Cancer is one of the most devastating diseases we face. It occurs when genes that manage cell activity mutate, creating abnormal cells that can grow out of control and damage our body’s organs and tissue. Scientists know that there are six factors that contribute to cancer:

Cellular evolution

Every cell in the human body is subject to natural selection. That’s because individual cells are competing with other cells for resources such as nutrients and space. Cells that have acquired genetic changes that confer an advantage in these competitive situations are more likely to survive and reproduce. The cells with these beneficial traits then pass on these advantages to their offspring, and over time this can lead to a mutational process that causes the growth and spread of cancerous cells (23).

A mutation in any of the genes that direct cellular growth or cell death could make a normal cell become cancerous. These mutations are called driver mutations. They can affect three main types of genes: proto-oncogenes, tumor suppressor genes and DNA repair genes. Cancers caused by these mutations tend to be aggressive and resistant to treatment.

In most cases, cancer starts when a normal cell undergoes long runs of rapid cell division. The resulting increase in cell number makes the cells grow faster and out-compete nearby cells for nutrients, space and other resources. Over time, the abnormal cell population becomes densely packed, and this gives rise to the lumps of tissue that are known as tumors. In addition, the cancerous cells often ignore the signals that would normally stop them from dividing or that trigger a process called programmed cell death (apoptosis).

These characteristics of cancerous cells give them the ability to invade other tissues, travel through the bloodstream and lymphatic system, and settle in new places where they can cause additional cancerous growths. This is known as metastasis.

While we don’t yet know what actually causes most cancers, we do know that they develop in response to a combination of heredity and lifestyle choices. The most common risk factors are smoking and diet. Excessive alcohol consumption also increases the risk of several types of cancer.

Eat a balanced diet that includes plenty of fruits and vegetables, lean protein sources, whole grains and healthy fats. Limit red meat and processed meat, and opt for beans, nuts, seeds and fish. Limit your intake of alcohol – men should have no more than two drinks a day, and women no more than one drink a day. A daily multivitamin is a good idea too. And exercise regularly to maintain a healthy weight and keep your immune system strong. These factors can help reduce the chance of getting cancer, and keep it from coming back once it has been treated.