Association between patients' perception of the comorbidity burden and symptoms in outpatients with common solid tumors.

BACKGROUND: Cancer patients' symptom burden is commonly attributed to their cancer and treatment. Increasingly, cancer patients have many other chronic comorbid conditions. However, the degree to which these comorbid conditions may contribute to the patient-reported symptom burden is unclear.

METHODS: This study explored the relations between the presence of comorbid conditions, the symptom experience and burden, and the perceived bother from cancer or comorbid conditions in 3106 cancer patients. The associations between the number of comorbidities (identified from current medications), the patient-reported symptom burden (the number of symptoms scored as ≥7 on the 13-item MD Anderson Symptom Inventory physical scale), the patient-reported bother from comorbid conditions and from cancer (from "not at all" to "extremely"), and the clinician-reported difficulty in caring for patients' symptoms were examined.

RESULTS: According to medication lists, 19% of the patients had at least 5 of 12 comorbid conditions. Approximately 39% rated at least 1 symptom as ≥ 7, and this proportion increased with an increasing number of comorbid conditions (48% with ≥ 5 comorbid conditions vs 36% with 1 comorbid condition). One-third of the patients reported moderate or worse bother, and this was significantly associated with an increased number of comorbid conditions (odds ratio [OR], 2.4) and an increased symptom burden (OR, 1.22). Clinician ratings of difficulty in managing patients' symptoms were significantly associated with bother from cancer (OR, 2.0), comorbid conditions (OR, 1.6), and symptom burden (OR, 1.1).

CONCLUSIONS: Comorbidity is common in cancer patients and is associated with a greater symptom burden and clinician reports of difficulty in managing patients' symptoms. Greater attention to comorbid conditions is needed to optimize the symptom management of cancer patients with multimorbidity. Cancer 2017;123:3835-3842. © 2017 American Cancer Society.