More than 1 in 10 Americans over age 60 years will be diagnosed with cancer, according to the National Cancer Institute, making screening for the disease in older patients imperative. Much of the burden of cancer screening falls on primary care physicians. This news organization spoke recently with William L. Dahut, MD, chief scientific officer of the American Cancer Society, about the particular challenges of screening in older patients.
Question: How much does cancer screening change with age? What are the considerations for clinicians – what risks and comorbidities are important to consider in older populations?
Answer: We at the American Cancer Society are giving a lot of thought to how to help primary care practices keep up with screening, particularly with respect to guidelines, but also best practices where judgment is required, such as cancer screening in their older patients.
We’ve had a lot of conversations recently about cancer risk in the young, largely because data show rates are going up for colorectal and breast cancer in this population. But it’s not one size fits all. Screening for young women who have a BRCA gene, if they have dense breasts, or if they have a strong family history of breast cancer should be different from those who are at average risk of the disease.
But statistically, there are about 15 per 100,000 breast cancer diagnoses in women under the age of 40 while over the age of 65 it’s 443 per 100,000. So, the risk significantly increases with age but we should not have an arbitrary cut-off. The life expectancy of a woman at age 75 is about 13.5 years. If you’re over the age of 70 or 75, then it’s going to be comorbidities that you look at, as well as individual patient decisions. Patients may say, “I don’t want to ever go through a mammogram again, because I don’t want to have a biopsy again, and I’m not going to get treated.” Or they may say, “My mom died of metastatic breast cancer when she was 82 and I want to know.”
Q: How should primary care physicians interpret conflicting guidance from the major medical groups? For example, the American College of Gastroenterology and your own organization recommend colorectal cancer screening start at age 45 now. But the American College of Physicians recently came out and said 50. What is a well-meaning primary care physician supposed to do?
A: We make more of guideline differences than we should. Sometimes guideline differences aren’t a reflection of different judgments, but rather what data were available when the most recent update took place. For colorectal cancer screening, the ACS dropped the age to begin screening to 45 in 2018 based on a very careful consideration of disease burden data and within several years most other guideline developers reached the same conclusion.
However, I think it’s good for family practice and internal medicine doctors to know that significant GI symptoms in a young patient could be colorectal cancer. It’s not as if nobody sees a 34-year-old or 27-year-old with colorectal cancer. They should be aware that if something goes away in a day or two, that’s fine, but persistent GI symptoms need a cancer workup – colonoscopy or referral to a gastroenterologist. So that’s why I think age 45 is the time when folks should begin screening.