Liver Metastases (Liver Secondary)

Currently surgical removal (i.e. resection/ metastectomy/ hepatectomy) is the preferred treatment option in view of its potential of long-term survival and chance of cure.

When resection is not technically feasible due to advanced disease, other modalities may utilized to either reduce (‘shrink’) the size of CLM (e.g. chemotherapy for downstaging of liver metastases), or induce liver hypertrophy of the likely liver remnant (portal vein embolization) and local ablative therapies (radiofrequency ablation) for multiple small LM.

All modalities are aimed at making safe liver resection feasible.

A tumor-free margin of1-cm is desirable for resection of CLM. However, several recent studies have demonstrated that R0 resection with ≥1 mm margin is also adequate particularly when the tumor is close to major blood vessels. Deeply situated or large or multiple CLM frequently require removal of large volume of liver. Liver resection is deemed technically safe as long as 2 contiguous segments of adequate volume (1% of total body weight) with intact biliary drainage and vascular inflow / outflow can be preserved in an otherwise healthy liver (i.e. not significantly affected by cirrhosis or fatty liver or previous chemotherapy).

Proper patient selection is the most important step for reduction of postoperative complications. The important aspects of preoperative workup of patients for major liver resection include:

1.   Assessment of fitness for major surgery
2.   Rule out extrahepatic disease i.e. metastatic tumor in other sites. High resolution CT scan of the chest may be performed to rule out lungs metastasis. A whole body PET-CT scan may also be performed to rule out tumor spread to other organs such as brain. However, PET CT scan is not a substitute for good quality CT of the abdomen.
3.   Assessment of feasibility of margin negative resection for CLM. A triple phase CT scan of the abdomen & pelvis is essential for this purpose.
4.   Assessment of liver function for major resection

a.   Functional status of the liver: Child – Pugh classification is a simple and reliable for this purpose.
b.   Future liver remnant volume (FLRV): Assessed at CT volumetry

In present era, novel surgical strategies such as staged hepatectomy or multiple parenchymal resections combined with local ablative therapies e.g. radiofrequency ablation have been successfully used to treat patients with multiple lesions / bilobar disease.

In patients where R0 resection appears doubtful or prognostic criteria are not favourable then neoadjuvant chemotherapy should be considered.

One of the three different surgical approaches in combination with chemotherapy may be applicable in this setting:

– Colorectal cancer (CRC) surgery followed by liver resection
– Liver first approach (resection of liver metastasis followed by resection of primary of CRC)
– Single stage surgery includes simultaneous CRC & liver resection

The decision regarding sequence of surgery should be individualized and is best determined by multi-disciplinary team.

In select patients with limited extrahepatic disease surgery is feasible and is associated with improved survival. Lung metastasis along with CLM has more favourable prognosis in comparison to peritoneal, periportal or paraaortic nodal metastasis.

Last two decades have witnessed many significant advances in surgical techniques and chemotherapy for colorectal cancers. Owing to these advancements CLM patients in whom surgery is feasible, have 5-year & 10-year survival rate of up to 40% & 25% respectively.