Triple-Negative Breast Cancer: New Therapies Yield Exciting Results
Triple negative breast cancer (TNBC) – cancer that doesn’t respond to either hormone or biologic therapy – is challenging to treat. Now, a new protocol of both chemotherapy drugs, and when they’re delivered, is showing very positive results.
If you’re a TNBC survivor, you know how scary it can be.
Unlike most breast cancer survivors, you don’t have the security blanket of 5 to 10 years of post-treatment hormone therapy, a major recurrence-risk reduction tool for most breast cancer patients.
Instead, you have to rely entirely on surgery and chemotherapy. Once that’s done, you just wait; and hope; and figuratively hold your breath for 5 years, until your recurrence risk reverts to the average for that of all breast cancer patients.
Women diagnosed with TNBC in the future (perhaps the near future) may soon find their chances of survival increased by a significant amount. How? Through the use of a series of specific chemo drugs, just now being identified, delivered prior to surgery.
Chemo before surgery? More and more oncologists are choosing this protocol in certain situations; and TNBC is one of them. By delivering cancer-fighting drugs to the patient, and monitoring how her tumor responds, doctors can quickly assess whether or not the “chemo cocktail” is working. If it’s working, keep it up. If it’s not, switch to a different group of drugs.
The goal of chemo prior to surgery isn’t simply to see if it’s effective; it also (hopefully) will shrink the tumor enough that instead of being forced into a mastectomy due to tumor size, a woman can make her choice: mastectomy, or breast conservation surgery (lumpectomy).
Two different chemo regimens, in two separate phase II clinical trials, have proven more effective than what’s currently being administered to most TNBC patients. The first, CALGB/Alliance 40603, teams a standard chemo drug protocol with carboplatin and Avastin. The women in the arm of this trial (all of whom had been diagnosed with TNBC) who received the new drugs, in addition to those received by the control group, were about 50% more likely to have what’s called a “pathologic complete response” – i.e., there were no cancer cells found in either breast or lymph nodes during surgery completed four to eight weeks post-chemo. In absolute terms, 67% of the women saw cancer eliminated in their breast; and 60% saw it disappear in their lymph nodes.
Women in the second trial also received a standard chemo protocol, with added carboplatin and veliparib. And results were similar: after chemo, 52% of women diagnosed with TNBC had no detectable cancer in either breast or lymph nodes.
This second study, the I-SPY 2 trial, is interesting as much for its method as its results. Using a new type of protocol called adaptive randomization, trial researchers monitored patients on the fly, and quickly switched them from a therapy that wasn’t working, to one that was.
The result? By the end of the trial, a large group of women all following what seemed to be the most successful protocol.
Dr. Hope S. Rugo, who presented the I-SPY 2 trial results at last December’s San Antonio Breast Cancer Symposium, said in a press release from that event, “These data show that the adaptive design of I-SPY 2 can generate results that will power phase III registration trials. By identifying which patients benefit, we can reduce trial size, accelerate drug development, and avoid overtreatment in the majority of patients, which is the future of drug development.”
With both of these trials moving into phase III – the final phase before FDA approval – it appears there’s hope on the horizon for future TNBC patients.
New presurgery treatment combination more effective for women with triple-negative breast cancer. (2013, December 13). Retrieved from http://www.aacr.org/home/public--media/aacr-in-the-news.aspx?d=3245
New presurgery combination therapy may improve outcomes for women with triple-negative breast cancer. (2013, December 13). Retrieved from http://www.aacr.org/home/public--media/aacr-in-the-news.aspx?d=3242