We have devoted considerable space in this column on when to screen for certain cancers. For those cancers for which screening is recommended (breast, colorectal, cervical, prostate, lung), there is invariably accompanying discussion and controversy regarding the best age at which to commence screening. Thus, the use of mammography for screening women in their 40s has been controversial and has only recently been promulgated by the U.S. Preventive Services Task Force as a reasonable age at which to begin. The initiation of colorectal cancer screening was recently advanced to age 45 years from the previous recommendation of 50 years. Much energy and thought goes into these choices and they are frequently revised as new data appears.
But we should be aware that the guidelines for screening also recommend the ages at which to cease screening. Why would this be so? One reason is that the studies that were done to establish the benefits of a screening test do not generally demonstrate that the putative screening test continues to be efficacious in reducing mortality at the older ages. A second reason that screening at older ages may not be advisable is that the remaining life expectancy of an older individual may not justify the further use of screening. For example, if the average survival for a cancer is 10 years, and a 75-year-old person has a life expectancy of nine years, it would not be logical to utilize screening over age 75 years. In general, cancer screening is almost never recommended for those who have a life expectancy of less than 10 years, as the cancers may take longer than that to develop and to cause death.
Another reason that stopping screening at older ages is recommended is that older people are more susceptible to the adverse effects of the screening. The sedation that accompanies colonoscopy, for example, is more dangerous to an older person than a younger person, and the risk of perforation is likewise dramatically higher. Thus, the risk/benefit ratio is altered at older ages. Likewise, other comorbidities, such as heart disease or diabetes or dementia, are more common in older individuals and may also complicate the screening test or its follow-up, or the management of an indolent cancer that is diagnosed.
Stopping screening does not mean abandoning one’s health or care. Certainly, if concerning symptoms develop or arise they should be brought to the attention of one’s healthcare provider and dealt with appropriately.
What are the ages that current guidelines recommend at which to stop screening?
- Colorectal cancer screening at age 75
- Breast cancer screening at age 74
- Cervical cancer screening at age 65
- Prostate cancer screening, if performed at all, at age 69
- Lung cancer screening, generally recommended for heavy smokers, at
age 79
Certain factors may affect the decision to continue screening. For those who are of outstanding health with an excellent life expectancy, it may be reasonable to extend the age at which cancer screening continues to be implemented. Special risk may also be an element in the decision, such as family history or the presence of a genetic mutation.
I recently reviewed the case of a 78-year-old man of average risk and good health who underwent a screening colonoscopy. Unfortunately, he suffered a perforation of the transverse colon and had to be admitted emergently to his local community hospital. There he underwent surgery for repair of the perforation, but one complication led to another, and he was hospitalized for several weeks. He ultimately expired from complications stemming from the perforation.
No errors were made by his treating doctors, and all his complications were well-recognized adverse effects of the procedures he underwent. Nonetheless, I found myself wondering why he was administered a colonoscopy in the first place. No procedure can be considered safe.
Alfred I. Neugut, MD, PhD, is a medical oncologist and cancer epidemiologist at Columbia University Irving Medical Center/New York Presbyterian and Mailman School of Public Health in New York. Email: ain1@columbia.edu.
This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment, and does not constitute medical or other professional advice. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition or treatment.
