Epidemiologic data on vulvar cancer: comparison of hospital with population-based data

Data on vulvar cancer are subject to a possible selection bias because older patients with vulvar cancer are sometimes not referred to specialized centers. The aim of this study was to compare the variables obtained from the population as a whole with variables obtained from referral and nonreferral hospitals. Population-based data on age, stage, histological type, and treatment modality were registered for 138 patients with vulvar cancer. The characteristics of the patients who were referred to a gynecologic oncology center were compared with those of the patients treated in nonreferral hospitals. The age-adjusted incidence was 2.3 per 100,000 women. Basal cell cancer was less common in the referral center than in the nonreferral centers (3% versus 28%). No difference was found in FIGO stage distribution in the different subgroups. Groin node dissection was omitted in 80% of the patients not referred to a center. Omission of groin node dissection was more common in patients older than 74 years (P = 0.002). Population-based data on vulvar cancer differ significantly from hospital-based data and give better insight into the real characteristics of patients with vulvar cancer.