Smoking concordance in lung and colorectal cancer patient-caregiver dyads and quality of life.

BACKGROUND Distress may be heightened among members of cancer patient-caregiver dyads that are mismatched on smoking status (either the patient or caregiver smokes, but the other does not), negatively affecting quality of life (QoL). The purpose of this study was to examine associations between patient-caregiver smoking concordance, caregiver psychological adjustment, and caregiver and patient mental and physical QoL. METHODS Lung and colorectal patient-caregiver dyads (N = 742) were identified from the Cancer Care Outcomes Research and Surveillance (CanCORS) and CanCORS Caregiver studies. The majority of the cancer patients were male (67.0%) with local (45.6%) or regional (12.9%) disease. The majority of the informal caregivers were females (78.6%), under 65 years of age (69.6%), and often spouses (57.8%) of the patients. RESULTS Lung and colorectal cancer caregivers, who were members of dyads where one or both members continued to smoke, reported worse mental health QoL than nonsmoking dyads. For colorectal cancer patients, continuing to smoke when the caregiver did not was associated with worse mental health QoL compared with nonsmoking dyads. Dyad smoking was less strongly associated with physical QoL for both caregivers and patients. CONCLUSION Results highlight the importance of assessing smoking in both cancer patients and their caregivers and referring families to appropriate psychosocial and smoking cessation services. IMPACT This is the first study to show associations between cancer patient-caregiver smoking status and QoL for both dyad members. Future studies will need to confirm these associations longitudinally and investigate potential mechanisms linking dyad smoking and QoL.