ORLANDO — Though up to 17% of early-onset colon cancers carry genetic markers for Lynch syndrome, only 30% of patients diagnosed with colon cancer younger than age 50 will receive genetic testing, partly due to lack of understanding about which physician should order the test, according to a poster presented at the World Congress of Gastroenterology at ACG 2017.
“It was very unclear who providers felt was responsible for ordering the testing,” Jordan Karlitz, MD, of Tulane University School of Medicine, said during a press conference. “The bottom line is this leads to a diffusion of responsibility where other people think they may be ordering the test and the test doesn’t get picked up.”
Karlitz and colleagues distributed a 21-question web-based survey two times to physicians on the ACG email listing. Of the 474 eligible responders, 97% were gastroenterologists.
Guidelines state that all patients diagnosed with colorectal cancers should undergo microsatellite instability (MSI)/immunohistochemistry (IHC) testing, which can lead to confirmation of Lynch Syndrome markers. Yet, in this survey, Karlitz and colleagues found that only 32.66% of respondents felt gastroenterologists should order this test while 38.19% said the pathologist should order it. Still others felt the surgeon (10.05%), medical oncologist (14.57%) and medical geneticist or counselor (4.52%) should order the test.
“This is a major issue and we need to identify these patients,” Karlitz said. “Not every colorectal cancer is going to be hereditary, but when you’re talking about 10%, 15%, 20% being hereditary, it’s very important we understand why testing is not being done to screen these patients.”
Additionally, respondents pointed to lack of genetic counseling at their facilities (15.42%, P = .009), lack of familiarity in interpreting MSI/IHC results (17.95%, P = .0004) and cost of testing (21.79%, P < .0001) as factors that prevented them from ordering MSI/IHC testing.
“Cost of testing, concerns that providers wouldn’t be able to interpret results properly and decreased access to genetic counseling — these are things preventing people from screening young patients for Lynch syndrome,” Karlitz said. – by Katrina Altersitz
Reference: Noll A. Poster 1884. Presented at: World Congress of Gastroenterology at American College of Gastroenterology Annual Scientific Meeting; Oct. 13-18, 2017; Orlando, FL.
Disclosures: Karlitz reports no relevant financial disclosures.