Adjuvant radiotherapy for vulvar cancer with close or positive surgical margins

The survival effect of adjuvant radiotherapy (RT) for vulvar cancer has been poorly investigated.

We performed a multicentre retrospective register study of 257 patients with primary squamous vulvar cancer. The survival effect of adjuvant RT was investigated in two groups of patients, dependent on surgical margins. The outcome measure was overall survival. All statistical tests were two-sided.

Of the 257 patients investigated, 192 had negative resection margins, while positive and/or close surgical margins were observed in 65 cases. Margin status was associated with unfavourable overall survival. The five-year overall survival was 66.1 and 49.2% in patients with negative and positive/close resection margins, respectively. Adjuvant RT directed to the vulva was associated with improved survival in patients with positive/close resection margins but not in patients with negative surgical margins. The 5-year overall survival of patients with positive/close surgical margins without RT was 29%, whereas with RT it increased to 67.6%. Notably, patients with positive/close surgical margins who received RT of the vulva had a 5-year survival rate similar to the patients with negative margins (67.6%). Multivariate analysis adjusted for age, stage of disease, tumour grade and lymph node metastases showed that adjuvant RT significantly reduced the mortality risk in patients with positive/close resection margins (HR 0.36, CI 0.14–0.94, p = 0.038). In the group of patients with negative resection margins, the involvement of lymph nodes was the strongest unfavourable prognostic factor.

Adjuvant RT should be used for patients with positive/close surgical margins to improve their outcome.