Liver and lung cancer can develop independent of each other. A person may, however, have both of these types of cancer at the same time. This typically occurs when cancer of the lung spreads to the liver. In most cases, liver cancer is a secondary cancer, which means the disease is less likely to start in the liver and spread to the lungs. This can happen, however. The risk factors for liver and lung cancer are generally different, so the two types of cancers are not connected in this way.
There is really no close relationship between liver and lung cancer. Essentially, this means a diagnosis of lung cancer doesn’t necessarily mean a person will develop liver cancer or vice versa. The way these conditions are related has more to do with secondary cancer cases. A person may, for example, develop a primary case of lung cancer, which means the cancer originated in his lungs. Eventually, the cancer may spread to the liver, which is referred to as a secondary cancer since it did not originate there.
If an individual has primary liver cancer, which means the disease originates in the liver, the cancer may also spread to the lungs and other organs. Primary liver cancer is, however, less common than secondary liver cancer. With primary liver cancer, a person does not develop cancer of the lungs at the same time as he develops cancer of the liver. Instead, cancerous cells from the liver move to the lungs. The cancerous cells spread through the patient’s lymph fluid or blood. Interestingly, doctors can tell whether the cancer originated in the liver or the lungs because liver cancer cells that make their way to the lungs still look and behave like liver cancer cells.
While it may seem logical that the relationship between liver and lung cancer would include risk factors, this is usually not the case. The primary risk factors for lung cancer differ dramatically from the primary risk factors of liver cancer. For example, some primary risk factors for lung cancer include smoking, exposure to secondhand smoke, exposure to chemical agents known to cause lung cancer, and a family history of this type of cancer. A few of the primary risk factors for liver cancer, on the other hand, include chronic hepatitis infection, cirrhosis of the liver, excessive alcohol consumption, and inherited conditions such as Wilson’s disease. Additionally, men and older adults are more likely than others to develop primary liver cancer.