pT4 stage II and III colon cancers carry the worst prognosis in a nationwide survival analysis. Shepherd's local peritoneal involvement revisited.

• Published in: International Journal of Cancer
• Main Authors: Snaebjornsson, P, Coupe, V M H, Jonasson, L, Meijer, G A, van Grieken, N C, Jonasson, J G
• Other Authors: Vrije Univ Amsterdam Med Ctr, Dept Pathol, Amsterdam, Netherlands Landspitali Univ Hosp, Dept Pathol, IS-101 Reykjavik, Iceland Vrije Univ Amsterdam Med Ctr, Dept Epidemiol & Biostat, Amsterdam, Netherlands Univ Iceland, Fac Med, Reykjavik, Iceland Icelandic Canc Soc, Icelandic Canc Registry, Reykjavik, Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Adolescent; Adult; Aged; 80 and over; Colonic Neoplasms; Female; Humans; Iceland; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm Staging; Peritoneal Neoplasms; Prognosis; Proportional Hazards Models; Retrospective Studies; Young Adult; Meier; TNM
• Online Access: http://hdl.handle.net/2336/325044; https://doi.org/10.1002/ijc.28676

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field. The aim of this study is to clarify the prognostic importance of several well-known but still debated pathological variables related to the survival of colon cancer patients. The study focuses on the definition and survival carried by the pT4 category and stage II where the presence of high-risk variables may determine whether or not adjuvant chemotherapy is administered. A retrospective nationwide study was carried out including all colon cancer patients that underwent resection in Iceland between 1990 and 2004 (n = 889). All histopathology was reassessed. Cancer-specific survival (CSS) and overall survival were analysed using Kaplan-Meier and Cox regression analysis. In stage II, the five-year CSS for pT4 was 50% (95% CI, 32-69%), which was the lowest survival observed in that stage. In stage III the five-year CSS was 30% (95% CI, 18-41%) and 37% (95% CI, 26-48%) for pT4 and pN2 tumors, respectively. Lymphatic invasion and differentiation had no prognostic value in stage II. The survival associated with pT4a versus pT4b depends on how these categories are defined with regard to Shepherd's local peritoneal involvement (LPI). In the present series, pT4 is a major indicator of poor prognosis in patients with stage II and III colon carcinoma. Four-tiered TNM or Dukes staging systems are insufficient by not taking this variable into account. Only Shepherd's LPI4 and a subgroup of LPI3 (i.e., borderline LPI3/LPI4) should qualify for the pT4a subcategory. The results do not support lymphatic invasion or poor differentiation as high-risk stage II variables. Landspitali-University Hospital Research Fund Memorial Fund of B. Magnusdottir, J. J. Bjarnason Gastrointestinal Science Fund of Wyeth-Lederle