Metastatic neoplasms represent the most common malignant tumors of the liver. The relative proportion of primary to secondary neoplasms is estimated to be 1:20. The liver is second only to the regional lymph nodes as site of metastases for tumors. 25% to 50 % of all patients dying of cancer, have been found to have hepatic metastases. 50% of patients with gastrointestinal tumors have hepatic metastases when autopsied.

Metastases appear in the liver at varying times in relation to the primary lesion:

1)       Precocious metastases are evident when the primary lesion is not suspected.

2)       Synchronous to the primary lesion.

3)       Metachronous to the primary lesion.

The growth pattern of the metastatic tumor is frequently more rapid than the original lesion, and the mitotic count of metastatic hepatic neoplasms has been shown to be five times greater than that of the extra-hepatic primary tumor.

Surgical treatment of hepatic metastases should be considered if:

(1)     Control of the primary tumor is accomplished or anticipated.

(2)     There are no systemic or intra abdominal metastases.

(3)     The patient condition enables the major operative procedure.

(4)     The extent of hepatic involvement is such that resection and total extirpation of the metastasis is feasible.

Resection of segments of the liver containing metastases has effected reasonable long-term survival without recurrence for patients with primary tumor in the colon and rectum and for those with Wilms’ tumor. Rare survivors have been reported for other primary tumors.

Palliative cytoreductive surgical measures are indicated for marked pain associated with hepatic neoplasms and in metastatic disease of carcinoid tumors. In recent years a few novel ablation technologies have appeared such as Cryotherapy, Radiofrequency and Laser ablation. These technologies, being less invasive than surgical resection, have broadened the indications for palliative ablative interventions.

FUS for liver tumors has been performed in the past and proved to be feasible and safe (Chen et al 1998, Chen et al 1999).  Since FUS totally non-invasive it has the potential to change the treatment limits of metastatic hepatic tumors that are currently defined by operability and/or resectability.

For more information about Focused Ultrasound research in liver cancer please check our Library.

For more information about liver cancer please look at the following sites:

American Cancer Society

National Cancer Institute

Liver Tumor.org