New treatments show benefits for older men with prostate cancer (PrCa) that has spread outside the gland itself, meaning no longer amenable to surgical cure; and for younger breast cancer victims via a different approach to post-operative recurrence prevention.
The standard approach to advanced PrCa has been to deprive the cancer cells of male hormone (androgens) which are fueling the growth of the tumor, by castration and/or by administering androgen blockers, often along with estrogenic drugs. Only when the inevitable failure of androgen-deprivation therapy (ADT) occurred was chemotherapy initiated. The new study combined ADT with docetaxel, a chemotherapy drug proven somewhat efficacious on its own, albeit minimally so.
The study (CHAARTED) randomized 790 men with newly-diagnosed PrCa into 2 groups: one received the standard therapy, ADT, initially; the 2nd group received ADT plus docetaxel from the start. After a median follow-up of 29 months, the study was stopped early due to the clearcut benefit of the combination: a 13 month survival improvement equal to a 39 percent reduction in PrCa-specific mortality.
ACSH scientific advisor and ASCO president, Clifford Hudis, MD, of Memorial Sloan-Kettering Cancer Center in New York City, commented to MedPage Today: "In prostate cancer, I'm not aware of any historical study that ever offered up this magnitude of improvement in survival. Quite frankly, across all of the solid tumors, this is an almost unprecedented improvement in median survival."
The other study of note reported at the ASCO meetings concerned younger women survivors of localized breast cancer, who had had lumpectomy or mastectomy, and whose tumors were estrogen-receptor positive. Combined results of two studies (which included a total of almost 4,700 subjects) found that adding a drug of the aromatase-inhibitor (AI) class (aromasin) to the standard recurrence-prevention regimen of tamoxifen led to a small but significant benefit in terms of 5-year recurrence rate: 91 percent were free of recurrence in the AI plus tamoxifen group vs. 87 percent in the tamoxifen-only group. (The survival benefit was not statistically significant 97 percent v. 96 percent not surprising considering the already-high survival rate).
Since AIs are not effective in the presence of estrogen at levels found in premenopausal women, estrogen suppression had to be included as well, adding to the already-substantial concerns of inducing early menopause in women getting this treatment.
ACSH s Dr. Gil Ross had these comments: While the good news on prostate cancer treatment seems likely to change the standard approach for men with advanced disease a one-year-plus survival benefit in older men is quite substantial the unpleasant side-effects and rather slim benefits for younger women with excised, localized breast cancer present quite a different picture. The pros and cons of that complex treatment plan need to be carefully discussed with potential candidates and their families before undergoing all those hormonal interventions in a generally low-risk situation.