Can liver metastases be removed if the primary tumor is not from the bowel?

Sometimes, yes. Surgery is most often considered for neuroendocrine and gastrointestinal stromal tumors, kidney cancer, and selected cases of breast cancer and melanoma. The condition is that the primary tumor is under control, there is no disease outside the liver or it is controlled, and all lesions can be removed completely.

Why is surgery offered to some patients with metastases but not to others?

Because the benefit of surgery depends on tumor biology. With some tumors, removing metastases prolongs disease control; with others, new lesions appear quickly and surgery only delays systemic therapy. That is why the decision takes into account the tumor type, extent of disease and response to treatment.

Why wait several months of treatment before surgery?

To see how the disease behaves. If new lesions appear on therapy, surgery is unlikely to help. If the lesions are stable or shrinking and no new ones appear, resection makes more sense. For well-differentiated neuroendocrine tumors with resectable metastases, such a waiting period is usually not needed.

Are liver metastases from pancreatic cancer operated on?

Usually not. Outside clinical trials, liver resection for pancreatic cancer metastases is not performed, because liver metastases in this cancer usually indicate systemic spread of the disease, and the benefit of removing them has not been proven. The main treatment is systemic therapy.

What if there are many lesions in the liver?

It depends on the tumor type. Systemic therapy remains the basis; for neuroendocrine tumors, hepatic artery embolization, radionuclide therapy and operations removing most of the lesions to reduce hormonal symptoms are also used.

Liver metastases from non-colorectal tumors: when surgery makes sense

Liver metastases occur with tumors of many organs, but the rules that apply to colorectal cancer do not carry over to other tumors. For most of them the main treatment is systemic therapy, and resection is appropriate only for some patients: when the primary tumor is under control, the disease is confined to the liver, the metastases can be removed completely, and the disease is behaving indolently. Surgery is most often considered for neuroendocrine tumors, gastrointestinal stromal tumors, kidney cancer, and selected cases of breast cancer and melanoma.

Kateryna Valikhnovska, MD, surgical oncologist, during a laparoscopic operation — The laparoscopic stage of an operation: the lights in the operating room are dimmed because the surgeon works from the camera image on the monitor.

Why metastases reach the liver

The liver filters a large volume of blood. Blood from the stomach, pancreas and bowel flows to it through the portal vein, so tumors of the digestive system metastasize here first. Tumors of other organs (breast, kidney, lung, melanoma) reach the liver through the general circulation, and in them liver metastases are often combined with involvement of other organs. The exception is uveal (eye) melanoma, which often produces isolated metastases in the liver.

A metastasis consists of cells of the primary tumor, not liver cancer, so it is treated by the rules of the tumor it came from. Colorectal cancer metastases have their own, best-studied rules, covered on the page colorectal liver metastases. A primary tumor of the liver itself is described on the page liver cancer.

Are there symptoms

Most often metastases are found on follow-up CT, MRI or ultrasound during treatment or surveillance after it, before there are any complaints. Large or numerous lesions can cause heaviness under the right ribs, weakness, weight loss and jaundice.

Neuroendocrine tumors sometimes produce hormones, and liver metastases then cause hormonal symptoms. With small bowel tumors this is most often carcinoid syndrome: episodes of facial flushing, diarrhea, sometimes wheezing; pancreatic tumors can cause other hormonal syndromes. In such patients surgery can be useful not only for tumor control but also for reducing these symptoms.

Examinations needed

Contrast-enhanced CT of the chest, abdomen and pelvis, to assess whether the disease is confined to the liver.
Liver MRI with a hepatobiliary contrast agent, which shows small lesions that CT misses; the surgical plan depends on the number of lesions.
PET-CT when indicated, to find spread outside the liver; for neuroendocrine tumors, somatostatin receptor PET-CT, and for high-grade tumors also FDG PET-CT.
Biopsy, when it is unclear whether this is a metastasis, a primary liver tumor or a second tumor of another organ; treatment depends on the answer.
Histology of the primary tumor: type, grade, and for neuroendocrine tumors the Ki-67 index; for some tumors, molecular markers that determine the choice of drugs.
Volumetry and liver function tests, if a major resection is being discussed.

