Analysis of Clinical and Epidemiological Profiles of Cancer Patients in the Southeast During Pre-Pandemic and Pandemic Periods: A Retrospective Study

Background: This study analyzed the epidemiological profile of patients with non-melanoma skin cancer, female breast cancer, prostate cancer, colon and rectum cancer, lung cancer, and stomach cancer in southeastern Brazil (Espírito Santo, São Paulo, Minas Gerais, and Rio de Janeiro), covering the pre-pandemic period (2017 to 2019) and the pandemic period (2020 to 2022). Methods: The DATASUS database was used to assess possible impacts of percentage differences between these periods through point regression analysis and comparisons between the pre-pandemic and pandemic periods, as well as between the sexes using the Student's t-test. Results: The results suggest that sex-specific characteristics impose varying impacts and incidences on each gender. In Espírito Santo, there was a growing trend in stomach and non-melanoma skin cancers, while in São Paulo, only stomach cancer showed a statistically significant upward trend. Regarding staging, it was observed that during the pandemic period, the highest incidence was in stage IV, whereas in the pre-pandemic period, the highest incidences were in stages 0 and I, with medium and small effect sizes. Furthermore, the loss of pre-pandemic data was 11.46% (54,080 cases), while during the pandemic, the loss was 27.52% (129,869 cases), both statistically significant values of considerable magnitude. Conclusion: It can be concluded that there was a significant increase in the temporal trend only for stomach cancer in the states of São Paulo and Espírito Santo; for the other cancers and states, the trends were stationary. The high rate of missing data during the pandemic suggests a considerable impact on the results, highlighting the importance of additional prospective studies to better understand the effects of COVID-19 on oncology.