DESCRIPTIVE EPIDEMIOLOGICAL PROFILE OF PATIENTS WITH HER2-POSITIVE METASTATIC BREAST CANCER SUBMITTED TO PERTUZUMAB AND TRASTUZUMAB AT THE CANCER HOSPITAL OF PERNAMBUCO
Authors: Silva Gabriela Calado , Viana Denise Sobral , Pessoa Cecilia Souza Avila , Costa Filho Erich Roberto Santos da 
Published: February 2023

Introduction: HER2-positive breast cancer is characterized by a hyperexpression or gene amplification of human epidermal growth factor receptor 2, a tyrosine kinase membrane receptor that has a profile with major aggressiveness and worse prognosis among all molecular subtypes. The metastatic pattern of this disease is one of the greatest challenges in mastology and requires an urgency and effective therapeutics to control this disease. Advances in therapy have allowed more specific treatments for anti-HER2 treatment that allowed improvement in the overall survival and disease-free survival of patients. Double-block therapy, performed by using Trastuzumabe and Pertuzumabe, is the first-line treatment for metastatic HER2-positive breast cancer. This kind of therapy was initially adopted effectively by SUS in 2019. Therefore, it is advisable to consider the use of this therapy at the Cancer Hospital of Pernambuco (HCP) to analyze the current results in patients and assess the local results. Objective: The goal of this study was to understand the epidemiological profile of patients with HER2-positive metastatic breast cancer treated at the HCP and submitted to double-block therapy with Trastuzumab and Pertuzumab, analyzing progression-free survival and overall survival. Methods: This is a retrospective descriptive study conducted in November 2021. Relevant aspects of treatment, analysis of disease-free survival, and overall survival were analyzed in the medical records of patients with metastatic HER2-positive breast cancer who used Trastuzumab and Pertuzumab. The survey of the analyzed data was carried out by completing a specific form created by the researcher especially for this study. Anonymity and clarity of the information were ensured. Results: From 124 selected medical records, this study selected 78 patients with metastatic HER2 breast cancer, with a mean age of 50.4 years; 62.34% had positive hormone receptors and 44.87% had metastasis de novo. About 36% of patients had been using double-block for up to 6 months, which made it difficult to assess the behavior of the disease from medical examinations and images, given the short time; but it was found that of all patients, 15.4% have disease stability, 32.1% had regression, and 28.2% had disease progression. There was a median of 12 months for disease progression, but with a median of 11 months of use of double-block therapy with Trastuzumab and Pertuzumab. As for the overall survival, it is estimated, based on statistical data from the current sample, that an accumulated probability of death of up to 16.7% in up to 5 years. Women older than 60 years and those who had disease progression had a higher risk of death. Conclusion: This study evaluated metastatic HER2-positive breast cancer as a particular behavior tumor. The patients selected from the HCP submitted to the use of Trastuzumab and Pertuzumab in the metastatic scenario have a follow-up time still recent, which causes incipient data for the evaluation of specific outcomes that depend on the temporal component. Follow-up and updates of the analysis of outcomes are suggested, in the near future, to enrich the treatments proposed for the target population. Ethical aspect: This study was conducted strictly based on the Resolutions 510/16 and 416/12 of the Health National Council and was only conducted after HCP Research Ethics Committee approval.