Lymph Node Examination in Colorectal Cancer: Predictors of Adequate Staging and Its Influence on Cancer Survival in Community Practice
Colorectal cancer is the third leading cause of cancer incidence and mortality among men and women in the United States. In 2009, the American Cancer Society projects that 146,970 colorectal cancers will be diagnosed; and 49,920 people will die of the disease. Surgery is curative for colorectal cancer, yet up to 30% of stage I - II cases die of disease recurrence or metastasis. In these cases it is likely there was undetected extracolonic disease at the time of diagnosis and surgery, often because of inadequate harvesting of lymph nodes. Stage III (node positive) cases receive chemotherapy as standard adjuvant treatment, reducing disease-specific mortality by 30%. Suboptimal lymph node harvesting during surgery can understage the patient, causing potentially life-saving adjuvant therapy to be withheld. Conversely, administration of chemotherapy to “truly” node-negative patients because of inadequate nodal dissection has not translated into clinical benefit and may expose those patients to the unnecessary toxicity of chemotherapy. Despite the agreed-upon importance of lymph node harvesting to stage and treat colorectal cancer appropriately, disagreement about the number needed for adequate prognosis and treatment, and important covariate factors, continues.
1) To assess the adequacy of nodal recovery at surgery in colorectal cancer patients by retrospective analysis of tumor and node data.
2) To better define “adequate lymph node recovery” by exploring associations between adequacy of lymph node harvesting and patient survival using various definitions of “adequacy”.
3) To determine factors that may influence adequacy of nodal recovery, including patient,provider and system variables.
This pilot is a retrospective analysis of Marshfield Clinic patients diagnosed from January 1, 1992 through December 31, 2008 with histologically confirmed primary colorectal cancer, stages I-III, definitively resected. The Cancer Registry, Electronic Medical Record, and CRN Virtual Data Warehouse will provide comprehensive data on demographics, co-morbidities, surgery, lymph node status, first definitive treatment, recurrence, and survival.
This pilot proposes to study adequacy of lymph node staging and survival outcomes for stage I-III colorectal cancer patients. This pilot will develop proven methodology and preliminary data for a CRN-wide RO1 proposal to better determine an important diagnostic and prognostic variable of one of the most important cancers in the United States. If successful, the study can lead to improved clinical management of colorectal cancer and help the CRN provide a major clinical contribution to cancer care.