New Combination Therapy for Anal Cancer: Isolated Hypoxic Pelvic Perfusion with Electroporation Leads to Complete Remission in All Treated Patients

A new, gentler combination therapy for the treatment of anal cancer has been developed at the Medias Clinic, which has shown encouraging results in a clinical case series. The aim of this method is to treat the tumors in a targeted manner with minimal side effects. The therapy combines isolated hypoxic pelvic perfusion (HPP) with reversible electroporation and led to complete tumor remission in all four treated patients. The remarkable aspect: Even recurrences after unsuccessful radiochemotherapy could be treated in an organ-preserving manner.

Squamous cell carcinoma of the anus affects approximately 2,500 people annually in Germany and accounts for about two percent of all gastrointestinal tumors. While standard radiochemotherapy yields good remission rates in many cases, it can cause significant side effects, including mucosal inflammation and skin reactions. Furthermore, in cases of relapse, surgery resulting in a permanent colostomy is often the only remaining option.

Precise drug delivery through isolated perfusion and electroporation

The two-stage procedure developed at Medias Clinic first isolates the blood supply to the pelvis from the general circulatory system using strategically placed stop-flow balloon catheters. Chemotherapy is then delivered directly to the tumor region via these catheters in rhythmic pulses. The five-minute interruption of normal blood flow creates hypoxic perfusion in the pelvis. This allows for extremely high drug concentrations to be achieved in the tumor area, which would not be possible with conventional therapy.

Additionally, reversible electroporation is used: Short electrical pulses are delivered via specially placed electrodes, temporarily making the tumor cells more permeable to the chemotherapeutic agents. The drugs are administered precisely during these electrical pulses, allowing them to penetrate the cancer cells even more effectively. Subsequent chemofiltration removes excess cytostatic drugs from the blood, thus minimizing systemic side effects for the patients.

Complete remission in all treated patients

The effectiveness of this innovative method was demonstrated in a clinical case series.

The medical team led by Prof. Dr. Karl R. Aigner, Chief Physician and Medical Director at the Medias Clinic, treated four patients with HPV-positive anal cancer: Two initially untreated G3 carcinomas (poorly differentiated, aggressive tumors) received isolated pelvic perfusion and achieved complete remission after two to three cycles.

Clinical-histological remission. Two recurrent G2 carcinomas (moderately differentiated tumors) after unsuccessful radiochemotherapy were treated with a combination of isolated pelvic perfusion and electroporation (electrochemotherapy) and also achieved complete tumor regression.

The documented disease-free intervals were 8, 10, 27, and 48 months. The therapy did not cause any serious hematological, gastrointestinal, or dermatological toxicities, and there was no therapy-related impairment of quality of life. This stands in stark contrast to conventional radiochemotherapy, where the 5-year survival rate is between 65 and 79 percent, and which is sometimes associated with significant long-term effects.

Applications and outlook

The case series suggests that the new combination therapy could represent an effective and, at the same time, gentler alternative to established radiochemotherapy for anal cancer. The method is particularly relevant for patients with primary, locally advanced tumors, therapy-resistant carcinomas, or local recurrences, for whom surgery with a permanent colostomy was often the only option until now.

“Despite the small cohort, the results are very encouraging. The case series is currently being continued,” explains Prof. Dr. Karl R. Aigner, Medical Director and Chief Physician at Medias Clinic. “The crucial point for us is that we can offer patients an organ-preserving alternative that causes hardly any side effects. This is a major difference compared to conventional radiochemotherapy, where about half of the patients have to interrupt treatment due to severe side effects."

Isolated hypoxic pelvic perfusion combined with electroporation allows for high local drug exposure with minimal systemic toxicity. However, further prospective studies with larger patient numbers are needed to evaluate the efficacy and safety of this method compared to established radiochemotherapy.

Further information on the study can be found here: Aigner, K.; Hendrikx, MJH; Bekrentchir, A.; Aust, H. Isolated hypoxic pelvic perfusion combined with electroporation is a valid alternative to traditional therapies for anal squamous cell carcinoma: a case study. Front. Oncol. 2025, 15, 1644317. doi: 10.3389/fonc.2025.1644317