Postmastectomy radiotherapy in premenopausal Vietnamese and Chinese women with breast cancer treated in an adjuvant hormonal therapy study.
BACKGROUND
Adjuvant postmastectomy radiotherapy (RT) decreases the risk of local recurrence of breast cancer and may increase overall survival (OS).


METHODS
After mastectomy, 656 premenopausal Vietnamese and Chinese women with clinical Stage II-IIIA breast cancer, in a clinical trial of adjuvant surgical oophorectomy and tamoxifen, were treated with adjuvant RT according to the availability in the institution. The short-term disease recurrence and OS experience of these 656 women were analyzed using univariate and multivariate methods.


RESULTS
The 193 patients who did not receive RT differed from the 463 who did in that they had larger tumors and more frequently Grade 3 tumors. With a median follow-up of 3.6 years, in univariate analysis, RT was associated with improved disease-free survival (DFS) (relative risk 0.66; 95% confidence interval 0.49-0.89; p = 0.007) and OS (relative risk 0.71; 95% confidence interval 0.50-1.00; p = 0.051). In multivariate analysis, the relative risk for DFS and OS associated with RT was 0.78 and 0.94, respectively (p = not significant for both). Kaplan-Meier estimates showed better 5-year DFS (72% vs. 59%; p = 0.006) and OS (78% vs. 70%; p = 0.05) rates with RT.


CONCLUSIONS
In the absence of detailed CT planning capacity, adjuvant RT for premenopausal Vietnamese women was associated statistically with short-term improvement in DFS and OS in univariate, but not multivariate, analysis.
Love
Richard R
RR
Department of Medicine, Section of Medical Oncology, University of Wisconsin School of Medicine, Madison, WI, USA. rrlove@facstaff.wisc.edu
Ba Duc
Nguyen
N
Cong Binh
Nguyen
N
Mahler
Peter A
PA
Thomadsen
Bruce R
BR
Hong Long
Nguyen
N
Shen
Tian-zhen
TZ
Havighurst
Thomas C
TC
D000328:Adult; D000704:Analysis of Variance; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D002681:China; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D015411:Mastectomy, Modified Radical; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D010052:Ovariectomy; D017697:Premenopause; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013629:Tamoxifen / Q000627:therapeutic use; D014744:Vietnam
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen