Study: High recurrence, metastasis rates of dermal neoplasms call for close follow-up

Key takeaways:

• Five-year local recurrence rates were 10% and 17% for atypical fibroxanthoma and pleomorphic dermal sarcoma, respectively.
• Five-year risk for metastasis was 0.8% and 16%, respectively.

High rates of recurrence and metastasis associated with mesenchymal dermal neoplasms — specifically pleomorphic dermal sarcoma — should prompt dermatologists to follow-up with their patients more often, according to a study.

“Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are mesenchymal dermal neoplasms and together, they are considered a spectrum disease,” Mathias Ørholt, MD, of the department of plastic surgery and burns treatment at Copenhagen University Hospital in Denmark, and colleagues wrote. “The current consensus is that AFX is an intermediate-risk tumor which is locally aggressive, but rarely metastasizes, whereas PDS is an aggressive tumor with a high risk of local recurrence and metastasis.”

Eight out of every 1 million people will get AFX each year, whereas only 1.5 out of every 1 million people will annually get PDS.

Currently, there are no standardized follow-up programs for this disease and the prognosis of patients over long periods remains uncertain. To recommend a follow-up program, the authors analyzed local disease recurrence and metastasis rates in patients with AFX and PDS using data from the Danish National Registries.

The authors collected data on 1,118 patients with AFX (n = 945; median age, 77.6 years; 79% men) or PDS (n = 173; median age, 78.4 years; 74% men) with a median follow-up of 7.3 years.

AFX recurrence and metastasis

Results showed that the 5-year risk for local recurrence was 10% for AFX with most recurrences occurring within 4 years (92%) and 5 years (94%). Only 1% of patients with AFX had a PDS recurrence.

The risk for metastasis for patients with AFX was very rare, according to the authors, with the 5-year risk being 0.8% (95% CI, 0%-1.4%) and the 10-year risk being 1.1% (95% CI, 0%-1.9%). Metastases that developed in the eight patients with AFX included regional and distant sites, with three experiencing metastases in the regional lymph nodes and five experiencing pulmonary metastases.

PDS recurrence and metastasis

The 5-year recurrence rate for PDS, on the other hand, was much higher at 17% (95% CI, 11%-23%). This rate only increased to 18% after 10 years (95% CI, 12%-24%). Of the PDS patients that had a local recurrence, 93% had the recurrence in the first 3 years.

The risk for metastasis for patients with PDS was 16% (95% CI, 10%-22%) with 92% of metastasis cases occurring within 3 years. Fifty percent of distant PDS metastasis cases included the lungs as the primary metastasis site followed by the brain (4%). As far as locoregional metastases, sites included the skin or deep tissue (25%), bone (7%), the parotid gland (7%) and regional lymph nodes (7%).

Follow-up program

According to the authors, dermatologists can limit their clinical visit follow-ups to 4 years for AFX patients. On the other hand, dermatologists should conduct clinical visits with their PDS patients paired with PET/CT scans twice a year for the first three years, the authors wrote, followed by a clinical visit and scan once a year for at least 1 year.