Ambiguous Effects of Obesity on Cancer Prognosis and Treatment Response: A Narrative Review

Obesity is a lifestyle disease that is a proven predisposing factor for many illnesses and is often associated with a poor prognosis. Here, the author tries to associate the relationship between the incidence of obesity in patients with cancer and the prognosis of the same. The present medical literature suggests an ambiguous and conflicting relationship. This study presents an extensive literature review of the mechanisms that may govern the survival outcomes of patients with cancer presenting with obesity. Medical literature databases, namely PubMed, Google Scholar, and BioMed Central databases, were searched. Out of 335 relevant results, 75 met the inclusion criteria. The results were varying in nature, with some papers showing poor prognosis due to the association of obesity with metabolic and endocrine abnormalities, which promote tumour growth, while others suggest that excess adiposity may promote a greater expression of programmed cell death protein-1 in effector CD8+ T lymphocytes, promoting a better response to immune checkpoint blockade therapies. Some even argue against the existence of the so-called ‘obesity paradox’, considering it a by-product of statistical misinterpretation and biases. In conclusion, the phenomenon is definitely intriguing but needs further investigation and research regarding other processes that may all in all affect cancer prognosis.