Dados do Resumo

Título

Oral contraceptive use and colorectal cancer risk: a literature review

Introdução

Both oestrogens and progestogens act in regulating cell growth and reproduction, interfering in the activity of carcinogenesis in susceptible tissues. This specific trait acknowledges a relationship between combined oral contraceptives and colorectal cancer, the second most prevalent cancer in females and a significant cause of morbidity.

Objetivo

This study aims to provide an in-depth review of, based on current literature, highlighting knowledge regarding the effects that combined oral contraceptives may have on colorectal carcinogenesis and if possible effects persist after stopping use.

Métodos

This integrative literature review, conducted in August 2024, was performed by searching the PubMed and Cochrane databases for scientific articles that correspond to the proposed theme. Eighty-nine publications, in any language, that included quantitative associations or trials examining the exposure to oral contraceptives and the risk of colorectal cancer and were date-limited from January 1, 2019, to August 20, 2024, were considered for the initial screening. Articles that did not meet these criteria or were repeated studies were excluded. Following the second screening, which involved analysis and evaluation of the eligible articles, a total of 12 articles were selected to compose the bibliographic sample for this review on the association between oral contraceptives and the risk of colorectal cancer. After analyzing and interpreting the data, we synthesized the knowledge obtained in the publications, describing common findings and divergences between the studies.

Resultados

Female hormones may lower colorectal cancer risk by altering bile synthesis, inhibiting colon cancer cell growth, and reducing serum IGF-1 levels. Estrogens impact the colonic mucosa through estrogen receptors and may act as tumor suppressors. However, the precise mechanisms remain unclear. A total of ten studies show that combined oral contraceptives act as a risk reduction for colorectal cancer, however, there is still conflict on whether increasing duration of oral contraceptive use is associated with higher protection, but there is a consensus that benefits are stronger with recent use. Two studies show that ever-use of combined oral contraceptives was found not to be associated with a reduction in the risk of colorectal cancer. These studies, however, were limited by their insignificance or were not consistent in their findings as other potential confounding factors were not explored in these studies. 

Conclusões

Colorectal carcinogenesis occurs less frequently among ever-users compared to never-users of oral contraceptives, with possible benefits persisting for many years after stopping use. Limitations of research results are mentioned due to the interference of behavioral and psychological risk factors that are shown to be linked to cancer development, potentially confounding studies as well as suggests cautious and individual evaluation from a benefit-risk point of view.

Financiador do resumo

Não houve.

Palavras Chave

Colorectal cancer; oral contraceptives; Risk factor