It is formed starting from some cells, the fibromyoblasts, present in connective tissues. These cells go crazy after a mutation so they start to grow irregularly forming a mass.

It can appear in any part of the body because soft tissues are present throughout the body. Based on the location, it tends to have different prognoses and behaviors.

It appears as a hard mass to the touch located deep down. Given the differential diagnosis with different diseases, such as sarcomas or GIST, it is always recommended to be visited by a doctor specialized in “sarcomas” when a hard mass larger than a golf ball is found in a deep seat.

Certain causes are not known.

We have seen correlations between high levels of estrogen (since the largest number of patients are women of childbearing age), probable trauma (in some cases they appear after surgery – such as in cases of caesarean or colectomy) and connective tissue disease.

In cases of desmoid tumor occurring in patients with familial adenomatous polyposis (FAP), the greater probability of forming desmoids is due to the mutation of the APC gene, related to β-catenin, a protein that plays a role in the pathogenesis of desmoid tumor.

Desmoid tumor is classified by the World Health Organization’s international guidelines as an “intermediate malignancy” tumor because it’s locally aggressive, but not metastasizing, i.e. it does not spread to other parts of the body.

The desmoid tumor has a very heterogeneous behavior from individual to individual and based on the site in which it’s localized. When a desmoid tumor is initially diagnosed, if there aren’t related issues or severe pain, we proceed with observation to evaluate its behavior.

By evaluating its growth rate, it is decided whether to continue monitoring it for a period – hoping for spontaneous stabilization/regression – or to start a treatment with drugs (especially in cases of rapid growth or cases where the tumor causes physical impossibility or severe unmanageable pain).

The patient must be followed by a sarcoma specialist (surgeon and/or oncologist) who will prescribe periodic checks (monthly, quarterly or half-yearly) to understand the behavior and evaluate the next step together (see FAQ n.11).

Yes, it can be cured in most cases. There are many types of therapies that are carried out based on the behavior of the tumor, which can be very heterogeneous. These therapies can “turn off” the tumor, until stabilization or regression, sometimes even complete (see FAQ n. 24). In other cases, however, patients live with the tumor for years.

Because it has been seen that in a certain percentage of cases, desmoid tumors have a spontaneous stabilization, in which the tumor can even regress spontaneously. So, before starting a therapy, you choose to observe its behavior through periodic checks (RMI or CT scans). Spontaneous regression is more likely in tumors localized in abdominal area.

In case the tumor continues to grow with a regular trend or it starts to cause pain, after initial period of observation.

Being a rare tumor (with an incidence of 6 persons in a million every year), not all doctors have a specific knowledge about it. For this reason, it is advisable to go to a Sarcoma Specialist, who knows how to diagnose and treat it in the best way.

Because in these centers you can be sure of finding up-to-date specialists on the pathology, who follow the latest guidelines, know the clinical trials in progress and deal specifically with desmoid tumor. Furthermore, centralizing patients in a few centers of reference allows the collection of useful data for research.

A suspected “desmoid tumor” is often diagnosed initially through image diagnostics (with RMI and CT scans – based on location). A biopsy is done after to confirm the diagnosis.

First of all, a macro and microscopic examination is carried out, in which the tissue is observed and a diagnosis is addressed based on its appearance. This is then confirmed through immunohistochemical analysis, where the presence or absence of particular surface antigens on tumor cells is studied, which confirm the diagnosis or not.

Finally, the mutational DNA analysis of cancer cells – carried out at particular reference centers – confirms the diagnosis with certainty and identifies the type of mutation.

Normally more than 90% of desmoid tumors have the mutation of the β-catenin gene: this type of mutation is present in sporadic desmoid tumors, i.e. not associated with hereditary syndromes and it’s expressed only in tumor cells.

On the other hand, tumors presenting mutated APC gene are associated with an hereditary syndrome: Gardner’s Syndrome, that is a Familial Adenomatous Polyposis (FAP) associated with the presence of desmoid tumors.

FAP is characterized by the presence of large amounts of polyps throughout the intestine. In this case, the mutation resides in all the patient’s cells, and this is the reason why patients with FAP may have multiple desmoid tumors localized in different sites of the body.

There are also rare cases in which there is no mutation in cancer cells, they are called “Wild Type”.

Esistono poi rari casi in cui non è presente alcuna mutazione nelle cellule tumorali, sono definiti “Wild Type”.

