Survival and prognosis of anus, anal canal and anorectal carcinoma: Analysis of National Surveillance, Epidemiology, and End Results database from 2000-2020.

e15501 Background: Anal cancer comprises about 2.5% of all gastrointestinal malignancies in the USA. The incidence of anal cancer is showing an increasing trend, however studies surrounding its prognostic factors and survival is limited. The aim of our study is to examine the prognostic factors and evaluate survival trends from 2000-2020 using the SEER database. Methods: SEER*Stat Version 8.4.3 software was used to extract anus, anal canal and anorectal carcinoma cases from SEER 17 registries (2000-2020). A total of 32315 patients were included in the study, data with unconfirmed histology were excluded. We analyzed overall mortality, and anal cancer specific mortality (CSM) using a Cox proportional hazards model. The survival analysis was carried out using the Kaplan–Meier method and the log-rank test was used to compare survival curves. Results: Crude analysis revealed a high overall mortality in patients above age 80 (HR = 11.085; 95% CI: 9.9113-13.485), p < 0.001), followed by age 60–79 (HR = 3.665, 95% CI: 3.303- 4.432, p < 0.003. Females were found to have better survival (HR = 0.705; 95% CI: 0.676-0.735). Non-Hispanic blacks were found to have the highest cancer-specific mortality compared to other ethnicities (HR = 1.294; 95% CI: 1.112-1.381). Patients who did not undergo surgical treatment had a significant cancer specific mortality (HR = 1.438; CI: 1.377-1.502). The highest cancer-specific mortality was observed in patients with distant metastases (HR = 2.461, 95% CI: 2.314– 2.616, p < 0.001). Irrespective of surgical status, patients who underwent either chemotherapy or radiation therapy had better survival rates. Multivariate cox proportional hazard regression analyses of CSM also revealed higher mortality among males and Non-Hispanic black patients. The mortality outcomes further become worse with advanced age and lack of application of available treatment options in the form of surgery, chemotherapy or radiotherapy. Conclusions: Our analysis indicated overall increased anal cancer specific mortality in Non-Hispanic blacks. Delayed diagnosis with distant metastasis and those who did not receive any of the available treatment modalities had worse prognosis. We recommend further research to develop better screening strategies for early diagnosis of anal cancer, identifying factors associated with increased mortality in certain ethnicities, and barriers to access available treatment modalities.