From the analysis of Swedish cancer registries, researchers at the Harvard TH Chan School of Public Health calculated the level of risk in children and siblings of people who had had colon polyps or colorectal cancers, suggesting that some of these could benefit from early screening.
Siblings and children of people with colorectal polyps have a higher risk of getting colorectal cancer (CRC), especially when the polyps have been diagnosed in more than one first-degree relative and/or before the age of 60. This is what emerged from a recent study whose results were published in the British Medical Journal. The increased risk of getting sick, according to the data, mainly concerns early-onset forms diagnosed before the age of 50.
“Our results suggest that, in order to better prevent early-onset colorectal cancer, first-degree relatives of individuals with polyps, but especially those with more than one family member affected by cancer, should anticipate the initiation of screening, and even more early if these family members were young at the time of diagnosis, ”Mingyang Song, of the Harvard TH Chan School of Public Health in Boston, and collaborators at the end of the article wrote.
The study analyzed several Swedish cancer registries which contain information on gastrointestinal biopsies performed in Sweden. The sample included 68,060 patients with CRC and 333,753 healthy individuals (controls) matched according to various parameters, including age. 8.4 percent of people with CRC and 5.7 percent of controls had at least one first-degree relative (parents or siblings) who had been diagnosed with a colorectal polyp.
The researchers found that people with at least one relative with polyps had a higher risk of getting CRC than those without a family history of polyps (62 percent). The association between family history of polyps and CRC risk increases with the number of relatives affected by polyps and inversely with age at diagnosis. Furthermore, if in addition to polyps in the family there have also been cases of true colorectal cancer, the risk increases even more.
Basically, people with two or more first-degree relatives with polyps but no colorectal cancer cases in the family have a slightly higher risk than people with a colorectal cancer case in the family but without. polyps, while people with two or more relatives with both polyps and colorectal cancer have a 5 times higher risk of getting sick and more than 16 times of having an early-onset form of CRC compared to unrelated individuals with polyps or CRC. “These results provide solid evidence of the impact of family history of polyps on colorectal cancer risk and have important implications for screening,” the researcher’s comment. For the authors, in fact, People with at least two first-degree relatives with polyps or with only one relative who was diagnosed with this cancer at a young age could benefit from early screening.