Comparison of cisplatin and mitomycin C/5-FU as radiosensitisers in the treatment of locally advanced vulvar cancer: results of a retrospective, observational, single-institutional cohort study

Purpose: We retrospectively investigated the widely used radiosensitisers cisplatin and mitomycin C/5-fluorouracil (5-FU) in patients with locally advanced vulvar cancer for outcome and toxicity.

Methods: We screened the archive for patients treated with chemoradiation for vulvar cancer diagnosed between 01/2010 and 08/2021 at our institution. The impact of both radiosensitisers on prognosis was compared using Kaplan-Meier method and Cox-regression analysis.

Results: One hundred and forty-three patients with vulvar cancer were screened. Twenty-nine patients received chemoradiation (mitomycin C/5-FU n = 14; cisplatin n = 12; others n = 3) as a primary, neoadjuvant or adjuvant treatment. Median follow-up was 15.5 months. Patients in the cisplatin group were older (mean age 54.4 vs. 70.7; p = 0.004). However, the mitomycin C/5-FU group had more advanced tumour stages. The 2-year recurrence-free survival (RFS) was comparable (44.5% vs. 33.3%; p = 0.932). The 2-year overall survival (OS) showed a numerical but not statistically significant difference in favour of the mitomycin C/5-FU group (59.7% vs. 31.7%; p = 0.37). 64.3% (9 out of 14) patients, who received mitomycin C/5-FU achieved clinical complete response (cCR) compared to 41.7% (5 out of 12) who received cisplatin (p = 0.505). Radiodermatitis was the most common adverse event in both groups (81%) and more severe in the mitomycin C/5-FU cohort. Myelotoxicity was frequently observed in both groups. Eighteen patients received an additional radiation boost with 10.0 (9-16) Gy and showed a significantly prolonged RFS (p = 0.027) and OS (p = 0.003).

Conclusion: Mitomycin C/5-FU may be considered in the treatment of young and healthy patients with locally advanced vulvar cancer.