Extended TNM Colon Cancer Staging Ups Prognostic Accuracy
Extended staging includes tumor grade, number of collected metastatic lymph nodes, age, gender
TUESDAY, Nov. 15 (HealthDay News) -- The prognostic accuracy and sensitivity of the seventh edition American Joint Committee on Cancer's (AJCC's) tumor, node, metastasis (TNM) staging for colon cancer is improved by inclusion of routinely available demographic and pathologic data, according to a study published online Nov. 14 in the Journal of Clinical Oncology.
Martin R. Weiser, M.D., from the Memorial Sloan-Kettering Cancer Center in New York City, and colleagues sought to improve the prognostic accuracy of the seventh edition of the AJCC staging system for colon cancer by including additional information available from tumor registries. Three survival models for patients with primary curative-intent surgery were constructed and validated using data from 128,853 patients reported to the Surveillance, Epidemiology, and End Results Program from 1994 to 2005. Alternative models were developed and tested from independent training/test data sets. After adding demographic and tumor variables, the models were compared by concordance index, performing calibration, and identifying the area under the receiver operating characteristic (ROC) curves.
The investigators found that prognostic estimates improved with inclusion of additional registry covariates. The concordance index for the AJCC model with T- and N-stage variables was 0.60, and increased to 0.68 for the model including age, gender, tumor grade, and number of collected metastatic lymph nodes. At all values of specificity, the ROC curves for the extended model had higher sensitivity than the TNM system. The calibration curve for the highest performing model showed no deviation from the reference line.
"Prognostic models incorporating readily available data elements outperform the current AJCC system," the authors write.