Mesothelioma vs. Lung Cancer

Differences Between Mesothelioma & Lung Cancer Development

Asbestos exposure can cause a malignant mesothelioma tumor and lung cancer to develop, but the two cancers differ in location, growth pattern, treatment and other aspects. Lung cancer develops inside the lung space, while pleural mesothelioma develops on the lung’s outer lining. Mesothelioma can also develop in the lining of the abdomen, heart or testes.

Doctors diagnose roughly 2,800 cases of malignant mesothelioma across all types of the rare asbestos-related cancer each year. Lung cancer is the second-most common cancer in the U.S., with about 222,500 new cases annually.

Mesothelioma grows slowly, with small nodules that eventually grow together into a sheath-like tumor around the organ. Lung cancer grows in larger, individual nodules with defined boundaries. Mesothelioma is a locally aggressive disease that tends to remain near its origin, while lung cancer spreads or metastasizes early to other organs.

Mesothelioma is often misconstrued as “mesothelioma lung cancer” but is almost exclusively the result of asbestos exposure. Conversely, most lung cancer cases are attributed to tobacco use and environmental exposures such as radon gas. Each risk factor damages lung tissue. Combined, smoking and asbestos increase lung cancer risk at least fiftyfold.

Similarities Between Mesothelioma and Lung Cancer

Mesothelioma and lung cancer are similar in the time they take to develop – often decades – and each can spread to distant organs within months. Both also have comparable diagnostic procedures and treatment techniques.

Death rates by state for mesothelioma and lung cancer tend to correlate with each other. The five states with the most mesothelioma deaths also have the most lung cancer deaths.

In addition, lung cancer and mesothelioma have overlapping symptoms. They both commonly cause chest pain, coughing, difficulty breathing, fatigue and weight loss. Doctors are more likely to suspect lung cancer or mesothelioma if a patient has these symptoms along with a history of asbestos exposure, smoking or both.

Despite having several similarities, lung cancer and mesothelioma differ in physical characteristics and nonasbestos risk factors.

Diagnosing Mesothelioma and Lung Cancer

Diagnosing mesothelioma and lung cancer requires a doctor to perform a biopsy. A CT or PET scan alone is unreliable for differentiating between lung cancer and mesothelioma. Biopsies may be performed via a bronchoscopy, needle biopsy or thoracoscopic surgery.

During a bronchoscopy, the doctor inserts a tiny camera down the throat and airways to detect abnormalities such as visible tumor growth. If the doctor finds irregular growth, they may collect a cell sample and test it for cancer.

A needle biopsy under local anesthesia involves placing a small needle into the tumor using an ultrasound machine or CT scan to visualize it. A thoracoscopic surgery under general anesthesia collects a solid tissue sample using a small camera inserted between the ribs. Fluid buildup is suctioned out for testing but isn’t a reliable way to confirm a diagnosis.

Most patients with pleural mesothelioma will either show pleural thickening, which is extensive scarring in the chest cavity lining, or pleural effusion, fluid buildup in the chest cavity. Pleural thickening may not appear in lung cancer. However, pleural effusion is shared in both.

Treating Mesothelioma and Lung Cancer

Mesothelioma and lung cancer treatment options largely depend on the cancer stage or how much the cancer has spread. Most treatment plans include some combination of surgery, radiation therapy or chemotherapy. Cisplatin is an effective chemotherapy drug for both lung cancer and mesothelioma.

If the cancer is localized to the lung area, surgery may be able to remove most or all of the tumor growth. In lung cancer, surgeons may remove the cancerous lobe of the lung via a lobectomy procedure. Mesothelioma surgeons might remove the pleural lining of the lungs in a pleurectomy and decortication.

A 2021 clinical research study found that certain types of radiation, such as focal radiotherapy, are less effective for the treatment of lung cancer than mesothelioma. Experimental therapies through clinical trials for both cancers include immunotherapy, gene therapy, photodynamic therapy and cryotherapy.

Watch: Dr. Fontaine explains why mesothelioma is more difficult to treat than lung cancer.

Prognosis for Mesothelioma vs. Lung Cancer

The prognosis for mesothelioma and lung cancer differs for each patient based on several factors, such as an accurate diagnosis, cancer stage, overall health and access to specialized care.

Survival rates for lung cancer and mesothelioma are similar after one year: 42% of lung cancer patients and 39% of mesothelioma patients are alive one year after diagnosis. However, more lung cancer patients than mesothelioma patients survive at least five years.

The higher rate of lung cancer cases means more widespread access to specialized treatment centers and doctors. Mesothelioma is much rarer, leaving patients with fewer options to improve their prognosis.

Common Questions About Mesothelioma Vs. Lung Cancer

Is mesothelioma a form of lung cancer?

Mesothelioma is not a form of lung cancer. Lung cancer develops inside the lungs while mesothelioma causes tumors of the pleural tissue, or pleura, that surrounds the outside of the lungs, diaphragm and chest cavity. Both diseases can be caused by inhaling asbestos fibers. Mesothelioma can also develop in the peritoneum, which lines the abdominal cavity, and in rare cases it can form in the testes or the lining of the heart.

What are the warning signs of mesothelioma?

The earliest signs of mesothelioma include:

• Shortness of breath
• Chest pain or discomfort
• Persistent cough
• Fever or night sweats
• Nausea, vomiting or diarrhea
• Abdominal pain or swelling
• Lack of appetite or weight loss

Should you see a mesothelioma specialist if you have asbestos-related lung cancer?

Pleural mesothelioma doctors are a patient’s best resource for receiving accurate and effective treatment for asbestos-related lung cancer. These specialists have expertise in diagnosing and treating several asbestos-related diseases, and they understand the complexities of lung cancer caused by asbestos. Top mesothelioma doctors can also connect you with clinical research trials and specialized treatments for patients with asbestos-related lung cancer.