Screening, Access to

Role of Society to Inform

Policies for site-specific cancer screening represent the culmination of many years of medical research. The American Cancer Society has set forth recommendations for early detection in average-risk, asymptomatic people. These recommendations include regular screening for breast, colorectal, prostate, cervix, and endometrial cancers.

Determining recommendations for cancer screening is a challenging task. Evidence must be considered from rigorously designed studies, with risk groups that have been carefully defined. Several lines of evidence form the empirical basis of cancer screening. These lines of evidence, more extensively described in the textbook Cancer Screening, Theory and Practice, are summarized as follows. First, evidence must be obtained from at least one randomized comparative trial. Second, evidence must be from controlled trials that use allocation methods other than randomization (e.g., allocation by birth date or hospital chart number). Third, evidence must be obtained from cohort or population-based case–control analytic studies, preferably from several studies and investigators. Fourth, evidence must be obtained from multiple time series, with or without intervention. Finally, opinions must be sought from respected authorities based on clinical experience, descriptive studies, or reports of expert committees.

In making policy decisions about screening, decision-makers need to factor in the perceptions and values of the people most affected by the screening policy. One would assume that decision makers are knowledgeable about the scientific evidence and familiar with the perceptions and values of the people, but once screening practices are being applied at the local level, these principles may not hold. In addition, decision makers need to weigh the benefits of screening with the harm. Harm resulting from screening includes high rates of false-positive results from the screening test. For instance, a high prostate-specific antigen (PSA) level may trigger fear of cancer, worry, and possibly unnecessary biopsies. These consequences of false test results become problematic given the potential inaccuracy of PSA screening for prostate cancer. PSA screening, in combination with digital-rectal examination (DRE), is now held to be the standard for prostate cancer screening. However, some racial and ethnic groups feel uncomfortable with the DRE portion of the screening exam. For instance, African-American and Caucasian men have similar PSA screening rates, but African-Amer-ican men have lower DRE examination rates than Caucasian men. Hispanic men, in contrast, avoid [Page 778]screening altogether; a much higher proportion of Hispanic men are detected by symptoms alone. Communication about the importance of screening to members of different racial and ethnic groups requires sensitivity and the capacity to tailor the message uniquely to each defined group. Because the incidence of prostate cancer is much higher among African-American men, the importance of effective communication to this population subgroup cannot be minimized.

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