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05-18-2005, 04:58 AM

This is from Dr. Susan Loves website:

HER2/NEU and Herceptin
My tumor was Her2/Neu positive. Does that mean my chance of recurrence is much greater?

Not necessarily. While it’s true that some early studies found that women with HER-2/neu+ tumors had a higher rate of recurrence, other studies haven’t found that to be the case. The reason for the discrepancy seems to be that HER 2/neu alone doesn’t mean much. We have to consider a lot of other factors as well.

First, HER2/neu is still an enigma. It is present in most DCIS -- precancerous breast disease -- but is present in only 15%-30% of frank cancers. Since DCIS usually doesn't progress to invasive cancer, it may be telling the cells to grow, but not necessarily to invade other tissues -- a condition for malignancy. This may mean that it probably needs other factors to become malignant.

Second, it matters whether HER2/neu is actually doing something or if it is just sitting there in the cancer cell. When HER2/neu is working, it acts as a receptor for growth factors. When a growth factor attaches to HER2/neu, signals go out that tell the cell to grow and divide. There is now an investigative test that can tell whether HER2/neu is active or inactive. Early studies indicate that inactive HER2/neu don’t have much effect on a woman’s prognosis, but that active receptors indicate more aggressive tumors.

Third, HER2/neu probably doesn’t act alone. Like most cellular criminals it does the most damage in collusion with other molecular bad guys. Some studies have found that HER2/neu may not cause much trouble unless other proteins such as epidermal growth factor receptor are also present.

Fourth, the likelihood of recurrence depends on the type of treatment. Overall, the studies suggest that HER2/neu signals a worse prognosis primarily in women who have node-positive disease and that women who overexpress HER2/neu may do better when chemotherapy includes doxorubicin (Adriamycin). The significance of HER2/neu in women who have node-negative disease isn’t as clear because fewer have HER2/neu positive tumors.

Unfortunately, the final word on the meaning of HER2/neu isn’t in. Although some oncologists may decide to treat HER2/neu tumors more aggressively – either by giving chemotherapy to women who are node negative or by substituting CAF for CMF treatment for women with positive nodes – there is no conclusive evidence that doing so will prevent a recurrence.

The question remains: Given the uncertain meaning of HER2/neu, is there any value in testing for it? I think there is. Herceptin is now approved for women with metastatic disease who have HER2/neu+ tumors, and a study is in progress to determine whether women newly diagnosed with HER2/neu+ breast cancer can also benefit from this drug. The more tumors that are tested, the more information we will have on HER2/neu and the outcomes of women with HER2/neu + tumors.

05-18-2005, 04:58 AM	#4
Rhonda4 Guest Posts: n/a	This is from Dr. Susan Loves website: HER2/NEU and Herceptin My tumor was Her2/Neu positive. Does that mean my chance of recurrence is much greater? Not necessarily. While it’s true that some early studies found that women with HER-2/neu+ tumors had a higher rate of recurrence, other studies haven’t found that to be the case. The reason for the discrepancy seems to be that HER 2/neu alone doesn’t mean much. We have to consider a lot of other factors as well. First, HER2/neu is still an enigma. It is present in most DCIS -- precancerous breast disease -- but is present in only 15%-30% of frank cancers. Since DCIS usually doesn't progress to invasive cancer, it may be telling the cells to grow, but not necessarily to invade other tissues -- a condition for malignancy. This may mean that it probably needs other factors to become malignant. Second, it matters whether HER2/neu is actually doing something or if it is just sitting there in the cancer cell. When HER2/neu is working, it acts as a receptor for growth factors. When a growth factor attaches to HER2/neu, signals go out that tell the cell to grow and divide. There is now an investigative test that can tell whether HER2/neu is active or inactive. Early studies indicate that inactive HER2/neu don’t have much effect on a woman’s prognosis, but that active receptors indicate more aggressive tumors. Third, HER2/neu probably doesn’t act alone. Like most cellular criminals it does the most damage in collusion with other molecular bad guys. Some studies have found that HER2/neu may not cause much trouble unless other proteins such as epidermal growth factor receptor are also present. Fourth, the likelihood of recurrence depends on the type of treatment. Overall, the studies suggest that HER2/neu signals a worse prognosis primarily in women who have node-positive disease and that women who overexpress HER2/neu may do better when chemotherapy includes doxorubicin (Adriamycin). The significance of HER2/neu in women who have node-negative disease isn’t as clear because fewer have HER2/neu positive tumors. Unfortunately, the final word on the meaning of HER2/neu isn’t in. Although some oncologists may decide to treat HER2/neu tumors more aggressively – either by giving chemotherapy to women who are node negative or by substituting CAF for CMF treatment for women with positive nodes – there is no conclusive evidence that doing so will prevent a recurrence. The question remains: Given the uncertain meaning of HER2/neu, is there any value in testing for it? I think there is. Herceptin is now approved for women with metastatic disease who have HER2/neu+ tumors, and a study is in progress to determine whether women newly diagnosed with HER2/neu+ breast cancer can also benefit from this drug. The more tumors that are tested, the more information we will have on HER2/neu and the outcomes of women with HER2/neu + tumors.