In the new study, Melnikow and her colleagues calculate that tamoxifen can be expected to extend life expectancy only when a woman's five-year risk of developing breast cancer reaches 3 percent or more. This is especially true for women who have not had a hysterectomy, and therefore face the risk of endometrial cancer related to tamoxifen use.
Cost-effectiveness was also calculated in the study. For women at the 1.67-percent risk level, taking tamoxifen to stave off breast cancer came to $1.3 million per year of life saved based on the U.S. price of the drug -- a prohibitively expensive cancer-prevention strategy. Melnikow and her co-authors note, however, that the cost-effectiveness equation could be improved if pharmaceutical prices were negotiated at a national level. At Canadian prices, for example, the researchers showed that taking tamoxifen to prevent breast cancer comes to $123,780 per year of life saved for women at the 1.67-percent risk level.
In comparison, annual flu shots cost about $980 per year of life saved for patients ages 65 and older; colonoscopy every 10 years costs about $11,000 per year of life saved for people 50 and older; and annual mammography costs about $58,000 per year of life saved for women ages 40 to 80.
To arrive at their findings, Melnikow and her colleagues used a complex mathematical model based on a hypothetical group of 50-year-old women.
Melnikow specializes in research to better understand women's health-care preferences and how women make health-care decisions. In a study published in the journal Cancer last year, she reported that among women with a five-year breast cancer risk of 1.67 percent or higher, fewer than one in five were inclined to take tamoxifen to prevent the disease. Concern about potential side effects was the primar
Source:University of California - Davis