Survival of patients with kidney cancer in central and northern Denmark, 1998–2009

Abstract

Objective

For decades, kidney cancer patients in Denmark have had lower survival than patients in the other Scandinavian countries. Our aim was to study possible changes in survival of patients with kidney cancer after implementation of two national Danish cancer plans.

Study design and setting

From 1998 through 2009 we included all patients (N = 2659) with an incident diagnosis of kidney cancer in two Danish regions (population 1.8 million). Data were retrieved from the Danish National Registry of Patients. We computed survival after 1, 3, and 5 years, stratified by age, and estimated mortality rate ratios (MRRs) using Cox regression to assess changes over time, controlling for age and gender. We lacked data on stage distribution. Among patients who had a nephrectomy we also computed 30-day mortality and 30-day MRRs.

Results

During the study period, we identified 2659 patients with kidney cancer. The annual number of patients increased from 583 in the period 1998–2000 to 853 in the period 2007–2009. The median age at diagnosis was 69 years throughout the study period. The overall 1-year survival improved from 56% (1998–2000) to 63% (2007–2009), corresponding to an adjusted MRR of 0.78 (95% confidence interval [CI] 0.66–0.93). We predicted the 3-year survival to increase from 40% to 51% and the 5-year survival to increase from 33% to 42%, corresponding to predicted MRRs of 0.76 (95% CI 0.66–0.87) and 0.77 (95% CI 0.68–0.89), respectively. Survival increased in all age groups (15–59 years, 60–74 years, 75+ years) and in both genders, except for men below 60 years, for whom the 1-year survival declined from 76% to 69%. The 30-day mortality after nephrectomy declined from 4% to 2% during the study period.

Conclusion

We observed an improvement in the survival and relative mortality in kidney cancer patients, although not in men younger than 60 years.

Keywords:

• kidney neoplasm
• outcome research
• mortality rate ratio
• MRR

Disclosure

The authors report no conflicts of interest in this work.

Financial support

The study received financial support from the Karen Elise Jensen Foundation, Department of Clinical Epidemiology’s Research Foundation, and the Regional Clinical Epidemiological Monitoring Initiative for central and northern Denmark regions.