24 04 2023
Metastatic liver tumours are a commonly encountered liver disease. They typically result from the metastasis of colon cancer, with approximately 50% of patients with this disease being at risk of developing liver metastases. Surgical intervention is possible for approximately 20% of these patients, with the remaining patients being treated using alternative modalities. Improvements in surgical techniques and medical advances have led to a significant improvement in long-term survival rates since the 1980s.
Liver metastases may be synchronous or metachronous, depending on whether they occur simultaneously with primary colorectal cancer or at a later stage. The decision to operate in one or two acts is made by the hepatobiliary surgical team based on the characteristics of primary cancer, the secondary deposits and the potential for intervention. Surgical treatment is the only option that offers the potential for a cure and long-term survival. The type of surgery and surgical approach will depend on the size and number of metastases, their location, the patient’s overall health and any comorbidities.
The initial step in deciding on the most appropriate treatment is a preoperative evaluation, which involves imaging methods such as CT or MRI of the abdomen with contrast. This is the method of choice for evaluating the number, size, localization and distribution of liver metastases. Our team is currently developing an additional imaging method known as three-dimensional liver reconstruction, which is based on a CT scan and will be discussed in more detail in one of our future blogs.
The choice of therapeutic approach for treating metastatic disease depends on the stage of the disease, which can be classified as resectable, borderline resectable, or unresectable. The resectable disease can be managed with surgery or a combination of chemotherapy and surgery. Preoperative hormone therapy (HT) can be used in two ways: neoadjuvant for resectable metastases, and conversion for potentially resectable metastases.
Neoadjuvant HT for resectable metastases aims to treat micrometastatic disease both inside and outside the liver, thereby reducing the risk of disease recurrence and increasing overall survival and survival until disease recurrence. A good response to HT, such as a size reduction of metastases, may allow for a reduction in the extent of planned liver resection. The application of preoperative therapy allows for the assessment of response to treatment, which can be helpful in planning further treatment. The period during which neoadjuvant HT is prescribed is sometimes referred to as the “test of time,” which provides insight into the nature of the malignant disease itself.
Conversion chemotherapy aims to reduce the diameter of metastases, making it possible to perform sparing surgery on the liver. A good radiological response is achievable in almost two thirds of patients. In addition to standard therapeutic protocols FOLFOX or FOLFIRI, where the conversion rate is 10-33%, biological drugs such as Bevacizumab are also introduced into the therapy. The addition of Bevacizumab to the FOLFOX protocol increased the radiological response and the percentage of patients who were converted to a resectable state. Epidermal growth factor antibodies, Cetuximab and Panitumumab, are ineffective in KRAS mutation carriers. The effect of conversion chemotherapy is evaluated every four cycles, and if resectability is not achieved even after 12 cycles, it is necessary to consider changing the therapeutic approach.
Metastases that are potentially or marginally resectable are characterized by a high number and size of tumours, resulting in a significant loss of liver volume after extensive resection. The first step in the therapeutic approach for these patients is to apply conversion therapy, followed by possible resection if a satisfactory response is achieved. The second approach involves methods that induce hypertrophy of the liver remnant in the absence of a tumour. The third method involves concurrent thermal ablation of metastases, which preserves a significant volume of parenchyma that would otherwise be sacrificed in the case of resection. Methods that stimulate hypertrophy of liver parenchyma include portal-venous occlusion, two-act hepatectomy, and combined liver partition and portal vein ligature in two-act hepatectomy (ALPPS).
For definitively unresectable metastases, the goal of treatment is to achieve good disease control and maintain a satisfactory quality of life. Unfortunately, most patients present with unresectable metastases at the time of diagnosis. The following treatments can be used: thermal ablation, intra-arterial therapy, stereotactic radiation, and systemic palliative chemotherapy. The role of liver transplantation in treating unresectable metastases is currently uncertain, and for now, it remains experimental until clear scientific evidence of success in treatment is established. The main limiting factors are the lack of donors and a high percentage of disease recurrence.
Recovery after surgical treatment typically involves a day in the intensive care unit, followed by several days in the surgical unit. Early mobilization and elevation of the patient are encouraged from the first day after surgery. Liquid intake begins on the first or second postoperative day, while food intake begins on the second or third postoperative day. Patients are continuously monitored by surgeons, anaesthesiologists, physiotherapists, and other medical staff throughout their hospital stay, including during surgery and in the postoperative period, to facilitate rapid recovery and the resumption of daily activities. Discharge from the hospital typically occurs on the fifth to seventh postoperative day.
Surgery on the liver is one of the most challenging surgical procedures, and as a result, only a small number of surgeons specialize in this area, with very few in our country. Our team specializes in a wide range of liver surgeries, from the simplest to the most complex and extensive operations.
