ESMO Congress 2024 | OncologyPRO

Abstract 313P

Background

During the COVID-19 pandemic, the previous study has shown a decrease in breast cancer screenings, diagnoses, and operations compared to the pre-pandemic period. This study aims to determine whether differences in outcomes between the cohorts analyzed in the previous study led to differences in prognosis.

Methods

This study conducted a retrospective analysis of 709 patients diagnosed with breast cancer between the pre-pandemic period (May and July 2019) and the pandemic period (May and July 2020) in six academic hospitals. Patients were divided into two groups based on these periods, and differences in breast cancer recurrence were analyzed using the chi-square test, Fisher’s exact test, and Kaplan-Meier method. The analysis was divided based on age 65, which is a risk factor for severe COVID-19.

Results

The recurrence was found in thirteen and twenty-three people during the pre-pandemic and pandemic periods, respectively, with this difference being statistically significant (3.49% vs. 6.74%, p-value 0.049). In survival analysis, the difference in recurrence between the two groups was also significant (p-value 0.0067). In patients under 65 years of age, there was a significant difference in recurrence between the two groups with a p-value of 0.001, whereas in patients over 65 years of age, there was no statistical significance (p-value: 0.491). The two groups had no significant differences in pathologic stage (p-value 0.471) and surgical methods (Breast surgery: p-value of 0.11, Axilla surgery: p-value of 0.64).

Conclusions

This study showed that there were more recurrences in patients diagnosed after hospital visits decreased due to the outbreak of COVID-19. This was not significant in those over 65 years of age but was noticeable in the younger age group. Therefore, young patients, who generally have a relatively low risk of complications from infectious diseases, should not delay visiting the hospital.