Patient, tumor, and health system factors affecting groin node dissection rates in vulvar carcinoma: A population-based cohort study

OBJECTIVE: To determine the rate of groin node dissection (GND) for invasive vulvar carcinoma in a population-based cohort, and the patient, tumor, or health system factors associated with having this procedure. METHODS: This retrospective population-based cohort includes all cases of invasive squamous cell carcinoma identified in the provincial cancer registry from 1998 to 2007. Chart abstraction was completed for all clinical and pathologic factors. Descriptive analyses with chi-squared tests were used for comparing proportions between patient groups. Multivariable logistic regression analysis was implemented to determine factors associated with having a GND. RESULTS: Data was collected for 1109 patients; 1038 patients were included in this analysis. 647 (62%) had a GND as part of primary management of their vulvar cancer, while 391 (38%) did not. When those with depth of invasion ≤1mm and no GND were removed, the GND rate increased to 68%. Reasons for no GND included age, obesity, advanced disease, or comorbidities. Factors significantly associated with omission of GND were increasing age (OR 0.98, CI 0.97-0.99), severe comorbidities (OR 0.57, CI 0.42-0.78), lower income quintile (OR 0.71, CI 0.54-0.95), and surgeon type (non-gynecologic oncologist vs gynecologic oncologist) (OR 0.43, CI 0.22-0.85), whereas depth of invasion >1mm was significantly associated with having a GND (OR 2.75, CI 2.08-3.62). CONCLUSION: This population-based cohort demonstrates 32% of invasive vulvar cancer patients did not have a GND at initial management. Vulvar cancer patients should be evaluated by clinicians with expertise in this rare disease to ensure that a GND is completed when feasible.