Medical research

Models for exploring the development of brain metastasis

The spreading of different types of cancer cells to the brain, forming brain metastases, is the main cause of morbidity and mortality associated with cancer. Now, a new study led by Cláudia C. Faria, principal investigator ...

Medical research

Breast cancer: Why metastasis spreads to the bone

When cancer cells break away from a primary tumor and migrate to other organs, this is called "metastatic cancer." The organs affected by these metastases, however, depend in part on their tissue of origin. In the case of ...

Oncology & Cancer

T-cell interactions vary between tumor microenvironments

A team led by Northwestern Medicine investigators has discovered differences in the distribution and interaction of T-cells within the microenvironment of different regions of both brain tumors and brain metastases, according ...

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Metastasis

Metastasis, or metastatic disease (sometimes abbreviated mets), is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research. The word metastasis means "displacement" in Greek, from μετά, meta, "next", and στάσις, stasis, "placement". The plural is metastases.

Cancer occurs after a single cell in a tissue is progressively genetically damaged to produce a cancer stem cell possessing a malignant phenotype. These cancer stem cells are able to undergo uncontrolled abnormal mitosis, which serves to increase the total number of cancer cells at that location. When the area of cancer cells at the originating site becomes clinically detectable, it is called primary tumor. Some cancer cells also acquire the ability to penetrate and infiltrate surrounding normal tissues in the local area, forming a new tumor. The newly formed "daughter" tumor in the adjacent site within the tissue is called a local metastasis.

Some cancer cells acquire the ability to penetrate the walls of lymphatic and/or blood vessels, after which they are able to circulate through the bloodstream (circulating tumor cells) to other sites and tissues in the body. This process is known (respectively) as lymphatic or hematogeneous spread.

After the tumor cells come to rest at another site, they re-penetrate through the vessel or walls, continue to multiply, and eventually another clinically detectable tumor is formed. This new tumor is known as a metastatic (or secondary) tumor. Metastasis is one of three hallmarks of malignancy (contrast benign tumors). Most tumors and other neoplasms can metastasize, although in varying degrees (e.g. basal cell carcinoma rarely metastasize).

When tumor cells metastasize, the new tumor is called a secondary or metastatic tumor, and its cells are like those in the original tumor. This means, for example, that, if breast cancer metastasizes to the lungs, the secondary tumor is made up of abnormal breast cells, not of abnormal lung cells. The tumor in the lung is then called metastatic breast cancer, not lung cancer.

This text uses material from Wikipedia, licensed under CC BY-SA