Breast carcinoma after cancer at another site: Method of detection, tumor characteristics, and surgical treatment

As the number of cancer survivors increases, so will the number of second primary cancers, including breast carcinoma after cancer at another site. Limited information is available regarding the clinical characteristics of breast carcinoma after a primary at another site. TUMORS (The Upper Midwest Oncology Registry Services) was used to identify 937 women with breast carcinoma occurring as a second primary after a first primary at a known site other than the breast. They were compared with a sample of 1874 women with first primary breast carcinoma, frequency-matched by age to the second primary group, for method of detection, tumor characteristics, and type of surgery. Women with breast carcinoma after cancer at another site tended to have smaller tumors and less extensive disease than women with first primary breast carcinoma and were somewhat more likely than first primary cases to have had their breast carcinoma detected by mammogram or clinical breast exam rather than detecting it themselves. Differences in method of detection accounted for differences in tumor size and extent. Second primary breast carcinoma was less likely to be lobular or mixed ductolobular carcinoma compared with first primary breast carcinoma. Surgical treatment (mastectomy vs. breast-conserving surgery) did not differ for first and second primary breast carcinoma. Clinical characteristics of breast carcinoma after cancer at another site were by and large similar to those of first primary breast carcinoma. The more favorable prognostic characteristics among women with a history of cancer were accounted for by increased medical surveillance.