Metastatic Colorectal Cancer to the Liver: Involve the Surgeon Early and Often

Hepatic resection for limited metastatic colorectal cancer to the liver (CRLM) is a surgical success story. An associated long-term survival after resection of CRLM has been known for decades. Furthermore, it has now been demonstrated that complete resection of limited CRLM is associated with cure, meaning alive and free of disease 10 years after resection. In most modern series, 5-year survival rates after complete resection are more than 50 % with actual cure rates estimated to be as high as 20– 25 %. For example, at Memorial Sloan Kettering Cancer Center patients with limited CRLM treated on trial with adjuvant hepatic artery infusional (HAI) floxuridine (5FUDR) and systemic 5-fluorouracil (5-FU) had 5and 10year survival rates of 59 and 40 %, respectively. More recently, in our patients treated on trial with adjuvant HAI and modern systemic chemotherapy, the 5-year survival rate has increased to greater than 70 %. While selection bias has an impact on some of the overall survival statistics, the potential for cure truly drives the incentive to operate. An important point also is that hepatic resection is now a safe procedure. Many may recall the days of massive blood loss and high mortality rates, but currently hepatic resection for metastases is performed with low blood loss and mortality rates of approximately 1 %. Chemotherapy for metastatic colorectal cancer has significantly improved during the past two decades. Response rates in excess of 50 % are commonly reported and 5-year survival rates approaching 10 % are seen in selected patients on trials. Unfortunately, systemic chemotherapy alone does not cure patients with CRLM and mandates chronic therapy. Interestingly, this improvement in outcomes seen in patients with unresectable disease has not translated into an improved survival when systemic therapy is given as an adjuvant following hepatic resection. This has now been shown in four randomized trials. Therefore, hepatic resection for limited liver-only metastatic colorectal cancer is the only potentially curative treatment option. In this nicely written manuscript by Krell et al., it is well demonstrated that medical oncologists (at least in Michigan) are not consistent in their referral practices for patients with CRLM. The majority of the surveyed oncologists work in a community setting that is likely representative of most of the country. Another interesting point is that approximately one-third of the oncologists stated that they did not have a liver surgeon whom to refer patients. As in most good studies, the authors demonstrate some simple but important points. The heterogeneity in referral practices is staggering. Referral rates to liver surgeons range from nearly never to nearly always. Single prognostic factors are commonly used by these oncologists to help decide whether to refer a patient. Many (approximately 40 % of respondents) consider metastasis size and presence of bilateral disease each to be contraindications to hepatic resection. This is troubling, because neither of these findings alone precludes cure or long-term survival. As an example, if a patient presents 2 years after resection of a node-negative primary colon cancer with two or three small hepatic metastases that happen to be on both sides of the liver (bilateral), many of the surveyed oncologists stated that they would not refer to a surgeon. This patient’s disease is potentially curable and should be assessed by a hepatic surgeon. It is unclear why patients are not being referred; is it lack of a liver surgeon in the oncologist’s practice area? Is it misinformation or misconceptions about Society of Surgical Oncology 2015