Difference between Cancer Cells and Normal Cells

Updated on June 23, 2017

Cancer cells and normal cells are distinct in a number of ways – ways that could literally make the difference between life and death. This article provides valuable information on the differences between the two.

Definitions

Cancer Cells
A graphic comparison of cancer cells and normal cells

Cancer cells are cells that incessantly divide and reproduce. Unlike healthy cells, cancer cells are unresponsive to external stimuli that signal cells to stop dividing. Since cancer cells are self-stimulating, they relentlessly divide until they flood the bloodstream with abnormal cells and form tumors.

Because they are not bonded by adhesion molecules, cancer cells can grow and reproduce in different parts of the body. Once a cancer cell reaches a secondary site, it colonizes the site and metastasizes (spreads).

Normal cells, on the other hand, are cells that are important for normal physiological function. They exist in different sizes and shapes, depending on their type and location. Since normal cells are bonded by adhesion molecules, they cannot transfer from one site to another. They are localized cells that respond to external signals sent by the body.

Normal cells divide to either form new tissues or replace damaged and old, dying cells. Once the body sends signals, normal cells stop reproducing.

Cancer Cells vs Normal Cells

So what’s the difference between cancer cells and normal cells?

Firstly, normal cells are cells that are essential for normal physiological function, while cancer cells are abnormal cells that rapidly grow and reproduce.

During cell division, normal cells replace damaged cells to form tissues and maintain normal bodily function. Unlike cancer cells, normal cells are responsive to external stimuli that signal them to stop multiplying. Cancer cells, on the other hand, ignore external stimuli and continuously divide and reproduce until they form clusters called tumors.

Similarly, normal cells can undergo cell division for a limited number of times, while cancer cells can multiply endlessly.

Additionally, normal cells secrete a sticky substance that binds them together as a group. This substance prohibits them from transferring from one site to another, enabling them to remain localized. Cancer cells, by contrast, can break away from other cells and leave their site of origin. Once they find a secondary region, they rapidly grow and metastasize within the area.

Normal cells undergo the process of apoptosis, a process where old or damaged cells either die or get repaired. Cancer cells, by comparison, refuse to self-destruct. Old or damaged cancer cells continue to multiply and metastasize.

Lastly, cancer cells prevent T cells, a lymphocyte in the immune system, from attacking tumors. They can even trigger the growth of additional blood vessels to encourage tumor development.

Comparison Chart

Cancer CellsNormal Cells

Abnormal cells that rapidly grow and reproduce

Cells that are essential for normal physiological function
Unresponsive to external stimuliResponsive to external stimuli
Can multiply endlesslyCan undergo cell division for a limited number of times
Not bonded by groupsBonded by groups
Capable of transferring from one site to anotherLocalized
Do not undergo apoptosisUndergo apoptosis
Capable of preventing T cells from attacking tumorsNot capable of preventing T cells from attacking tumors
Trigger the growth of blood vessels to encourage tumor developmentDo not trigger the growth of blood vessels to encourage tumor development