Impact of concurrent versus sequential tamoxifen with radiation therapy in early-stage breast cancer patients undergoing breast conservation treatment.
OBJECTIVE
To assess the impact of sequencing of tamoxifen and radiation therapy (RT) on outcomes in early-stage breast cancer.


METHODS
This retrospective study evaluates the effect of the sequence of tamoxifen with RT on outcomes in stage I to II breast cancer patients who underwent breast-conservation treatment (BCT) and received adjuvant tamoxifen, with or without adjuvant chemotherapy. Patients were grouped as concurrent (tamoxifen given during RT followed by continued tamoxifen; 174 patients) and sequential (RT followed by tamoxifen; 104 patients).


RESULTS
Median follow-up after RT was 8.6 years for both groups. The pathologic T and N stage, race, estrogen and progesterone status, number of positive nodes, and RT were comparable between the two groups (all P >/= .08). More women age 49 years or younger and women who received chemotherapy were in the sequential group than the concurrent group (6% and 25%, respectively; P < .0001). The sequence of tamoxifen therapy did not influence 10-year local recurrence rates (sequential, 7%; concurrent, 3%; P = .52), overall survival (sequential, 86%; concurrent, 81%; P = .64), or relapse-free survival (sequential, 76%; concurrent, 85%; P = .35). When adjusting age and chemotherapy use in the multivariable Cox model, hazard ratios comparing sequential versus concurrent tamoxifen therapy were 1.56 (95% CI, 0.87 to 2.79), 1.23 (95% CI, 0.63 to 2.41), and 1.22 (95% CI, 0.33 to 4.49) for the overall survival, relapse-free survival, and local recurrence, respectively.


CONCLUSIONS
The therapeutic regimens of tamoxifen given concurrently or sequentially with RT both appear to be reasonable options for patients treated with BCT.
Harris
Eleanor E R
EE
Department of Radiaton Oncology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104, USA. harris@xrt.upenn.edu
Christensen
Vasthi J
VJ
Hwang
Wei-Ting
WT
Fox
Kevin
K
Solin
Lawrence J
LJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011878:Radiotherapy / Q000379:methods; D012189:Retrospective Studies; D015996:Survival Rate; D013629:Tamoxifen / Q000008:administration & dosage*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D013629:Tamoxifen