Many patients learn to live with the disease, as stabilization of the tumor can occur after drug treatment or spontaneously. It is important to treat the symptoms, especially any pain caused by the presence of the tumor, in order to improve the patient’s quality of life.

For this it’s important to be followed by a Pain Therapist, who helps us to manage pain since it’s essential to have a good quality of life.

Sometimes this can be psychologically difficult, which is why the Association is also involved in providing coaching and psychology services.

The desmoid tumor has a locally aggressive behavior. Its removal is often followed by high recurrence’s rate in a short time. In addition, the surgery must include large negative margins around the tumor and this is often not possible, because it could lead to large functional and aesthetic deficits (especially in the limbs).

In some cases, especially in abdominal desmoid tumors, surgery may still be a first-line treatment, since this site is characterized by a lower risk of recurrence.

There are also cases of intra-abdominal desmoid tumors that are not responsive to chemotherapy and tumor growing inside the abdomen can be responsible of issues, so in this case surgery is still carried out.

Since most cases of desmoid tumor are sporadic type, they usually present as a single solitary mass.

Rarely, a patient with a sporadic tumor (β-catenin mutation) may form a desmoid tumor elsewhere in the body – this risk increases in the case of tumors treated with surgery, where the mass may recur in a site close to the site of removal of the previous one.

There are very rare cases of patients with a “sporadic multifocal limb tumor”, characterized by the presence on a single limb (upper or lower) of multiple desmoid tumors, for example hand, arm and forearm.

Patients with Gardner’s Syndrome (FAP) more commonly may develop multiple desmoids in various sites of the body.

Pazienti che presentano la Sindrome di Gardner (FAP) più comunemente possono sviluppare più desmoidi in varie sedi del corpo.

Familial Adenomatous Polyposis (FAP) is characterized by the appearance of hundreds or thousands of polyps in the rectum and colon. Polyps form already in adolescence and tend to turn into colorectal cancer in adulthood.

It is caused by germline mutations (i.e. mutations present in all cells of the individual, even those responsible for reproduction) in the APC gene and the children of affected people have a 50% risk of inheriting the mutation.

The clinical diagnosis is suspected based on the number of polyps but the confirmation of the diagnosis is entrusted to genetic tests. When the mutation that occurs in the family is identified, relatives at risk can use genetic test to find out if they have inherited the mutation. Carriers of the mutation will follow a specific surveillance program that begins around 11-14 years of age.

The main treatment for this disease is surgical, with prophylactic removal of the colon.

Patients with FAP have a greater risk of developing desmoid tumors than the rest of the population, often intra-abdominal after surgery, and in this case we speak about Gardner’s syndrome.

In order to avoid the formation of desmoid tumors following colectomies, in many centers it is preferred to use a laparoscopic technique during such operations to avoid the large incisions required by traditional “open” surgery.

There are cases of non-inherited FAP, where patients have discovered the disease due to bowel symptoms with no family history of colorectal cancer.

β-catenin mutation, responsible of sporadic desmoid tumor, and APC gene mutation, present in the desmoid tumor associated with FAP, are mutually exclusive: patient has β-catenin gene mutation (and therefore a tumor sporadic desmoid) OR APC gene mutation(and therefore a tumor in the presence of FAP), therefore by carrying out the mutational analysis you can know what type of desmoid tumor you have.

Patients with FAP normally have family cases of polyposis/colorectal cancer since this disease is transmissible, so most of the time they are already aware of polyposis in family history.

The suspicion of FAP can arise in wild-type tumors, which do not have either mutation, or in patients who have not carried out the mutational analysis and have intestinal symptoms that give rise to the suspicion.

In addition, there have been rare cases of patients with FAP who first discovered desmoid tumor and subsequently polyposis, since sometimes they did not know their family history or they were the only case in the family with FAP.

If you do not have gastrointestinal symptoms, if there are no cases of FAP in the family and especially if there has already been a mutational analysis that has shown the presence of a mutation in the β-catenin of the tumor, colonoscopy is generally not indicated.

In intra-abdominal desmoid tumors and in case of tumors with APC mutation, colonoscopy is performed to confirm the presence or absence of concomitant Familial Adenotamous Polyposis.

However, refer to your oncologist who specializes in sarcomas, who will direct you to the right diagnostic tests to perform.

