Desmoid Tumors: Current Perspective and Treatment

Desmoid tumors are rare tumors with a tendency to infiltrate locally. The lack of a standard treatment approach makes choosing the most appropriate treatment for patients challenging. Most experts recommend watchful observation for asymptomatic patients as spontaneous regression of tumor is observed in up to 20% of patients. Upfront resection of the desmoid tumor has fallen out of favor due to high morbidity and high relapse rates associated with the tumor. Systemic therapy has evolved over several decades. Where chemotherapy, hormonal therapy, and non-steroidal anti-inflammatory drugs were used over the last several decades, tyrosine kinase inhibitors came to the forefront within the last decade. Most recently, gamma-secretase inhibitors have shown significant clinical benefit in patients with desmoid tumors, bringing forth an entirely new mechanistic approach. Several Wnt pathway inhibitors are also under development. Invasive approaches like cryoablation have also shown clinical benefit in patients with extra-abdominal desmoid tumors in recent years. The recent approval of nirogacestat has ushered in a new era of treatment for patients diagnosed with desmoid tumors. Several new molecules are expected to be approved over the coming years.

Desmoid tumours are benign but locally aggressive mesenchymal neoplasms that occur most commonly in the abdomen, with the potential to invade surrounding structures causing significant morbidity. Lateral abdominal wall defects are known to be more challenging and less frequently encountered compared to ventral abdominal wall defects. Asymmetric forces caused by contraction of remnant rectus and contralateral oblique muscles increase the risk of herniation postoperatively. We report a case of a challenging abdominal wall reconstruction after desmoid tumour resection in a 62-year-old male patient who presented to our hospital with a progressively enlarging left upper back lump of 6 months duration. A venous supercharged pedicled anterolateral thigh flap was combined with PROLENE® mesh for reconstruction, and the patient recovered well with good functional and aesthetic outcomes at 2-year follow-up. The pedicled anterolateral thigh flap with venous supercharging can be effectively used for the reconstruction of extensive lateral abdominal wall defects.

Background: Desmoid tumors are fibroblastic lesions which often have an unpredictable and variable clinical course. In the context of familial adenomatous polyposis (F.A.P.), these frequently occur intra-abdominally, especially in the small-bowel mesentery resulting in sepsis, fistulation, and invasion of the abdominal wall and retroperitoneum. In selected cases where other modalities have failed, the most radical option is to perform a total enterectomy and intestinal transplantation (ITx). In this study, we present our center’s experience of ITx for desmoid in patients with FAP.

Methods: We performed a retrospective review of our prospectively collected database between 2007 and 2022. All patients undergoing ITx for F.A.P.-related desmoid were included.

Results: Between October 2007 and September 2023, 144 ITx were performed on 130 patients at our center. Of these, 15 patients (9%) were for desmoid associated with F.A.P. (7 modified multivisceral transplants, 6 isolated ITx, and 2 liver-containing grafts). The median follow-up was 57 mo (8-119); 5-y patient survival was 82%, all with functioning grafts without local desmoid recurrence. These patients presented us with several complex surgical issues, such as loss of abdominal domain, retroperitoneal/abdominal wall involvement, ileoanal pouch-related issues, and the need for foregut resection because of adenomatous disease.

Conclusions: ITx is a viable treatment in selected patients with F.A.P. and extensive desmoid disease. The decision to refer for ITx can be challenging, particularly the timing and sequence of treatment (simultaneous versus sequential exenteration). Delays can result in additional disease burden, such as secondary liver disease or invasion of adjacent structures.

Extra-abdominal desmoid-type fibromatosis (EADTF) is a rare neoplastic condition of monoclonal fibroblastic proliferation characterized by local aggressiveness with a distinct tendency to recur. Although EADTF is a benign disease entity, these tumors have a tendency to infiltrate surrounding normal tissues, making it difficult to completely eliminate them without adjacent healthy tissue injury. Surgical excision of these locally aggressive tumors without clear resection margins often leads to local recurrence. The aim of this thorough review was to assess the current treatment concepts for these rare tumors. A comprehensive search of articles published in the Cochrane Library, MEDLINE (PubMed), and EMBASE databases between January 2008 and February 2023 was conducted. Surgical intervention is no longer the first-line approach for most cases; instead, strategies like active surveillance or systemic therapies are used as initial treatment options. With the exception of EADTFs situated near vital structures, a minimum of 6-12 months of active surveillance is currently advocated for, during which some disease progression may be considered acceptable. Non-surgical interventions such as radiation or cryoablation may be employed in certain patients to achieve local control. The currently preferred systemic treatment options include tyrosine kinase inhibitors, low-dose chemotherapy, and gamma-secretase inhibitors, while hormone therapy is not advised. Nonsteroidal anti-inflammatory drugs are utilized primarily for pain management.

A desmoid tumor (DT) is a rare benign neoplasm arising from muscle aponeurosis, associated mostly with trauma or pregnancy. DT has an infiltrative and locally aggressive growth pattern and usually does not metastasize. However, it has a high recurrence and complication rate. When it occurs in pregnancy, the pregnancy and delivery is taken as an individual case for optimal management by physicians and midwifes, who need to be cautious in finding the optimal delivery mode for the patient, which depends on the tumor size, location, behavior, and past history. The authors report a case of 29-year-old pregnant woman who previously underwent systemic oncological treatment for a large abdominal wall desmoid tumor and became pregnant afterwards. The history of DT presented a follow-up and delivery challenge. Observational management was chosen with an elective cesarean section at week 38 + 4 of pregnancy with uncomplicated postpartum follow-up. The authors detail the clinical management and chosen therapeutic approach; chemotherapy can be a choice in the treatment options for patients with DTs, although the majority of DTs are treated surgically with subsequent mesh plastic. Moreover, the authors provide a systematic review of the literature focused on the treatment management of DTs in pregnant women during pregnancy and the postpartum period, as pregnancy-associated desmoid tumors are a specific condition, where the optimal management is not well established, despite some guidelines for non-pregnant patients.

Purpose: Desmoid tumor (DT) is a rare monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Initial active surveillance is recommended by current guideline, and surgery is one of the main therapies for DT. Predicting the prognosis and outcome of active surveillance for intra-abdominal DT is pressing issue.

Methods: The study included eighteen patients with intra-abdominal DT. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were measured. We analyzed their relationship with the outcome of active surveillance, as well as clinical, prognostic, and pathological data.

Results: The MTV and TLG of recurrent DT were significantly higher than those of non-recurrent DT (P < 0.001 and P = 0.00, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing recurrent DT from non-recurrent DT were 760.8 for MTV (sensitivity = 1, specificity = 0.857 and AUC = 0.929), and 1318.4 for TLG (sensitivity = 1, specificity = 0.786, and AUC = 0.911). The cutoff values of MTV and TLG significantly correlated with PFS using the Kaplan-Meier method (P = 0.002 and P = 0.007, respectively). MTV and TLG could distinguish DTs with subsequent progression from stable ones (P = 0.004 and P = 0.004, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing DTs with subsequent progression from stable ones were 197.1 for MTV (sensitivity = 0.9, specificity = 1, and AUC = 0.900), and 445.45 for TLG (sensitivity = 0.9, specificity = 1, and AUC = 0.900). Conclusion: Volume-based 18F-FDG-PET can predict prognosis of intra-abdominal DT. MTV and TLG can predict the outcome of active surveillance for intra-abdominal DT. MTV and TLG can potentially be predictors of surgical risk and difficulty.