Tumor Progression

Tumor progression is a phenomenon where the pre-formed tumor acquires successive morphological and molecular changes to become more aggressive and malignant in its  character.

Cancer begins as a single genetic change in a healthy cell, and with time, the progenies of that cell continue to proliferate and pass on the mutation to all the daughter cells.  The genome of these mutant cells becomes increasingly unstable, allowing more mutations to accumulate.

For instance, in the initial stages of Chronic Myelogenous Leukemia or CML, the mutant cells exhibit a chromosomal aberration called the Philadelphia chromosome, which is formed by a reciprocal translocation, where the parts of chromosomes 22 and 9 swap places.

This creates a fusion protein BCR-ABL1 that helps cells  increase the cell division rates, escape terminal differentiation, and avoid apoptosis, resulting in the accumulation of abnormal cells.

As the tumor progresses, the tumor cells stimulate the formation of new blood vessels around them by a process called angiogenesis.

These new blood vessels supply the cancer cells with oxygen, nutrients, and growth factors for rapid growth and proliferation. They also help the cancer c