Mesothelioma develops into cancer at a very slow rate, making it hard to initially diagnose. It can take anywhere from 25 to 40 years. The amount of time a patient takes to report symptoms varies from two weeks to two years, averaging about two months. Up to 25% of patients with Mesothelioma can have symptoms for six months or more before seeking medical attention. Since Mesothelioma is a slow developing disease, it tends to affect people between the ages of 50 and 70. Men are three to five times more likely to contract Mesothelioma than women, and it is less common in African Americans than Caucasians. The right lung is larger than the left lung, so the right side of the chest tends to be more affected than the left side of the chest.
The most common features associated with the development of symptoms include the presence of fluid, thickening of the pleura, and specific nodules or tumors that may develop in the chest of abdomen. Over half of the patients have chest pain, usually located low in the chest and toward the back and side. The pain has usually increased over time and can be severe enough to require narcotic pain medication. Severe, uncontrolled pain may be a sign of tumor invasion into the chest wall. The chest wall refers to the structures outside the lungs that move as a part of breathing, including the rib cage and diaphragm. Dyspnea (difficulty breathing) is another symptom commonly seen with this disease. This shortness of breath is usually due to fluid that has accumulated in the pleural space ( the space between the chest wall and the lung) from cancer. This fluid accumulation is called pleural effusion. In 95% of the cases, patients with pleural mesothelioma will have a pleural effusion at some time during the course of the disease. Cough, fever, fatigue, and weight loss will occur in about 30% of cases, and a small minority will have hoarseness or will cough up blood (hemoptysis). In only about 5% will the disease have spread out of the initial area of cancer (metastasis), usually traveling from the pleura spreading to the lungs, which can cause these last symptoms to occur
In abdominal or peritoneal mesothlioma, patients most frequently have increased abdominal swelling from fluid that has accumulated in the abdomen (ascites). They may also have pain and weight loss. Pain in the abdomen is usually due to an increase in the amount of solid tumor they have, and not because of fluid. Weight loss can be due to a decreased appetite because of the disease.
