Liver Metastasis

What is Liver Metastasis?

The liver is commonly affected by cancer spread, making up nearly a quarter of all such cases. The original cancer can be from different sources, but colon and rectal cancers are the most studied because they’re the most common ones to spread to the liver. The liver’s unique two-pathway blood supply makes it more susceptible to cancer spread from the digestive system but also means it can be treated more easily with interventional therapies. The way we treat liver cancer is changing quickly all over the world, with specialists from different fields working together for better results.

What Causes Liver Metastasis?

Metastatic liver tumors, which are tumors that start elsewhere in the body and then spread to the liver, are more common than tumors that start in the liver or bile ducts. Most of these metastatic tumors are a type called adenocarcinomas. However, other types like squamous cell carcinoma, neuroendocrine carcinoma, and less common ones like lymphoma, sarcoma, and melanoma can also be found.

Most of the research and medical literature focus on managing adenocarcinoma that starts in the colon or rectum, known as colorectal adenocarcinoma. This is the third most common type of cancer found worldwide. Reports show that in almost 70% to 80% of patients, these types of cancer, when they spread (or metastasize), only spread to the liver.

Risk Factors and Frequency for Liver Metastasis

Colorectal cancer is a serious illness and unfortunately, about 20% to 25% of patients with this condition end up with liver cancer as well. Of all these patients, 15% to 25% will have both types of cancer at the same time. The liver cancer usually starts from colorectal cancer but it can also begin from pancreatic and breast cancer.

Women under 50 who have liver cancer most likely got it from breast cancer. However, for people over 70, the liver cancer usually starts from a disease in the gastrointestinal tract. Interestingly, 92% of liver cancer cases are of the type called carcinomas. Among these carcinoma cases, 75% are a subtype known as adenocarcinomas.

It’s also worth noting that liver cancer is more common in men than in women. Most patients who are diagnosed with this are over 50 years old.

• 20% to 25% of colorectal cancer patients also develop liver cancer.
• 15% to 25% have both types of cancer at the same time.
• Most liver cancers start from colorectal cancer but can also originate from pancreatic and breast cancer.
• In women under 50, liver cancer often comes from breast cancer.
• In those over 70, liver cancer usually starts in the gastrointestinal tract.
• Most liver cancers (92%) are carcinomas, and 75% of these are adenocarcinomas.
• Liver cancer is more common in men than women, and most who get it are over 50.

Signs and Symptoms of Liver Metastasis

Medical professionals from a variety of fields, including oncologists, radiologists, and surgeons, collaborate to address patients’ conditions. Patient symptoms often vary, but potential signs of metastatic disease might include abdominal discomfort, feeling full early during meals, changes in bowel habits, bloody stools, weight loss, mental confusion, yellowing skin (jaundice), fluid in the abdominal cavity (ascites), and disturbances in metabolism. It’s important to note that these signs do not definitively confirm liver metastasis.

Classic symptoms of liver disease, like visible veins on the abdomen (caput medusa), enlarged liver or spleen (hepatosplenomegaly), and ascites, call for an exhaustive evaluation. A rectal exam and colonoscopy to look for masses and blood in the stool should be conducted. Particular attention should be given to patients with a strong family history of colon cancer or those who have not received a colonoscopy when due. Since liver disease can originate from other places, a thorough physical exam which includes listening for normal breathing sounds and feeling for swollen lymph nodes is crucial in deciding the best course of treatment.

• Abdominal discomfort
• Feeling full early during meals
• Changes in bowel habits
• Bloody stools
• Weight loss
• Mental confusion
• Yellowing skin (jaundice)
• Fluid in the abdominal cavity (ascites)
• Disturbances in metabolism
• Visible veins on the abdomen (caput medusa)
• Enlarged liver or spleen (hepatosplenomegaly)

Testing for Liver Metastasis

If your doctor suspects that your liver has cancerous growths originating from another part of your body (known as liver metastases), they will need a clear and detailed image of your liver. These images can both confirm the presence of these growths as well as help determine where they’re originally coming from. The most common methods used to obtain these images are triple-phase CT scans and MRI scans.

In the case of the triple-phase CT scan, your doctor will capture three stages. These include a non-contrast phase (without dye), arterial phase (when dye is in the arteries), and a venous phase (when dye is in the veins). Both liver metastasis and primary liver tumors tend to become most visible during the arterial phase and are less visible during the non-contrast studies. One advantage of CT scans is that it can localize tumors, which helps when planning targeted liver therapies.

