Trends in pathology and long-term outcomes after resection of colorectal cancer: 1971-2013

The aim of this study was to describe temporal trends in tumour pathology and long-term outcomes in 5217 patients recorded in a registry of colorectal cancer resections initiated at Concord Hospital, Sydney, Australia, in 1971.

This report is based on consecutive resections up to December 2013, with no exclusions. Categories in variables examined were expressed as percentages over annual totals of relevant patients or annual mean values. The statistical significance of temporal trends was examined by least squares regression.

The percentages of patients with local spread beyond the muscularis propria, nodal metastasis, distant metastasis and tumour in a line of resection all declined significantly. In consequence, the percentage of stage D patients fell, whereas the percentage in stage A rose. Other tumour variables that increased significantly were polypoid morphology, contiguous adenoma and invasion of a free serosal surface. Tumours in which an adherent adjacent structure was partly or completely removed also increased. There were significant declines in high-grade malignancy, venous invasion and tumour size. The recurrence rate for rectal cancers declined significantly, whereas for rectal and colonic cancers combined, both the overall 5-year survival rate and the 5-year cancer-specific survival rate increased markedly.

These results show a reduction in adverse pathology findings and favourable trends in recurrence and survival after colorectal cancer resections in a high-incidence country over a period of 43 years.