Trends in colorectal cancer in the south of the Netherlands 1975-2007: Rectal cancer survival levels with colon cancer survival

Objective. In the Netherlands over 11 200 patients are yearly diagnosed with colorectal cancer (CRC), of who about 4 700 are expected to die of the disease ultimately. Investigating long-term trends is useful for clinicians and policy makers to evaluate the impact of changes in practice and will help predict future developments. Patients. The 26 826 cases of primary CRC (C18.0-C20.9) diagnosed between 1975 and 2007 in the Dutch population-based Eindhoven Cancer Registry area were included. We analysed trends in incidence, prevalence, stage distribution, treatment, survival, and mortality. Results. The age-standardised incidence of colon carcinoma kept increasing, most markedly in males (up to 39 patients per 100 000 inhabitants) and for tumours of the colon ascendens (subsite-specific incidence doubled). The incidence of rectal carcinoma remained stable. The share of patients aged 80 or older rose from 12 to 19% (p<0.0001). The proportion of patients diagnosed with distant metastases increased up to 25% for colon carcinoma (p<0.0001). Resection rates of the primary tumour remained high except for patients with metastasised disease, showing a decrease since 2000. Recently, the use of adjuvant chemotherapy seemed to level off among patients with stage III colon carcinoma, but the use of neo-adjuvant chemoradiation clearly increased among patients with stage II/III rectal cancer (p<0.0001). Five-year relative survival of colon cancer improved from 51% in 1975-1984 to 58% in 2000-2004, for rectal cancer it improved from 44 to 59%. Two-year relative survival of colon cancer in 2005-2006 was 69%, and 77% for rectal cancer. Conclusions. The changes in management of rectal cancer led to a superior increase in survival of these patients compared to patients with colon cancer, even surpassing the latter.