VTE increased mortality risk among elderly patients with colon cancer
Elderly patients with stage III colon cancer who developed venous thromboembolism after cancer diagnosis were at increased mortality risk compared with patients who did not in a recent study.
In a retrospective study, researchers evaluated data from the Medicare Surveillance, Epidemiology, and End Results (SEER) database on 4,985 elderly patients (mean age, 78 years) with stage III colon cancer diagnosed between 2004 and 2005, with follow-up through 2007. Incidence rates of venous thromboembolism (VTE) were recorded, along with all-cause mortality rates.
Death occurred in 44% of cases during a median 28 months of follow-up from cancer diagnosis. VTE was diagnosed in 20.7% of the cohort, with a diagnosis rate of 9% at 3 months, 13% at 6 months and 16% at 1 year. The mortality rate was higher among patients with VTE than in those without (49% vs. 43%). Investigators observed a higher all-cause mortality risk for participants with VTE (adjusted HR=1.15; 95% CI, 1.04-1.27) via multivariate analysis.
Although patients who underwent adjuvant chemotherapy after cancer diagnosis (53.2% of the cohort) had reduced mortality risk and longer survival, treated patients who developed VTE after diagnosis were at increased risk for death (HR=1.41; 95% CI, 1.21-1.64), while untreated patients with new VTE diagnoses were not.
Other factors increasing risk for death included more comorbidities (HR=1.29, 1.15-1.45 for a Charlson comorbidity index score of ≥2), cancer substage IIIC (HR=1.72, 1.57-1.88 compared with substage IIIB), male sex (HR=1.15, 1.06-1.26) and advanced age (HR=1.60, 1.40-1.82 for those aged ≥85 years compared with those aged 66 to 74 years) (95% CI for all).
“Our results underscore the impact of VTE on mortality as a major public health problem and provide a reason for increased management and prevention of VTE among elderly patients with stage III colon cancer,” the researchers wrote. “Patients treated with chemotherapy may benefit the most from prophylactic antithrombotic treatment. Other patients with a high risk of VTE may also benefit from anticoagulation prophylaxis. It is noted, however, that VTE may reflect aggressive tumor biology, so the association of VTE and mortality is not always a direct effect.”
Disclosure: See the study for a full list of relevant disclosures.