Hepatic metastasis from colorectal cancer

Abstract

Colorectal cancer (CRC) is one of the most common cancers in the world. About two third of patients with CRC will develop distant recurrence at some point in time. Liver is the most common site where distant metastasis takes place. While the overall survival (OS) of patients with metastatic CRC was poor about 3 decades ago, there has been tremendous improvement in this area in the recent years. With the advent of effective systemic chemotherapy and biologic agents and better understanding of the biological behaviour of the tumour, aggressive treatment strategies such as metastatectomy of the liver metastases (or lung metastases) are now acceptable. More importantly, it has transformed the way how stage IV CRCs are being managed. From predominantly palliative as the primary aim, a comprehensive multidisciplinary approach is now the mainstay of treatment with very successful outcomes. Combination of systemic therapies with liver resection has been shown to be effective in providing promising survival benefits. In addition, other adjunctive modalities in targeting the liver metastases such as ablation, combining resection and ablation, transarterial chemoembolization, stereotactic body radiotherapy (SBRT), hepatic artery perfusion, etc. have also been demonstrated variable outcome in treating colorectal liver metastasis (CRLM). Very recently, transplant oncologists have also explored using liver transplantation as a treatment modality for unresectable CRLM, which has demonstrated very good long-term survival in well selected cases. The new paradigm in the treatment of metastatic CRC has dawned.

Keywords: Colorectal liver metastasis (CRLM); liver resection; liver targeted therapy; liver transplantation; systemic chemotherapy.

Figure 1

Current treatment options for colorectal liver metastasis.

Figure 2

Potential scenarios of colorectal liver metastasis.

Figure 3

Key considerations in resectability of CRLM. CRLM, colorectal liver metastasis.

Figure 4

Resection of colorectal liver metastasis and attempt to grow the future liver remnant (FLR). (A,B,C) Metastatic lesions appearing as hypodense lesion in the liver parenchyma in segment VIII (A), segment IVb (B) and segment VI of the liver (C). In order to help the patient gained a status of “No evidence of disease”, an extended right hepatectomy was required. Based on the CT volumetry, the remnant left lateral section was too small. (D) Based on the CT volumetry, the remnant left lateral section was too small. The FLR of this liver was on 21% of the total volume. As a result, an ALPPS procedure was proposed. As the lesions were all within the liver parenchyma in the right trisection of the liver and not involving the inflow pedicle to the left lobe, it was technically suitable to perform the ALPPS procedure using full laparoscopic method. (E,F) The FLR of this liver had grown from 21% to 35% within 14 days of the ALPPS procedure. In between, the patient was discharged to rest at home on POD 4 following the first surgery and returned to hospital for a scan to assess the volumetry and then proceeded to the second staged of ALPPS later on. The second stage operation took place on the 14th POD after the first stage and the patient recovered uneventfully.

Figure 5

Resection of liver metastasis from colorectal cancer at difficult location. (A,B,C) The patient has liver metastasis to segment II of the liver. Concurrently, there are two more lesions in segment IVA (B) and caudate lobe of the liver (C). (C) Tumour located at segment I (Caudate lobe) is technically very difficult to resect either open or laparoscopically due to its anatomically location, being situated between the IVC posteriorly and all the inflow structures to the left and right anteriorly. There are plenty of direct branches of PV and bile ducts connected to the caudate lobe e.g., the Spigelian branch of the portal vein.

Figure 6

Repeat resection of CRLM that can still confer survival benefits but each time, making it more difficult to resect the tumours. (A) Patient presented with a solitary CRLM in segment VI/VII of the liver with the primary tumour in situ. After initial 3 cycles of systemic chemotherapy, he underwent posterior sectionectomy and anterior resection of the colon simultaneously. (B) He received another 3 rounds of chemotherapy after the surgery. At 2 years after the initial simultaneous colon and liver resection, he remained free of disease without any chemotherapy. (C) Unfortunately, he was found to have a solitary recurrence in segment V/VIII of the liver and he underwent completion right hepatectomy 2 and a half years after the initial resection of the liver. He received a few more rounds of chemotherapy after that. (D) He remained disease for another 2 years and was found to have another new liver metastasis in segment IVA of the liver at 4 and half years after the initial simultaneous surgery. He opted to have the 3rd liver resection of wedge out the segment IVA lesion. Following that, he has survived for 6 years since the initial diagnosis of stage IV colorectal cancer with liver metastasis. CRLM, colorectal liver metastasis.