Cancer Explained Simply

Cancer happens when some cells in your body start growing out of control. Normally, your body makes new cells to replace old or damaged ones. But sometimes this process goes wrong — cells grow when they shouldn't, and they don't die when they should.

These extra cells can form a lump called a tumor. Not all tumors are cancer — benign tumors don't spread. But malignant (cancerous) tumors can invade nearby tissues and spread to other parts of the body.

Cancer is not one disease — it's hundreds of different diseases, each with different causes, behaviors, and treatments. That's why your treatment plan is unique to you.

Chemotherapy ("chemo") uses powerful medicines to kill cancer cells or stop them from growing. It works throughout your entire body — that's why it can treat cancers that have spread.

How it's given: Usually through an IV drip (infusion) at the hospital, sometimes as tablets you take at home. Treatment happens in "cycles" — treatment days followed by rest days so your body can recover.

Side effects: Because chemo affects fast-growing cells (both cancerous and healthy ones), you may experience hair loss, nausea, fatigue, or low immunity. These are manageable and usually temporary.

It's not as scary as it sounds. Modern anti-nausea drugs and supportive care have made chemotherapy much more tolerable than it was 20 years ago.

Immunotherapy helps your own immune system recognize and fight cancer. Think of it like removing the "brakes" that cancer puts on your immune cells.

Unlike chemotherapy, which directly kills cells, immunotherapy trains your body to fight the cancer itself. This means it can sometimes produce longer-lasting responses.

Not all cancers respond to immunotherapy — it works best in certain types. Your oncologist will test your tumor to see if you're a candidate.

Targeted therapy uses drugs that specifically attack the changes (mutations) in cancer cells that help them grow. It's like a "smart bomb" compared to the "carpet bombing" approach of traditional chemotherapy.

Examples include HER2-targeted drugs for breast cancer, EGFR inhibitors for lung cancer, and PARP inhibitors for ovarian cancer.

These drugs often have fewer side effects than chemotherapy because they're more precise. Your doctor will order molecular tests on your tumor to find out if targeted therapy is right for you.

Cancer staging tells us how far the cancer has grown or spread. It helps decide the best treatment.