By Dr. Javier Rivera | May. 30, 2021 | Cancer

Many of the articles on this blog are suggested to me by the patients I see in the clinic when they tell me about the characteristics surrounding their disease, the evolution of their symptoms or the doubts they have.

On many occasions, it saddens me to see that part of the suffering could have been avoided if certain aspects of the disease had previously been taken into account and some actions aimed at avoiding the most common complications had been initiated.

In the daily consultation, I often see people with the association of cancer and fibromyalgia and, like any other association of diseases, it is also accompanied by greater difficulties for the adequate treatment of the patient.

Basically, I see two different types of patients with this association:

a) patients with fibromyalgia already diagnosed, who over time have developed cancer.

b) and those others, who begin with the symptoms of fibromyalgia after being diagnosed with cancer.

Regarding the first group of patients, the first thing to say is that the frequency of patients with fibromyalgia -compared to other diseases- who develop cancer throughout their lives is unknown, because there are no long-term studies that allow us to know this data.

We know that patients with fibromyalgia and chronic fatigue syndrome/myalgic encephalitis have a certain degree of immune depression that favors the appearance of some infections, so it could be thought that they could also have a greater predisposition to cancer. However, although cancer can develop in patients with an impaired immune system, the degree of immunosuppression to predispose to cancer seems to be more severe than that in the patients with fibromyalgia.

As indirect data, we know from studies on the causes of death in patients with fibromyalgia that the presence of cancer is significantly lower than in the rest of the population, which indirectly suggests that the frequency of developing cancer in a patient with fibromyalgia should also be lower than among the general population.

In these patients, of course, priority is always given to the oncological problem and its treatment, and fibromyalgia often goes unnoticed. Obviously, this should not be the case and within cancer treatment this possibility should also be taken into account to improve the general situation of the patient.

The second group of patients that I see in the consultation are those women who start with symptoms of fibromyalgia for the first time after being diagnosed with cancer.

Without knowing the exact percentage of cancer patients to whom this happens -because there are no studies on the matter either-, in my personal experience I see this association with some frequency once the patient has finished everything related to cancer treatment and it is already in the stage of periodic reviews that are done to ensure that the treatment has been successful and the cancer should no longer cause problems.

However, some patients then begin with fatigue, malaise, sleep disturbances, anxiety, depression and a poor quality of life, all of which are symptoms that are clearly compatible with fibromyalgia.

On many occasions, the oncologist is forced to continue looking for a possible spread of cancer to other organs to explain the poor situation of the patient and begins with new examinations and tests, prolonging the stress and uncertainty of the patient.

If the possibility that the patient had developed fibromyalgia, and that the symptoms could be in this context and not as another manifestation of cancer, had been taken into account, many doubts and some of their negative consequences would have been avoided.

Thus, establishing the diagnosis of fibromyalgia as an associated comorbidity in a cancer patient is always important because it offers us a new vision of what is happening to the patient and, furthermore, because by treating it, other potentially more harmful unnecessary treatments and examinations are avoided.