A nationwide study in the USA in May 2010 has confirmed the benefit of giving estrogen-lowering drugs before surgery to breast cancer patients. The treatment increased the likelihood that women could undergo breast-conservation surgery, also called lumpectomy, instead of mastectomy.
These findings are due to be presented on June 7, 2010 at the annual meeting of the American Society of Clinical Oncology. The study involved 352 postmenopausal women with estrogen-receptor positive (ER+) breast tumours. The participants received aromatase inhibitors for 16 weeks before surgery for breast cancer, and the extent of their tumours was monitored before and after the drug treatment.
The link between breast cancer and excessive estrogen is already well known, and it is encouraging to see that this is being acknowledged with the recommendation that estrogen levels needs to be reduced in order to have the most positive outcome for breast cancer surgery.
Aromatase inhibitors are also referred to as estrogen-lowering agents because they interfere with the body’s production of estrogen, a hormone that stimulates the growth of ER+ breast tumors. ER+ is the most common breast cancer, accounting for three-quarters of cases.
All women in the study had stage II or III breast cancer, in which tumours are about an inch or larger in size and may have spread to the lymph nodes in the underarm area.
The participants were placed in one of three groups:
- Marginal: meaning breast-conservation surgery was possible but likely to be disfiguring or to require several surgical procedures;
- Mastectomy-only: meaning breast-conservation surgery was not possible; and
- Inoperable: meaning mastectomy would not completely remove the cancer.
After the 16-week aromatase inhibitor therapy, the women were re-evaluated to see which surgical option was appropriate for them. The results showed that 82 percent of women in the marginal group, 51 percent in the mastectomy-only group and 75 percent in the inoperable group had successful breast-conservation surgery instead of mastectomy.
This makes it clear that reducing estrogen helped shrink the tumors in a substantial number of these women and improved surgical outcomes. Applying estrogen-lowering agents before surgery is not a widespread practice at the moment, but it certainly seems to offer women a much improved outcome for their surgery. Interestingly, the research indicates that women may be given such drugs for many years after surgery to repress recurrence but there has previously been no continual monitoring of the effect of the drugs on their systems.
However, encouraging though it might be, it is still a better policy to ensure that hormone levels are kept in balance so that oestrogen dominance does not have a chance to take hold and wreak potential havoc – particularly after breast cancer has been diagnosed and/or surgery has taken place.
Dr John Lee wrote a wonderful book called ‘What Your Doctor May Not Tell You About Breast Cancer’. Sad to say, I don’t think it is required reading for oncologists.