Cachexia is wasting of both adipose tissue and skeletal muscle. It occurs in many conditions and is common with many advanced and metastatic cancers when treatment fails.
Some cancers, especially pancreatic and gastric cancers, cause profound cachexia. Affected patients may lose 10 to 20% of their body weight (1). Males tend to experience worse cachexia due to cancer than females do. Neither tumor size nor the extent of metastatic disease predicts the degree of cachexia. Cachexia is associated with reduced response to chemotherapy (see also Overview of Cancer Therapy), poor functional performance, and increased mortality.
The primary cause of cachexia is not anorexia or decreased caloric intake. Rather, this complex metabolic condition involves increased tissue catabolism; protein synthesis is decreased and degradation increased. Cachexia is mediated by certain cytokines, especially tumor necrosis factor-alpha, interleukin (IL)-1b, and IL-6, which are produced by tumor cells and host cells. The adenosine triphosphate (ATP)–ubiquitin-protease pathway plays a role as well.
Cachexia is easy to recognize, primarily by weight loss, which is most apparent with loss of temporalis muscle mass in the face (Hippocratic facies). The loss of subcutaneous fat increases the risk of pressure injury over bony prominences.
General reference
1. Siff T, Parajuli P, Razzaque MS, Atfi A: Cancer-Mediated Muscle Cachexia: Etiology and Clinical Management. Trends Endocrinol Metab 32(6):382–402, 2021. doi:10.1016/j.tem.2021.03.007
Treatment of Cachexia in Cancer
Treatment involves treatment of the cancer. If the cancer can be controlled or cured, cachexia resolves.
Adequate nutrition for the patient's age, size, and activity level should be a target; additional caloric supplementation is often given. Any weight gain is usually minimal and is likely to consist of adipose tissue rather than muscle. Neither function nor prognosis is improved. Thus, in most patients with cancer and cachexia, high-calorie supplementation is not recommended. Parenteral nutritional support is not indicated except in situations where oral intake of adequate nutrition is impossible.
Other interventions can sometimes mitigate cachexia and improve function.
Corticosteroids increase appetite and may improve a sense of well-being but do little to increase body weight.
Androgenic steroids are sometimes given but may adversely affect liver function and potentially accelerate growth of some cancers such as prostate cancer.
Medications to alter cytokine production and effects are being studied (1).
Treatment reference
1. Kadakia KC, Hamilton-Reeves JM, Baracos VE: Current Therapeutic Targets in Cancer Cachexia: A Pathophysiologic Approach. Am Soc Clin Oncol Educ Book 43:e389942, 2023. doi:10.1200/EDBK_389942
