Adherence to national guidelines for treatment and outcome of endometrial cancer stage I in relation to co-morbidity in southern Netherlands 1995-2008

Background: Endometrial cancer (EC) occurs more frequently amongst women over 60years old, who often also suffer from co-morbidity. Since treatment guidelines are derived from clinical trials that usually exclude such patients, nevertheless these guidelines are also applied for older EC patients. We assessed the independent influence of age and co-morbidity on treatment modalities and survival of patients with stage I EC in everyday clinical practice, thereby also examining the implementation of Dutch guidelines on treatment, since 2000.

Methods: All 2099 stage I EC patients diagnosed between 1995 and 2008 in the southern Netherlands were registered in the ECR (Eindhoven Cancer Registry) were included for analysis of the influence of age and co-morbidity on treatment and survival. For co-morbidity we used a modified version of Charlson's list, uniquely recorded in the ECR since 1993. A subgroup analysis was performed of patients who should have received adjuvant radiotherapy based on the risk factors advised in the Dutch guidelines of 2000. We considered five periods (1995-97; 1989-2000; 2001-03; 2004-06; 2007-08).

Results: Having two or more co-morbid conditions resulted in a significant reduction of receiving adjuvant radiotherapy (Odds Ratio: 0.6, 95% Confidence Interval (95% CI): 0.3-1.0)) but receiving adjuvant radiotherapy did not appear to improve survival. After adjustment for age, tumour stage, tumour grade, period of diagnosis and treatment, co-morbidity increased the risk of death, especially diabetes (Hazard Ratio (HR) for mortality: 2.9,95% CI: 2.2-4.0), a previous cancer (HR: 2.6, 95%CI: 1.9-3.7) and cardiovascular disease (HR: 2.3, 95%CI: 1.7-3.2). The combination of two or more co-morbid conditions resulted in a HR of 3.0 (95%CI: 2.2-3.9).

Conclusion: Co-morbidity decreased the likelihood of receiving adjuvant radiotherapy in patients with stage I EC qualifying to undergo this according to the Dutch guidelines of 2000. Whereas adjuvant radiotherapy did not seem to affect survival in those patients, co-morbidity significantly did.