Search for new treatments intensifies for triple-negative breast cancer.

M any physicians consider triple-negative breast cancer (TNBC) the most difficult type to treat, and some patients think it is a death sentence. This subtype of breast cancer is extremely aggressive, has limited treatment options, and carries a high risk of recurrence and death. Unlike breast cancers that express hormone receptors for estrogen and/or pro-gesterone and over-ex press the HER-2/ neu protein, TNBC is negative for all three proteins, so it cannot be treated with drugs specifically targeted at them. Although TNBC accounts for only 15% of breast cancer, it causes a disproportionate number of deaths, particularly among young, black, and Hispanic women, and those with BRCA1 and BRCA2 mutations. But a spate of recent studies has some experts feeling more optimistic. " Triple negative breast cancer is now receiving a tremendous amount of research, " said Comprehensive Cancer Center in Chapel Hill. That research includes the development of new molecular targets and drugs aimed at them, including poly(ADP – ribose) polymerase (PARP) inhibitors, which drew national attention after this year's meeting of the American Society of Clinical Oncology. Analyses of larger breast cancer trials are yielding clues about possible drug combinations for TNBC. And promising leads are coming from basic and transla-tional laboratories, according to Harvard's Eric Winer, M.D., who heads the breast oncology center at the Dana – Farber Cancer Institute in Boston. " I believe that we are on the verge of important discoveries that will have a lasting impact on the care we deliver to women with triple-negative breast cancer, " Winer said. Paradoxically, TNBC cells are initially more sensitive to DNA-damaging effects of chemotherapy than are other breast cancer types. Chemotherapy kills TNBC cells more effectively than it does other cancer " We want to determine if it is possible to reduce relapse for women with TNBC who have completed primary treatment but who have a high risk of recurrence. "