Potentially Resectable Colorectal Cancer Liver Metastases : Treatment Options

Introduction

Colorectal cancer is the third most common type of carcinoma in the world. Colorectal cancer is highly metastasizing, and the liver is a common metastasis site. They are the most common cause of mortality in colorectal cancer patients. Some colorectal cancer that metastasizes to the liver can be potentially resectable.

What Is Colorectal Cancer Liver Metastases?

Colorectal cancer can metastasize to different parts of the body. It can also metastasize to the liver. Some colorectal cancer is only seen metastasized to the liver. This is called isolated liver metastasizing. For colorectal liver metastasize, targeted or regional therapy is recommended other than systemic therapy to minimize the adverse effects. Some colorectal cancer metastasizing to the liver is not resectable because of its severe liver involvement and poor prognosis. But depending on the tumor size and extent, some colorectal cancer metastasizing to the liver is potentially resectable.

What Are the Symptoms of Colorectal Cancer?

The signs and symptoms present when, colorectal cancer metastasizes to the liver, can include

• Fatigue or weakness.

• Fever and chills.

• Reduced appetite.

• Jaundice (yellowish discoloration of skin and sclera of the eyes).

• Bloated stomach.

• Swelling is seen on the legs.

• Itching in the skin.

• Stomach pain in the upper right corner.

What Are the Stages of Colorectal Cancer?

Colorectal cancers are staged according to the extent of the spread of cancer by using diagnostic methods.

• Stage 0- The cancerous cells are seen only in the inner lining of the mucosa of the colon and rectum. This stage is called carcinoma in situ.

• Stage 1- The cancerous cells can be seen on the muscular layer invading the mucosa of the colon and rectum. Cancer has not spread to other organs, tissues, or lymph nodes.

• Stage 2A- Cancer has not spread to other organs, tissues, or lymph nodes, but growth increases through the wall of the colon and rectum.

• Stage 2B- Cancer has spread to the abdomen's muscle lining but not to other tissues, lymph nodes, or organs.

• Stage 2C- The cancer cells start to grow to nearby structures but have not yet spread to other organs or lymph nodes.

• Stage 3A- The growth of the cancer cells increases from the mucosa to the muscular layer of the intestine. Starts to spread through the lymph nodes but not to other tissues or organs.

• Stage 3B- The tumor cells grow in the surrounding organs and lymph nodes. It has not started to spread to other body parts.

• Stage 3C- Involvement of most of the lymph nodes. The tumor has not yet started to spread to different tissues or organs.

• Stage 4A- The tumor has spread to a distant body part. For example, lungs or liver.

• Stage 4B- The tumor has spread to more than one part of the body or organs.

• Stage 4C- The tumor has spread to different body parts, organs, and peritoneum.

How Are Colorectal Cancer Liver Metastases Diagnosed?

Apart from the physical examination, the diagnostic test used for diagnosing colorectal cancer are

• Colonoscopy- With the help of a fiber optic camera, the large intestine and rectum area are endoscopically examined.

• Biopsy- A small amount of tissue is removed from the tumor and is examined under the microscope for the confirmation of cancer. If abnormal cells are present in the microscopic examination, staging can also be done by evaluating the extent of the cancerous cells.

• Blood Tests- In people with colorectal cancer, there is a chance of internal bleeding, so a complete blood count (CBC) is performed.

• Computed Tomography (CT)- Uses a high amount of X-ray radiation and computer technology to get a cross-sectional view of the gastrointestinal tract and the liver.

• Magnetic Resonance Imaging (MRI)- Using a large magnetic field and computer technology, a three-dimensional image of the cancerous area is recorded.

• Positron Emission Tomography (PET) Scan- Abnormal growth can be identified using a radioactive substance.

• Ultrasound- Using high-frequency sound waves to produce echoes to create images of the organs.

What Are the Treatment Options for Colorectal Cancer Metastasized to the Liver?

The treatment of choice for people with potentially resectable colorectal cancer metastasizing to the liver is surgical resection, even if it is synchronous (occurs simultaneously) or metachronous (occurs at a different time like the recurrence of cancer), along with systemic chemotherapy. The treatment options for colorectal cancer metastasizing to the liver include

• Neoadjuvant Chemotherapy- Using drugs to shrink or reduce the tumors before the surgical resection is called neoadjuvant chemotherapy. It is indicated in resectable or potentially resectable tumors. Fluorouracil-based drugs are first-line neoadjuvant therapy like Oxaliplatin, Irinotecan, Leucovorin, and Capecitabine or a combination of these drugs. Neoadjuvant chemotherapy is a controversial method in the routine delivery of drugs as it can cause chemotherapy-associated liver injury, sinusoidal injury, etc. So it is indicated only in high-risk patients.

• Surgical Resection- Surgical tumor resection is indicated for long-term survival rates. Laparoscopic surgery (an instrument is passed through the gastrointestinal tract to remove the tumor). For a better prognosis, radical surgery is the treatment of choice by preserving the normal functioning liver.

• Adjuvant Chemotherapy- After surgical resection of cancer, there is a 70 percent chance of cancer recurrence. So to prevent a recurrence, adjuvant chemotherapy is used. A combination of Fluorouracil, Irinotecan, Oxaliplatin, Leucovorin, Bevacizumab, and Cetuximab can be used as adjuvant therapy after surgical resection of colorectal cancer metastasized to the liver.

• Targeted Therapy- Targeted therapy aims at the specific cancer site. Cetuximab, Panitumumab, and Bevacizumab can be used for targeted therapy.

What Is the Surgical Treatment Option in Potentially Resectable Colorectal Cancer Liver Metastasis?

Most studies show that radical tumor resection with adjuvant chemotherapy results in long-term survival rates. Surgical resection is considered the gold standard for potentially resectable colorectal liver metastases. The tumor should be resected along with at least one centimeter of normal tissue surrounding it to prevent a recurrence. After the surgical resection of the tumor, radiofrequency ablation is done to freeze or kill any remaining tumor cells that are left back during resection of the tumor.

What Are the Contraindications for Surgical Resection?

Surgical resection is contraindicated if the liver has uncontrollable hepatic or extrahepatic diseases like

• Primary tumors that cannot be treated.

• Interstitial lung disease (group of diseases causing inflammation of lungs).

• Peritoneal diseases.

• If lymph nodes are affected.

• Metastasized to bone or spinal cord.

Conclusion

Colorectal cancer has very high recurrence rates. In 60 percent of people who had a surgical resection, colorectal cancer metastasized to the liver can reoccur, and it can be detected within two years of surgery. Patients with fewer colorectal tumors, which metastasized to the liver, are the best candidates for surgical treatment. Surgical resection of the tumors is advised with the combined decision by the radiologist and hepatologist (liver specialist).