Medical researchers are coming to realize that there are many different forms of breast cancer. Each is caused by a different type of tumor, and each requires a different type of treatment.

Now, new research from Dartmouth University Medical School in New Hampshire has found a way to identify an especially aggressive type of breast cancer tumor. Doctor James DiRenzo is a professor of pharmacology and toxicology at Dartmouth. He says his work builds on previous studies, which looked at basal cell epithelial type breast cancer tumors. "This particular subtype had a very short time to relapse, which means that it'll come back very quickly. It had an early age of onset, so it really contributes to tumor burden on the population much greater than one that comes on much later in life." DiRenzo adds basal cell epithelial type breast cancer tumors are "particularly difficult to treat."

DiRenzo and his colleague Hua Lee studied tumor samples to see if they could find some kind of biological marker indicating whether these were the aggressive basal cell tumors. Researchers have already identified markers for other types of breast cancer tumors.

DiRenzo and Lee identified a protein they're calling nestin that was only present in tumors of this aggressive type.

DiRenzo says this could be very important for women with basal cell cancer, because the tumors respond differently to chemotherapy than other types of breast cancer. "It means that now, if a marker like nestin were used clinically, you could make a definitive diagnosis and say 'this patient has a basal breast tumor' and that would be very informative in terms of their surgical and chemotherapeutic options."

DiRenzo adds that choosing the right courses of therapy can mean the difference between success and failure in the battle against breast cancer. Prior research has shown that women with basal cell tumors are prone to have relapses of their cancers, even after they've completed courses of chemotherapy and radiation treatment.

"Somewhere between 17 and 37 percent of breast cancers are this phenotype," DiRenzo says. Those patients and their physicians may soon have a way to check for recurrence at a very early age in a way he says is "quite non-invasive."

DiRenzo says the next step is finding an efficient and non-invasive way to detect nestin in tumor cells. He predicts it will be several years before such a commercial test is available. The research was published in a recent issue of Cancer Research.