Abstract PS13-30: Evaluation of factors related to efficacy and safety of neo/adjuvant chemotherapy for breast cancer as a brief estimate of the impact of COVID-19 pandemic
Authors: Pimentel Franklin F , Borba Jessica MC , Rodrigues Tamara CGF , Peruchi Karoline PI , Carrara Helio HA , de Andrade Jurandyr M , Candido dos Reis Francisco J 
Published: February 2021

Abstract
Background
COVID-19 pandemic presented as a challenge to breast cancer (BC) treatment, especially considering safety concerns and resource scarcity. Treatment choices have been taken mainly based on safety according to guidelines which aim hierarchically categorize the clinical benefits of any clinical decision. Considering the magnitude of benefit, neo/adjuvant breast cancer treatment is positioned at medium/high levels. Despite these recommendations, patients might be refusing chemotherapy (CT) or avoiding emergency care utilization due to concerns about COVID-19 infection. There have been described factors related to the reduction of effectiveness of neo/adjuvant CT for breast cancer, like relative intensity dose (RDI) &lt;85%, which could be used to a brief analysis of latter impact of modifications in clinical protocols. We aimed to analyze the impact of COVID-19 pandemic, to the date, in the neo/adjuvant breast cancer chemotherapy in a university hospital to support strategies to minimize unfavorable outcomes.
Methods
Medical records from 307 breast cancer patients who started neo/adjuvant chemotherapy from January 2018 to June 2020 at the Hospital das Clínicas de Ribeirão Preto, University of Sao Paulo (HCRP-USP) were retrospectively analyzed, with a total of 2,074 cycles. It was considered the period from June 2018 to June 2020 to analyze the total cycles prescribed/month. Clinical data, treatment information and outcomes were collected. Considering COVID-19 restraining policies in our region were initiated on March 23th 2020, we considered the pandemic period from April 2020 to June 2020, and compared to the period before pandemic (Jan/2018-Mar/2020). A RDI &lt;85% was considered a factor related to worse efficacy of chemotherapy. For safety assessment, it was considered the demand for medical care at emergency unit. The study was approved by the local ethics committee (HCFMRPUSP-33148920.5.0000.5440).
Results
During the period before pandemic, an average of 10% (±4%) of the patients who received CT, monthly, sought the emergency unit, while only 3% (±4%) sought during the pandemic (p=0.17). In our institution, the average number of neo/adjuvant CT initiated monthly during pandemic tended to be lower than before the pandemic (7.0 ± 2.0 vs. 10.6 ± 3.5; p=0.06), while the average cycles prescribed monthly showed a 14% reduction compared to the period before pandemic (68 ± 5 vs. 79 ± 13; p=0.02). The frequency of treatments with RDI &lt;85% during the pandemic was lower than before pandemic (6% vs. 23%; n=275; p=0.03).
Conclusions
COVID-19 pandemic presented as a challenge for the treatment of BC patients, including lower acceptance of neo/adjuvant treatment and reduced search for emergency unit due to chemotherapy adverse effects, which could compromise the of the treatment goals. In our institution, we found 23% of patients treated with neo/adjuvant chemotherapy had not reached the expected RDI ≥85% before the pandemic, similar to the literature. Despite the lower rate of RDI &lt;85% during pandemic (6%), this may be related to treatments that are still in progress, greater refusal of chemotherapy by patients with morbidities or advanced age, or even related to treatment modification aiming to minimize toxicities and avoid interruptions (ie. prescription of colony-stimulating factors). Further analysis may help to identify the factors related to these findings. Despite this, every effort must be made to achieve the maximum effectiveness of CT and to ensure safety during treatment. The impact of treatment modifications should be monitored to minimize unfavorable outcomes.
Citation Format: Franklin F Pimentel, Jessica MC Borba, Tamara CGF Rodrigues, Karoline PI Peruchi, Helio HA Carrara, Jurandyr M de Andrade, Francisco J Candido dos Reis. Evaluation of factors related to efficacy and safety of neo/adjuvant chemotherapy for breast cancer as a brief estimate of the impact of COVID-19 pandemic [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-30.