Association between obesity with disease-free survival and overall survival in triple-negative breast cancer: A meta-analysis
In a systematic review, published in Medicine, the authors sought to investigate whether obesity conveyed a benefit to disease-free survival (DFS) and overall survival (OS) in patients with triple-negative breast cancer. Breast cancer is a complex condition with many different subtypes, which each behave in different ways. Triple negative breast cancer means that there is not enough expression of three receptors, ER, PR and HER-2. It is a rare and often aggressive form of breast cancer, characterised by short recurrence time and greater chance of metastasis via the bloodstream.
The effect of obesity on cancer survival is still contested, and it varies between each type of cancer. The rationale behind it increasing survival is that by having a greater body mass, an obese patient is better able to survive the wasting effects of cancer and its treatment. Conversely, it is argued that many endocrine, metabolic and inflammatory complications that result from a persistent obese state, predispose these patients to cancer and limits there survival ability. This review included data from 9 studies for DFS meta-analysis (4,412 patients) and 8 studies for OS meta-analysis (4,392 patients). It found a number of controversial studies, which suggested obesity conveyed a very significant survival advantage, and others, which concluded that the opposite was true. The result of their analysis is that there was no statistically significant difference between the DFS and OS rates of obese patients compared to normal weight patients in triple negative breast cancer.