When surgery is possible

There is no single rule for all tumors, but the decision rests on common conditions:

the primary tumor has been removed or is controlled;
there is no disease outside the liver, or it is limited and controlled;
all metastases can be removed completely while preserving enough liver;
if the patient is receiving systemic therapy, the disease is not progressing on it: for many tumors surgery is discussed after several months of treatment, once it is clear how the disease behaves, while for well-differentiated neuroendocrine tumors resection is often considered straight away;
the patient’s condition allows a major operation.

The strongest evidence for surgery is in neuroendocrine tumors: resection is recommended for resectable metastases of well-differentiated tumors, and in some cases most of the lesions are removed to reduce hormonal symptoms. In gastrointestinal stromal tumors surgery is combined with targeted therapy. In kidney cancer, breast cancer with a good and durable response to treatment, and melanoma, including uveal melanoma, resection is considered selectively. For gastric cancer metastases, surgery is considered only for selected patients with solitary lesions after systemic therapy, mainly within clinical trials; for pancreatic cancer metastases, liver resection is generally not performed outside clinical trials.

If surgery is not possible now

For most patients, systemic therapy chosen according to the tumor type remains the basis of treatment: chemotherapy, hormonal, targeted therapy or immunotherapy. If the disease stabilizes or the lesions shrink on it, surgery is reconsidered on subsequent follow-up scans.

For small solitary lesions, ablation can be used instead of or together with resection. For neuroendocrine tumors with many lesions, hepatic artery embolization and, if the tumor expresses somatostatin receptors, radionuclide therapy are also used. The final plan is determined by the MDT together with the oncologist managing the main treatment.

How the operation is performed

The extent is determined by the number, size and location of the lesions. When their location allows, parenchyma-sparing resections are preferred: removing the lesions with a margin of healthy tissue instead of a large part of the liver. This leaves more liver working and preserves the possibility of repeat surgery if new metastases appear.

During surgery the liver is examined with an ultrasound probe to find lesions not visible on scans. Small deep lesions can be destroyed by ablation during the same operation. If the primary tumor has not yet been removed, for example a neuroendocrine tumor of the small bowel or pancreas, a simultaneous or staged operation is discussed.

When the location of the lesions and the extent of resection allow, the operation is performed laparoscopically, through several small incisions.

A liver metastasis in itself is neither an indication nor a contraindication for surgery. The decision depends on which tumor it came from and how that tumor behaves.

Kateryna Valikhnovska, MD, surgical oncologist

Recovery after surgery

Care follows the enhanced recovery after surgery (ERAS) protocol: early mobilization, early feeding, controlled pain relief. After a parenchyma-sparing or laparoscopic resection, recovery is usually faster than after a major open operation. A healthy liver regains its volume within a few weeks.

Systemic therapy after surgery is resumed or continued as decided by the medical oncologist, taking into account the tumor type and previous treatment.

Follow-up

After resection of metastases the risk of new lesions remains, so regular CT or MRI and monitoring of tumor markers, where they are informative for that tumor, are needed. The schedule depends on the tumor type and is set together with the medical oncologist.

New liver metastases after surgery do not always mean the end of surgical options: some patients undergo repeat resection or ablation if the conditions described above are met again.

What to bring to the consultation

CT, MRI or PET-CT discs and reports, both the latest and earlier ones, to show the trend;
the histology and immunohistochemistry reports of the primary tumor, with the Ki-67 index for neuroendocrine tumors;
discharge summaries of surgery on the primary tumor;
regimens and dates of systemic therapy and the oncologist’s assessment of its effect;
blood tests and tumor markers, if they were measured.

If some materials are missing, that is no reason to postpone the consultation: some examinations can be done on site.

The consultation is free of charge. How it goes and how long it takes is described on the page “Oncologist Consultation”.