Changes in vulvar cancer incidence from before COVID-19 through the first year of the pandemic (350)

Objectives: The primary objective of this study was to evaluate the trend in vulvar cancer incidence before and during the COVID-19 pandemic. Methods: A retrospective analysis was conducted of patients diagnosed with new high-grade vulvar intraepithelial neoplasia 3 (VIN3) or stage I-IV squamous cell carcinoma of the vulva between January 2015 and June 2021 at a single institution. All diagnoses were confirmed by histologic identification of invasive squamous cell carcinoma on either biopsy or surgical excision. Incidence rate ratios were calculated before and after the April 2020 - June 2020 COVID- 19 lockdown. U charts were created to identify the change in incidence before and after the COVID-19 lockdown. Nominal variables and continuous variables associated with increased risk for vulvar cancer were analyzed using Fisher’s exact test and two-sample tests, respectively. Results: The incidence of stage I vulvar cancer and stage II-IV vulvar cancer was 2.13 and 2.19 times as high following the COVID-19 lockdown compared to the incidence prior to the COVID-19 lockdown, respectively. Cumulatively, the incidence of invasive vulvar cancer (stage I-IV) was 2.14 times as high following the COVID-19 lockdown. Comparatively, the incidence of high-grade VIN3 in the year following the COVID-19 lockdown was 0.7 times the incidence of VIN3 in the five years prior to the lockdown. Using a U chart, three of the four consecutive quarters following the lockdown had incidence values greater than the centerline, with an incidence in 2020 quarter-4 greater than two standard deviations from the centerline proportion. No differences existed between pre- and post-COVID-19 lockdown groups in terms of age, BMI, gravidity, parity, race, history of HIV/AIDS, chronic immunosuppression, lichen sclerosus, or smoking history. Conclusions: The incidence of invasive squamous cell carcinoma of the vulva increased following the COVID-19 lockdown. Vulvar cancer development and progression have been shown to be time-sensitive and delayed care has been broadly reported during the COVID-19 pandemic. However, the etiology of the increase in the diagnosis of vulvar cancer during the pandemic is most likely multifactorial, given the overall rapid increase. [Figure: see text]