5 things you should know about: Treatment of desmoid tumors

Desmoid tumors (DTs) are rare. They account for less than 3% of all soft tissue tumors. DTs are histologically benign proliferations of stromal cells but may grow locally aggressive. They are classified as a non-metastasizing, intermediate malignant tumor and they can be characterized clinically by a variable and often unpredictable course. The molecular events that lead to desmoid tumor formation are incompletely understood. However, increasing evidence points to involvement of the APC gene and beta-catenin in the molecular pathogenesis of desmoids both in Gardner syndrome as well as in sporadic desmoids . Antecedent trauma has been described in up to 30% of patients with DTs. Most commonly from surgical interventions in patients with FAP. DTs have been associated with high estrogen states and extra-abdominal and abdominal desmoids tend to occur in females during or following pregnancy.

First line treatment for most patients should start with active surveillance with initial MRI or CT as an alternative. Some may think that a resectable tumor should be treated with surgery upfront, however, up to 50 to 60% do not grow after diagnosis, also 20 to 30% may shrink and even disappear after initial progression. Pain control and quality of life are to be considered the 2 priorities in the overall management strategy of patients with desmoid tumors. In case of progressive symptoms or persistent growth, intervention might be 1 considered and assessed with further assessments and possibly not before 1 year after initial diagnosis. This avoids overtreatment in patients who could spontaneously regress and avoids interventions for stable disease. If the desmoid tumor location is close to critical structures, an earlier decision towards therapy can be made.

The review by Kasper et al. is discussed, summarizing the latest guidelines to desmoid tumor management.