Treating patients with colon cancer liver metastasis: A nationwide analysis of therapeutic decision making

Background. Criteria for resectability of colon cancer liver metastases (CLM) are evolving, yet little is known about how physicians choose a therapeutic strategy for potentially resectable CLM. Methods. Physicians completed a national Web-based survey that consisted of varied CLM conjoint tasks. Respondents chose among three treatment strategies: immediate liver resection (LR), preoperative chemotherapy followed by surgery (C → LR), or palliative chemotherapy (PC). Data were analyzed by multinomial logistic regression, yielding odds ratios (OR). Results. Of 219 respondents, 79 % practiced at academic centers and 63 % were in practice ≥10 years. Median number of cases evaluated was four per month. Surgical training varied: 51 % surgical oncology, 44 % hepatopancreato- biliary/transplantation, 5 % no fellowship. Although each factor affected the choice of CLM therapy, the relative effect differed. Hilar lymph node disease predicted a strong aversion to LR with surgeons more likely to choose C → LR (OR 8.92) or PC (OR 49.9). Solitary lung metastasis also deterred choice of LR, with respondents favoring C → LR (OR 4.43) or PC (OR 6.97). After controlling for clinical factors, surgeons with more years in practice were more likely to choose PC over C → LR (OR 1.94) (P = 0.005). Surgical oncology-trained surgeons were more likely than hepatobiliary/transplant-trained surgeons to choose C → LR (OR 2.53) or PC (OR 4.15) (P<0.001). Conclusions. This is the first nationwide study to define the relative impact of key clinical factors on choice of therapy for CLM. Although clinical factors influence choice of therapy, surgical subspeciality and physician experience are also important determinants of care.