The combination of radiotherapy and immunotherapy is effective and well tolerated for unresectable biliary tract cancer
Menée sur la période 2018-2020 auprès de 117 patients atteints d'un cancer des voies biliaires non résécable, cette étude évalue l'intérêt, du point de vue des événements indésirables, de la survie globale et de la survie sans maladie, d'une radiothérapie combinée avec un anti-PD-1 par rapport à une chimiothérapie seule
Purpose: For unresectable biliary tract cancer (BTC), chemotherapy (CT) alone is associated with poor survival and severe toxicity. Immunotherapy (IO) is potentially effective for BTC and radiotherapy (RT) may synergize with IO. We investigated CT versus combined RT and anti-programmed cell death-1 (PD-1) IO for unresectable BTC. Methods and Materials: We prospectively observed 117 participants with unresectable BTC either at initial diagnosis or at 1st recurrence at a single center who chose 1 of 2 treatment options between August 2018 and October 2020. The 2 options included: (1) external beam RT combined with anti-PD-1 IO (RT/IO) or (2) CT alone. In the RT/IO group, Camrelizumab (200 mg intravenously every 3 weeks) was initiated within 7 days after the completion of RT and continued until progression or intolerable side effects were noted. The median dose/fraction was 55 Gy/25 fractions (range: 50-60 Gy/20-25 fractions). In the CT group, cisplatin and gemcitabine were delivered intravenously every 3 weeks for 8 cycles. We analyzed the adverse events (AEs), overall survival (OS) and disease-free survival (DFS), and performed subgroup analysis according to tumor mutational burden (TMB) and microsatellite status in the combination group. Results: Thirty-nine and 78 participants received RT/IO and CT, respectively. The crude rate of severe AEs (grade ≥3 AEs) was higher in the CT group (79.4% vs. 7.7%, P <0.001). The OS and DFS after RT/IO were longer than that after CT (median OS: 17.0 vs. 11.5 months, P =0.01; median DFS: 12.5 vs. 7.9 months, P =0.008). Participants with low TMB or microsatellite stability had a shorter median OS (13.6 vs. 25.7 months, P =0.03) and median DFS (9.8 vs. 19.3 months, P =0.012) than participants with high TMB or microsatellite instability. Conclusions: RT combined with anti-PD-1 IO may be well tolerated and associated with an improved response rate, DFS and OS compared to CT alone in patients with unresectable BTC.
International Journal of Radiation Oncology, Biology, Physics 2022