Colorectal Cancer Incidence May Be Rising in Younger People

BOSTON—Surgeons at the University of Texas–Southwestern Medical Center (UT-SW), Dallas, have documented a rising incidence of colorectal cancer among people aged 40 to 49. They presented the results of the retrospective study at the American Society of Colon and Rectal Surgeons (ASCRS) annual meeting.

The results have led the investigators to question whether the current recommendation to start colorectal cancer screening at age 50 is out of date and to suggest that moving the start of routine screening back to age 40 should be considered.

The researchers identified 1,128 patients diagnosed with colorectal cancer from 1978 to 1998 at Parkland Memorial Hospital, Dallas. They then compared the incidence with respect to age for the first 5 years of the study with the last 5 years to see whether there had been a change.

From 1978 to 1982, people in their 40s accounted for 8.1% (14) of 173 patients diagnosed with colorectal cancer. From 1994 to 1998, the total number of colorectal cancer cases was 340 patients, of which 14.4% (49) were in their 40s.

“We need other institutions to verify our findings,” senior author Sharon G. Gregorcyk, MD, told ONI in a postcon-ference interview. “If we can find a nationwide trend, that would definitely indicate to us that something is going on, and we should probably change routine screening guidelines.”

An assistant professor of surgery at UT-SW, Dr. Gregorcyk is director both of Parkland Surgical Clinics at Parkland Memorial Hospital and of the University of Texas-Parkland Anorectal Physiology Laboratory. She said she proposed the study after seeing a 17-year-old colon cancer patient and several others in their 30s. This led her to suspect that colon cancer patients were being diagnosed at a younger age. “A lot of us had the feeling that we were seeing colon cancer in younger and younger patients,” she said. “ It was hard to know, is that a true fact, or is it just that those cases stand out in our minds?”

Indeed, the review showed only a modest increase among patients under age 40: from 8.1% of the 1978 to 1982 group to 9.7% of the patients diagnosed from 1994 to 1998. Dr. Gregorcyk said she has no explanation for why the incidence increased significantly among patients in their 40s.

Studies done from 1966 to 1994 are the basis of the current recommendation that routine screening begin at age 50. Issued in 1997, the recommendation has been endorsed by the American Cancer Society, American College of Gastroenterology, American Gastroenterological Association, American Society of Colon and Rectal Surgeons, American Society for Gastrointestinal Endoscopy, Crohn’s and Colitis Foundation of America, Oncology Nursing Society, and Society of American Gastrointestinal Surgeons.

Dr. Gregorcyk called on surgeons at other cancer centers to do similar studies to be sure that the growing number of younger patients at the Dallas hospital is not an isolated event. Meanwhile, she said she plans to continue tracking the incidence of colorectal cancer at Parkland.