Abstract & Commentary
Synopsis: Cancer screening for older women remains an area of active investigation. One current recommendation is to perform screening for individuals with a life expectancy of 5 years or more, as early detection of tumor in these individuals is more likely to have an impact on survival. In this cross-sectional population based study from California, it is apparent that screening is currently applied to older women without consideration of health status. Thus, for many, mammography and Pap smears are being obtained with little hope of benefit.
Source: Walter LC, et al. Ann Intern Med. 2004;140: 681-688.
In general, the rates of screening mammography and Papanicolaou (Pap) smears decrease with advancing age. However, the benefit of these cancer-screening tests is better predicted by health status than age alone. It is improbable that older women whose life expectancy is less than 5 years would benefit from screening mammography and Pap smears.1,2 Previous studies examining associations between health status and recent receipt of cancer screening tests have been inconsistent. As a result, it is currently unclear to what extent screening mammography and Pap smears are actually targeted to healthy older women who may plausibly benefit from these tests and are avoided in older women with limited life expectancies and for whom the potential harms (additional diagnostic tests, surgery, etc) may outweigh the benefits. To examine this question, Walter and colleagues from San Francisco Veterans Affairs Medical Center and University of California, San Francisco conducted a cross-sectional population-based study using data from the 2001 California Health Interview Survey (CHIS). In this survey, 4792 women 70 years of age or older were separated into 4 distinct categories based on health status and were analyzed for the receipt of screening mammography within the previous two years and a screening Pap smear within 3 years. Health Status was assessed by using the Medical Outcomes Study 12-item Short Form Physical Summary Scale.
Overall, 78% of women included in the study reported receiving screening mammography within 2 years of the survey and 77% reported a recent Pap smear. In general, screening rates decreased with advancing age. For those 70-74 years of age, 88% reported screening mammography and 86% reported a screening Pap smear. In comparison, for those 85 years of age or older, 61% reported screening mammography and 60% reported a screening Pap smear. However, within each age category, the percentage of women who were screened did not significantly decrease with worsening health status (P >0.1 for all comparisons). Women 75 to 79 years of age in the worst health status category were more likely to receive a screening mammogram than women 80-84 years of age in the healthiest PCS-12 quartile (82% vs 66%; P = 0.002), despite life expectancy. In addition, except for women 85 years or older, those with the worst PCS-12 quartile reported the same or more screening Pap smears than those women in the best PCS-12 quartile. Greater than 50% of women 80 years or older and in the worse health quartile reported recent screening mammography or Pap smears, corresponding to approximately 81,000 mammograms and 35,000 Pap smears when extrapolating these data to the California population. In contrast, an estimated 97,000 women 70 to 84 years of age in the best two health status quartiles had not recently received screening mammography (95% CI, 85,000-109, 000) and 58,000 had not received a recent pap smear.
Comment by William B. Ershler, MD
The current report indicates that physicians are not determining candidates for screening based upon health status. The incidence of breast cancer increases with advancing age and accordingly, mammography is more likely to reveal previously unrecognized lesions in older women. However, the impact of early detection might be of little consequence to individuals of limited life expectancy because of other comorbidities. This is the foundation for the recommendation to limit screening to individuals with a life expectancy of 5 years or more. In the current survey, it was encouraging to see a relatively high rate of screening in older women. However, it appears that a good deal of the screening is inappropriately prescribed. Physicians and other health care providers who prescribe screening should take note. It is health status and life expectancy that are determinants of who among geriatric patients might benefit from screening. If estimated survival is 5 years or more, screening is appropriate.
Dr. Ershler is Director, Institute for Advanced Studies in Aging, Washington, DC.
1. Walter LC, Covinsky KE. JAMA. 2001;285:2750-2756.
2. Madelblatt J, et al. Ann Intern Med. 2003;139:835-842.