Incidence and survival of vulvar and vaginal cancers in a province of Northern Italy: a population-based study.

Background: This study aims to describe the incidence, mortality, and survival trends of vulvar and vaginal cancers in a population-based cohort from Northern Italy, with a particular focus on the development of second primary malignancies. Methods: Data were retrieved from the Cancer Registry of Reggio Emilia, covering the period 1996-2021. Vulvar and vaginal cancers were classified according to ICD-O-3 topography codes C51 and C52, respectively. Age-standardized incidence and mortality rates were calculated using the European Standard Population. Relative survival estimates were computed using the Pohar Perme method. Time trends were analyzed using Joinpoint Regression, and the occurrence of second primary malignancies was assessed based on medical records. Results: A total of 328 cases were identified: 264 vulvar (80.5 %) and 64 vaginal cancers (19.5 %). The median age at diagnosis was 76.1 years for vulvar cancer and 70.2 years for vaginal cancer. Squamous cell carcinoma was the predominant histological subtype (78 % vulvar, 57.8 % vaginal). The incidence of vulvar cancer showed a significant annual decrease (APC -2.3 %, 95 %CI -3.5; -1.0), while mortality remained stable. Vaginal cancer also exhibited a decreasing incidence trend (APC -3.3 %, 95 %CI -9.1; 2.9), though not statistically significant. The five-year survival rate was 63 % for vulvar cancer and 44 % for vaginal cancer, with a significant improvement for vaginal cancer in the years (1996-2006: 33 %; 2007-2018: 61 %). Second primary malignancies were observed in 30 patients (27 with vulvar and 3 with vaginal cancer). Conclusion: Although vulvar and vaginal cancers remain rare, their burden is significant, particularly in older women. The declining incidence may be attributed to the effects of HPV vaccination and improved screening practices. However, the stable mortality rates underscore the need for optimized treatment strategies. Given the association with second malignancies, long-term surveillance is essential to improving patient outcomes. Policy Summary: Vulvar and vaginal cancers are rare but require careful and continuous monitoring. Knowledge of the incidence curves and survival of these tumors should encourage stakeholders to invest both in terms of primary prevention (smoking cessation and sex education) but also secondary prevention by implementing screening campaigns without neglecting the importance of HPV vaccination and access to care for all, without regional disparities.