Intensive dose-dense compared with high-dose adjuvant chemotherapy for high-risk operable breast cancer: Southwest Oncology Group/Intergroup study 9623.
OBJECTIVE
Southwest Oncology Group (SWOG)/Intergroup study 9623 was undertaken to compare treatment with an anthracycline-based adjuvant chemotherapy regimen followed by high-dose chemotherapy (HDC) with autologous hematopoietic progenitor cell support (AHPCS) with a modern dose-dense dose-escalated (nonstandard) regimen including both an anthracycline and a taxane.


METHODS
Participants in this phase III randomized study had operable breast cancer involving four or more axillary lymph nodes and had completed mastectomy or breast-conserving surgery. Patients were randomly assigned to receive four cycles of doxorubicin and cyclophosphamide followed by HDC with AHPCS or to receive sequential dose-dense and dose-escalated chemotherapy with doxorubicin, paclitaxel, and cyclophosphamide. The primary end point of this study was disease-free survival (DFS).


RESULTS
Among 536 eligible patients, there was no significant difference between the two arms for DFS or overall survival (OS). Estimated five-year DFS was 80% (95% CI, 76% to 85%) for dose-dense therapy and 75% (95% CI, 69% to 80%) for transplantation. Estimated 5-year OS was 88% (95% CI, 84% to 92%) for dose-dense therapy and 84% (95% CI, 79% to 88%) for transplantation.


CONCLUSIONS
There is no evidence that transplantation was superior to dose-dense dose-escalated therapy. Transplantation was associated with an increase in toxicity and a possibly inferior outcome, although the hazard ratios were not significantly different from 1.
Moore
Halle C F
HC
Cleveland Clinic Foundation, Cleveland, OH, USA.
Green
Stephanie J
SJ
Gralow
Julie R
JR
Bearman
Scott I
SI
Lew
Danika
D
Barlow
William E
WE
Hudis
Clifford
C
Wolff
Antonio C
AC
Ingle
James N
JN
Chew
Helen K
HK
Elias
Anthony D
AD
Livingston
Robert B
RB
Martino
Silvana
S
D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008875:Middle Aged; D012008:Recurrence; D033581:Stem Cell Transplantation; D016019:Survival Analysis