[New primary malignancies after breast cancer diagnosis: interplay of genetics, risk factors and treatment modalities]. / Novi primarni zlocudni tumori nakon dijagnoze raka dojke: meduodnos naslijeda, rizicnih cimbenika i modaliteta lijecenja.

ABSTRACT

Significant advances in early breast cancer detection and increased quality of care within developed countries resulted in longer than five years survival in almost 90% of women diagnosed and treated for breast cancer. One in twenty women diagnosed with breast cancer will develop a new primary non-breast malignancy within 10 years from initial diagnosis. Mutations in BRCA 1 i 2, RAD51C, MMR, p53, CDKN2A and 113insArg genes are linked with increased risk of breast cancer and other cancer sites. It seems that treatment modalities also play significant role in development of new primary malignancies. Tissues that receive higher doses of radiation during radiotherapy of breast cancer are under increased risk of developing new primary tumor, especially in younger women, ten years after the treatment. Chemotherapy may cause higher incidence of leukemia and myelodysplastic syndrome but lower overall risk for development of other malignancies. Connection between tamoxifen therapy and increased risk of endometrial cancer is well known and confirmed also in recent studies. The true mechanism of cancer development is still unclear. Significance of hereditary factors, possible common environmental risk factors or unwanted side effects of the specific anticancer treatments are yet to be discovered.