Impact of complete response to chemotherapy on overall survival in advanced colorectal cancer: results from Intergroup N9741.
OBJECTIVE
To evaluate clinical characteristics and survival outcomes among patients with locally advanced or metastatic colorectal cancer who achieve a complete response (CR) to systemic treatment either alone or with multimodality approach.


METHODS
Data were collected retrospectively from CRC patients enrolled onto the phase III trial N9741, a National Cancer Institute-funded and Gastrointestinal Cancer Intergroup-sponsored study coordinated by the North Central Cancer Treatment Group. Patients were randomly assigned to combinations of oxaliplatin, fluorouracil (FU)/leucovorin (LV) and irinotecan. The three treatment arms consist of IFL (irinotecan + FU/LV), FOLFOX4 (oxaliplatin + FU/LV), and IROX (irinotecan + oxaliplatin). Median follow-up was 42.6 months.


RESULTS
Sixty-two (4%) of 1,508 patients had a CR to chemotherapy alone, and an additional 32 (2%) had a CR after multimodality treatment. Factors associated with achieving CR with systemic chemotherapy alone included FOLFOX4 treatment, patients with assessable disease, or a single site of metastasis. Continuing protocol treatment beyond two cycles after documentation of CR was not associated with improved survival. The rate of curative intent resection was significantly higher for patients treated with oxaliplatin-containing regimens (P = .02). Median survival was similar between patients with CR after chemotherapy alone (44.3 months) or after multimodality approach (47.4 months; P = .81).


CONCLUSIONS
FOLFOX4 was more likely to produce a CR than were IFL or IROX. Oxaliplatin regimens were more likely to result in successful surgical resections. Patients who have CR to systemic chemotherapy alone can achieve impressive survival outcomes similar to those seen among patients who attained a CR status after multimodality treatment.
Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. dy.grace@mayo.edu
Grace K
GK
Dy
James E
JE
Krook
Erin M
EM
Green
Daniel J
DJ
Sargent
Thierry
T
Delaunoit
Roscoe F
RF
Morton
Charles S
CS
Fuchs
Ramesh K
RK
Ramanathan
Stephen K
SK
Williamson
Brian P
BP
Findlay
Barbara A
BA
Pockaj
Robert P
RP
Sticca
Steven R
SR
Alberts
Henry C
HC
Pitot
Richard M
RM
Goldberg
D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002166:Camptothecin / Q000031:analogs & derivatives / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009944:Organoplatinum Compounds / Q000627:therapeutic use*; D000077150:Oxaliplatin; D012074:Remission Induction; D012189:Retrospective Studies; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin