Straight Talk about Mesothelioma, a blog series created by Michael T. Milano, M.D., Ph.D., a radiation oncology specialist, as a resource for mesothelioma patients and their loved ones.

Even though there has been a significant reduction in asbestos use in the U.S. since the 1970s, the incidence of mesothelioma has continued to rise over the past several decades. With all of the known dangers associated with asbestos, why is that the case?

The main reason for this rise in cases of this rare form of cancer is the long latency period between asbestos exposure and development of symptoms from the cancer. Whenever mesothelioma is suspected in a patient, the doctor will always first ask about prior exposure to asbestos in a past job or occupation (e.g. shipbuilding, mining, construction, or electrical work) or about potential secondhand exposure (e.g., washing clothes of someone who was exposed to asbestos).

What Are the Symptoms of Mesothelioma?

The majority of individuals who have early mesothelioma – mesothelioma which has not fully presented itself – usually will not show any noticeable symptoms, which makes mesothelioma a “sneaky” kind of cancer that is often extremely difficult to detect, even by some of the best doctors.

By definition, “symptoms” means the patient has been experiencing something adverse or unusual, and when it comes to mesothelioma, often these effects do not present themselves until very late in the cancer’s development. Mesothelioma is a cancer that grows very slowly, often taking 20 to 50 years to develop. However, as the tumor grows in size, the following symptoms may occur:

  • A Cough which is often dry and hacking in nature. The cough is persistent and does not go away. When the cough is severe, some individuals may develop hoarseness of voice.
  • Vague pain along the lower rib cage or in the back can occur. The pain is most often not excruciating but persistent and achy. Sometimes the pain may be worsened when the affected person coughs or tries to take a deep breath.
  • Shortness of breath is a very common symptom when the tumor is advanced. Most people with an advanced mesothelioma tumor will not have any exercise endurance and will get tired quickly, even with minimal activity.
  • A low-grade fever may occur and persist. Often such a fever is mistaken for a throat infection because throat infections are commonly associated with a cough.
  • Fatigue is another delayed symptom which can be moderate to severe, depending on each individual. The fatigue is chronic and is not relieved by rest.
  • Excess sweating can occur and sometimes be profuse.
  • In advanced cases of mesothelioma, unintentional weight loss is common. The individual has decreased appetite and may appear thin and emaciated.
  • The individual may cough up tiny streaks of blood (a condition known as hemoptysis).
  • Swelling of the arms and/or face is uncommon with mesothelioma, but may occur in individuals whose cancer is located in the center of the chest cavity rather than in the periphery.

Of the above symptoms, the majority of individuals will at some point present with either shortness of breath and/or vague chest pain. Unlike many other cancers, mesothelioma usually remains localized to the chest area and hence patients very rarely have symptoms related to other organs.

It is also important to note that the above symptoms are very common and can be mistaken for a number of other medical disorders like emphysema, bronchitis, heart failure, and even fibrosis of the lung. Most medical professionals will agree that it is not possible to make a diagnosis of mesothelioma based only on presence of symptoms alone. In general, because of the vagueness of the symptoms, there is a usually a delay of 3-to-6 months before a definitive diagnosis can be made.

What Are the Signs of Mesothelioma?

It is important to note that a “sign” in comparison to a “symptom” is something that a physician discovers during a physical exam. During the early stages of mesothelioma, there may be no specific physical findings. During advanced cases, however, most of the findings – or “signs” – are related to the chest cavity. For example, there may be a large collection of fluid or the patient may have obvious difficulty with breathing. Rarely, the physician will discover enlarged lymph nodes in the armpit (axilla). With a stethoscope, the doctor may discover the presence of fluid in the chest.

How Is the Diagnosis of Mesothelioma Made?

When a patient makes a visit to his or her doctor and mentions a history of asbestos exposure and, at the same time, presents with some, or all, of the above symptoms – especially shortness of breath and vague chest pain – the physician will first request imaging tests and then if an abnormality is seen, the physician will arrange for a biopsy to confirm the presence of mesothelioma.