Vulvar cancer survival by primary treatment modality: A retrospective cohort study

Objective: To compare survival and complications for women with vulvar cancer treated with primary radiation vs surgery.

Methods: Retrospective cohort study of Kaiser Permanente members diagnosed with vulvar squamous cell carcinoma (SCC) between 2008 and 2018 and treated with primary surgery (PS only), surgery with adjuvant radiation (PS + RT), or primary radiation (PRT). Primary outcomes were 1- and 3-year overall (OS) and progression-free (PFS) survival. Multivariable regression adjusted for age, stage, comorbidities, and smoking.

Results: We included 201 women: 114 PS only (56.7%), 36 PS + RT (17.9%), and 51 PRT (25.4%). PS only patients had less advanced disease. Crude 1- and 3-year OS were 96.5% and 82.6% for PS only compared to 72.2% and 48.3% for PS + RT and 72.6% and 53.9% for PRT (p < 0.001). There were no statistical differences in hazard of death when controlling for stage and other covariates (PRT vs PS only: aHR 1.35, 95% CI 0.61-2.99; PS + RT vs PS only: aHR 1.28, 95% CI 0.60-2.75; PS + RT vs PRT: aHR 0.95, CI 0.48-1.90). Older age and stage III disease were poor prognostic factors. Risk of lymphedema was elevated with PS + RT (36.1% vs 20.2% for PS only and 9.8% for PRT, p = 0.011). Wound infection was more likely in surgical groups, whereas hospital readmission and blood transfusion were more common with PRT.

Conclusions: Vulvar cancer survival was not statistically different among women treated with primary radiation compared to primary surgery when controlling for stage. Surgery followed by adjuvant radiation demonstrated elevated rates of lymphedema. Primary radiation therapy may be an acceptable alternative to primary surgery in women who are likely to need adjuvant therapy.