Liver Tumors

There are two kinds of liver tumors. Primary liver tumors are caused by malignant cells originating from the liver itself. The second type are liver metastasis which are formed when cancer cells migrate to the liver. Due to the liver's location and extensive blood supply, metastatic disease is far more common than primary liver disease.

Options for treatment of liver tumors, whether primary or metastatic, are limited. The "gold standard" for treatment remains surgical resection, as a potential cure of the disease. Numerous conditions, like extent of disease in both liver lobes or presence of disease beyond the liver make a surgical cure impossible and therefore few patients qualify for surgical resection.

Other therapeutic options are available, including:

1. systemic chemotherapy
2. localized therapy (hepatic artery chemotherapy, chemo-embolization, hepatic artery ligation), and
3. tumor ablation (ethanol injection, cryotherapy, high energy ultrasound ablation).

These methods are used as an alternative to liver resection. But there is no doubt, that patients with unresectable liver lesions will benefit from these alternative treatments.

The concepts of cancer therapy

To understand the different treatment options for liver cancer, it may be helpful to know two principal concepts of cancer treatment - local and systemic treatment. Cancer stems mostly from a single primary site (colon, breast, lung, thyroid gland), and thereafter can spread to distant parts of the body. Today's medical imaging methods can not detect spreading cancer cells which might develop into a distant metastatic site.

Local treatment tries to eliminate cancer at a specific location (in this case the liver), which has been diagnosed with various imaging methods. There is the possibility, however, that some cancer cells at other distant sites remain undetected and untreated.

In contrast, systemic treatment modalities like chemotherapy can treat cancer cells not seen with today's medical imaging methods. Systemic therapy treats cancer cells irrespective to their location. So, shouldn't all cancer be treated systemically?

Cancer which can be seen on CT scans or ultrasound poses the biggest threat for the patient and determines the prognosis. Local treatment methods control visible tumors better than systemic treatments because more aggressive treatment can be applied. On the other hand, systemic therapy like chemotherapy and radiation therapy have many unwanted side-effects.
Therefore, the goal of chemotherapy and radiation therapy is primarily tumor reduction whereas local therapy methods attempt to completely remove the tumor.

The reason why systemic therapy methods sometimes fail is the way they are applied. Chemotherapy drugs are transferred to the tumor cell via the bloodstream and not every cell will get a high enough dosage. Radiation beams are dimished by distance - the deeper the beam has to go into the body, the lower the effective dosage. Because of side-effects, there is always an upper dosage limit.

In conclusion, the different treatment modalities can accomplish different goals in cancer treatment, to get the maximum success, physicians frequently combine different cancer treatments.
In addition, when there is no definite cure for a patient, treatment decisions focus heavily on possible side-effects such as toxicity, difficulty of application, pain, length of hospitalization and so forth.

With the developement of the Radiofrequency Ablation treatment approach, we have a new local treatment for liver tumors with few side effects. The treatment itself will have a relatively small negative impact on quality of life.

The next section gives a short history of this ablation technique.