Multidisciplinary palliation for unresectable recurrent rectal cancer: Hypoxic pelvic perfusion with mitomycin C and oxaliplatin in patients progressing after systemic chemotherapy and radiotherapy, a retrospective cohort study

Background: Innovative systemic treatments and loco-regional chemotherapy by hypoxic pelvic perfusion (HPP) have been proposed for unresectable recurrent rectal cancer (URRC). Regorafenib and trifluridine-tipiracil reported significantly increased PFS 1.9-2.0 months, OS 6.4-7.1 months vs placebo, respectively. Present study evaluated safety and efficacy of mitomycin/oxaliplatin HPP associated to intravenous cetuximab, and of third line systemic therapy in clinical practice. Methods: HPP consisted of: Isolation, perfusion, chemofiltration. Patients received mitomycin 25 mg/m2 and oxaliplatin 80 mg/m2 during HPP; from days 21 to 28, cetuximab 250 mg/m2/week. In case of partial response or stable disease, HPPs were repeated every 8 weeks. In control group, systemic third and further lines of therapy were defined in clinical practice according to clinical (age, comorbidities, performance status), biological parameters (KRAS, NRAS, BRAF genotype). Results: From 2005 to 2018, 49 URRC patients were enrolled; 33 in HPP/target-therapy, 16 in systemic therapy control group. No HPP related complications were reported. Most common adverse events were skin, bone marrow toxicities. In HPP/ target-therapy group, ORR and DCR were 36.4 and 100%; in systemic therapy control group, 18.7 and 31.25%, respectively. In HPP/target-therapy compared with systemic therapy group, respectively, DCR seemed significantly favourable (P = 0.001), as PFS 8 vs 4 months (P = 0.018), and OS 15 vs 8 months (P = 0.044). Conclusions: Present data showed that integration of HPP/target-therapy may be effective in local control, and efficacy as third line treatment of URCC patients. This therapeutic strategy deserves further prospective randomized trials to be compared to conventional systemic treatments.