Cumulative incidence of first recurrence after curative treatment of stage I–III colorectal cancer. Competing risk analyses of temporal and anatomic patterns

Abstract

Background

Updated knowledge about the rates of recurrence and time to recurrence following curative treatment of colorectal cancer is essential to secure better patient information on prognosis, to serve as a premise in the discussion on adjuvant chemotherapy, and help to properly scale the intensity and length of follow-up.

Methods

This is a population-based study investigating aspects on first recurrence after radical treatment of clinical stages I-III of colorectal cancer in Central-Norway during 2001–2015. To reveal any time-trends, data were stratified by the time periods 2001–2005, 2006–2010 and 2011–2015. The cumulative incidence of first recurrence was calculated, treating death of unrelated causes as a competing event. Multivariable Cox analyses were done to calculate cause specific hazard ratios (HR) for risk of recurrence.

Results

At a minimum follow-up of six years, a first recurrence was detected in 1,113/5,556 patients at risk (20.0%). The recurrence rate was reduced from 23.6% in the first time period, through 20.0% in the second, and to 17.2% in the last, p < 0.001. The reduction applied to all tumor locations, to pathological disease stages II and III, to both gender, across different tumor differentiations, and to both elective and emergency surgery. In multivariable analyses time period, gender, disease stage, and tumor differentiation were significant determinants for risk of recurrence.

Conclusions

The rate of first recurrence after curative surgery for colorectal cancer was substantially reduced from 2001 to 2015. The reason for the reduction could not be attributed to a single factor only. A combined effect of several incremental improvements, such as an increased use of preoperative radiation for rectal cancers, improved adjuvant chemotherapy for colon cancer, and a reduced proportion of emergency surgery, is suggested.

Keywords:

• Colorectal cancer
• population based study
• competing risk analysis
• first reccurence
• stage I–III colorectal cancer

Data availability statement

The datasets generated and analysed during the current study are not publicly available due to hospital policy, but are available from the corresponding author on reasonable request.

Disclosure statement

No potential conflict of interest was reported by the authors.

Disclaimer

The study has used data from the Cancer Registry of Norway. The interpretation and reporting of these data are the sole responsibility of the authors, and no endorsement by the Cancer Registry of Norway is intended nor should be inferred.