Exploring the Promise of Second-Line Chemotherapy in Biliary Tract Tumours: A Glimpse into Novel Treatment Approaches.

Biliary tract tumours, including bile duct, gallbladder, and ampulla of Vater malignancies, pose a rare but formidable oncologic challenge. Typically diagnosed at advanced stages, these tumours offer limited treatment options and dismal prognoses, with a five-year survival rate below 20%. First-line chemotherapy with gemcitabine-cisplatin has demonstrated only modest efficacy, leaving a pressing need for improved therapeutic strategies. This comprehensive review provides a detailed examination of the current landscape of second-line chemotherapy for biliary tract tumours. The pivotal ABC-06 trial established FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) as the standard second-line therapy, demonstrating improved overall survival compared to active symptom control alone. Conversely, the NIFTY trial introduced nal-IRI (nanoliposomal irinotecan) plus 5-FU/LV (5-fluorouracil and leucovorin) as an alternative option, demonstrating substantial gains in progression-free and overall survival. However, the posterior NALIRICC trial presented conflicting results, raising questions about the added benefit of nal-IRI. Challenges in delivering second-line chemotherapy include rapid patient performance deterioration post-first-line treatment and limited access to second-line therapy. Only a fraction of eligible patients receive second-line therapy, emphasising the need for more effective first-line therapies to maintain patient fitness. The role of monotherapy in the second-line setting remains uncertain, particularly in unfit patients, and the absence of biomarkers for tailored treatment underscores the need for ongoing research. While challenges persist, ongoing investigations offer hope for optimising second-line therapy for biliary tract tumours, promising improved outcomes for patients facing this disease. This review provides an overview of current facts and challenges when delivering second-line chemotherapy for advanced biliary tract tumours.