Abstract P4-07-64: Impact of baseline ECOG, comorbidities, and surgery treatment election on overall survival
Authors: Rodriguez-Melendez Elina A. , Pulla-Cadmilema Emiliano , Avila Lissette P. Velez , Salazar Maria del Mar Sanchez , Aguilar Patricia Tamayo , Bohorquez Lissette Yagual , Martin-Delgado Jimmy , Martinez Glenda Ramos , Matamoros Katherine Garcia , Maridueña Mayra Santacruz , Vivanco Ruth Engracia , Cornejo Roberto Escala , Merchan Felipe Campoverde , Guerrero Isabel Delgado , Floril Veronica Torres , Gamboa Diego Garcia , Gomez Luis Pendola , Cabezas Elizabeth Gamarra , Santos Juan Carlos Garces , Valencia-Espinoza Evelyn 
Published: March 2023

Abstract
Background: Breast cancer is the most common type of neoplasm in women. According to statistics from Globocan 2020, the incidence of breast cancer in Ecuador, as well as worldwide is 47.8 per 100,000 people/year, with a mortality rate of 13.6 per 100,000 people/year. Our health system provides coverage to approximately 60% of the population by the Ministry of Public Health (MSP), 30% by The Ecuadorian social security Institute (IESS), 5% by other entities (ISSFA, ISSPOL, MUNICIPIOS), and &lt; 3% of the population have private medical coverage. Medical care attentions for breast cancer, covered by the MSP was 7,134 consults in 2013, with an increase to 8,767 in 2018. SOLCA Guayaquil, as a national reference Center, provides 24.425 oncologic consults per year, with 38% corresponding to breast cancer. The presentation of breast cancer, at diagnosis, corresponds approximately to 63% in localized stage, 29% as locally advanced, 6% as metastatic disease, with a 5-year overall survival of 99%, 85% and 29% respectively. The proportion of clinical stage IV breast cancer diagnoses varies from 5-10%, with an average of 6% in urban areas, reaching up to 50% in rural areas, so metastatic breast cancer is a public health challenge, especially for countries with emerging economies like ours. Methods: An observational, retrospective, descriptive, single-center study was carried out. All patients with metastatic breast cancer who had been treated at the National Oncology Institute SOLCA Guayaquil, in the period from 2016 to 2020 were included in the analysis. The clinical and pathological characteristics were recorded and their impact on overall survival was calculated by the Kaplan-Meier method and compared by the long-rank test, multivariable adjusted hazard ratios (HR) were estimated by Cox regression models. Results: 3700 patients were identified between January 2016-December 2020. A total of 2587 patients were excluded. Of a total of 1113 remaining patients, 84 debuted as metastatic disease. No male patients where reported with metastatic breast cancer in the past 5 years. Median age at diagnosis was 53,31 years (28-88 years). The most frequent metastatic sites, were: bone 63.86% (N:53), lungs 50.6% (N:42), liver 30,12% (N:25), soft tissue 22.89% (N:19), CNS 16.87% (N:14); A multivariable analysis was performed, all metastatic sites have a higher risk of mortality vs not having any metastasis, but the only significant one is CNS metastases RR 1.31 (1.08-1.61), p&lt; 0.005. A total of 28 patients (33.73%) had 2 metastatic sites at presentation; 21 patients (25.30%) had 3 o more metastatic sites at presentation with a RR 1,22 (0.95-1,57) p:0,011, with overall survival -OS- (36 months vs 15 months) (long Rank 0,001). ECOG 1 was reported in 59 patients (71.08%), ECOG 2 in 18 (21.69%) and ECOG 3 in 5 (6,02%). A multivariable analysis was perform with ECOG 2-3, RR 1.03 (0,43-2-44), p:0,94. Principal reported comorbidities where: hypertension in 28 patients (33,73%), dyslipidemia in 16 (19,28%), obesity 14 (16,87%), Diabetes 8 (9,64%). By grouping 2 or more comorbidities, the RR 1,04 (0,83-1.30), p:0,71. Surgery was classified as done or not, where 33 patients (39,77%) underwent rescue mastectomy. Multivariable analysis shows Not Surgery with a RR 1,88 (1.07-3,3) p:0.02. Median OS was estimated for surgery 44,48 months +/-4,7SD; Not surgery 20,72 months +/-2,8 SD. Conclusions: In our population, metastatic breast cancer occurs in 7.6% (84 patients out of 1113 total), similar to that reported worldwide. Being a neoplasm with multiple immunophenotypes, and therefore, different treatment options, OS depends on multiple clinicopathological variables. This study showed that CNS metastases have a negative impact on OS, it is an independent variable for RR of mortality. ECOG and comorbidities did not show an impact on OS. Ultimately, mastectomy was offered to patients with good clinical response to systemic chemotherapy, and shows positive impact in OS.
Citation Format: Elina A. Rodriguez-Melendez, Emiliano Pulla-Cadmilema, Lissette P. Velez Avila, Maria del Mar Sanchez Salazar, Patricia Tamayo Aguilar, Lissette Yagual Bohorquez, Jimmy Martin-Delgado, Glenda Ramos Martinez, Katherine Garcia Matamoros, Mayra Santacruz Maridueña, Ruth Engracia Vivanco, Roberto Escala Cornejo, Felipe Campoverde Merchan, Isabel Delgado Guerrero, Veronica Torres Floril, Diego Garcia Gamboa, Luis Pendola Gomez, Elizabeth Gamarra Cabezas, Juan Carlos Garces Santos, Evelyn Valencia-Espinoza. Impact of baseline ECOG, comorbidities, and surgery treatment election on overall survival [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-64.