Genetic Changes in Breast Tissue Caused by Pregnancy Hormone Helps Prevent Breast Cancer
A full-term pregnancy at an early age is one of the most effective ways to reduce the lifetime risk of breast cancer, according to research pathologist Irma H. Russo, M.D., of Fox Chase Cancer Center in Philadelphia. A number of studies around the world have established that a full-term pregnancy by age 20 reduces breast cancer risk by half.
Previous studies by Russo and colleagues suggest that breast cells reach full maturity - a process called differentiation - only after a full-term pregnancy. Once this process is complete, the cells are less vulnerable to cancer-causing changes. An early pregnancy confers the strongest protection by limiting the time breast cells remain immature.
A new study finds poor survival rates among young adults and older adolescents with some cancers may be partially explained by the lack of participation in clinical trials. The study, published in the journal Cancer, found that age-dependent survival rates among patients with sarcomas - except Kaposi Sarcoma (KS) - correlated with clinical trial participation rates.
The authors conclude, "based on the study reported here and others in leukemias, brain tumors, and cancer in general, lack of clinical trial participation (and of the increased knowledge of tumor biology that derives from modern clinical trials) offers one explanation" for the poor cancer survival improvements in young adults.