Molecular tag pinpoints which tumors are most likely to spread.(cyclin E aids in prediction of breast cancer invasiveness)

2002 DEC 12 - (NewsRx.com & NewsRx.net) -- A new molecular tag discovered by scientists at the University of Texas M.D. Anderson Cancer Center may help doctors decide which breast cancer patients need more aggressive treatment and which can forgo the potentially toxic course of chemotherapy.

Khandan Keyomarsi, PhD, associate professor in experimental radiation at M.D. Anderson, and her colleagues reported that high levels of a protein called cyclin E are closely associated with aggressive, invasive breast cancer. The study, conducted with tissue samples of current or former breast cancer patients, appears to show that cyclin E is a much better predictor of patient outcome than any current predictive marker. However, said Keyomarsi, the study must be repeated with newly diagnosed patients to determine its true predictive value.

The ability to predict which breast cancer tumors will recur or spread throughout the body is an important aspect of breast cancer treatment, said Keyomarsi. Currently, the prognosis for women diagnosed with breast cancer is determined by whether tumor cells have spread to lymph nodes. But some women who have cancer cells in the lymph nodes never have a recurrence, while others whose cancer has not spread do have a recurrence.

Yet many women, after discussions with their doctors, opt to undergo grueling chemotherapy in hopes of ensuring any rogue cancer cells that may be present are killed. If an accurate predictive marker were available, many women could be spared chemotherapy, she said.

In the study, published in the November 14, 2002, issue of the New England Journal of Medicine, Keyomarsi and her colleagues looked for the presence of cyclin E because when this protein is present at high levels inside cancer cells it signals cells to multiply all the time. In normal cells, cyclin E is present only for a short time and helps keep cell division under tight control. In addition, the scientists discovered smaller versions of cyclin E that are not present in normal cells. These low molecular weight versions are generated by an enzyme that chops up the normal cyclin E and in the process creates a new form that is even better ...