Exposure to asbestos generally causes two major types of cancer: Mesothelioma and asbestos-related lung cancer. Both types of cancers affect the lungs and chest and can cause pain and difficulty breathing.
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.
Each disease can take decades to develop yet only months to spread to distant organs. Both have similar diagnostic procedures and treatment techniques.
In addition, lung cancer and mesothelioma have overlapping symptoms. They both commonly cause chest pain, coughing, difficulty breathing, fatigue and weight loss. If a patient has these symptoms along with a history of asbestos exposure and/or a history of smoking, doctors should immediately suspect lung cancer or mesothelioma.
But despite having a number of similarities, lung cancer and mesothelioma differ in physical characteristics and non-asbestos risk factors.
While mesothelioma and lung cancer can develop after exposure to asbestos, each occurs in different areas of the body. Lung cancer develops in the lung itself, while mesothelioma usually develops in the lining of the lung. Mesothelioma can also develop in the lining of the abdomen, heart or testes.
The two cancers grow differently. Lung cancer tends to grow in individual masses with defined boundaries. Mesothelioma starts as tiny tumor nodules that scatter the mesothelial lining, and eventually grow together to form a sheath-like tumor around the organ.
Mesothelioma is almost exclusively the result of asbestos exposure, while the majority of lung cancer cases are attributed to tobacco use and environmental exposures to substances such as radon gas and secondhand smoke.
And while smoking does not influence risk of mesothelioma, it greatly increases an individual’s risk of developing lung cancer. Those with the highest risk of lung cancer are smokers with a history of asbestos exposure.
By themselves, each risk factor damages lung tissue and makes it more susceptible to diseases. So when smoking and asbestos are combined, an individual’s lung cancer risk increases at least fiftyfold.
Statistics about mesothelioma show that more than 80 percent of mesothelioma cases are the result of asbestos exposure.
This cancer typically takes 20 to 50 years to develop after initial exposure to asbestos.
90 percent of all lung cancer deaths are attributed to tobacco use.
Radon exposure is the second-leading cause of lung cancer.
Lung cancer has a shorter latency period and may appear 10 to 30 years after first exposure to a carcinogen like asbestos or cigarette smoke.
To diagnose either type of cancer, a doctor may perform an X-ray, a bronchoscopy or a biopsy. During a bronchoscopy, the doctor inserts a tube down the throat and into the airways of the lung to detect abnormalities such as visible tumor growth. If the doctor finds irregular growth, he or she may collect a cell sample and test it for cancer.
In a biopsy, the doctor removes a small portion of suspicious tissue and tests it for cancer growth. The doctor may be able to perform this procedure using only a needle and no incision. To collect a larger sample, however, he or she may need to perform a minor biopsy surgery.
Another test is performed only when doctors suspect a patient has lung cancer. In this test, called sputum cytology, the doctor collects and tests a sample of thick phlegm that the patient coughed up from the lungs. This test may reveal abnormalities like blood or cancerous cells in the phlegm.
For mesothelioma and lung cancer, treatment options largely depend on how much the cancer has spread. Most treatment plans include some combination of surgery, radiation therapy or chemotherapy.
If the cancer is localized to the lung area, surgery may be able to remove all or most of the tumor growth. But surgeries vary by specific type of cancer.
To treat pleural mesothelioma a surgeon may remove the lining of the lung, the affected portion of the lung or the entire cancerous lung and its linings.
Typical lung cancer surgeries include removing a small portion of the lung, a lobe of the lung or the entire lung.
For both types of cancer, chemotherapy and radiation therapy are also considered as possible additional approaches to treatment. If the mesothelioma or lung cancer is localized, either treatment can be used to shrink tumor growth and potentially kill all tumor cells. When used in this potentially curative way, chemotherapy and radiation therapy are typically combined with surgery. These treatments can still be used if the cancer has spread beyond its original location. In these cases, treatments are palliative and aim to reduce symptoms.
Experimental therapies are being tested through clinical trials for both cancers. Some of these innovative therapies include immunotherapy, gene therapy, photodynamic therapy and cryotherapy. Photodynamic therapy is used more routinely in the treatment of lung cancer than in mesothelioma.
One year after diagnosis, survival rates for lung cancer and mesothelioma are close: 42 percent for lung cancer patients and 39 percent for mesothelioma patients. Survival rates diverge after several years, with lung cancer patients having a long-term survival advantage.
Beyond the statistics, though, is the need for someone with an asbestos cancer to secure an accurate diagnosis: Is it asbestos-related lung cancer or is it mesothelioma? The next step would be to formulate the best individual treatment plan.
Karen Selby joined Asbestos.com in 2009. She is a registered nurse with a background in oncology and thoracic surgery and was the director of a tissue bank before becoming a Patient Advocate at The Mesothelioma Center. Karen has assisted surgeons with thoracic surgeries such as lung resections, lung transplants, pneumonectomies, pleurectomies and wedge resections. She is also a member of the Academy of Oncology Nurse & Patient Navigators. Read More