Is chemotherapy necessary for premenopausal women with lower-risk node-positive, endocrine responsive breast cancer? 10-year update of International Breast Cancer Study Group Trial 11-93.
BACKGROUND
International Breast Cancer Study Group (IBCSG) Trial 11-93 is the largest trial evaluating the role of the addition of chemotherapy to ovarian function suppression/ablation (OFS) and tamoxifen in premenopausal patients with endocrine-responsive early breast cancer.


METHODS
IBCSG Trial 11-93 is a randomized trial comparing four cycles of adjuvant chemotherapy (AC: doxorubicin or epirubicin, plus cyclophosphamide) added to OFS and 5 years of tamoxifen versus OFS and tamoxifen without chemotherapy in premenopausal patients with node-positive, endocrine-responsive early breast cancer. There were 174 patients randomized from May 1993 to November 1998. The trial was closed before the target accrual was reached due to low accrual rate.


RESULTS
Patients randomized tended to have lower risk node-positive disease and the median age was 45. After 10 years median follow up, there remains no difference between the two randomized treatment groups for disease-free (hazard ratio=1.02 (0.57-1.83); P=0.94) or overall survival (hazard ratio=0.97 (0.44-2.16); P=0.94).


CONCLUSIONS
This trial, although small, offers no evidence that AC chemotherapy provides additional disease control for premenopausal patients with lower-risk node-positive endocrine-responsive breast cancer who receive adequate adjuvant endocrine therapy. A large trial is needed to determine whether chemotherapy adds benefit to endocrine therapy for this population.
Thürlimann
Beat
B
Senology Center of Eastern Switzerland, Kantonsspital, St. Gallen, Switzerland. beat.thuerlimann@kssg.ch
Price
Karen N
KN
Gelber
Richard D
RD
Holmberg
Stig B
SB
Crivellari
Diana
D
Colleoni
Marco
M
Collins
John
J
Forbes
John F
JF
Castiglione-Gertsch
Monica
M
Coates
Alan S
AS
Goldhirsch
Aron
A
D000971:Antineoplastic Combined Chemotherapy Protocols; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality; D017024:Chemotherapy, Adjuvant; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D017697:Premenopause; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D018570:Risk Assessment; D016019:Survival Analysis; D017741:Survivors; D013629:Tamoxifen / Q000627:therapeutic use
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen; D015251:Epirubicin; D004317:Doxorubicin; D003520:Cyclophosphamide