Background Cancer patients often have other noncancer medical conditions. Presence of comorbidities negatively affects cancer survival. Objective The aim of this study was to investigate comorbidity, risk factors for comorbidity, and how comorbidity was associated with symptoms and quality of life in patients being treated for breast cancer. Methods One hundred and one breast cancer chemotherapy outpatients completed this study. Comorbid conditions, weight, height, and smoking status were identified by chart review. Symptoms and quality of life were self-reported using psychometrically sound instruments. Log-linear regression analyses with age as the covariate examined impact of ethnicity, body mass index (BMI), and smoking on comorbidities. Results Approximately 84% of the participants had 1 or more comorbid conditions. Adjusting for age, number of comorbidities differed by BMI (P =.000); the obese group had significantly more comorbidities than the normal and overweight groups. The interaction between BMI and smoking was significant (P =.047). The obese participants who smoked had significantly more comorbidities compared with those who were obese but did not smoke (P =.001). More comorbid conditions were associated with greater pain (P <.05) and poorer sleep quality (P <.05). Comorbidity significantly correlated with symptoms and functional aspects of quality of life (P <.01 and P <.05, respectively). A greater number of comorbidities was associated with lower physical and role functioning and worse fatigue, dyspnea, appetite loss, and nausea and vomiting (all P <.05). Conclusions Comorbidity exerts negative impacts on symptoms and quality of life. Weight and smoking status are strong determinants of breast cancer comorbidity. Implications for Practice Personalized care planning, weight management, and smoking cessation may lead to better cancer outcomes.
- Body mass index
- Quality of life