What is fibromyalgia?
Fibromyalgia is a chronic disease characterised by widespread musculoskeletal pain, often accompanied by fatigue, sleep disturbances, and cognitive issues. It is a common condition, affecting approximately 2% to 8% of the population globally, with a higher prevalence in women [1, 2, 3].
The pain associated with fibromyalgia is typically widespread and persistent, it can sometimes last multiple months. The American College of Rheumatology's classification criteria define fibromyalgia by widespread pain of at least three months and the presence of 11 tender points on physical examination among 18 specific anatomic sites, including areas on the chest, abdomen, extremities and head and neck [4, 5, 6].
In addition to pain, fibromyalgia patients often experience fatigue, low quality of sleep, and cognitive dysfunction, including memory loss and mood disturbances [2, 7]. Digestive problems can also manifest [8].
The exact causes of fibromyalgia are unknown, but it is believed to involve a variety of genetic, environmental, and psychological factors. While it is not an autoimmune disease, it can coexist with other inflammatory rheumatic diseases such as rheumatoid arthritis and spondyloarthritis [9]. An autoimmune disease means the body's immune system, the set of defence mechanisms we possess to fight diseases, is attacking one's own body.
Fibromyalgia can affect all areas of an individual's functioning, including the social life [10]. However, with appropriate management, the symptoms can be controlled and the quality of life can be improved.
The treatment of fibromyalgia requires a comprehensive approach involving pharmacotherapy (drugs), complemented by exercise, cognitive behavioural therapy, and education [11]. The most effective drugs available for the treatment for fibromyalgia are the antidepressants milnacipran and duloxetine, which are serotonin noradrenaline reuptake inhibitors. They work by prolonging the time that serotonin and noradrenaline are present in the neurons. An anti-epileptic, pregabalin, is also used [11, 10].
Nonpharmacological treatments including exercise, and cognitive behavioral therapy were also shown to improve patient's pain and function [12]. As the exact symptoms differ between patients, the treatment plan should be individualised for every patient based on their individual goals [13].
What is the link between fibromyalgia and cancer?
There may be a connection between fibromyalgia and cancer, although the nature of this link is complex and not fully understood. This is very difficult to investigate, as both cancer and fibromyalgia are highly complex diseases.
One study found that 10.7% of hospitalized cancer patients were diagnosed with fibromyalgia [14]. Another study found that fibromyalgia was detected in 12.2% of patients with lung cancer [15]. In a study of breast cancer patients, it was found that women with breast cancer develop chronic widespread pain syndromes, including fibromyalgia, more often than healthy women [16]. Another study found that the frequency of fibromyalgia in breast cancer patients post surgery was higher than that reported in normal populations [17].
These findings suggest that fibromyalgia may be more common in cancer patients than in the general population. However, it is unclear whether fibromyalgia precedes cancer or is one of the symptoms or conditions occurring as a consequence of some cancer treatments such as radical surgery. One study found no association between fibromyalgia and an increased incidence of cancer [18]. Another study found no significant difference in the prevalence of cancer between patients with polymyalgia rheumatica, a condition similar to fibromyalgia, and healthy patients [19].
In conclusion, while there seems to be a higher prevalence of fibromyalgia among cancer patients, additional research is needed to fully understand the nature of this link. Having fibromyalgia does not mean a predisposition to cancer based on the current evidence. If you are concerned about fibromyalgia or cancer, contact your doctor who will be able to advise you and perform further tests.