Does adjuvant treatment improve survival in R1 resected perihilar cholangiocarcinoma? The risk of overtreatment.

Background: Resection of perihilar cholangiocarcinoma (pCCA) is associated with positive margins in up to half of the patients. It remains unclear whether adjuvant therapies contribute to improved survival in patients undergoing R1 resection for pCCA.

Methods: The National Cancer Database was queried for patients diagnosed with pCCA between 2004 and 2016. Patients with metastatic disease at the time of diagnosis were excluded.

Results: A total of 1756 patients were included (286 surgical patients and 1470 nonsurgical patients). Patients who underwent R0 resection showed a significantly better median overall survival (OS) than that of patients who underwent R1 resection (41.7 vs 21.4 months, respectively; P = .003). Nevertheless, OS was better in patients who underwent R1 resection than in nonsurgical patients (21.4 vs 6.3 months, respectively; P < .001). Patients undergoing chemoradiation after R1 resection had similar OS to that of those receiving any other adjuvant therapy (21.4 vs 19.4 months, respectively; P = .789) or no adjuvant treatment (21.4 vs 19.8 months, respectively; P = .925). After uni- and multivariable analyses, T stage ≥3 and R1 margins were independently associated with worse survival after surgery.

Conclusion: As currently neither radiation, chemoradiation, nor chemotherapy seem to significantly improve survival in patients who underwent R1 resection for pCCA, high-quality surgical resection remains critically important. Moreover, the concern of overtreatment of patients who underwent R1 resection with current adjuvant therapeutic regimes exists.