Limitations and Benefits of Mass Screening for Detection of Breast Cancer through Observation and Palpation-Verification in Terms of Tumor-Doubling Time / 日本農村医学会雑誌

ABSTRACT

A total of 146 patients with breast cancer were operated on at our hospital between April 1991 and January 1997. The number of those patients who had undergone mass screening was 37. Those 37 patients were divided into three groups 18 patients with interval breast cancer (the interval group), 12 patients having breast cancer detected by mass screeing (the mass screening group) and 7 patients diagnosed with breast cancer in outpatients clinics during the course of periodic routine examinations (the outpatient clinic group). To investingate the limitations and beneficial effects of mass screening programs consisting of observation and palpation, seven clinicopathological factors were analyzed, with special attention paid to tumor doubling times. These factors were % body fat, tumor size at the time of mass screening calculated from the age-dependent tumor doubling times, interval between mass screening and surgery, actual tumor size at the time of surgery, histological type, extent of nodal involvement and pathological staging. The percentage of early breast cancer was higher for these groups than for the other 109 patients, who had never undergone mass screening (59.4% versus 32.1%, p<0.01). However, the following limitations were found. In mass screening, it was difficult to detect masses smaller than 2 cm in diameter. Analysis of th data for the interval group showed that it was possible for women to find a breast mass measuring around 2cm through self-examination and that mass screening had no difinite advantage over the self-examination. In addition, it was found that earlier detection was called for in outpatient clinics in terms of the nodal status. We concluded that the benefits of the currently organized mass screening programs were doubtful. Women should be educated about the importance of self-examining their breasts and taught how to practice the self-examination. Goals should include finding women who considered at high risk and detecting breast cancer 1 cm or smaller in diameter during the course of periodic examinations at medical institutions.