Cancers are one of the leading causes of death worldwide with a combined death toll of 8.2 million in 2012. Cancers are a group of related diseases in which cells divide in an uncontrolled manner. They can occur in almost all dividing cells. Common forms of cancer include lung (1,590,000 per year), liver (745,000), stomach (723,000), colorectal (694,000) and breast cancer (521,000). Cancer is malignant meaning that it can spread to other parts of the body when a cancerous cell is transported somewhere else in the body. This cancer is a metastatic cancer.
Overall for all cancers, the 5 year survival rate in the US was 66.5%, in 2011. The 5 year survival rate has increased dramatically from 48.7% in 1975 to 66.5% in 2011. This is a huge change in the relative survival rate. Despite that, the fact that 40% of men and women in the US will be diagnosed with cancer at some point in their lives shows us just how deadly this set of diseases is. In 2012, it is thought that almost 14 million Americans were living with cancer.
Obesity and smoking are key factors in causing cancer with about 30% of cancers caused by lack of exercise and poor diets, as well as alcohol and tobacco use. Smoking is the leading cause of cancer accounting for 1/5 of cancer deaths and 70% of lung cancer deaths. Cancers can also be caused by viruses such as human papilloma virus (HPV) and hepatitis B virus (HBV) which we can vaccinate against.
Over the next 20 years global cancer cases are projected to increase by two-thirds from 14 million in 2012 to 22 million by 2032. The most effective way to reduce this will be by combatting the 30% of cases caused by lifestyle choices. All this said, different types of cancer are very different in prognosis and symptoms, so they probably shouldn’t be analysed as a set.