Management patterns and survival outcomes in biliary tract malignancies: a 3-year retrospective cohort from Karachi, Pakistan

Background: Biliary tract malignancies (BTMs), including gallbladder carcinoma (GBC) and cholangiocarcinoma (CCA), are aggressive cancers with poor prognosis. Data from South Asia remain limited. Objectives: To evaluate patient characteristics, diagnostic patterns, treatment modalities, and survival outcomes among BTM patients at a tertiary care center in Karachi, Pakistan. Methods: This retrospective cohort study included patients ≥16 years with histologically confirmed GBC or CCA between May 2022 and May 2025. Data on demographics, clinical presentation, laboratory values, imaging, stage, treatment, and survival were collected. Kaplan–Meier analysis and Cox regression identified survival outcomes and predictors. Results: A total of 141 patients were included (GBC, n=99; CCA, n=42). Median age was similar between groups (GBC 58.1 vs CCA 58.5 years; p=0.971), with female predominance (GBC 58.6%; CCA 64.3%; p=0.527). Gallstones were more frequent in GBC (46.5% vs 26.2%; p=0.025). Adenocarcinoma was the predominant histology, while rare histologies were more frequent in CCA (16.7% vs 4.0%; p=0.022). Lymph node and liver metastases were common; median time from symptom onset to diagnosis was 2.33 months. Curative surgery was more frequent in Stage I–III GBC (53.6%) than Stage IV (23.9%; p=0.032), whereas CCA surgery was less common and location-specific. Adjuvant capecitabine and palliative gemcitabine-based regimens were used; biliary drainage was more frequent in advanced disease. In GBC, multivariate Cox analysis identified advanced stage (HR 4.85; p=0.010) and treatment group (HR 2.21; p=0.003) as independent predictors of survival; combined surgery and chemotherapy reduced mortality by 73% compared to chemotherapy alone (HR 0.27; p=0.019). mRECIST response rates were comparable between GBC and CCA (ORR 18.7% vs 15.0%; DCR 34.7% vs 32.5%). Early-stage disease and aggressive treatment were associated with longer survival (median 28.6 vs 12.0 months, p=0.040; log-rank p<0.001). At last follow-up, more CCA patients were alive than GBC patients (76.2% vs 38.4%; p<0.001). Conclusion: Advanced disease stage is the strongest independent predictor of poor survival in BTMs. Multimodal treatment combining surgery and chemotherapy significantly improves outcomes, though overall response rates remain modest. Early detection, aggressive management, and improved access to care are critical to enhance survival in high-risk South Asian populations.