Adjuvant chemotherapy for t1 node-positive colon cancers provides significant survival benefit.
BACKGROUND
Contemporary treatment of node-positive (N+) colon cancer consists of adjuvant chemotherapy; however, randomized data supporting this practice were derived from lesions T2 or greater. Minimal data exist regarding the use and need for adjuvant chemotherapy in T1N+ disease.


OBJECTIVE
The aim of this study was to determine treatment trends and the effects of adjuvant chemotherapy on T1N+ colon cancers by using the National Cancer Database.


METHODS
This was a retrospective study. Baseline demographics, tumor, and cancer treatment characteristics were compared. Groups were matched on the propensity to receive chemotherapy. Adjusted long-term survival stratified by chemotherapy use was compared by using the Kaplan-Meier method with the log-rank test. Predictors of not receiving chemotherapy were identified by using a multivariable logistic regression model.


METHODS
Data were collected from the National Cancer Database, which collects cancer data from over 1500 cancer centers.


METHODS
We identified patients from 1998 to 2006 with T1N+ disease, excluding those with metastatic disease or previous cancer. Patients were stratified based on whether or not they received chemotherapy.


METHODS
The primary outcome measure of this study was long-term survival.


RESULTS
Three thousand one hundred thirty-seven patients had T1N+ disease; 70.6% (n = 2216) received chemotherapy, and utilization significantly increased from 1998 to 2011 (p < 0.001). Unadjusted analysis revealed that patients treated with chemotherapy were statistically younger and healthier, and had shorter postoperative lengths of stay (all p < 0.001). Unadjusted 5-year survival was higher in patients receiving chemotherapy (87.9% vs 63.0% in patients with no chemotherapy; p < 0.001) and this persisted after propensity matching with (83.4% and 63.0% in patients with or without chemotherapy; p < 0.001). Only age (OR, 0.29; p < 0.001) predicted not receiving chemotherapy.


CONCLUSIONS
Limitations include potential selection bias as well as the inability to compare disease-free survival/recurrence.


CONCLUSIONS
Adjuvant chemotherapy appears to significantly improve long-term survival in patients receiving chemotherapy in T1N+ disease. Thus, the use of chemotherapy in T1N+ disease is justified and provides a highly significant survival benefit.
1Section of Colorectal Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina 2Division of Medical Oncology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
Asvin M
AM
Ganapathi
Paul J
PJ
Speicher
Brian R
BR
Englum
Anthony W
AW
Castleberry
John
J
Migaly
David S
DS
Hsu
Christopher R
CR
Mantyh
D000367:Age Factors; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant / Q000379:methods / Q000706:statistics & numerical data; D003082:Colectomy / Q000379:methods; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D007902:Length of Stay; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D017741:Survivors / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology