Metastasis is a clinical term describes cancer spreads to a different part of the body from where it started, in other words, the development of secondary malignant growths at a distance other than the primary site of cancer. The majority of cancer deaths are caused by metastasis. In many types of cancer, it is referred to as stage IV (four) cancer.
What Is The Major Cause Of Liver Metastases?
Liver metastasis is not the similar as cancer that starts in the liver (i.e. called primary liver cancer). It is much more common than primary liver cancer. It is cancer that started in another part of the body and spread to the liver. The liver is richly supplied with blood vessels, so cancer can spread easily to any part of the liver. Sometimes liver metastasis occurs in both the lobes of the liver. Colorectal, lung, breast, pancreatic, stomach, melanoma and neuroendocrine cancers can able to induce liver metastases. The liver is the most frequent sites of metastasis accounting 82.5% followed by lungs 43.8%.
Liver Metastasis Feature
Hepatomegaly, tenderness, cachexia, ascites, jaundice, pyrexia and elevated level of alkaline phosphatase and gamma glutamyl transpeptidase are some of the condition associated with liver metastasis. Among other cancer, up to 70 percent of people with colorectal cancer eventually develop liver metastases. This occurs because the blood supply from the intestines is associated directly to the liver through the portal vein.
How Metastases Occur?
The primary cancers cells continuously shed a large number of cancer cells into systemic circulation. A small portion of these cells is responsible for the manifestation of cancer in distant organs forming metastases. This significant proportion of cells medically referred to as “metastasis-initiating cells”. Metastasis-initiating cells, by definition, are cancer cells capable of seeding clinically significant metastatic colonies in secondary organs. The metastasis-initiating cells rate of transmission in the distant organ is remarkable. Its unique proportion has many advantages during metastasis such as cellular plasticity, metabolic reprogramming, the ability to enter and exit dormancy, resistance to apoptosis, immune evasion, and co-option of other tumor and stromal cells.
Metastases Progression
Metastasis is a highly challenging process. Surgical debulking and systemic adjuvant treatment eliminate most of the tumor cells at the primary site and throughout the body. Only a few cells i.e. less than 0.02 % cells can able to seed successfully during metastases. This is medically referred to as disseminated tumor cells. Majority of disseminated tumor cells eventually dies during metastasis except for cells those have strong anoikis resistance. The survived disseminated tumor cells remains a period of dormancy with no clinical sign of cancer. The period of dormant could happen a month or years until a detectable proportion of cells start to emerge metastasis. The following treatment only temporarily reduces the cancer burden but metastatic injuries eventually progress resistance and sooner or later overcome the patients. The ability to initiate metastatic outgrowth is, therefore, a major bottleneck in cancer progression.
How Long Can A Person Survive With Liver Metastases?
Liver metastasis is a chronic condition. A person with liver metastases has loss of appetite which is the most common symptom. Fatigue with chronic pain greatly affects the quality of life. Survival with liver metastases depends on the type of cancer, age, and immune status of the affected individuals. Some people may live much longer than expected, while others may die sooner than expected.
Conclusion
The liver is one of the most common sites for metastatic disease, accounting for 25% of all metastases to solid organs. The majority of cancer deaths are caused by metastasis. Once cancer spreads from its primary location, it is very difficult to manage. Most of the stage IV cancer i.e. metastatic cancer cannot be cured with current treatments.
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