Mesothelioma and Lung Cancer

Most assume that mesothelioma is the same disease as lung cancer. Over the years, we have learned so much about mesothelioma and we’ve learned what sets this disease apart from lung cancer. Mesothelioma and lung cancer are diagnosed and treated very differently, so it is important to understand the fundamental difference between the two.

Lung Cancer, What is it?

Lung cancer is an abnormal growth of cells (cancer cells) that begin to grow in one or both lungs. Lymph nodes may or may not be involved. When these abnormal cells begin to fester and grow rapidly, they can start to interfere with daily activities. Symptoms may begin to appear as these cells continue to grow. Some symptoms are: shortness of breath, cough, decreased oxygenation, and/or chest discomfort.

Types and Staging

Lung cancer can be divided into two main categories: small cell and non-small cell. The largest group of lung cancer (85%) is non-small cell lung cancer and it can be divided into stages (I, II, IIIA, IIIB, IV). To make matters a little more complicated, there are three different forms of non small cell lung cancer. Adenocarcinoma (most common), squamous cell (also called epidermoid), and large cell. The main type of non-small cell lung cancer that is associated with non-smokers is adenocarcinoma. We all know the leading cause of lung cancer is cigarette smoking, but this is not always true.

Then there’s the bad boy – small cell lung cancer. Small cell lung cancer is not staged in the same way as non small cell lung cancer. It is staged differently and the two categories are limited stage or extensive stage. Small cell lung cancer is very aggressive as it is not only fast growing, but also fast spreading in nature. This should be treated immediately with chemotherapy and/or radiation to quickly slow the growth of these rapidly producing cells.

Carcinoid

We are seeing more and more lung carcinoid now than ever before. This is very different from non-small cell and small cell lung cancers. This tumor actually begins with different types of cells – neuroendocrine cells (cells that produce hormones). These types of cells line the small intestines as well as the lungs. These are grouped into two different groups: typical and atypical. Many cancer centers have developed carcinoid programs to better assist patients with this specific malignancy.

Mesothelioma

Malignant Mesothelioma is not the same as lung cancer. This cancer affects the lining of organs – this includes not only the lung, but also the abdomen and heart.
There are three main types of mesothelioma: epithelioid (most common type), sarcomatoid, and mixed/biphasic. Epitheliod mesothelioma is a slower growing process and has more of a likelihood of recovery with treatment.

There are several factors that make mesothelioma stand out from all different types of cancer.

• Mesothelioma is not directly linked with smoking. The stigma of lung cancer is the association with smoking. Cigarette smoking can worsen the symptoms of mesothelioma, however, the direct cause of mesothelioma is not smoking.
• This is the only type of cancer that has a known direct link with asbestos exposure. The exposure to asbestos may not only be direct (working in a shipyard or installing asbestos drive ways many years ago), but it may also be indirect contact (washing the clothes of a spouse working in a plant or shipyard). The exposure may occur via inhalation (breathing in asbestos) or the ingestion (swallowing asbestos fibers). Both forms of consumption are typically unknown at the time of exposure.
• Mesothelioma is not found as a tumor in a certain part of the lung or abdomen, it is found in the lining of the lung (pleura), lining of the heart (pericardium), or lining of the abdomen (peritoneum).

Asbestos Related Lung Disease

While mesothelioma and lung cancer are two separate diseases, it is important to discuss asbestos related lung cancer. With an exposure to asbestos, it is still possible to have lung cancer and not have mesothelioma. There are many studies that link an increased risk of lung cancer to workers exposed with asbestos. In those who have been exposed to asbestos and smoke, their chance of lung cancer greatly increases.

Asbestosis is also important to discuss as this is a condition that is directly related to asbestos exposure that will require long term surveillance. Over time, the lung tissue becomes scarred and this process can become lung cancer. The risk of asbestosis becoming lung cancer greatly increases with smoking.

After discussing what mesothelioma and lung cancer are as separate diseases, you can see how very different they are. Although both diseases have very similar symptoms, they are both very different cancers in the way they are diagnosed and treated.