� � Oct-01-2010
The female hormone estrogen is known to aggravate cancerous tumors on the breast. According to a new study, these tumors can be reduced appreciably before surgery, if the affected women are given hormone blocking treatment for a few months. This may enable surgeons to remove only the tumor or the lump, and do away with the need of removing the whole breast, or mastectomy, in many women.
The method has already been tried in Europe. The study was its first large scale test in the US. However, things are not going to change immediately; a second study is to begin shortly to see if the results of the first are repeated, and to identify the drugs that are most effective in it.
The study raises the hopes of a better care of thousands of women with breast cancer. Many of them are facing mastectomy, as the tumors have become too large due to the effect of estrogen. The new approach may give them not only the option of a gentler surgery, but also help many others avoid chemotherapy and its ill effects.
The study put 374 women, facing likely mastectomy from more than 100 places across the US, on hormone blockers for a period of 4 months before surgery.
"Half of them were able to go away with successful breast conserving therapy," said Dr. John Olson, chief, breast cancer surgery, Duke University. "It's a huge deal."
The study was led by Dr. John Olson who announced the results in a telephonic news conference. The results will shortly be presented before the American Society of Clinical Oncology in a meeting in Washington, as well as many other organizations dealing with cancer. The details of the study have already been given to a scientific journal which is reviewing the results.
More than 200,000 cases of breast cancer are diagnosed in the US each year. About 70% of them are aggravated due to the effect of estrogen.
All the women chosen for study were particularly vulnerable to the effects of estrogen. It's already known that chemotherapy does not work well in such women. So, the doctors were interested in knowing whether hormone blockers would improve the condition to an extent that removal of the whole breast could be avoided.
Tamoxifen is a time honoured hormone blocker. However a particular class of newer drugs, called aromatase inhibitors, do the same with fewer after effects.
The study chose three of these aromatase inhibitors: Pfizer's Aromasin, Novartis' Femara, and AstraZeneca's Arimidex. Women were chosen randomly to be given any one of these medicines. The cost of these medicines at present works out to $340-$420 a month. However, a generic version of Arimidex is available, and patents on other two are going to expire shortly.
After a period of four months, the tumors of 71% women taking Femara, 67% taking Arimidex, and 61% taking Aromasin were reduced to half or less, of the original size. Of those women who had earlier been recommended mastectomy, 50% were able to go away with a lump removal surgery. Of those who were marginal candidates for mastectomy, 82% were successfully treated with less severe surgery.
Of the 374 women, only 23 had their tumors grown by 25% or more in the period of four months by which the surgery was delayed.
So, the risk is small and compares well with the results of studies testing effectiveness of chemotherapy before surgery, says Dr. Burstein, breast cancer specialist, Dana Faber Cancer Institute, Boston, who also heads the expert panel on hormone treatment of the oncology society.
"Postponing surgery to try hormone treatment in order to shrink tumor is a viable option for most women", he asserted.
"Hopefully we can build on this and identify women who can have hormone blocking treatment instead of chemotherapy", he said.
The study was funded by National Cancer Institute, although Pfizer and Novartis too provided some support.
The differences in the performance of the three drugs were very small and could be attributed to chance factors. Yet the larger study has chosen the two that have given the best results, that is, Femara and Arimidex. It will further compare these two with chemotherapy as treatment option before surgery, it was told by Olson.