Introduction/Background The COVID-19 pandemic which began in 2020 disrupted healthcare services and changed patient behavior. Our objective was to identify changes in hospitalization rates of ovarian cancer patients from 2016 to 2020, comparing pre-pandemic and pandemic levels. We also aimed to assess, if these changes happened and whether they were correlated with pandemic-related variables.

Methodology Aggregated data were obtained from the State of Sao Paulo Secretary of Health regarding ovarian cancer hospitalization, average social distancing rates, COVID-19 incidence, mortality, lethality, and both COVID-specific infirmary and ICU bed occupation rates. Hospitalizations for ovarian cancer were categorized as either clinical or surgical treatments. These data were available at the state level and for each state’s subdivisions. We performed a Joinpoint analysis in order to verify if there were changes regarding hospitalization rates during the study period. We also calculated hospitalization rate ratios and verified if they were correlated with pandemic-related variables.

Results Overall hospitalization rates in the state fell coinciding with the start of the pandemic. At the state level, clinical hospitalization rates did not show changes in their trend during the study period, while surgical hospitalization rates started to decrease two trimesters before the pandemic began and remained decreasing. Surgical hospitalization rate ratios were inversely correlated with COVID-specific ICU bed occupation rates during the third trimester of 2020, with a Pearson Correlation coefficient of -0.50 (95% CI: -0.78 to -0.05, p = 0.03). An increasing number of exclusively public-insured persons were identified in the state, with a Pearson Correlation coefficient of 0.95 (95% CI: 0.88–0,98, p < 0.001).

Conclusion Surgical hospitalization rate ratios fell during the third trimester of 2020 and were inversely correlated with ICU occupation. This demonstrates the impact of the COVID-19 pandemic on the treatment of conditions that compete for the same healthcare resources.