Clinical and Pathological Factors Influencing the Survival of Breast Cancer Patients with Malignant Pleural Effusion

Abstract

INTRODUCTION: in recent decades, we have observed an increasing incidence of breast cancer worldwide. In Brazil, the occurrence rate of breast cancer is estimated at 52, 689 new cases in 2012. In the state of Rio Grande do Sul, the crude incidence rate of primary breast cancer, is 81, 97 every 100 000 inhabitants, representing the Brazilian state with the second highest incidence of breast cancer. This neoplasm is considered a public health problem because of its high incidence, morbidity and mortality, and the high cost of treatment. Complications triggered by distant metastases may affect many patients who have breast cancer. Organs, such as brain, lungs, liver and bones are the main ones to be likely to develop the disease due to breast cancer metastases. Lastly, this study aims to identify clinical and pathological factors that affect the survival of patients with history of breast cancer and pleural effusion neoplastic. MATERIALS AND METHODS: A clinical cohort study, in which the exams of patients who had malignant pleural effusion from 2006 to 2010 were analyzed. Throughout these exams, there was a search for the history of breast cancer in medical charts, as well as pathological and cytopathological data related to the primary tumor and pleural metastasis. Statistical analyses were done using SPSS 18. 0, carrying out descriptive analyses, survival curves were estimated by using Kaplan-Meier method and Cox univariate analysis. RESULTS: Among 145 patients, 87 (60%) were diagnosed as positive for malignant cells in pleural fluid, 119 presented ductal histology. There was a worse prognosis in patients with triple-negative phenotype, showing a sharp decline in the survival curve, and of the 25 patients with triple- negative phenotype, 20 (80%) died. Following up the sample, it was possible to observe an average survival of 6 months for patients who have positive cytological diagnosis for malignant cells in pleural fluid. DISCUSSION: There was worse prognosis in relation to patients classified as triple-negative, confirming the literature data, presenting a more aggressive tumor, a consequent reduction in survival, and higher incidence of metastasis distant, particularly in visceral organs, such as lung. Studies related to neoplastic spread of breast cancer present a longer interval free of pleural metastases as an indicator of worse prognosis, and this reduction may be associated with poor prognosis factors, such as: site of metastasis and positive diagnosis of malignant cells in pleural fluid, the expression of c-erbB-2, the triple-phenotype negative, and ki-67 protein expression. CONCLUSIONS: in our study, we found the triple-negative phenotype identification in the primary tumor as an unfavorable characteristic to patients, associated with the cytological diagnosis of neoplastic cells in pleural fluid, which indicate a worse prognosis, reflecting in reduction of life expectancy. KEYWORDS: malignant pleural effusion, survival, metastatic breast cancer.