It depends on the tumor rate of growth: normally during the “active” periods checks are closer, every 2-3 months; in cases of disease stabilization or slow growth they can be lengthened and performed every six months or annually.

Unlike other types of tumor, especially in cases of desmoid tumor that have not completely regressed, checks can be recommended even after 5 years from the stabilization of it.

These checks are performed through MRI scans with or without contrast medium (contrast is prescribed in the case of more active tumors to be evaluated during therapy), CT scans (mainly used in intra-abdominal tumors) or rarely ultrasound scans.

In desmoid tumor, different pharmacological treatments can be used: initially we tend to use anti-inflammatory drugs, such as Colecoxib, or anti-estrogen drugs, such as Tamoxifen or Toremifene, which are easier to handle and have fewer side effects.

The second step involves the use of low-dose chemotherapy, especially with Vinblastine and Metrotrexate.

In cases it’s necessary to be more aggressively and suddenly in decreasing the tumor, chemotherapy at higher doses can be used.

There are also antithyrosine kinase drugs such as Pazopanib and Sorafenib.

New drugs, currently under study through clinical trials, are Nirogacestat, an inhibitor of γ-secretases, and Tegavivint, which acts directly on β-catenin.

Low-dose chemotherapy is given for desmoid cancer and generally does not cause hair loss. However, this therapy can make them more fragile and sparse, mainly due to the toxicity added up over time (see FAQ n.27). Side effects can be various and depend on the type of therapy chosen: it is always advisable to discuss and evaluate the various possibilities with your oncologist.

They are catheters inserted in the veins, medical devices that represent a quick access to chemotherapy drugs, allowing easier management during therapies and avoiding excessive stress to patient’s veins.

They are usually implanted on a day-hospital basis.

Low-dose chemotherapy lasts about 50 weekly sessions, so the therapy lasts almost a full year. Sometimes, with the toxicity that increases over time, after the first period you can ask to extend the frequency of therapy to 10/15 days by a few days in order to allow the body to recover between one session and another; in this case the total period of chemotherapy is lengthened.

There are several drug treatments and the oncologist decides which therapy to administer depending on the patient and the adverse effects.

The topic of pregnancy is very delicate: it depends on the localization of the desmoid and on the risk of the mass to start growing again (a correlation has been seen between high estrogen levels in pregnancy and tumor growth), so the choice must be discusses together to your trusted oncologist and gynecologist.

Some therapies for desmoid may have effects on fertility, some mild and others to an extent not yet confirmed.

The Association supports patients to think about preserving fertility in certain cases.

No, but a distinction must be made between sporadic desmoid tumor and FAP.

Sporadic desmoid tumors are not transmitted to children, being random tumors occurring in a single part of the body for which the mutation is not present in all cells of the individual.

In patients with FAP, on the other hand, APC gene mutation is also present in the germ cells, i.e. the cells responsible for the reproduction and “creation” of the new individual; in this case, therefore, patients with FAP can transmit the APC gene mutation to their children and, in 50% of cases, the latter may have FAP and consequently a greater predisposition to desmoids than the rest of the population.

The contraceptive pill affects estrogen hormones levels. Given the probable correlation between desmoid tumor and these hormones (see FAQ n.5), their use is not recommended.

However, it’s important to replace it with other methods of contraception and to talk to your oncologist about this topic.

No, non esistono diete particolari studiate per far diminuire o eliminare un tumore. Tuttavia, si consiglia un’alimentazione sana ed equilibrata che ha sempre dei benefici sulla salute, soprattutto per le persone affette da patologie e sottoposte a trattamento farmacologico.

No, there are no special diets designed to decrease or eliminate a tumor. However, we recommend an healthy and balanced diet that always has health benefits, especially for people suffering from diseases and undergoing drug treatment.

In patients undergoing chemotherapy, a correct diet – balanced and based on potential side effects of chemo, such as nausea and / or diarrhea – can help to better address and support therapies.

In patients with FAP and / or patients with intra-abdominal desmoid tumor who have undergone surgery and / or therapies with consequences on the proper functioning of the intestine, it’s recommended to follow a specific diet for any absorption and digestion problems, in order to have a better quality of life.

This is why the Association offers a consultation service with a Nutritionist.

Yes, you can if tumor does not cause pain; it’s always recommended to continue an healthy lifestyle that also includes sporting activity. However, you should avoid to stress the tumor too much.