months vs 17.3 months). However, this apparent improvement in OS with single-agent adjuvant chemotherapy disappeared following multivariable analysis (hazard ratio [HR], 0.97, 95 percent CI, 0.89–1.05; p=0.44).

Factors associated with poorer OS included age at diagnosis of at least 80 years (HR, 1.35, 95 percent CI, 1.28–1.42; p<0.001) and treatment at nonacademic centres (HR, 1.14, 95 percent CI, 1.07–1.20; p<0.001).