The decision to move it up the treatment ladder followed publication of results of a comparative study between letrozole and tamoxifen. After a year of treatment, the number of women whose cancer had not progressed was 50 per cent greater in the group taking letrozole as compared to those taking tamoxifen. The tumour response rate for letrozole was 30 per cent, versus 20 per cent with tamoxifen. And letrozole delayed progression of advanced breast cancer for, on average, 9.4 months, as compared to six months for tamoxifen. There was no major difference in the range and rate of side effects.
Breast cancer is the most common form of cancer to strike women in Canada.
It is estimated that 19,500 women will be diagnosed with the disease this year and 5,500 will succumb to it. Like most types of cancer, early detection and treatment offer the best hope for survival. While letrozole's performance as a weapon against advanced breast cancer is impressive, the major enthusiasm surrounding the drug relates to its perceived promise as a therapy for early stages of the disease and for breast cancer prevention among high risk women. Letrozole is what's known as an aromatase inhibitor, binding to the estrogens that many breast cancer tumours need to grow and spread. Eliminating estrogen may induce remission - but it may also promote osteoporosis and heart problems in women using it, Shepherd noted.