© 2004 Foundation for Promotion of Cancer Research
Identification of Patients with High-risk Lymph Node-negative Colorectal Cancer and Potential Benefit from Adjuvant Chemotherapy
1 Gastroenterology Department, Surgery Division, 3 Pathology Department and 4 Medical Oncology Department, Internal Medicine Division, Instituto Nacional de Cancerología, México DF, México and 2 Centre for Paediatric Epidemiology and Biostatistics, Institute of Child Health, University College London, London, United Kingdom
Background: Adjuvant chemotherapy is not indicated in lymph node-negative colorectal adenocarcinoma (CRC), even though some cases will present recurrent disease. It is important to identify a subgroup of patients with the highest risk of relapse because of the potential benefit of adjuvant chemotherapy. The objective of this study is to define the prognostic factors and describe a method for the selection of this subgroup.
Methods: A retrospective cohort of 124 patients with lymph node-negative CRC with complete surgical resection was studied. Cox’s proportional hazards model was used to define the prognostic factors associated with CRC-related survival and to develop a method for prediction of recurrence probability.
Results: The cohort included 62 women and 62 men with mean age 55.8 years. The mean follow-up period was 11.7 years. T classification of the primary tumor, differentiation grade, carcinoembryonic antigen level, gender and the presence of neural invasion were significant prognostic factors according to the multivariate analysis (final model P = 0.00001). Using risk ratios for these prognostic factors, we defined a high-risk group of 78 patients and a low-risk group of 46 patients with 24 and 5 recurrences, respectively (recurrence rates of 30.8% and 10.9% respectively, P = 0.011).
Conclusions: Using these factors, a prognostic scale was developed to predict high risk of recurrence in cases of completely resected CRC and to identify them as a subgroup of patients with potential benefit of adjuvant chemotherapy.
+ For reprints and all correspondence: Luis F. Oñate-Ocaña, Departamento de Gastroenterología, Instituto Nacional de Cancerología, San Fernando 22, México DF 14080, México. E-mail: lonate{at}prodigy.net.mx