Cryotherapy shows promise against extra-abdominal desmoid tumours

Cryotherapy is a safe and effective treatment approach for extra-abdominal desmoid tumours, achieving clinical efficacies comparable to traditional therapies, according to a recent Singapore study.

“The estimated pooled proportion of nonprogressive disease rate … is comparable to current front line or alternative therapies, although the lack of long-term data and heterogeneity of response criteria used by the selected studies in the review must be taken into consideration,” the researchers said.

“Additionally, varying methods were used to assess tumour volume by the different studies, which could affect accuracy in tumour volume computation,” they added. Nevertheless, despite such lack of standardization, the results suggest that cryoablation could help reduce symptom burden and, in turn, boost patient quality of life.

The present systematic review and meta-analysis drew a total of nine studies (all nonrandomized and eight were retrospective in design) from online databases of Medline and the Cochrane Central Register of Controlled Trials. Only those enrolling ≥10 patients, administered treatment with curative and/or palliative intent, and imposed no restrictions on the type of cryoprobe design were eligible for enrolment.

The Downs and Black checklist was used to assess the quality of the enrolled study. It found a mean quality score of 10.4 points over 14, suggestive of good to high quality. No study was able to exceed 12 points of 14. All funnel plots generated had visible asymmetry, indicating the potential for publication bias. [PLoS One 2021;doi:10.1371/journal.pone.0261657]

Cumulatively, the studies yielded a sample of 214 patients with 234 extra-abdominal desmoid tumours. In total, 282 cryoablation procedures were performed from 2004–2020. During this time, 2.4 percent to 14.2 percent of patients developed major complications for all procedures, while minor complications had prevalence rates ranging from 4.8 percent to 23.3 percent.

The respective cumulative rates for major and minor complications were 4.2 percent and 10.2 percent. No deaths were reported. Nerve injuries were the most common type of major complication, most of which reached near-complete to complete recovery within 4 months to 2 years. Common minor complications included frostbite, pain, haematomas, and swelling.

In terms of efficacy, cryotherapy led to an estimated pooled proportion of nonprogressive disease of 85.8 percent. Meanwhile, the resulting 1-year progression-free survival rate was 84.5 percent, dropping slightly to 78.0 percent at 3 years.

Similarly, cryotherapy yielded good pain control outcomes. For instance, of patients with visual analogue scale pain ratings ≥3 at baseline, 87.5 percent of patients reported a decrease of ≥3 points after cryotherapy. In addition, 37.5 percent of participants experienced partial or complete symptom relief.

“A key advantage of cryoablation, over other ablation techniques, is that the ice ball can be monitored with imaging, resulting in low complication rates,” the researchers said. However, “not all extra-abdominal sites are technically feasible for cryoablation, with a craniofacial location deemed excessively high risk for neurovascular and cutaneous complications. Common complications include common peroneal nerve injury and skin necrosis.”

Operators and physicians should take extra precaution when applying cryotherapy in these high-risk extra-abdominal locations, they added. Future studies employing high-quality data reporting protocols and longer-term observation windows are needed.