Your doctor will use CT imaging to examine the size, shape, the extent to which your liver is affected, and what portion of your liver might be left untouched by the disease. It’s crucial that your doctor determines the potential to surgically remove liver tumors, as lesions close to major blood vessels may not be operable.

MRI is another imaging method that might be used if it’s difficult to identify a liver lesion. On an MRI scan, liver metastases appear less intense on T1-weighted images and more intense on T2-weighted images. Images that use a special dye, such as gadolinium, can show total or part enhancement depending on the size.

Certain other contrast agents like gadoxetate disodium (also known as Eovist) and gadobenate dimeglumine (Multihance) have been designed to increase the sensitivity of the MRI. However, there are a few benign conditions that can look very similar to liver metastasis on imaging.

Fluorodeoxyglucose-18 (FDG) PET/CT can help in detecting liver metastases and may also assist in identifying primary and additional metastasis. However, it’s not as clear as a CT and isn’t great for spotting growths smaller than 1cm. Even so, it can be helpful in detecting specific types of cancerous growths like metastatic neuroendocrine carcinomas.

Ultrasound is not often used during the diagnostic stage due to its lower sensitivity. In addition to imaging, the doctor would also check your liver function with a liver function test, a complete blood count, an upper endoscopy (also known as an esophagogastroduodenoscopy or EGD), and a colonoscopy.

Treatment Options for Liver Metastasis

Surgery is considered the typical course of action when treating liver metastasis, which is when cancer has spread to the liver from another part of the body. However, there are various other treatment options for those who can’t undergo surgery or have other health issues. The majority of the information about outcomes for these alternative methods comes from cases involving colorectal (relating to the colon and rectum) cancers, but data from neuroendocrine (nervous and hormonal systems) and primary liver diseases has also been useful.

Less invasive techniques have been developed and applied to this issue. For example, stereotactic body radiotherapy is a type of cancer treatment that delivers very precise, high-dose radiation to the tumor while aiming to reduce the chance of damaging healthy tissues. Embolization techniques, which involve blocking blood flow to the tumor, have also been used. These may involve chemotherapy (drugs to kill cancer cells), or radioactive isotopes (a type of radiation therapy). These methods have shown positive results and acceptable levels of side effects in patients.

What else can Liver Metastasis be?

Determining the cause of liver lesions can be tricky since there are many possibilities. Doctors would use medical history and imaging techniques to identify the most likely cause. However, the potential culprits could include:

• Primary liver cancer (hepatocellular carcinoma)
• Bile duct cancer (cholangiocarcinoma)
• Adenoma (benign tumor)
• Hemangioma (blood vessel mass)
• Hematoma (clot or bruise)
• Focal nodular hyperplasia (abnormal growth)
• Abscess (pus-filled pocket)
• Secondary masses from cancer spreading from other areas (metastatic disease), including carcinoma, lymphoma, or sarcoma.

Surgical Treatment of Liver Metastasis

Having surgery to remove cancer that has spread to the liver, along with follow-up chemotherapy, can help to save more lives and can reduce the risk of illness and death. Colorectal adenocarcinoma, or cancer that starts in the colon or rectum, is the type of cancer most often found to have spread to the liver. Because of this, the discussions about liver surgery for cancer were usually focused on this type. Unique treatment plans may be needed for other situations.

Surgery is considered the best treatment for colorectal cancer that has spread to the liver if it is possible to remove it entirely. We aim to leave at least around 20% of a liver that is healthy, about 30% of a liver that has mild to moderate damage, and 40% of a liver that has cirrhosis or scarring of the liver. We might use tools such as chemotherapy before surgery or blocking blood flow in the liver to help increase the size of the part of liver that is free of cancer. In some cases, we might perform the surgery in two parts, removing the cancer in the colon or rectum first, and then removing the cancer from the liver later, versus doing it all at once.

The goal of the surgery is to remove all visible cancer and have a clear area around the cancer that is free of cancer cells. Studies have shown that the exact size of this clear area does not make a big difference in how long patients survive, as long as there are no cancer cells present. The surgery can be done through a larger open cut or a smaller cut using a camera called lapatoscopy. Recent studies have suggested that procedures done using a smaller cut can have similar long-term results with fewer short-term complications. If it is possible to remove only part of the liver and the colon or rectum at the same time, this can be done in one surgery. Doing it all at once can reduce overall hospital stay. However, some other things, like risk of illness or death, have different outcomes depending on the study. In some cases, waiting to do the liver surgery does not decrease survival rates, especially when chemotherapy before surgery is considered.

