Incidence, mortality, and patterns of care for patients with multiple primary lower genital tract squamous cell carcinoma

Abstract

<h3>Objectives:</h3> To define the incidence, prognosis, and treatment patterns associated with multiple primary lower genital tract squamous cell carcinoma (LGTSCC). <h3>Methods:</h3> Surveillance, Epidemiology, and End Results (SEER) database patients diagnosed with synchronous cervical, vaginal, vulvar, and/or anal SCC from 2000-2016 were included. Incidence and mortality were evaluated using Kaplan-Meier curves. Multivariable Cox proportional hazards regression was used to identify treatment patterns, risk factors, and mortality associated with LGTSCC. <h3>Results:</h3> Among 15,424 women with any LGTSCC, 138 patients had multiple primary LGTSCC (0.89%). Vulvar and vaginal SCC was the most common combination (49.3%), and cervical with anal SCC was the least common (1.4%). Only one patient had 3 or more primary LGTSCC (vulvar, cervical, and anal). Multiple primary LGTSCC was independently associated with higher mortality compared to single site LGTSCC (adjusted hazards ratio [aHR]=1.67; p<0.001). Multiple primary LGTSCC was significantly associated with older age (63 vs. 58 years, p<0.001) and have lower stage (adjusted odds ratio [aOR]=0.38; p<0.001) and grade of disease (aOR=0.32; p<0.001). Patients with multiple primary LGTSCC were more likely to receive radiation overall (aOR=1.74, p=0.005) and were more likely to receive adjuvant radiation after primary surgical resection compared to single site LGTSCC (aOR=1.88, p=0.007). Receipt of any treatment including radiation (aHR=0.85; p<0.001), chemotherapy (aHR=0.50; p<0.001), and surgery (aHR=0.70; p<0.001) was independently associated with decreased mortality hazard. <h3>Conclusions:</h3> Multiple primary LGTSCC is rare but is associated with increased mortality, and higher rates of adjuvant radiation compared to single site LGTSCC despite lower stage and grade at diagnosis. More research is needed to define optimal therapy for patients with multiple primary LGTSCC.