6 March 2019 Adenomas (adenomatous polyps) are considered the main precursor lesion of most coloretal cancers. It is estimated the probability of having coloretal cancer at some point in life is one in 25 for men and one in 30 for women. However, polyps can be detected and removed by endoscopic techniques. This has been shown to reduce the incidence of this type of cancer. Is bowel cancer linked to your family history? About 75% of bowel cancers are sporadic . Of the remaining 25%, family history may suggest a genetic contribution, exposure to environmental conditions that family members have in common, or both. The most significant aspects of family history include: Several family members with the condition (particularly if they are first-degree family members); Being diagnosed with cancer at a young age (under 50 years). In around 5% of cases , increased susceptibility is conferred by the presence of mutations in predisposed genes. In some of these syndromes, there is a significantly increased predisposition to the formation of colon adenomas; these can be as many as hundreds or thousands. In other syndromes, there are not many colon adenomas, but the probability and speed of their development into cancer is greater. Mutations in these genes can be also be associated with an increased risk of other tumours. Are there many cases of hereditary coloretal cancer syndrome? No. In the rare cases in which personal and family history suggest a syndrome of hereditary coloretal cancer, specific genetic (and other) studies are justified. However, most cases of family aggregation do not correspond to hereditary syndromes. In these families, genetic risk factors are likely to act cumulatively in combination with non-genetic factors. Most of these factors are unknown and cannot be directly investigated. However, the assessment of family history makes it possible to calculate an empirical risk for each individual of developing bowel cancer. Individuals who are at increased risk are indicated for earlier and/or more intensive colonoscopic surveillance than the general population. This article was written with the support of physicians and other clinical professionals from the Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
