Though Chinese women are less likely to develop breast cancer than women in Western countries, the incidence rate for breast cancer in China is increasing at a rate of 2 to 3 percent annually, according to doctor Jiang Zefei, a breast cancer expert at the Beijing-based Academy of Military Medical Sciences.
He attributes the increase to more Westernized living habits among Chinese women, such as a higher intake of fat and less breast-feeding.
In recent years, seemingly as a response to this change, hormonal therapy is providing an important new treatment option for certain postmenopausal breast cancer patients.
Hormonal therapy inhibits the effects of estrogen, said to be a major factor in the development of breast cancer. Aromatase inhibition, a newer kind of hormonal therapy, is a sensitive, targeted approach to limiting the growth of estrogen induced breast cancer.
According to data from the Early Breast Cancer Trial Group in Oxford in Britain, more than 50 percent of breast cancer recurrence happens in women more than five years after initial diagnosis.
According to interim results of a study published in October 9's New England Journal of Medicine, postmenopausal women with early breast cancer who completed five years of post-surgical hormonal therapy with tamoxifen benefited significantly from extended adjuvant treatment with Femara (letrozole).
"Historically, there is no proven post-tamoxifen therapy to address the significant ongoing risk of recurrent breast cancer," said Paul Goss, director of Breast Cancer Prevention and Research at the Princess Margaret Hospital in Toronto, Canada. "The data announced provide the first clinical evidence that extended adjuvant drug therapy with Femara, following five years of treatment with tamoxifen, may have a substantial impact on the overall treatment outcome for postmenopausal breast cancer patients."
The international breast cancer trial group of nearly 5,200 women, called MA-17, is the first study to examine the effectiveness of an aromatase inhibitor, Femara, in the extended adjuvant setting -- the period following five years post-surgery tamoxifen treatment.
At a median follow-up of 2.4 years, the data in a Femara group showed a 43 percent reduction in risk of overall recurrence compared with those taking a placebo as well as a significant reduction (46 percent) in the spread of contralateral disease (cancer occurring in the other breast). The estimated absolute improvement rate in disease-free survival at four years was higher for postmenopausal patients taking Femara compared with those taking a placebo -- 93 percent for those on Femara vs 87 percent for those on a placebo.
Tamoxifen, which reduces the risk of breast cancer recurrence during the first five years of post-surgical therapy, has been shown not to be beneficial beyond five years of treatment.
In China, "Femara has already demonstrated its effect during the clinic treatment of breast cancer in the late stage, and the new publication further shows its effect in preventing breast cancer reoccurrence," said doctor Jiang.
However, despite Femara's good curative effect, Chinese breast cancer patients have not taken hormonal therapy seriously, according to professor Song Santai with the Beijing-based No 307 Hospital of the PLA, affiliated with the Academy of Military Medical Sciences. Medical expenses for hormonal therapy accounts for only 4 percent of the total for all forms of therapy, well below the 55 percent in America.
"Chinese patients generally are dubious about hormonal therapy and are not fully aware of its curative effectiveness," said Song. ''That is a major problem in the treatment of breast cancer in China. "
(China Daily October 14, 2003)