Localized Colon Cancer, Version 3.2013

Abstract

The NCCN Clinical Practice Guidelines in Oncology for Colon Cancer begin with the clinical presentation of the patient to the primary care physician or gastroenterologist and address diagnosis, pathologic staging, surgical management, perioperative treatment, patient surveillance, management of recurrent and metastatic disease, and survivorship. The NCCN Colon Cancer Panel meets annually to review comments from reviewers within their institutions and to reevaluate and update their recommendations. In addition, the panel has interim conferences as new data necessitate. These NCCN Guidelines Insights summarize the NCCN Colon Cancer Panel's discussions regarding the treatment of localized disease for the 2013 update of the guidelines.

Genomic era diagnosis and management of hereditary and sporadic colon cancer

“…Surveillance colonoscopy is repeated based on findings (3 years if normal and 1 year if concerning adenomatous polyp removed), with CEA, history and physical exam spaced to every 6 mo to complete the first 5 years of posttreatment surveillance [77] . Patients with a history of CRC have a particularly high risk of another cancer within 2 years after resection, and recommended surveillance frequencies for the first 5 years post treatment vary with stage of CRC and patient characteristics such as age of onset and history of hereditary CRC [80] . Chest, abdominal and pelvic CT scans are recommended yearly for 3-5 years for stage Ⅱ-Ⅲ CRC patients at high risk for recurrence and every 3-6 mo for 2 years spaced to every 6-12 mo for a total of 5 years for individuals with stage Ⅳ CRC [77] .…”

“…Current recommendations include assessment of new CRC for evidence of MMR deficiency for patients younger than 50 years old, though many centers assess for MMR deficiency, and sometime MSI, on all patients with CRC. This is done for two reasons: (1) it can be used as a screening tool to identify individuals at risk to have Lynch syndrome, causing hereditary colon and endometrial cancer [14] , for whom genomic sequence analysis for mutations in MLH1, MSH2, MSH6 or PMS2 would be diagnostic; (2) deficiency in tumor MMR (as measured by protein immunohistochemistry) or high MSI tumor status is suggested to indicate decreased likelihood to metastasize [80] and be a prognostic indicator of more favorable outcome [89,90] . The application of genome sequencing technology has also led to an evolving array of clinical tools to augment the diagnosis and treatment of CRC (Table 1).…”

“…Current recommendations are for patients with high-risk stage Ⅱ and stage Ⅲ CRC to receive 6 mo of adjuvant chemotherapy after primary surgical resection, and for patients with low-risk stage Ⅱ CRC to be considered for adjuvant chemotherapy, enrolled in a clinical trial or observed without adjuvant therapy [77,79] . The specific chemotherapeutic regimens have been reviewed recently in detail [77,80] . These recommendations are derived from various studies which have shown survival benefit in patients with resected early stage CRC who received adjuvant chemotherapy, with most of the benefit being seen with stage Ⅲ CRC, but not with node negative stage Ⅱ disease, suggesting the benefit is increased in patients at higher risk related to nodal status [81][82][83] .…”

“…Genomic era colon cancer diagnosis for mutations in MLH1, MSH2, MSH6 or PMS2 would be diagnostic; (2) deficiency in tumor MMR (as measured by protein immunohistochemistry) or high MSI tumor status is suggested to indicate decreased likelihood to metastasize [80] and be a prognostic indicator of more favorable outcome [89,90] . The application of genome sequencing technology has also led to an evolving array of clinical tools to augment the diagnosis and treatment of CRC (Table 1).…”

“…Several such multigene panels are currently available (Oncotype DX Colon, ColoPrint, ColDX), simultaneously assessing 18 genes or more, using the data to predict an individual tumor's risk of recurrence [80] . While early trials have found such multigene panels can help predict recurrence risk for stage Ⅰ-Ⅲ CRC, they do not appear to predict the benefit of adjuvant therapy [80] , and further studies are necessary before such genomic assessment tools will have clinical relevance for choice of adjuvant therapy.With detailed genomic information now more easily obtainable for individual tumors, the potential for delivering treatments more specifically targeted to a tumor' s molecular signature is becoming a reality. For example, MSI observed in CRC tumors by the TCGA study, has been found to be a potential predictor of benefit from adjuvant therapy, with fluoropyrimidine specifically [89] .…”