Objective: To investigate the epidemiological and clinical characteristics of breast cancer associated with multiple primary malignant neoplasmas (MPMNs).
Methods: The data of 519 patients of breast cancer associated with MPMNs admitted to the Cancer Hospital, CAMS and diagnosed by operation and pathology in the period of 1958 to 2001 were studied retrospectively to analyze the morbity, age of onset, sex ratio, predilection site of tumor, and the interval time between sequential tumors. The 519 patients, all female, were divided into four groups: bilateral primary breast cancer (1st group), synchronic Paget's disease (PD) associated with breast cancer in the same breast (2nd group), breast cancer as the first tumor associated with MPMNs (3rd group), and breast cancer as the second or third tumour associated with MPMNs (4th group).
Results: The constituent rate of bilateral primary breast cancer, synchronic Paget's disease (PD) associated with breast cancer in the same breast, breast cancer as the first tumor associated with MPMNs, and breast cancer as the second or third primary tumour associated with MPMNs was 3.0%, 0.8%, 3.2%, and 2.5% respectively. The median age of onset was 42.5, 47.3, 51.4, and 51.8 years respectively for the four groups. The mean interval time between the appearance of the first tumor and the appearance of the second tumor was 5.4, 0, 8.6, and 7.6 years in the four groups respectively. The predilection sites of second and third primary cancers in the third group were lung, breast, esophageal, ovary, and large intestine. The predilection sites of first primary cancer in the 4th group were uterus, ovary, large intestine, lung, lymphatic tissue, and esophagus successively. The involvement rate of breast in breast cancer associated with MPMNs was 72.4%.
Conclusion: (1) Breast is one of the predilection organs of MPMNs. (2) The predilection organs of breast associated with MPMNs are the target organs of female hormone (eg, breast, ovary and uterus) and the organs involved by radiotherapy for breast cancer (eg, lung and esophagus). (3) Early diagnosis and timely and proper treatment have satisfactory effect.