RF ablation may prolong OS in unresectable CRC with liver metastases
The addition of aggressive local ablation to systemic therapy may extend overall survival (OS) in patients with unresectable colorectal cancer (CRC) with liver metastases compared with systemic therapy alone, according to a phase II trial.
Researchers randomized 119 patients with unresectable CRC with liver metastases without extrahepatic disease to receive systemic treatment alone (n=59) or combined modality consisting of systemic treatment plus aggressive local radiofrequency ablation (RFA) with or without resection (n=60). [J Natl Cancer Inst 2017;doi:10.1093/jnci/djx015]
OS rates were higher in the combined modality vs systemic treatment arm at 3 years (56.9 percent vs 55.2 percent), 5 years (43.1 percent vs 30.3 percent), and 8 years (35.9 percent vs 8.9 percent), which translated to a significant improvement in OS when aggressive treatment was added to systemic therapy (hazard ratio, 0.58, 95 percent confidence interval, 0.38–0.88; p=0.01).
The improved outcomes clearly reflected the benefit of the combined treatment approach on OS, noted the researchers. “This encourages the early integration of local ablative techniques alone or in combination with surgical resection in patients with unresectable CRC [with] liver metastases,” they said.
After an extended follow-up of 9.7 years, median OS was 45.6 months and 40.5 months in the combined modality and systemic treatment arms, respectively.
Surgery remains the ‘gold standard of treatment’ in patients with resectable CRC with liver metastases. However, factors such as extensive tumour size or poor anatomical position such as proximity to critical vascular and/or biliary structures preclude resection, confining unresectable cases to systemic therapy, said the researchers.
“[Although] the goal [is to improve] survival or potentially convert patients into resection candidates … the realistic goal of systemic treatment remains palliative,” they added, hence the incorporation of more aggressive therapeutic modalities such as RFA for unresectable cases.
The researchers acknowledged the small sample size as a limitation, as it was difficult to eliminate the possibility of small imbalances in baseline characteristics such as the number of lesions or synchronicity. “A larger sample size would have offered better protection against possible risks of imbalances between treatment arms and a better reassurance on the external validity of the results,” they said.