The role of somatic symptoms has been investigated in many studies and in various clinical settings because of its impact on patients. Studies have shown that somatic symptoms are frequently persistent, accounting for more than half of all general medical visits. Physical and psychological factors also appear to contribute to somatic symptom reporting. “Somatic symptoms are associated with substantial functional impairment, disability, and healthcare use, even after controlling for medical and psychiatric comorbidities,” says Kurt Kroenke, MD.
In investigations on the prevalence of symptoms in cancer, research has often focused on patients with advanced cancer or with certain types of cancer. Data demonstrate that symptoms like fatigue, pain, weakness, appetite loss, dry mouth, depressed mood, constipation, insomnia, dyspnea, nausea, and anxiety occur in at least 30% of patients with cancer. “These symptoms can have a substantial effect on functional status and quality of life,” explains Dr. Kroenke. “In some circumstances, they can hasten the desire of patients to die.”
The relationship between psychological distress and somatic symptoms—somatization—has not been studied extensively in cancer, but Dr. Kroenke and colleagues recently addressed this knowledge gap. In a study published in the October 11, 2010 Archives of Internal Medicine, they examined the impact of somatic symptom burden on disability and healthcare use in patients with cancer experiencing pain, depression, or both. “Pain and depression are two of the most common and potentially treatable symptoms in patients with cancer,” Dr. Kroenke says. “We measured somatic symptom burden using a 22-item scale. We also sought to determine the association of somatic symptom burden with disability and healthcare use.”
Analyzing Prevalence of Somatic Symptoms
According to Dr. Kroenke’s study, many somatic symptoms were highly prevalent in patients with cancer and comorbid pain, depression, or both, and these symptoms had a significant effect on patients (Figure). Dr. Kroenke says “we found that 15 of 22 symptoms assessed in the study were reported in more than half of all patients. In addition, 14 of the symptoms were reported as ‘very bothersome’ by more than 20% of patients in the investigation.”
“When patients report multiple symptoms, it’s important to assess their severity as well as patient preferences and concerns as these factors will likely have implications on how treatment decisions are made.”
Fatigue, sleep concerns, memory impairment, and musculoskeletal pain were the most common symptoms reported in the Archives of Internal Medicine study. “Many patients in the study noted that they were bothered a lot by their symptoms, regardless of the type of symptom,” says Dr. Kroenke. “However, some symptoms were rated as more severe than others. The lesson learned here is that when patients report multiple symptoms, it’s important to assess their severity as well as patient preferences and concerns as these factors will likely have implications on how treatment decisions are made.”
Assessing Somatic Symptom Burden
Somatic symptom burden was similar across a range of cancer types and phases (Table). Study patients experienced substantial disability, reporting almost 17 of the past 28 days as either “bed days” or days in which they had to cut back their usual activities by at least half. However, somatic symptom burden was not associated with healthcare use. “This finding differs from other published studies, but this may be due to the fact that the baseline healthcare use was already high in our study sample,” says Dr. Kroenke. “Four of every five study patients had cancer under active treatment.”
Many factors can account for the somatic symptom burden in patients with cancer, including cancer type and severity, the spread of cancer to other organs, and adverse effects of therapies used to treat cancer. “At the same time,” notes Dr. Kroenke, “the degree to which somatization contributes to somatic symptom burden in some cancer patients needs to be evaluated further. More data are needed to explore the effect of psychological factors and the individual’s pre-morbid symptom reporting history. Furthermore, patients with cancer pain or depression were experiencing multiple additional symptoms, or symptom clusters. Finding out more about these clusters may enhance the management of patients in the future.”
Considering the Whole Patient
In 2008, the Institute of Medicine issued a report on improving the cancer care of the whole patient. A benefit of Dr. Kroenke’s study is that it strengthens the case for improving the recognition and treatment of somatic symptoms in cancer patients. “If only a few symptoms are present, symptom-specific evaluations and treatments may get the job done for patients,” he says. “We do have evidence-based therapies that are well established for some somatic symptoms. However, if patients have many symptoms and they’re persistent or fail to respond to specific treatments, clinicians should consider more general strategies. This may mean treating comorbid depression and anxiety, assessing symptom reporting histories before the cancer diagnosis, and considering non-pharmacologic interventions like cognitive behavioral therapy, exercise, symptom self-management, and other strategies. Although these extra steps may be time-consuming, the effort is clearly worthwhile for patients.”
Kroenke K, Zhong X, Theobald D, Wu J, Tu J, Carpenter JS. Somatic symptoms in patients with cancer experiencing pain or depression: prevalence, disability, health care use. Arch Intern Med. 2010;170:1686-1694.
Katon W, Lin EH, Kroenke K. The association of depression and anxiety with medical symptom burden in patients with chronic medical illness. Gen Hosp Psychiatry. 2007;29:147-155.
Barsky AJ, Orav EJ, Bates DW. Somatization increases medical utilization and costs independent of psychiatric and medical comorbidity. Arch Gen Psychiatry. 2005;62:903-910.
Portenoy RK, Thaler HT, Kornblith AB; et al. Symptom prevalence, characteristics and distress in a cancer population. Qual Life Res. 1994;3:183-189.