What is the optimal means of staging colon cancer?

Abstract

Although staging for colon cancer has become more complex over time, it is not clear that this complexity has improved prognostic assessment. Even with revisions in the 7th edition of the AJCC staging system, a clear rank order of prognosis from substage to substage has not been established. Improved staging models will need to be developed, and attempts at further identifying those high-risk patients within each stage may be clinically useful. Through improved quality measures with lymph node yield, advances in colon cancer staging accuracy have been made over the last decade. Determining how to incorporate ultrastaging and molecular techniques will be the challenge for future staging models.

Figure 1

Current guidelines for the staging of colon cancer. Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York.

Figure 1

Current guidelines for the staging of colon cancer. Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York.

Figure 1

Current guidelines for the staging of colon cancer. Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York.

Figure 2

Cumulative survival of patients with stage I, II or III colon cancer increases with more extensive nodal examination. Survival was greatest when more than 15 lymph nodes were evaluated. Reprinted from Chen SL, Bilchik AJ: More extensive nodal dissection improves survival for stages I to III of colon cancer: a population-based study. Ann Surg 2006;244:602–610 with permission.

Figure 3

Lymphatic mapping using isosulfan blue dye to identify a sentinel node in a patient with colon cancer. Reprinted from Bilchik AJ, DiNome M, Saha S, et al.: Prospective multicenter trial of staging adequacy in colon cancer: preliminary results. Arch Surg 2006;141:527–533; discussion 533–524 with permission.

Figure 4

Prognostic significance of ultrastaging in colon cancer. A. Disease-free survival according to nodal disease volume in all patients. N0 (i+) and N0 (i−) represent patients whose nodes were positive or negative for isolated tumor cells or small clusters, respectively. B. Disease-free survival of node-negative patients randomized to standard pathological evaluation (Control) versus targeted nodal assessment and ultrastaging (TNA-us). Reprinted from Nissan A, Protic M, Bilchik AJ, et al.: United States Military Cancer Institute Clinical Trials Group (USMCI GI-01) randomized controlled trial comparing targeted nodal assessment and ultrastaging with standard pathological evaluation for colon cancer. Ann Surg 2012;256:412–427 with permission.