metastasis

noun

me·​tas·​ta·​sis mə-ˈta-stə-səs 

plural metastases mə-ˈta-stə-ˌsēz 

1

a

: change of position, state, or form

b

: the spread of a disease-producing agency (such as cancer cells) from the initial or primary site of disease to another part of the body

Metastases of breast cancer to bone …

—Medical Physics

also : the process by which such spreading occurs

2

: a secondary malignant (see malignant sense 1) tumor resulting from metastasis

metastatic

ˌme-tə-ˈsta-tik 

adjective

metastatically

ˌme-tə-ˈsta-ti-k(ə-)lē 

adverb

Examples of metastasis in a Sentence

Recent Examples on the Web

However, the untreated men had a higher risk of metastases. —Howard Wolinsky, STAT, 21 Jan. 2026

Brain metastases develop in up to 60% of patients with advanced melanoma, according to the National Library of Medicine. —Emily Blackwood, PEOPLE, 16 Jan. 2026

One way to assess possible malignancy is irregularity of a growth, speed of growth, localized lymph node metastasis as evidenced by enlargement of the nodes, and more but there is no substitute for an FNA or removal and biopsy. —Dr. John De Jong, Boston Herald, 26 Oct. 2025

Clinical trials testing the ability of these devices to deliver drugs to the brain to treat conditions like glioblastoma, brain metastases and Alzheimer’s disease are underway. —Richard J. Price, The Conversation, 15 Oct. 2025

Word History

Etymology

New Latin, from Late Latin, transition, from Greek, from methistanai to change, from meta- + histanai to set — more at stand

First Known Use

1663, in the meaning defined at sense 1a

Kids Definition

metastasis

noun

me·​tas·​ta·​sis mə-ˈtas-tə-səs 

plural metastases -ˌsēz 

1

: the spread of something that produces disease (as cancer cells) from the original location of disease to another part of the body

2

: a growth of a malignant tumor in another part of the body resulting from metastasis

Medical Definition

metastasis

noun

me·​tas·​ta·​sis mə-ˈtas-tə-səs 

plural metastases -ˌsēz 

1

a

: change of position, state, or form

b

: the spread of a disease-producing agent (as cancer cells or bacteria) or disease from the initial or primary site of disease to another part of the body

The overwhelming concern about prostate cancer is its potential for metastasis—for cells to escape the gland and take root in lymph nodes, bones, lungs, skin, or other tissue.

—Tom Alexander, Fortune

also : the process by which such spreading occurs

2

: a secondary malignant tumor resulting from metastasis

… radiation has no known effect on distant metastases from breast cancer …

—David Plotkin, The Atlantic Monthly