Definition & Overview
Metastasectomy is a medical procedure that involves the surgical removal of metastatic cells, which are cancerous growths of a secondary origin. Metastases are cancerous cells that have spread to other parts from cancer that originated from another organ in the body.
Metastasectomy is often suggested in cases of metastatic cancer, a type of cancer that has spread away from where it first started to another organ or part in the body. Metastatic cells are the same type of cancer cells as the primary cancer cells. For instance, lung cancer that has spread to the breast and forms metastatic tumour is metastatic lung cancer, not breast cancer.
The spread of cancer cells is a complicated topic altogether. In general, the ability of cancer cells to spread out to other organs, nearby or otherwise, depend on individual circumstances, such as the original location, the nature of the immune system, and the properties of non-cancerous cells, among many other factors.
Most cancers can spread virtually in many different parts of the body. However, studies have found that certain cancer types have common sites of metastasis, as shown in the table below:
Type of cancer Main sites of metastasis Breast bone, liver, brain, lung Lung adrenal glands, brain, bone, liver Colorectal lung, liver, peritoneum Kidney adrenal glands, brain, bone, lung Ovary lung, liver, peritoneum Prostate adrenal glands, lung, bone, liver Stomach lung, liver, peritoneum
As can be seen in the table, metastatic cells are usually found in the lungs, liver, brain, and bone. Sites where metastasectomy is usually performed include the lungs and the liver. However, surgery of metastatic cancer cells is not feasible in certain organs such as the bone and the brain for discernible reasons.
Who Should Undergo and Expected Results
Metastatic cancer is treated through various methods. Among widely used include:
- Systemic therapy – This includes chemotherapy as well as hormonal, targeted, and biological therapies
- Local therapy – This includes radiation therapy and surgery
- Combination of local and systemic therapy
As mentioned earlier, metastasectomy is recommended for metastatic growths in the lungs and the liver. Patients who need the procedure are cancer patients who developed metastatic pulmonary lesions and liver tumours due to certain cancers such as kidney and colorectal cancer. The aim of the surgery is to completely remove metastatic growths in the affected area.
Metastasectomy has been found to be safe, cost-effective, and usually successful in removing metastasis.
How is the Procedure Performed?
Metastasectomy is performed in various ways depending on the extent, size, and affected organ. Proper pre-operative evaluation is performed prior to the procedure. Patients may be subjected to various tests such as ultrasound, magnetic resonance imaging (MRI) or computed tomography (CT-scan), and positron emission tomography (to check entire body for metastases), as well as blood tests to ensure that they are fit for surgery.
Lung metastasectomy, for instance, can be performed through:
- Lobectomy, where the entire lobe of the lung is removed to include cancer cells
- Wedge resection, where the surgeon removes only the tumour, leaving healthy parts of the lungs
- Radiofrequency ablation (minimally invasive, RFA), where a needle is inserted into the tumour to destroy the metastasis with an electric current
For liver metastasectomy, on the other hand, either of the following may be performed:
- Hepatectomy, where only a part of the liver is surgically removed, leaving other healthy parts. This can be performed only if the liver is healthy and there is no cirrhosis
- Radiofrequency ablation (RFA), as described previously or through laparoscopy
- Percutaneous ethanol injection where alcohol is directly injected into the tumour to destroy it
Oncologists and surgeons plan out the surgical procedure depending on the health condition of the patient, the extent and size of the cancerous growth, and location of metastases, among other factors.
Metastasectomy is also usually recommended in combination with other treatments such as radiation therapy and chemotherapy, especially in cases where cancer has spread to more than one metastatic site. Studies have shown that metastasectomy performed before systemic or targeted therapy can significantly increase the overall survival in patients with metastatic cancer.
Possible Risks and Complications
Cancer is a condition that is difficult to treat. It is for the same reason that metastasectomy is not without risks and complications. As a procedure, surgery to remove cancer cells can lead to side effects, which include:
- Loss of appetite
- Bruising and swelling in the affected area
- Organ dysfunction
Due to recent technological advances in metastasectomy and cancer surgery, including minimally invasive surgical methods, the procedure can be performed with relatively milder side effects.
Also, just like all other cancer treatment methods, metastasectomy does not guarantee the complete removal of all cancer cells. However, going through the surgical procedure can increase one's chances for a more favourable prognosis.
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Fiorentino F, Treasure T. Pulmonary metastasectomy for colorectal cancer: making the case for a randomized trial in the zone of uncertainty. J. Thorac. Cardiovasc. Surg. 146, 748–752 (2013).