It’s crucial to understand how the primary tumor or first place where the cancer started is affecting the patient. Patients who are anemic (low in red blood cells), have a blocked intestines, or are otherwise ill due to the tumor, should have surgery to remove the tumor first. Patients with cancer spread to the liver and other parts of the body have lower chances of survival at five years compared to only liver spread (28% vs 55%). Several factors can decrease chances of survival, including cancer spread to other parts of the body, a tumor marker level called CEA higher than 10ng/mL, cancer that started in the right side of the colon, and more than six spots of cancer in the liver.

If using chemotherapy before surgery, generally, patients will receive 4 to 6 months of treatment before surgery. A chemotherapy called Fluorouracil is a common base treatment and is often given with other drugs. This can help reduce the number and size of the spots of cancer before surgery and also can reduce the risk of cancer coming back after surgery. Even though the standard treatment is surgery and chemotherapy before and after, some studies have questioned whether there is benefit of using chemotherapy. Some findings indicate there’s no improvement in the average length of survival, while other studies have shown benefits. Specifically, a study showed that patients who got chemotherapy before surgery had higher chances of being free of cancer at three years compared to those who had surgery followed by chemotherapy (31.7% vs 20.4%).

What to expect with Liver Metastasis

Most research has focused on colorectal metastases, which is when cancer spreads from the colon or rectum to other areas of the body. Without treatment for this type of cancer, the prognosis (or long-term outcome) is quite serious. If left untreated, only 5% of patients typically survive beyond five years.

However, if the affected parts of the liver are surgically removed (a process known as hepatic resection), the five-year survival rate increases to up to 58%. Without any treatment, the average survival time is usually around 6 months.

For neuroendocrine liver metastases, which are tumors that start in the cells of the nervous and endocrine (hormone) systems, survival rates can be slightly higher if a portion of the liver is surgically removed. With this approach, the survival rate stands at 61% after five years.

Possible Complications When Diagnosed with Liver Metastasis

After liver surgery (hepatectomy), patients may face different complications. These include the formation of abscesses, leaks in the bile duct, return of the disease, bleeding, widespread infection, damage to surrounding structures, and the need for additional surgery.

People who have undergone systemic chemotherapy before surgery can experience other problems. These might include an inflammatory condition of the liver (steatohepatitis), blocked small blood vessels in the liver (sinusoidal obstruction), a decrease in white blood cells (leukopenia), infections throughout the body, fever, fatigue, weight loss, slower wound healing, and other potential side effects.

Sometimes, if a high dose of radiation is given to the whole liver, radiation-induced liver disease (RILD) can occur. The chance of this happening depends on the liver’s volume, the dose of radiation, and the fractionation (how the dose is divided). External beam radiotherapy, another treatment method, can also cause complications such as bowel perforation and spinal cord injury.

In addition, a common complication of transarterial radioembolization (TARE), a type of targeted liver therapy, is post-embolization syndrome. This includes symptoms like fatigue, nausea, vomiting, and abdominal pain.

Common Complications:

• Abscesses
• Bile duct leaks
• Return of the disease
• Bleeding
• Widespread infection (sepsis)
• Damage to nearby structures
• Need for additional surgery
• Inflammatory liver condition (steatohepatitis)
• Blocked liver blood vessels (sinusoidal obstruction)
• Decreased white blood cells (leukopenia)
• Body-wide infections
• Fever
• Fatigue
• Weight loss
• Slow wound healing
• Result of high dose radiation to liver (RILD)
• Bowel perforation from external beam radiotherapy
• Spinal cord injury from external beam radiotherapy
• Fatigue, nausea, vomiting, and abdominal pain after TARE

Preventing Liver Metastasis

Diagnosing a disease that has spread to the liver from another part of the body, known as metastatic liver disease, can be difficult. This is considered a late-stage disease that generally has a poor outlook without treatment. To manage this condition, a team of different healthcare professionals like medical doctors, imaging specialists, and cancer surgery doctors work together to create a care plan focused on the patient. The goal is to use drugs for cancer treatment and potentially surgery to help the patient live longer.

There’s general agreement on which drugs to use for cancer treatment, but the surgical approach can differ based on the patient’s particular situation. While there’s currently no way to prevent the spread of cancer to other parts of the body, it’s crucial to have yearly check-ups with a primary care provider. These check-ups should include physical exams, colonoscopy (a test to examine the inside of one’s colon), and blood tests. This routine helps monitor your health and detect any potential concerns early.