The impact of concurrent versus sequential tamoxifen and radiation therapy in breast cancer patients undergoing breast conservation therapy.

Reviewer: Tracy d'Entremont, MD
OncoLink
Last Modified: June 1, 2003

Presenter: Vasathi J. Christnesen
Presenter's Affiliation: Hospital of the University of Pennsylvania
Type of Session: Poster

Background

Hormonal Therapy plays an important role in the adjuvant therapy of breast cancer patients.
The optimal sequencing of tamoxifen therapy and radiation (XRT) is not well established.
This study was conducted in order to assess the impact of tamoxifen timing on cosmesis, complications of radiotherapy, local and regional recurrence rates as well as on overall survival

Materials and Methods

This is a retrospective analysis of 268 women diagnosed with Stage I or II breast cancer who underwent breast conseravation therapy and received their XRT treatments at the HUP between the years of 1980 and 1995.
The patients were grouped based on timing of tamoxifen therapy as "concurrent" or "sequential".
There were 166 patients in the concurrent group and 102 patients in the sequential group.
The main outcomes were Local and Regional Recurrence rates, Overall Survival, Relapse-Free Survival, Cosmesis, Breast edema and Arm edema.
The groups were well balanced in terms of T and N stage, ER/PR status, radiation treatment, and use of chemotherapy.
The only difference between the groups was with respect to age with more women age 45 years or younger in the sequential group.

Results

Among all endpoints evaluated, there were no significant differences between the two groups.
Local recurrence rates in the sequential and concurrent groups were 7% and 3% respectively.
Overall Survival was 87% and 81% respectively.
Relapse-Free Survival was 77% and 84% respectively.
Excellent/Good Cosmesis at 3 years was 94% and 95% respectively.
Breast Edema overall was 64% and 56% respectively, grade 3/4 edema was seen in 36% of sequential patients and 44% of concurrent.
Arm Edema rates overall were 75% and 73% respectively with grade 3/4 being 25% and 27% respectively.

Author's Conclusions

The therapeutic regimens of tamoxifen given concurrently or sequentially with XRT are both good choices for patients without significant differences in efficacy or toxicity.

Clinical/Scientific Implications

Clinical trials have warned of the combination of tamoxifen therapy with chemotherapy because of the resultant high rate of thromboembolic complications. Up until this analysis, it was believed that tamoxifen could be given safely with XRT, although this had never been proven. This study gives us the proof that tamoxifen is safe in conjunction with XRT without increased toxicity.

Oncolink's ASCO Coverage made possible by an unrestricted Educational Grant from Bristol-Myers Squibb Oncology.