The most important factors in the evaluation and treatment of breast pain consist of a thorough history, physical, and radiologic evaluation. These can be used to reassure the patient that she does not have breast cancer. In the 15% of mastalgia patients who have life-altering pain and still request treatment, therapy may consist of a well-fitting bra, a decrease in dietary fat intake, and discontinuance of oral contraceptives or hormone replacement therapy. Those women still resistant to therapy may experience relief from evening primrose oil supplements, bromocriptine, tamoxifen, or GnRH analogues. Predicting which treatment will be most useful for any particular woman may be challenging. No differences in success rates were found to be associated with factors such as reproductive history, presenting complaint, personal or family history of breast disease, or subsequent need for breast surgery. The peak (but not basal) serum prolactin levels in response to thyrotropin releasing hormone stimulus has been predictive of success for hormonal treatment but is relatively invasive. A survey of treatments actually used was obtained from 276 consultant surgeons in Britain in 1990. Of those, 75% prescribed danazol. Others used analgesia (21%), diuretics (18%), local excision (18%), bromocriptine (15%), evening primrose oil (13%), tamoxifen (9%), a well-fitting bra (3%), and no treatment (10%). Breast specialists were more likely to begin treatment with primrose oil, tamoxifen, vitamin B6, and analgesia, reserving other hormonal therapies for more difficult cases. To further evaluate the women who have severe mastalgia but do not complete treatment regimens, a questionnaire was sent to 79 patients who failed to return to the Longmore Breast Unit of Western General Hospital, Edinburgh. Seventy-one women responded. Of these, 36 said they felt better, 19 said they felt no more could be done, 18 learned to live with it, 14 were not worried even if the pain recurred, 2 were pregnant, 10 were postmenopausal, and 5 were still taking the medications previously prescribed. The prognosis for women with breast pain is not always predictable. Women with cyclic breast pain often are relieved by events that alter their hormonal milieu, whereas noncyclic breast pain may last only 1 to 2 years. Sitruk-Ware and colleagues conducted a study of French women with fibroadenomas. They found an association between fibroadenomas and cyclic mastalgia occurring more than 1 year prior to the first full-term pregnancy. A retrospective, case-control study to determine if cyclic mastalgia was a risk factor for breast cancer was conducted on 210 newly diagnosed women with breast cancer.(ABSTRACT TRUNCATED AT 400 WORDS)