From the Guidelines
Gardner syndrome is associated with several non-gastrointestinal malignancies, with desmoid tumors being the most common, occurring in approximately 10-20% of patients, and management requires a multidisciplinary approach with regular surveillance and prompt evaluation of suspicious findings, as recommended by the most recent guidelines 1.
Non-GI Malignancies in Gardner Syndrome
The most common non-GI malignancy in Gardner syndrome is desmoid tumors (aggressive fibromatosis), which are benign but locally aggressive tumors that can cause significant morbidity through local invasion of surrounding structures. Other non-GI malignancies associated with Gardner syndrome include:
- Thyroid cancer (particularly papillary thyroid carcinoma)
- Adrenal adenomas
- Brain tumors (particularly medulloblastomas)
- Osteomas (benign bone tumors)
- Epidermoid cysts
- Dental abnormalities These manifestations occur because Gardner syndrome is caused by mutations in the APC gene, which regulates cell growth and division in multiple tissue types beyond just the colon.
Management of Non-GI Malignancies in Gardner Syndrome
Management of non-GI malignancies in Gardner syndrome requires a multidisciplinary approach, including:
- Regular surveillance for extra-intestinal manifestations, such as thyroid ultrasounds and CT or MRI for desmoid tumors when clinically indicated
- Prompt evaluation of any suspicious findings
- Systemic treatments, such as sorafenib, pegylated liposomal doxorubicin, and pazopanib, for symptomatic disease progression of fibromatosis
- Radiotherapy and other local ablative therapies for fibromatosis at critical sites
- Surgery alone for localized tenosynovial giant cell tumor (TGCT), although the role for surgery in diffuse disease is less clear
Recent Guidelines
The most recent guidelines for the management of soft tissue sarcomas, including desmoid fibromatosis and TGCT, recommend a multidisciplinary approach with regular surveillance and prompt evaluation of suspicious findings 1. The guidelines also recommend systemic treatments, such as sorafenib, pegylated liposomal doxorubicin, and pazopanib, for symptomatic disease progression of fibromatosis, and radiotherapy and other local ablative therapies for fibromatosis at critical sites.
From the Research
Non-GI Malignancy with Gardner Syndrome
- Gardner syndrome is a variant of familial adenomatous polyposis (FAP) that results in numerous external and internal symptoms, including gastrointestinal polyps, osteomas, tumors, and epidermoid cysts 2.
- Desmoid tumors are a common manifestation of Gardner syndrome, and they can be challenging to manage, especially when they are unresectable or recur after surgery 3, 4, 5, 6.
- Non-GI malignancies associated with Gardner syndrome include desmoid tumors, osteomas, and epidermoid cysts, as well as an increased risk of thyroid cancer and other extra-colonic malignancies 2.
- Treatment options for non-GI malignancies in Gardner syndrome include surgery, radiotherapy, and chemotherapy, depending on the location, size, and number of tumors 3, 4, 5, 6.
- Radiofrequency ablation (RFA) is a promising option for the management of extraabdominal desmoid tumors in patients with Gardner syndrome, as it is less invasive and expensive than surgical resection 5.
- Close follow-up and regular clinical examinations, along with imaging studies, are essential to detect any signs of tumor recurrence or new tumor development in patients with Gardner syndrome 6.
Desmoid Tumors in Gardner Syndrome
- Desmoid tumors are benign, myofibroblastic stromal neoplasms that are common in Gardner syndrome 5.
- They can occur in various locations, including the abdominal wall, mesenteric root, and extraabdominal sites such as the breast 6.
- Surgical resection is the primary treatment for desmoid tumors, but it can be challenging, especially when the tumors are large or located in difficult-to-reach areas 3, 4, 6.
- Adjuvant radiotherapy and chemotherapy may be used to reduce the risk of recurrence or to treat unresectable tumors 3, 4.