Continued progress with stage III colorectal cancer--a triple cohort study.

INTRODUCTION

Colorectal cancer is a common cause of death in New Zealand and its burden is projected to increase in the future. Oncological outcomes from modern treatment have improved, but evidence from the published literature is conflicting. We studied survival outcomes from a series of patients at our local health board.

METHODS

A retrospective analysis of disease patterns, surgical procedures, adjuvant therapy and oncological outcomes was performed in three patient cohorts; January 1993-December 1994, January 1998-June 1999, and January 2004-December 2005 at Christchurch Hospital. Univariate, multivariate and Kaplan-Meier survival analysis was performed to identify differences between the three cohorts.

RESULTS

There were 1091 patients [(355, 317, 419 per cohort, 808 colon (281,227,300) and 283 rectal (74,90,119)] with cancer over the 3 cohorts. Median age was 76 (IQR 67-84) years. Median follow-up was 44 (IQR 13-81) months. For both colon and rectal cancer, patients in later cohorts had early disease, were more likely to have the operation performed by a consultant, were more likely to be referred for an oncological opinion and were more likely to receive adjuvant treatment (p<0.05 respectively). Differences in survival were particularly marked in the later cohort of patients with Stage III colonic cancer.

DISCUSSION

There have been significant improvements in oncological outcome with stage three colon and rectal cancer over the study period. Greater specialisation of surgeons, more operations by consultants and use of chemotherapy are all likely contributing factors.