Continuing adjuvant tamoxifen leads to higher quality of life

A desire to improve health-related quality of life may be the deciding factor when considering whether to continue tamoxifen for recurrence-free, postmenopausal breast cancer patients or switch them to anastrozole, according to research presented at the 31st San Antonio Breast Cancer Symposium.

Quality-of-life scores were higher for patients who continued tamoxifen after one to four years of adjuvant tamoxifen than for patients who switched to anastrozole in a Japanese study.

Disease-free and relapse-free survival, however, were higher among patients who switched to anastrozole, explained Shozo Ohsumi, M.D., Ph.D., chief of breast oncology at NHO Shikoku Cancer Center, Matsuyama, Japan.

"We believe recurrence-free survival rate should be regarded as a more important outcome than quality of life in general", Ohsumi said. "Therefore, we would advise recurrence-free postmenopausal breast cancer patients who had undergone initial treatment with tamoxifen after surgery to switch from tamoxifen to anastrozole."

"However, if they experience side effects that make their quality of life worse, such as severe joint pain with anastrozole, we will give patients an option to switch back to tamoxifen with an explanation that tamoxifen will give better quality of life but a little worse recurrence-free survival rate", he said.

The patients were part of the National Surgical Adjuvant Study of Breast Cancer 03. All patients received definitive surgery for hormone-receptor-positive breast cancer, followed by tamoxifen for one to four years. At that point, patients were randomized to continue tamoxifen or switch to anastrozole. Total time on adjuvant drug therapy, including tamoxifen before randomisation, was five years.

Patients answered several questionnaires designed to score quality of life and psychological distress at randomization and at three months, one year and two years after randomisation. Significant differences were seen in FACT-G and FACT-ES (endocrine symptom scale) scores between treatment groups.

At baseline, patients who remained on tamoxifen had a mean FACT-ES score of 143.8. Two years later, the mean score for this group was 143.8. In the anastrozole group, the mean score at baseline was 143.9; this decreased to 143.1 at two years.

Mean FACT-G scores in the tamoxifen group began at 84.0 at baseline and decreased to 83.1 at two years. In the anastrozole group, the mean score decreased from 83.4 at baseline to 81.5 at two years.

"Psychological change such as anxiety and depression can happen as menopausal symptoms, and we know endocrine therapies can cause menopausal symptoms," Ohsumi said. "Therefore, we thought psychological distress should be measured as part of a quality-of-life study."

Ohsumi and his colleagues used the Center for Epidemiologic Studies Depression scale (CES-D) to measure psychological distress. There was no significant difference between treatment groups.

At 42 months of a median follow-up period, patients taking anastrozole had a 31 percent improvement in disease-free survival and a 48 percent improvement in relapse-free survival.

After randomisation, patients in the anastrozole group experienced fewer incidents of hot flash and vaginal discharge but more incidents of arthralgia or joint pain and liver dysfunction than patients in the tamoxifen group.