Tumor metastasis is a multistage process during which malignant cells spread from the primary tumor to discontiguous organs

• It involves arrest and growth in different microenvironments that are treated clinically with different strategies depending on the tumor histiotype and metastatic location

• Because of cellular heterogeneity, therapeutics have varying efficacy challenging the oncologist and our understanding of the metastatic process

The process of cancer metastasis consists of sequential and interrelated steps, each of which can be rate-limiting since a failure at any step may halt the process

The sequential process of metastasis:

• Transformation --> Angiogenesis --> Motility & Invasion --> Transport --> Adherence --> Extravasation --> Response --> Cell proliferation