Qualitative and Quantitative Issues of Lymph Nodes as Prognostic Factor in Colon Cancer

Abstract

For patients undergoing curative resections for colon cancer, the nodal status represents the strongest prognostic factor, yet at the same time the most disputed issue as well. Consequently, the qualitative and quantitative aspects of lymph node evaluation are thus being scrutinized beyond the blunt distinction between ‘node positive' (pN+) and ‘node negative' (pN0) disease. Controversy ranges from a minimal or ‘least-unit' strategy as exemplified by the ‘sentinel node' to a maximally invasive or ‘all inclusive' approach by extensive surgery. Ranging between these two extremes of node sampling strategies are factors of quantitative and qualitative value, which may be subject to modification. Qualitative issues may include aspects of lymph node harvest reflected by surgeon, pathologist and even hospital performance, which all may be subject to modification. However, patient's age, gender and genotype may be non-modifiable, yet influence node sample. Quantitative issues may reflect the balance between absolute numbers and models investigating the relationships of positive to negative nodes (lymph node ratio; log odds of positive lymph nodes). This review provides an updated overview of the current controversies and a state-of-the-art perspective on the qualitative and quantitative aspects of using lymph nodes as a prognostic marker in colon cancer.

The prognostic impact of the log odds of positive lymph nodes in colon cancer

“…Lymph node status is considered to be among the most important prognostic factors in colon cancer [17]. Despite advances in surgery and histopathological examination techniques, an adequate NELN cannot be achieved in approximately half of patients [17][18][19].…”

Influence of Microsatellite Instability and KRAS and BRAF Mutations on Lymph Node Harvest in Stage I–III Colon Cancers

“…Obtaining an adequate LN harvest is therefore essential for guiding postoperative treatment. The LN harvest has become an extensively investigated quality standard for both surgeons and pathologists (1)(2)(3)(4), and the number of LNs examined is associated with survival (2). The recommended number of nodes for appropriate staging is a minimum of 12 (5), although this goal has been achieved in as low as 50% of the patients (6).…”

Prognostic Impact of Lymph Node Ratio in Obstructive Colorectal Cancer

“…Despite the TNM tumor staging being the standard for determining prognosis while guiding treatment, LNR has emerged as an alternative prognostic indicator for colon and rectal cancer [4,10]. This study's aim, to assess whether or not LNR is prognostic in obstructive colorectal cancers, has yet to be elucidated in the literature.…”

“…Of the TNM parameters, nodal status is the strongest predictor of survival. The College of American Pathologists [3] endorses the pathologic examination of a minimum of 12 lymph nodes based on the 7 th edition of the American Joint Committee on Cancer (AJCC) Staging Manual [4]. Factors that impact lymph node retrieval include age, immune response, tumor location, hospital volume, emergent cases, and tumor size [4,5].…”

“…The College of American Pathologists [3] endorses the pathologic examination of a minimum of 12 lymph nodes based on the 7 th edition of the American Joint Committee on Cancer (AJCC) Staging Manual [4]. Factors that impact lymph node retrieval include age, immune response, tumor location, hospital volume, emergent cases, and tumor size [4,5]. Other prognostic factors such as lymph node ratio (LNR) have been described to further predict outcomes of patients with colorectal cancer [6].…”