When people inhale the fibers of asbestos, they can develop a range of different respiratory diseases. These include benign pleural effusion, pleural plaques, asbestosis, lung cancer, and malignant mesothelioma. Asbestos is now strictly regulated, but because asbestos-related illnesses can take a long time to develop, patients continue to present with the disease to this day.

The signs and symptoms of asbestos exposure can be very nonspecific. As a result, physicians will usually question the patient’s history in order to determine whether asbestos exposure took place. Those who worked on the railroads or shipyards, boilermakers, construction workers, and U.S. Navy veterans will be tested for asbestos-related illnesses.

What Is Asbestos?

Asbestos is a mineral that was long known as a ‘miracle mineral’ because of its heat and fire resistant properties. There are deposits all over the world, including in the air. It is flexible, durable, and resistant to corrosion, which made it very popular for use in construction. The first time that there was any scientific proof on the link between asbestos and lung disease was in 1890, although there are suggestions that this link existed dating back as far as the Ancient Roman Empire. By 1907, the first deaths linked to asbestos exposure were reported. In 1931, the United Kingdom led the way by instating legislation to control exposure. The U.S. didn’t follow suit until 1971.

Asbestos-Related Illnesses

The vast majority of asbestos-related illnesses have a very poor prognosis. Those who are identified to have been exposed to asbestos can be tested and assessed regularly, but it is not clear whether this will improve the outcomes in any way. Those who know they have had significant exposure and who present with dyspnea are tested through spirometry and chest radiography.

In terms of prognosis, the entity of the disease will be the main determining factor. Usually, those who have asbestosis present a very slow progression of the condition. The worst prognosis is for those with malignant mesothelioma. Treatment tends to be the same as for patients who have lung cancer. It is also essential that they stop smoking, as this is a significant contributing factor to the development of the disease. Patients will also be given pneumococcal and influenza vaccinations as a precaution.

Malignant mesothelioma, in particular, has a very long latency, averaging at around 30 to 40 years. As such, it is believed that incidents of mesothelioma will continue to rise until at least 2020. Interestingly, it is not clear how prevalent exposure has been in this country. However, some 20,000 people have been diagnosed with asbestosis and discharged from hospital in 2000, and there were 2,000 deaths associated with it. It is believed that these numbers will continue to rise throughout this decade. Similar increases are expected with regards to malignant mesothelioma and asbestos-related lung cancer.

Currently, no link has been found between tuberculosis and asbestos exposure. However, it can easily be mistaken for benign pleural disease, which those who have been exposed to asbestos can expect to develop. This is because of the presence of collagen deposits in the lungs, which may calcify. In most cases, no symptoms are present and there is no evidence to suggest these plaques can become malignant lesions. Around 50% of all those who have had prolonged or significant exposure to asbestos will develop benign pleural disease. The plaque deposits are often hard to spot, being almost invisible on an x-ray. In fact, only 50% are found with a full CT scan. Generally, the plaque formations become clear some 10 or 20 years after someone was exposed. Also, the effusions may come and go over time. Those who develop exudative pleural effusions will need to have a biopsy taken. This is because it is possible that the condition is actually tuberculous. There is also the possibility, particularly if the patient suffers from pain, that the condition is actually malignant mesothelioma.

Malignant Mesothelioma

Pleural malignant mesothelioma is the most often encountered type of mesothelioma. It is a rare cancer type that affects the lungs’ outer lining, although it can also appear in the vaginalis, pericardium, or abdominal cavity lining. It is caused by breathing in airborne asbestos fibers, which lodge themselves in the chest wall and the lungs. The latency period of mesothelioma can be as short as ten years, but is usually closer to 60 years. As a result, many people currently have the condition but are not aware of it yet. Thus, those who know that they have been exposed to asbestos should seek medical attention to be monitored.

One of the reasons why the prognosis of malignant mesothelioma is so poor is that it is often not caught until it is in an advanced stage. In fact, when someone starts to show symptoms of mesothelioma, physicians will often consider other conditions. These include pneumonia, influenza, and tuberculosis. Thus, there is a significant danger of physicians misdiagnosing someone because of the non-specific symptoms.

Similarities Between Mesothelioma and Tuberculosis

There are a number of reasons why physicians can confuse tuberculosis and mesothelioma. These reasons include the fact that:

  • Both conditions are quite rare in today’s day and age.
  • Both conditions come with chest pain, inexplicable weight loss, night sweats, shortness of breath, and a persistent dry cough.
  • Both conditions leave patients coughing up blood and having difficulty in swallowing.
  • With both conditions, lumps can be found under the skin of the chest.

Differences Between Mesothelioma and Tuberculosis

The differences between mesothelioma and tuberculosis, from a clinical perspective, are huge. They include the fact that:

  • Tuberculosis is a bacterial infection, through which nodules are grown on the tissue of the lungs. Mesothelioma is a form of cancer that usually takes over all of a person’s healthy lung tissue.
  • Tuberculosis will appear in both lungs. Mesothelioma, in the first three stages in particular, will only appear on one side of the chest.
  • Tuberculosis can be treated with broad spectrum antibiotics. Mesothelioma, if it can be treated at all, requires surgery, chemotherapy and radiotherapy.
  • Tuberculosis is a wholly curable disease. The prognosis for mesothelioma, by contrast, is very poor with few people surviving one year after diagnosis.

Prognosis of Mesothelioma

The prognosis for people with mesothelioma is incredibly poor. Even if caught early, the outlook isn’t very good. The survival rate 10 years after diagnosis of mesothelioma is just 10%, and just half of those will survive a further five years. Treatment exists, but mesothelioma cannot be cured, which is the same with all cancers. If caught soon enough, people can attempt treatment through chemotherapy, radiation therapy, and surgery, More often than not, however, palliative care is offered instead, which focuses mainly on alleviating the symptoms.

Those who have mesothelioma often develop pleural effusions, which are the most life-limiting and uncomfortable symptoms associated with the illness. It refers to a buildup of fluids in the lungs, which makes breathing painful and limited. Again, this can be confused with tuberculosis, although a good physician should be able to tell the difference.

Mesothelioma Could Respond to Tuberculosis Treatment

Interestingly, there is now a suggestion that patients with mesothelioma could respond positively to treatment usually reserved for tuberculosis patients. Many people who develop pleural effusions opt for pleurodesis, which is a dangerous, painful, and only marginally effective treatment to drain the fluids from the lungs. Researchers have been trying to develop a non-invasive method to provide relief to patients, and this has led them to develop a whole new cancer treatment based on tuberculosis treatment.

For example, a 54 year old woman in China presented with pleural effusion. It was believed that she had late stage mesothelioma with effusion due to her symptoms, which included fevers, night sweats, chest pains, shortness of breath, and coughs. It was later found that she had squamous cell carcinoma rather than mesothelioma, however. Nevertheless, her doctors tried to treat her by providing her with anti-tuberculosis drugs. The therapy was a combination of ethambutol, rifapentine, pyrazinamide, and isoniazid, which are all antibacterial drugs and which are always provided to patients with tuberculosis. What they found was that her pleural effusion was fully eliminated and did not come back while she took the medication. In fact, she took the drugs for 16 months and was completely free of symptoms during that time. As a result, research is now taking place as to how tuberculosis drugs could potentially help people who have developed mesothelioma, be that as a palliative care method, or an actual cure for the disease.