In the last two decades, the indications for liver surgery have greatly expanded. The combined advances in surgical technique and systemic chemotherapy have rendered many patients candidates for a curative treatment, notably in cases of colorectal cancer with liver metastasis (CRLM). Furthermore, with studies proving a survival benefit when achieving a complete resection, and with advances in thermal ablation techniques allowing a combined surgical-percutaneous approach, there has been a notable expansion in the eligibility criteria for surgical interventions particularly in regard of the number and location of metastases [[1], [2], [3]].

The enthusiasm from the observed improved survival in cases where a complete resection is achieved has pushed oncologists and surgeons to explore a potential role for surgical intervention in patients where an R0 resection is not possible. In fact, while surgery in such cases has historically been considered contraindicated, a concept of cytoreductive or “debulking” liver surgery has recently emerged and is becoming today a topic of major interest with the tremendous results observed with current systemic treatments in terms of disease regression and long-term stabilization in patients with colorectal cancer with unresectable liver metastasis.

A retrospective study looked at the benefit of an interventional palliative treatment in patients with unresectable colorectal liver metastases, comparing patients receiving systemic treatment alone to patients receiving systemic and local palliative treatment (surgery, radiofrequency ablation and radiotherapy). Median overall survival was significantly longer in the latter group, 19.8 months vs 38.7 months respectively (p < 0.01) [4]. The prospective phase II CLOCC study comparing patients receiving systemic chemotherapy alone to those receiving further palliative radiofrequency ablation identified a significant difference in progression free survival (PFS) rate at 3 years, 10.6% vs 27.6% respectively (p = 0.025) [5]. Moreover, in a series of 165 patients receiving debulking liver surgery, Tanaka et al. suggested a potential survival benefit in patients with multiple bilobar metastases especially in cases that exhibit a good response to the induction systemic treatment [6].

These data suggest a potential role for a palliative interventional treatment challenging the dogma of surgical contraindication when a complete resection is not achievable. However, the literature remains poor on the matter rendering not only the benefit of a debulking liver surgery unclear, but further, the criteria for patient selection and decision-making unknown. This study aims at evaluating the benefit of liver debulking surgery in cases of unresectable colorectal liver metastases as well as identifying relevant individual factors as to aid in patient selection and decision making.