Radiotherapy improves outcomes in anal margin cancer

Radiation treatment boasts of high locoregional control of anal margin cancer, as well as positive outcomes in the long term, according to a study.

The authors compared relevant literature with 38 patients (median age 51 years) in a local institution who were treated with radiotherapy from 1979 to 2019. Based on the American Joint Committee on Cancer staging, four patients had T1, 22 had T2, and 12 had T3 at the time of diagnosis. Nodal staging distribution was as follows: N0=33; N1=2; N2=2; N3=1.

Radiation dose had a median of 56 Gy/30 fractions. Five and 29 patients received nodal radiation for node positivity and elective nodal radiation, respectively, while another 29 had perineal boost. In addition, concurrent chemotherapy was given to 27 patients.

Isolated local recurrence occurred in three patients, isolated inguinal node recurrence in two, and distant metastases in two, of whom one also experienced local and regional recurrence.

Ten-year disease-free survival (DFS) was 87 percent, cause-specific survival was 92 percent, and overall survival was 68 percent. One patient failed to complete radiation treatment and four had unexpected treatment breaks, while two received salvage abdominoperineal resections.

At last follow-up, 17 patients remained alive and showed no evidence of disease, while two were alive but with anal margin cancer present. Additionally, three patients died with anal margin cancer present at 11, 18, and 21 months from radiation therapy, while 16 succumbed to intercurrent disease. Median follow-up was 6.6 years.

Notably, age ≥51 years correlated with worse locoregional control (p=0.018) and DFS (p=0.0233). Male patients had worse DFS (p=0.0311), while patients living with HIV had poorer overall survival (p=0.006).