Better Survival for Young Women with Breast Cancer - New Study Overturns Old Beliefs
Tamoxifen has not usually been given to younger patients because doctors did not believe it helped pre-menopausal women. But new findings in today's * Lancet, from the largest ever randomised study of any cancer drug, overturn this perception and pave the way for a worldwide change in medical practice that would prevent thousands more deaths from the disease.
Most breast cancers have hormone receptors that can be blocked by tamoxifen, interfering with the growth of the cancer cells. Tamoxifen can either be started immediately after breast surgery to reduce the chances of the disease recurring, or, alternatively, used only if recurrence does occur.
An international collaboration, organised from Oxford University, followed 30,000 women with hormone-sensitive breast cancer. Within 10 years of surgery about one-third had relapsed and died. Starting tamoxifen early and continuing it for around five years halved the recurrence rate, irrespective of age, and improved long-term survival. It was effective whether or not chemotherapy had been given, and whether or not the cancer had already spread to the local lymph glands.
Professor Richard Peto, from Oxford University, said:
"Starting tamoxifen immediately after breast cancer surgery prevented one in six women from relapsing and one in twelve from dying, irrespective of age. Tamoxifen for older women is already saving more lives than any other cancer drug. But, most of the young breast cancer patients who need tamoxifen aren't yet getting it."
Even when no measurement had been made of whether or not there were hormone receptors on the original cancer, immediate tamoxifen improved survival.
Tamoxifen also has both bad and good side-effects. For example, it can cause cancer of the lining of the womb (endometrial cancer) or a blood clot in the lungs (pulmonary embolus), but these risks are relatively small. Moreover, this study shows that tamoxifen can halve the risk of a new cancer arising in the other breast. Overall, for women with hormone-sensitive breast cancer, tamoxifen prevents about 30 times as many deaths as it causes.
Professor Rory Collins, from Oxford University, said:
"For healthy women, even if they are at increased risk of developing breast cancer, the balance between the beneficial and adverse effects of tamoxifen remains uncertain. By contrast, for women who have already developed breast cancer the beneficial effects of tamoxifen far outweigh any adverse effects on survival. If all the breast cancer patients who need tamoxifen get it, this will save another 20,000 lives each year."
This collaboration brought together detailed information from 55 randomised trials conducted over the past two decades in more than a dozen countries. Dr Michael Clarke, the study coordinator, said:
"This huge study has shown that tamoxifen could save even more lives. Tamoxifen is not expensive: in most countries, five years of treatment costs only a few hundred pounds - or, to put it another way, a few thousand pounds per life saved."
The study was funded by the UK's Imperial Cancer Research Fund, one of the world's leading cancer charities.
For more information, see the FACT SHEET.
* "Tamoxifen for early breast cancer: an overview of the randomised trials." Early Breast Cancer Trialists' Collaborative Group. Lancet 16 May 1998.
