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.