Surgery plus RT improves outcomes in cutaneous adnexal carcinoma

Surgical resection and adjuvant radiotherapy (RT) show effective control of cutaneous adnexal carcinoma (CAC), a rare skin cancer with no established treatment guidelines, while definitive RT does not, a study has found.

Forty-nine patients (mean age 65 years) were included in the study, most of whom had head and neck tumours. The common subtypes were as follows: adnexal adenocarcinoma, sebaceous carcinoma, and microcystic adnexal carcinoma.

The median overall survival was 44 months over a median follow-up of 41 months for survivors. Among 22 patients with de novo cancer treated with surgery plus RT, progression-free survival (PFS) was 77 percent and overall survival (OS) was 95 percent at 2 years.

In addition, 2-year local recurrence (LR), regional recurrence (RR), locoregional recurrence (LRR), and distant metastasis (DM) were 5 percent, 0 percent, 5 percent, and 10 percent, respectively. All LRR events occurred outside the irradiated area.

On the other hand, the nine patients with de novo cancer who received definitive RT had 2-year PFS and OS of 30 percent and 67 percent, respectively. The corresponding LR, RR, LRR, and DM were 46 percent, 13 percent, 55 percent, and 40 percent. All LRR events occurred within the irradiated area.

Notably, LR occurring within the irradiated volume correlated with immunosuppression. In addition, inferior outcomes were observed among patients treated at recurrence.

“Novel strategies are needed to improve outcomes in patients receiving definitive RT,” the authors said. 

This study included patients diagnosed with CAC between 2000 and 2020 who received RT. The authors used Kaplan-Meier methods to measure time to LR, RR, LRR, DM, and PFS. They also used Fisher exact test to compare frequency distributions.