How Cancer Kills: A Closer Look

In 2025, the NIH estimates that 2 million Americans will be diagnosed with cancer. The most common types—breast, lung, prostate, and colorectal—make up nearly half of all cases and deaths. But it’s not always the cancer itself that kills—it’s often the complications it causes.

Dr. Paulien Moyaert shared a powerful 3D simulation on YouTube showing how cancer progresses. The video explains how metastatic cancer—where cells break off and spread—can overwhelm organs, shutting them down entirely.

For example, if cancer grows in the digestive tract, it can block digestion or the expulsion of waste, leading to deadly complications like perforation. Pancreatic cancer is especially lethal, as it may cause the pancreas to digest itself—making it one of the most painful forms of cancer.

Lung cancer can lead to asphyxiation, a lack of oxygen throughout the body, which is often fatal. Meanwhile, weakened immunity is another danger. Cancer and chemotherapy suppress bone marrow, reducing white blood cells and increasing infection risk.

As bone marrow deteriorates, it can no longer produce healthy blood cells. This leads to anemia, infection, and internal bleeding due to a drop in platelets and immune cells.

Another severe complication is cachexia, or muscle wasting, which affects about half of cancer patients and significantly weakens the body.

Despite the grim picture, Dr. Moyaert emphasizes that cancer pain can be controlled. Treatments like morphine ensure that no one should suffer unnecessarily.

Understanding how cancer harms the body highlights the importance of early detection, proper care, and compassionate treatment. Dr. Moyaert’s video—viewed over 6.6 million times—offers insight into the realities of this disease and the importance of patient-centered care.