A family history of colorectal polyps could present vital info to integrate into screening, according to findings from Scandinavian investigators.
“Our findings counsel that early screening could also be tailored for first-degree relatives of individuals with polyps, notably these with multiple first-degree relatives having a historical past of polyps and whose first-degree relatives’ polyps were identified at a younger age,” said Mingyang Song, MBBS, ScD, an Assistant Professor in the Departments of Epidemiology and Nutrition at the Harvard T.H. Chan School of Public Health, in Boston.
Dr. Song and his colleagues from Norway and Sweden reported their findings on the 2021 virtual Digestive Disease Week (summary 82) and published them in the British Medical Journal (2021;373:n877).
Previous data indicating an association of CRC with a family history of polyps have been inconsistent, in response to Dr. Song. Present guidelines suggest that individuals with a household history of superior adenomas be screened sooner than those without, but these suggestions are considered weak and based mostly on low-quality evidence, he said.
The recent study used a Swedish registry to identify 68,060 people with CRC who were matched with 333,753 controls from the final inhabitants. For these roughly 401,000 people, FDRs were found via the country’s multigeneration register. They usually were linked to a histopathology database that additionally included sublocation, year of diagnosis, and age of FDR at polyp diagnosis.
The researchers calculated CRC odds ratios utilizing three different models and estimated CRC incidence based on national data.
Polyps in the family are linked to an increased risk
The prevalence of a minimum of one polyp in an FDR was 7.7% among instances and 5.3% among controls while advanced polyps accounted for 3.2% and 1.9% of lesions, respectively. The prevalence of CRC in an FDR was 10.4% for cases and 6.4% for controls.
In contrast with individuals with no constructive family historical past, those with an FDR with any polyp had a 62% increased danger for CRC on multivariable evaluation and a 40% increased risk when the analysis adjusted for family history of CRC. The presence of a complicated polyp increased these risks to 76% and 44%, respectively, Dr. Song’s group found.
Two scenarios additional enhanced this risk: the presence of at least two FDRs with polyps, which increased risk by 70% in comparison with no affected close relation, and diagnosis of a polyp in a near relative before age 50, which increased the risk by 77%.
“The risk elevation was extra prominent for early-onset CRC and heightened by the coexistence of a family history of CRC,” Dr. Song said. “Given the increasing incidence of early-onset CRC, this family history is valuable data to integrate. Perhaps we introduce earlier screening for people with a family history of polyps.”
The registry info lacked data on the size of the polyps; subsequently, the study couldn’t tackle the risk related to small polyps. “This query wants additional study. However, based on the literature, it’s unlikely that a history of small polyps would improve risk notably,” he said.
A family history of serrated polyps gave the impression to be strongly related to the risk for proximal colon cancer, but not distal colon or rectal cancer, Dr. Song added.
‘Difficult to Get’ Polyp History, But Important
Mohit Girotra, MD, a consultant gastroenterologist and therapeutic endoscopist at Swedish Medical Center, in Seattle, agreed that getting a household history of polyps is tough but needs to be strongly inspired. “Most patients could not know the precise kind and size of polyp their family member had, but could possibly inform if their family member was suggested repeating colonoscopy at three or 5 years versus 10 years, which is a refined trace towards the polyp type,” Dr. Girotra said.
Sonia Kupfer, MD, an Associate Professor and the Director of the GI Cancer Risk and Prevention Clinic at the University of Chicago, said that the new study “confirmed comparable general trends to what has been beforehand reported, together with increased danger with increasing numbers of affected people in addition to youthful ages at diagnosis. Of note, in this study, family history of serrated polyps was a risk issue particularly for proximal colon cancer.”
Dr. Kupfer stated that she sees room for enhancement in incorporating polyp history into screening suggestions. In a current survey of 137 patients who had undergone polypectomy, 40% said that they believed their polyps positioned their close relatives at increased risk for CRC, but only 7.3% of their endoscopists made recommendations for screening family members (Dig Dis Sci 2020;65:2542-2550). “This implies areas for high-quality enhancement to assist help individuals with familial CRC about their risks,” she said. “Whereas it’s robust to get a polyp history, family history remains to be the most effective risk stratification instruments we now have.”