Epidemiological changes in the histological subtypes of 35,018 non-small-cell lung cancer cases in Brazil

Regarding the fatality rates stemming from various existing forms of cancers worldwide, lung cancer (LC) is ranked as the main cause of death amongst those who suffer from cancer. Although the epidemiological, clinical, and histological profile of patients with this type of cancer is largely unknown, Brazil has made tremendous efforts to generate data for supporting healthcare policies concerning lung cancer. Taking these factors into account, this study aims to analyse the epidemiological, clinical, and histological profiles of patients with non-small-cell lung cancer (NSCLC) in Brazil.

For this study, a cross-sectional epidemiological study was conducted to nationally analyse patient's data within the cancer hospital registries found in the National Cancer Institute (INCA) and the São Paulo Cancer Foundation (FOSP) between 2000 and 2011.

A total of 35,018 patients diagnosed with NSCLC in Brazil between 2000 and 2011 were analysed. The analysis demonstrated the occurrence of an epidemiological shift, related to the most prevalent histological type of NSCLC in the study population from 2003. The shift resulted in a higher percentage of adenocarcinoma (43.3%) over squamous cell carcinoma (36.5%). Additionally, there was a significant increase in both the number of cases of LC in women and in the rates of patients diagnosed with metastatic disease.

The use of filtered cigarettes since the 60's and the increase in the number of LC cases in women, were one of the causes for the switch in the histological profile of NSCLC in Brazil. Consequently, adenocarcinoma is now the predominant type of cancer detected. Late diagnosis is a hallmark sign.