SABCS 2015: Patients With Ductal Carcinoma in Situ Receiving Anastrozole Reported Symptoms Different From Those in Patients Receiving Tamoxifen
Analysis of patient-reported outcomes, a secondary endpoint of the phase III NSABP B-35 clinical trial, in which anastrozole and tamoxifen were compared in postmenopausal women with ductal carcinoma in situ (DCIS) who underwent lumpectomy plus radiotherapy, found that there were no differences in outcomes related to quality of life but some differences in outcomes related to symptoms in the two treatment groups. These data were presented by Ganz et al at the 2015 San Antonio Breast Cancer Symposium, held December 8–12 in San Antonio, Texas (Abstract S6-04).
Study Details
The study confirmed some of the expected outcome differences in symptoms between the two drugs, which included more hot flashes with tamoxifen treatment, and more vaginal problems and musculoskeletal complaints with anastrozole treatment.
“The NSABP B-35 trial enrolled 3,104 postmenopausal women with DCIS that was hormone receptor–positive, and the primary endpoint was to determine whether anastrozole was superior to tamoxifen. Anastrozole was found to be slightly but significantly better than tamoxifen in terms of breast cancer–free interval, and it was most beneficial in women younger than 60 years. There was no overall survival difference between the two treatments,” said Patricia A. Ganz, MD, Distinguished Professor at the University of California, Los Angeles, Schools of Medicine & Public Health, and the Jonsson Comprehensive Cancer Center.
“The secondary endpoints of the trial were quality-of-life and symptom outcomes, measured as patient-reported outcomes. Because these two drugs have different side-effect profiles, it was important to hear from women about their experiences to add that information to decision-making,” she said.
Patient-reported outcomes data include information obtained from each patient participating in the trial about her experience with the drug in terms of physical and emotional functioning, and various symptoms such as hot flashes, vaginal dryness, muscle and joint aches, and pains, Dr. Ganz explained. Since this was a double-blind trial, assessments were done without the bias of knowing what medication the women were taking, she added.
“The information from this trial is important for women diagnosed with DCIS in the future who may be deciding which medication to take, along with their doctors,” Dr. Ganz commented.
Dr. Ganz and colleagues used data from 1,193 patients enrolled in the patient-reported outcomes portion of the NSABP B-35 trial. Quality-of-life and symptom data were collected at baseline prior to randomization to anastrozole or tamoxifen every 6 months during the 5 years of treatment and 12 months after treatment.
Quality of life was measured using the SF-12 Physical Component Summary and Mental Component Summary. Symptoms were measured using the BCPT Symptom Checklist and other standardized methods. Patients were grouped into those younger than 60 years or those 60 years or older.
Study Findings
Five years after treatment, there were no differences in quality-of-life outcomes. However, the severity of hot flashes was greater in those who received tamoxifen than in those who received anastrozole, and this experience varied over time; the severity of musculoskeletal pain and vaginal problems at 6-month to 24-month time points was greater in those who received anastrozole than those who received tamoxifen. Sexual functioning was slightly worse for those who received anastrozole compared with those who received tamoxifen.
There was no worsening of physical or emotional health and depression with either drug, and overall, both drugs were found to be safe, according to Dr. Ganz. All symptoms were worse in women younger than 60 years than those 60 years or older, she added.
“Both of these drugs are excellent and can reduce the risk for breast cancer recurrence. Physicians and patients need to use this information along with the main trial outcomes to choose the optimal treatment for each woman. This is part of personalized or precision medicine,” Dr. Ganz concluded.
This study was supported by the National Cancer Institute and AstraZeneca. Dr. Ganz declared no conflicts of interest.
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