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Medroxyprogesterone acetate (MAP) in the treatment of advanced breast cancer has been regarded as a minor agent according to the previous reports when used at low doses (less than 500 mg/day). High doses of more than 500 mg which have come into use since 1973 give a response rate of over 40%, but sometimes cause gluteal abscess or induration because of daily intramuscular injections. In order to administer easily and to avoid the side effect, we have attempted to use oral administration in a daily dose of 1200 mg (400 mg X 3). Of those 20 patients treated with oral high-dose MAP, 1 showed complete response, 6 showed partial response, 7 no change, and 6 progressive disease. As for site of lesion, 4 out of 6 (67%) in skin and 4 out of 16 (25%) in bone responded. Neither severe side effects nor abnormal laboratory data were seen. Then, we examined the blood levels of MAP in vivo by RIA in 9 patients. The blood level of MAP reached 39-250 ng/ml in 3 days and was maintained at least over 50 ng/ml for 1 or 2 months of continuous administration. Subsequently, we examined the effects of MAP on binding to ER in vitro. The inhibition of binding of estradiol-17 beta to ER was about 60% at 10(-5) M MAP. The blood level of 50 ng/ml in vivo corresponds to about 1.3 X 10(-5) M.

To investigate the effect of breast self‐examination (BSE), we compared the stages, survival, and the risk of death for 355 patients with breast cancer detected by BSE with those for 1,327 patients with breast cancer detected by chance. The early stages of the disease were found to be more common among the symptomatic breast cancer patients detected by BSE than those by chance. The 5‐year overall survival rate was 94.4% for the symptomatic patients detected by BSE, and was significantly higher by 8.7% than that (85.7%) for patients detected by chance (P< 0.001). The 10‐year survival rate was 81.6% for patients detected by BSE, and 76.6% for cases detected by chance (the difference was not significant). The overall difference between the two survival curves was statistically significant by the Iogrank test (P<0.01). A multivariate analysis using the Cox proportional hazards model showed that the risk of death for patients detected by BSE was smaller by 0.570 times than that for patients detected by chance, which was statistically significant (P< 0.05). The effect of biases inherent to BSE in the survival analysis cannot be controlled completely even after conducting multivariate analysis. These results suggest that BSE may contribute to the reduction of the risk of death through early detection of breast cancer. However, further examination should be conducted by other methods to obtain conclusive evidence.

To establish the criteria for assessing the life‐prolonging effect of mass screening for breast cancer, clinical stage and prognosis of breast cancer detected by mass screening in 11 regions of Japan were compared with those for matched patients in out‐patient clinics. A total of 728 patients detected by mass screening and 1,450 found in the out‐patient clinics were reviewed. The stage of the disease was Tis or I in 40.9% of the patients detected by mass screening, and 28.7% of those found in the out‐patient clinics. In contrast, stage III was found in 9.3% and 14.6%, respectively, indicating that early stages were significantly more common in the patients detected by mass screening. The overall survival curve for the patients detected by mass screening was compared with that for those found in the out‐patient clinics. The 5‐year survival rate was significantly higher in the patients detected by mass screening (91.7% vs. 85.6%; P<0.01), while the 10‐year survival rate was slightly higher in the same group of patients, but the difference from the other group was not significant (80.5% vs. 78.1%). Women who had conducted breast self‐examination (BSE) showed a higher survival rate than those who had not conducted BSE.

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