240P - Covid-19 pandemic impact on diagnosis and management of breast cancer in northern Portugal

Background

COVID-19 pandemic brought pressure to Portuguese National Health Service (NHS). We aim to assess pandemic impact on diagnosis and management of breast cancer (BC) in a high-volume Portuguese comprehensive cancer centre, which was classified as a COVID-free institution by public health authorities.

Methods

Observational retrospective cohort study. We evaluated medical records of newly diagnosed BC patients (pts) between March 2017 and February 2020 (three-year period, pre-pandemic group, PPG,) and during one-year period, from March 2020 to February 2021 (Pandemic Group, PG). Descriptive statistics were used to access clinical-pathological characteristics. Comparisons between groups were performed, using ANOVA for continuous variables. Fisher’s or χ² tests were used to evaluate association between two categorical variables. Statistical significance was established at 5%. Software R 4.0.1 was used.

Results

We identified 2611 pts in PPG (860, 881, 870, from 1^st to 3^rd year) and 714 pts in PG, showing a clear reduction in total number of yearly new BC diagnoses in PG. There was a reduction from those appointed from primary care BC screening as opposed to symptom onset (28.5%, 31.7%, 37.1% in PPG vs 24.5% in PG; p<0.001) and a trend towards a smaller proportion of patients with 50-69 years old (46.9% vs [50.3%, 52.2%, 52.3%]; p=0.073). We identified a higher proportion of G3 tumours in PG (p=0.039). There was a significant decrease of pts with early breast cancer (EBC) (PG: 68.1% (n=486) vs 79.4% (n=683), 77.0% (n=678), 75.4% (n=656); p<0.001). Pts were diagnosed in a more advanced stage in PG: 25.2% (n=180) vs [14,3% (n=123), 16.0% (n=141), 19.8% (n=172)] were locally advanced (LABC) and 6.7% (n=48) vs [6.3% (n=54), 7.0% (n=62), 4.8% (n=42)] were metastatic. Treatment patterns were similar between the two groups.

Conclusions

There were fewer new cancer diagnoses in pandemic 1st year than in previous years and a clear decrease of patients with EBC. The shift towards a greater proportion of more advanced disease is probably due to diagnostic delays and NHS screening failure. Nevertheless BC standard of care was not negatively affected. Future studies are needed to identify long-term impact of COVID-19 pandemic in BC cancer survival.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.