Long-term survival results of surgery alone versus surgery plus 5-fluorouracil and leucovorin for stage II and stage III colon cancer: pooled analysis of NSABP C-01 through C-05. A baseline from which to compare modern adjuvant trials.
BACKGROUND
The objective of this study is to conduct a pooled analysis of National Surgical Adjuvant Breast and Bowel Project (NSABP) colon trials involving surgery and surgery plus 5-fluorouracil and leucovorin (5-FU/LV) to compare survival and establish a baseline from which to evaluate future studies.


METHODS
All patients enrolled in NSABP adjuvant trials C-01 through C-05 with stage II and III disease who were treated with surgery or with surgery plus 5-FU/LV were examined for overall survival (OS), disease-free survival (DFS), and recurrence-free interval (RFI). Time-to-event by treatment group was examined using adjusted Kaplan-Meier estimates and multivariable Cox regression analysis.


RESULTS
There were 2,966 eligible patients: 693 (23%) surgery and 2,273 (77%) surgery plus 5-FU/LV; 1,255 (42%) stage II and 1,711 (58%) stage III. Age > or =60 years [hazard ratio (HR) = 1.36, P < 0.0001], male gender (HR = 1.20, P = 0.0012), and more nodes positive or fewer nodes examined (P < 0.0001) were associated with worse survival. At 5 years, the adjusted OS was 0.62 [confidence interval (CI) = 0.60-0.63] in the surgery group and 0.76 (CI = 0.74-0.78) in the surgery plus 5-FU/LV group. Treatment with 5-FU/LV was associated with improved outcome compared with surgery: OS (HR = 0.62, P < 0.0001), DFS (HR = 0.66, P < 0.0001) and RFI (HR = 0.64, P < 0.0001). Improved OS with adjuvant treatment was seen in both stage II (HR = 0.58, 95% CI = 0.48-0.71) and stage III disease (HR = 0.65, 95% CI = 0.55-0.75).


CONCLUSIONS
This analysis demonstrates that treatment of colon cancer patients with 5-FU/LV following surgery provides benefit over surgery alone and can provide anticipated survival outcomes with which to compare modern adjuvant trials.
Wilkinson
Neal W
NW
National Surgical Adjuvant Breast and Bowel Project, Pittsburgh, PA, USA. neal-wilkinson@uiowa.edu
Yothers
Greg
G
Lopa
Samia
S
Costantino
Joseph P
JP
Petrelli
Nicholas J
NJ
Wolmark
Norman
N
D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000401:mortality* / Q000628:therapy*; D003131:Combined Modality Therapy; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D013514:Surgical Procedures, Operative; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
D002955:Leucovorin; D005472:Fluorouracil