CONTEXT: Among patients surgically treated for colon cancer, better survival has been demonstrated in those with more lymph nodes evaluated. The presumed mechanism behind this association suggests that a more extensive lymph node evaluation reduces the risk of understaging, leading to improved survival. OBJECTIVE: To further evaluate the mechanism behind lymph node evaluation and survival by examining the association between more extensive lymph node evaluation, identification of lymph node-positive cancers, and hazard of death. DESIGN: Observational cohort study. SETTING: Surveillance, Epidemiology, and End Results (SEER) program data from 1988 through 2008. PATIENTS: 86,394 patients surgically treated for colon cancer. MAIN OUTCOME MEASURE: We examined the relationship between lymph node evaluation and node positivity using Cochran-Armitage tests and multivariate logistic regression. The association between lymph node evaluation and hazard of death was evaluated using Cox proportional hazards modeling. RESULTS: The number of lymph nodes evaluated increased from 1988 to 2008 but did not result in a significant overall increase in lymph node positivity. During 1988-1990, 34.6% of patients (3875/11,200) had 12 or more lymph nodes evaluated, increasing to 73.6% (9798/13,310) during 2006-2008 (P < .001); however, the proportion of node-positive cancers did not change with time (40% in 1988-1990, 42% in 2006-2008, P = .53). Although patients with high levels of lymph node evaluation were only slightly more likely to be node positive (adjusted odds ratio for 30-39 nodes vs 1-8 nodes, 1.11; 95% CI, 1.02-1.20), these patients experienced significantly lower hazard of death compared with those with fewer nodes evaluated (adjusted hazard ratio for 30-39 nodes vs 1-8 nodes, 0.66; 95% CI, 0.62-0.71; unadjusted 5-year mortality, 35.3%). CONCLUSION: The number of lymph nodes evaluated for colon cancer has markedly increased in the past 2 decades but was not associated with an overall shift toward higher-staged cancers, questioning the upstaging mechanism as the primary basis for improved survival in patients with more lymph nodes evaluated.
CONTEXT: Among patients surgically treated for colon cancer, better survival has been demonstrated in those with more lymph nodes evaluated. The presumed mechanism behind this association suggests that a more extensive lymph node evaluation reduces the risk of understaging, leading to improved survival. OBJECTIVE: To further evaluate the mechanism behind lymph node evaluation and survival by examining the association between more extensive lymph node evaluation, identification of lymph node-positive cancers, and hazard of death. DESIGN: Observational cohort study. SETTING: Surveillance, Epidemiology, and End Results (SEER) program data from 1988 through 2008. PATIENTS: 86,394 patients surgically treated for colon cancer. MAIN OUTCOME MEASURE: We examined the relationship between lymph node evaluation and node positivity using Cochran-Armitage tests and multivariate logistic regression. The association between lymph node evaluation and hazard of death was evaluated using Cox proportional hazards modeling. RESULTS: The number of lymph nodes evaluated increased from 1988 to 2008 but did not result in a significant overall increase in lymph node positivity. During 1988-1990, 34.6% of patients (3875/11,200) had 12 or more lymph nodes evaluated, increasing to 73.6% (9798/13,310) during 2006-2008 (P < .001); however, the proportion of node-positive cancers did not change with time (40% in 1988-1990, 42% in 2006-2008, P = .53). Although patients with high levels of lymph node evaluation were only slightly more likely to be node positive (adjusted odds ratio for 30-39 nodes vs 1-8 nodes, 1.11; 95% CI, 1.02-1.20), these patients experienced significantly lower hazard of death compared with those with fewer nodes evaluated (adjusted hazard ratio for 30-39 nodes vs 1-8 nodes, 0.66; 95% CI, 0.62-0.71; unadjusted 5-year mortality, 35.3%). CONCLUSION: The number of lymph nodes evaluated for colon cancer has markedly increased in the past 2 decades but was not associated with an overall shift toward higher-staged cancers, questioning the upstaging mechanism as the primary basis for improved survival in patients with more lymph nodes evaluated.
Authors: Carolyn M Rutter; Eric A Johnson; Eric J Feuer; Amy B Knudsen; Karen M Kuntz; Deborah Schrag Journal: J Natl Cancer Inst Date: 2013-10-30 Impact factor: 13.506
Authors: Pamela Farley Short; John R Moran; Tse-Chuan Yang; Fabian Camacho; Niraj J Gusani; Heath B Mackley; Stephen A Matthews; Roger T Anderson Journal: Med Care Res Rev Date: 2015-11-27 Impact factor: 3.929
Authors: A Dubecz; N Solymosi; M Schweigert; R J Stadlhuber; J H Peters; D Ofner; H J Stein Journal: J Gastrointest Surg Date: 2013-01-24 Impact factor: 3.452