Cancer is not a foreign invader; it is your own cells malfunctioning

Science · Published 27 October 2026 Swipe more like this →

In short: Unlike an infection caused by a virus or bacteria, cancer originates from within. It is the result of your own body's cellular machinery following corrupted instructions. When these internal rules break down, normal cells begin to behave like rebels, growing uncontrollably and eventually threatening the entire organism.

At its core, cancer is a breakdown of the orderly process of cell division. In a healthy human body made of trillions of cells, new cells are created as needed while old or damaged ones undergo apoptosis, a form of programmed cell death. Cancer occurs when this cycle fails. Abnormal cells begin to multiply even in the absence of growth signals and ignore the biological commands that should tell them to stop dividing or die.

These malfunctioning cells can accumulate multiple chromosomal changes, such as deletions or duplications. In some cases, cancer cells may possess double the normal number of chromosomes. To sustain this rapid growth, they employ several survival strategies: they trigger angiogenesis—the growth of new blood vessels to supply oxygen and nutrients; they adapt to utilize different types of nutrients for energy; and they actively hide from or trick the immune system into protecting them rather than destroying them.

The danger of cancer lies in its ability to invade nearby tissues and travel to distant parts of the body, a process known as metastasis. While benign tumors remain localized and usually do not grow back once removed, malignant (cancerous) tumors can spread and recur. Because cancer is an evolving disease with over 200 different types, it remains difficult to defeat; however, as our understanding of these genetic mutations deepens, treatments like immunotherapy and targeted therapy are becoming more precise.

In the UK, statistics show that approximately 1 in 2 people will be diagnosed with cancer during their lifetime. Because it can start almost anywhere in the body—ranging from solid tumors to blood cancers like leukemias—the diversity of its presentation makes early detection and specific targeting the primary goals of modern medicine.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

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