Poorer Survival after Out-of-Hospital Cardiac Arrest among Cancer Patients - A Population-Based Register Study.

Abstract

The association between cancer and survival after out-of-hospital cardiac arrest (OHCA) has not been thoroughly investigated. We aimed to address this knowledge gap using national, population-based registries. For this study, 30,163 OHCA patients (≥18 years) were included from the Swedish Register of Cardiopulmonary Resuscitation. Via linkage to the National Patient Registry, 2,894 patients (10%) with cancer diagnosed within 5 years prior to OHCA were identified. Differences in 30-day survival between cancer patients and controls (defined as OHCA patients without previous cancer diagnosis) were assessed related to cancer stage (locoregional vs metastasized cancer) and cancer site (i.e. lung cancer, breast cancer etc.) using logistic regression adjusted for prognostic factors. Long-term survival is presented as a Kaplan-Meier curve. For locoregional cancer no statistically significant difference in return of spontaneous circulation (ROSC) was seen compared to controls, metastasized disease was associated with poorer chance of ROSC. Cancer was associated with lower 30-day survival for all cancers (Adjusted odds ratio, OR, 0.57, CI 0.49-0.66), locoregional cancer (Adjusted OR 0.68, CI 0.57-0.82) and metastasized cancer (Adjusted OR 0.24, CI 0.14-0.40) compared to controls. Lower 30-day survival compared to controls was seen for lung cancer, gynaecological and haematological cancers. Cancer is associated with poorer 30-day survival after OHCA. This study suggests that cancer site and disease stage are more relevant factors than cancer in general with regard to its effect on survival after OHCA.