We may debate about when an asymptomatic woman should receive her first mammogram or begin annual mammography screening, how long the interval should be between mammograms for women or about what situations warrant cessation of screening, but on this we agree: early detection through annual mammography and clinical breast examination decreases mortality from breast cancer in older women. The evidence is solid and irrefutable. Annual screening of all women over 50 years of age would result in a decrease of 25 to 40 percent in deaths from breast cancer.¹

Unfortunately, although utilization of mammography screening has increased in recent years, underutilization remains the norm. In 1993, only 47 percent of women 50 to 64 years of age and 39 percent of women age 70 or older reported having received a recent mammogram.² Screening rates have been especially low among black women and women with low incomes. These women have higher rates of breast cancer mortality. Family practitioners play a crucial role in addressing the persistent problem of underutilization of mammography screening.

Physician recommendation is the most powerful predictor of whether a woman will or will not have mammography screening. Numerous studies have demonstrated that women who receive physician encouragement are four to 12 times more likely to have mammograms than those who do not receive encouragement.^3,4 Differences in physician referral rates were found to account for 60 to 75 percent of racial differences in mammography use in two North Carolina counties,⁵ suggesting that greater involvement of physicians in referring white women partially accounts for the recently documented decline in mortality from breast cancer in white but not black women.⁶

Although many factors contribute to physician nonreferral, an important obstacle to overcome is physician underestimation of the impact that they have on their patients. Our recent three-year longitudinal study,⁷ sponsored by the National Cancer Institute (NCI), strongly refutes the notion that physician referral does not make much difference in patient compliance. This study was conducted among community practices of family practitioners and general internists in two major cities and examined the impact of physician referral on mammography completion and compliance of women 50 years of age and older. Referral and mammography compliance data were gathered by audits of over 11,000 patient charts of 95 physicians.

Physician referral and patient compliance were found to be strongly related in our study⁷; of patients referred for mammography by their physician, 70 percent had a mammogram within the year, whereas only 18 percent completed one on their own initiative.

Why are physician referrals so powerful? The NCI's Breast Cancer Consortium studies found that women who never had a mammogram said that they just never thought of it or that they did not think there was a problem that warranted mammography (40 percent); that their physician never recommended it (28 percent); or that they had never heard of it (10 percent).³ With brief office counseling, a physician can efficiently address these three most common reasons women cite for not having been screened. No wonder that when a physician recommends mammography, it makes a difference!

The problem is that physicians make too few referrals. In our study,⁷ physicians averaged a referral rate of only 20 percent at baseline, based on audits of medical charts for the three months preceding the study. Only 38 percent of patients at baseline had received mammograms in the previous 14 months. Referral rates and patient compliance rates were comparable for family physicians and general internists.

Why don't physicians order more mammograms? Sixty percent of physicians in our study⁷ reported that, at least some of the time, they did not discuss mammography because they assumed that the patient saw a gynecologist who would make the referral. However, visits to gynecologists decrease with age and are lowest among the very women who are at most risk for not being referred—older women, nonwhite women, and women insured by Medicaid or Medicare. In contrast, older women typically see a primary care physician three or more times a year, and the frequency of visits increases with age. Given these realities, it is reasonable to assume that the primary care physician is the person on whom older women most rely for advice on breast cancer screening.

Other reasons given by physicians in our study⁷ for not referring women were comorbidity and advanced age. At what point is a woman too sick or too old to benefit from early detection of breast cancer? Although there are no official guidelines for weighing these factors, family physicians can help patients balance considerations of longevity, comorbidity and the quality of life as these relate to preventive screening. Physicians can empower patients by explaining the assumptions that underlie clinical judgments and inviting patients to participate in decision-making.

Many physicians in our study⁷ reported that they rely on appointments with patients for full physical examinations or annual Papanicolaou tests and pelvic examinations to discuss cancer screening. This practice has the unfortunate result of missing the opportunities for referral available to women who only see their physician for acute care. These women are less likely to be missed if every office visit is seen as an opportunity to mention screening mammography.

An office reminder system can alert the physician to a woman's mammography screening status, whatever the reason for an office visit. In our study,⁷ rates of patient compliance with screening were significantly higher in the practices randomly assigned to use a chart sticker system. Numerous options to streamline office practice with cueing and tracking systems have been described.^8–10 The development of an efficient system for ensuring the delivery of preventive care should be a high priority for physicians who are setting up their office practices.

Family physicians can have a direct impact on mortality from breast cancer by becoming strong advocates of screening mammography for asymptomatic women 50 years of age and older. Physician recommendation and referral are powerful predictors of who gets screened. Because older women are less likely to see gynecologists than younger women, their contacts with primary care physicians are especially important. Any office visit for routine or acute care can be an opportunity for mentioning screening mammography and addressing patient concerns.

Family physicians are in the ideal position to help reach the goal of Healthy People 2000: a screening mammogram and a clinical breast examination for 60 percent of women over age 50 by the year 2000.¹¹