A population-based analysis of the impact of 1 vs. 2 doses of mitomycin on patterns of failure of anal cancer patients treated with concurrent chemoradiotherapy.
Radiother Oncol 2024;
196:110219. [PMID:
38479443 DOI:
10.1016/j.radonc.2024.110219]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 02/27/2024] [Accepted: 03/06/2024] [Indexed: 05/06/2024]
Abstract
PURPOSE
We report the impact of 1 vs. 2 doses of mitomycin-C (MMC) based chemoradiation (CRT) on patterns of treatment failure and long-term patient outcomes in anal squamous cell carcinoma (ASCC) and the predictors for locoregional failure (LRF) and distant metastasis (DM).
METHODS
In this population-based study, we identified all patients with anal cancer in our province treated radically with radiation and concurrent 5-Fluorouracil (5FU) and 1 vs. 2 doses of MMC between the years 2000-2019. The primary outcomes analyzed were locoregional recurrence (LRR), disease free survival (DFS), ASCC cancer-specific survival (ASCC-CSS) and overall survival (OS).
RESULTS
451 patients were identified. 272 (60%) patients received 1 cycle of MMC (MMC1) and 179 (40%) received 2 cycles (MMC2) as part of the CRT regimen. The median follow-up was 57 (36-252) and 97 (38-239) months for MMC1 and MMC2, respectively. Cox Regression analysis showed stage IIIb and IIIc were associated with worse locoregional recurrence free survival (RFS) (HR=2.851, p=<0.001) and distant RFS (HR=3.391, p=<0.001). Similarly, stage IIIb and IIIc patients had poorer DFS (HR 3.439, p=<0.001), ASCC-SS (HR 3.729, p=<0.001) and OS (2.230, p=<0.001). The use of MMC2 showed a positive impact on improved ASCC-SS (HR 0.569, p=0.029) and distant RFS (HR 0.555, p=0.040) in patients with stage IIIb and IIIc.
CONCLUSIONS
Our analysis showed that 1 vs. 2 cycles of MMC along with 5FU and radiation is associated with comparable treatment outcomes in general. However, in patients with stage IIIb and IIIc cancer, 2 doses of MMC were associated with improved ASCC-SS and distant DFS.
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