Many people have been diagnosed with cancer or have a loved one who has received such a diagnosis.

In fact, according to estimates from the International Agency for Research on Cancer, by 2030 there will be 21.7 million new cases of cancer. That estimate means cancer cases will have increased considerably since 2012, when the IARC reported there were 14.1 million new cases of cancer.

The World Health Organization notes that between 30 and 50 percent of cancers can currently be prevented by avoiding risk factors and implementing evidence-based prevention strategies. That requires men, women and children to learn as much as they can about cancer, including how it grows.

The Canadian Cancer Society notes that the human body is made up of trillions of cells that are grouped to form tissues and organs. Each cell contains genes within its nucleus that tell it when to grow, work, divide and die. In healthy people, cells follow these instructions.

However, sometimes a change in DNA or damage to DNA can result in mutated genes that don’t work properly. In such instances, the communication between genes and cells is mixed up, and that miscommunication can cause cells that should be resting to divide and grow uncontrollably. That uncontrolled growth can lead to cancer.

The CCS notes that gene mutations can sometimes be inherited. In other instances, genes may mutate as the body ages and the genes wear down. External factors, such as cigarette smoke, ultraviolet radiation from the sun and alcohol can damage genes, paving the way for mutations to transform genes from normal cells into cancer cells. No cell in the body is immune to becoming a cancer cell.

While there are no ways for people to guarantee they won’t get cancer, avoiding tobacco and embracing a healthy lifestyle that includes routine exercise and a diet that’s rich in fruits and vegetables can help reduce risk.