Multimodality Therapy Including Salvage Surgical Resection and Intraoperative Radiotherapy for Patients with Squamous-cell Carcinoma of the Anus with Residual or Recurrent Disease After Primary Chemoradiotherapy

Background: For patients with residual or recurrent squamous-cell carcinoma of the anus after primary chemoradiotherapy, the standard treatment is surgical salvage. Patients with unresectable or borderline unresectable disease have poor outcomes, thus adjunctive treatments should be explored.

Objective: The aim of this study is to report outcomes for patients with residual/recurrent anal cancer treated with multimodality therapy including salvage surgical resection and intraoperative radiotherapy.

Design: This is an observational study.

Settings: This study was conducted at a tertiary referral center.

Patients: Thirty-two patients were treated between 1993 and 2012. Median age was 53 years (range, 34-87). Salvage treatment was performed for residual disease (n = 9), first recurrence (n = 17), or second recurrence (n = 6) after primary chemoradiotherapy.

Interventions: Patients with recurrent disease received preoperative external beam reirradiation with concurrent chemotherapy. All patients underwent salvage surgical resection and intraoperative radiotherapy. Extent of surgical resection was R0 (negative margins, n = 16), R1 (microscopic residual, n = 13), or R2 (macroscopic residual, n = 3). The median intraoperative radiotherapy dose was 12.5 Gy.

Main Outcome Measures: Treatment-related adverse events were classified according to the National Cancer Institute - Common Toxicity Criteria. Overall and disease-free survival were estimated by using the Kaplan-Meier technique. Central, local-regional, and distant failure were estimated by the use of the cumulative incidence method.

Results: Median length of hospital stay was 9 days. Mortality at 30 days after surgery and intraoperative radiotherapy was 0%. Fifteen patients (47%) experienced a total of 16 grade 3 treatment-related adverse events (wound complication (n = 6), bowel obstruction (n = 5), and ureteral obstruction (n = 3)). The 5-year estimates of overall and disease-free survival were 23% and 17%. The 5-year estimates of central, local-regional, and distant failure were 21%, 51%, and 40%.

Limitations: This was a single-institution observational study with limited patient numbers.

Conclusions: In this heavily pretreated, high-risk patient population, multimodality therapy including salvage surgery and intraoperative radiotherapy was associated with long-term survival in a small, but significant subset of patients.