Sylvester Breast Cancer Specialist Publishes Commentary in New England Journal of Medicine
On June 4, The New England Journal of Medicine published an update to a large, international study of two clinical trials that examined the comparative survival rates for adjuvant therapies for hormone-receptor-positive breast cancer in premenopausal women. The study, which had reported similar outcomes for the trials’ various therapeutic combinations in an earlier five-year analysis, is now generating statistically meaningful divergent outcomes for them at the eight-year mark, although at the cost of more significant side effects.
The journal’s editors believed the report on the study results was important enough to benefit from additional commentary, and they turned to Marc E. Lippman, M.D., a breast cancer specialist at Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, to write an accompanying editorial, in which he describes the findings as “practice-changing.”
The two connected trials discussed in the article, “Tailoring Adjuvant Endocrine Therapy for Premenopausal Breast Cancer,” involved a total of 3,047 women. In the Suppression of Ovarian Function Trial (SOFT), premenopausal women received five years of tamoxifen (a treatment standard for more than four decades), tamoxifen plus ovarian suppression, or exemestane (an estrogen modulator) plus ovarian suppression. In the Tamoxifen and Exemestane Trial (TEXT), the women received tamoxifen plus ovarian suppression or exemestane plus ovarian suppression.
“The addition of ovarian suppression to tamoxifen resulted in significantly higher eight-year rates of both disease-free and overall survival than tamoxifen alone,” wrote the journal article authors. “The use of exemestane plus ovarian suppression resulted in even higher rates of freedom from recurrence. The frequency of adverse events was higher in the two groups that received ovarian suppression than in the tamoxifen-alone group.”
After reporting strong similarities in outcomes at five years, the investigators are now finding differences between certain treatment groups as high as 5 to 7 percent.
“I’m not surprised by the comparative outcomes described in the latest report,” said Lippman, who is Sylvester’s deputy director and Leonard M. Miller Professor of Internal Medicine and Psychiatry and Behavioral Sciences at the Miller School. “More patients recur after five years than before — particularly those this article was addressing. Late relapses, unfortunately, are not rare, and sometimes you have to wait a long time to see which treatment is better.”
Still, he expects the latest findings to change how many breast cancer patients are treated.
“The most common treatment after surgery for women who had hormone-responsive breast cancer has been tamoxifen,” said Lippman. “This shows that more intensive endocrine therapy is significantly more effective, and that’s a big deal.”
In his editorial, “Endocrine Adjuvant Therapy for Localized Breast Cancer,” Lippman wrote, “These data make sense. Since these trials were restricted to patients with tumors that were estrogen-receptor-positive, we would anticipate that patients with the greatest reduction in estrogen levels would have the greatest benefit.”
Noting that recurrences can happen up to 25 years, he predicts that the results will continue to be more definitive.
The article authors concur. Writing that, “the effects of ovarian suppression and aromatase inhibitors may not yet be fully appreciated,” they are planning longer-term follow-ups for both SOFT and TEXT studies.
“There are other ways in which endocrine therapy can be made more effective, and they will likely be built on the backbone of these observations,” said Lippman. “One-third of all breast cancer occurs in premenopausal women, and more have this type, so this research is going to affect a lot of women.”