In 1999, a multidisciplinary panel of experts in colorectal cancer reviewed the relevant medical literature and issued a consensus recommendation for a 12-lymph node (LN) minimum examination after resection for colon cancer. Some authors have shown racial/ethnic differences in receipt of this evidence-based care. To date, however, none has investigated the correlation between disparities in LN examination and disparities in outcomes after colon cancer treatment.
This retrospective analysis used California Cancer Registry linked to California Office of Statewide Health Planning and Development discharge data (1996-2006). Chi-square analysis, logistic regression, and Cox proportional hazard models predicted disparities in receipt of an adequate examination and the effect of an inadequate exam on mortality and disparities. Patients with stage I and II colon cancers undergoing surgery in California were included; patients with stage III and IV disease were excluded.
A total of 37,911 records were analyzed. Adequate staging occurred in fewer than half of cases. An inadequate examination (<12 LNs) was associated with higher mortality rates. Hispanics had the lowest odds of receiving an adequate exam; however, blacks, not Hispanics, had the highest risk of mortality compared with whites. This disparity was not completely explained by inadequate LN examination.
Inadequate LN exam occurs often and is associated with increased mortality. There are disparities in receipt of the minimum exam, but this only explains a small part of the observed disparity in mortality. Improving the quality of LN examination alone is unlikely to correct colon cancer disparities.