HOLLYWOOD, FLA. — Nearly 50% of patients who were diagn with colorectal cancer at two large tertiary-care hospitals in Michigan would fall outside recommendations that favor limiting routine screening to patients who are 50–75 years of age.
Last year, the U.S. Preventive Services Task Force released a recommendation statement following two studies that assessed expected health outcomes and resource utilization from screening with fecal occult blood testing, sigmoidoscopy, and colonoscopy (Ann. Intern. Med. 2008;149:627–37). This report recommends against routine screening of patients aged 76–85 years, but notes that screening may be warranted in some individuals outside of that age group. They also recommended against screening any adult older than 85 years.
Dr. Jason Shellnut and his associates launched a study to assess the appropriateness of these guidelines at William Beaumont Hospital System in Royal Oak, Mich. They identified 6,925 patients with colorectal cancer treated at one of their two referral hospitals with a total of 1,357 beds between January 1973 and December 2007. They divided patients into three groups by age at diagnosis—younger than 50 years, 50–75 years, or older than 75.
They also evaluated the 35 years' worth of data in 5-year increments to assess trends over time.
“Not screening those older than 75 and younger than 50 would miss 49% of our diagnosed patients in the last 5-year period [2003–2007],” said Dr. Shellnut, a colorectal surgery fellow at William Beaumont Hospital. This 49% is a significant increase, compared with 36% in the first 5 years (1973–1978) of the tumor registry data. Most of the increase is attributed to the older patient group.
The percentage of patients who were older than 75 years at diagnosis rose from 29% (1973–1978) to 40% (2003–2007). This includes a significant increase in patients older than 85 years, from 6% to 12%. In contrast, the percentage of patients younger than 50 did not change significantly from 1973 to 2007, staying within a 6% to 8% range.
At the same time, the percentage of patients in the age range recommended for screening declined significantly. Specifically, patients in the age range of 50-75 years decreased from 64% (1973–1978) to 52% (2003–2007) of those diagnosed.
The researchers looked for any differences in pathologic stage and tumor location. “Pathologic stage data did not vary [significantly] across the years,” Dr. Shellnut reported at the annual meeting of the American Society of Colon and Rectal Surgeons.
However, patients under 50 years old were significantly more likely to present with advanced disease. A total of 51% of these younger patients were diagnosed with either stage III or IV colorectal cancer, compared with 41% of the 50- to 75-year-olds and 35% of patients older than 75.
By age of diagnosis, there were significant differences in terms of rectal and left-sided cancer diagnoses. These tumors were most common in the younger age group, 68%, compared with 64% of the patients aged 50–75 years and 50% of the older group.
The retrospective design of the study is a potential limitation, Dr. Shellnut said, and applicability of the findings beyond their health system is unknown. In addition, the tumor registry data track only patients who underwent resection of their cancer.
Dr. Shellnut had no disclosures.
'Not screening those older than 75 and younger than 50 would miss 49% of our diagnosed patients.' DR. SHELLNUT