Soluble mesothelin-related peptides

This test is limited to patients who have already been diagnosed with malignant mesothelioma. It is not used to diagnose the disease. This test is most often used in conjunction with imaging tests such as positron emission tomography (PET) and computed tomography (CT) to:

• determine if you are responding to treatment,
• see if the disease has spread,
• determine if the disease has returned after you have been treated.

However, if mesothelioma is a possible, but not yet a definite diagnosis, the test is not used to diagnose the disease but can also be used to help plan further investigations. For example, if SMRP is significantly elevated in a patient in which mesothelioma is a possible diagnosis a high resolution CT scan investigation may expedited. This can be particularly useful in a rural setting where access to such technology involves a decision to transport the patient a significant distance.

A physician might order a series of SMRP tests to monitor progression of mesothelioma or its recurrence:

• after diagnosis,
• after surgery to remove tumour tissue in the chest cavity,
• during and/or after chemotherapy or radiation therapy.

SMRP might be requested when a physician is planning the investigations for a patient in which mesothelioma is a possible diagnosis.

If a series of SMRP tests show SMRP levels are increasing, it may indicate that mesothelioma has progressed. If the series of tests indicates that SMRP levels are decreasing, you may be responding to therapy. If the levels are unchanged, it may mean that your disease has stabilised.

The interpretation of your SMRP test results will likely be done in conjunction with results from imaging studies. That is because:

• the test does not always provide physicians with useful information. Patients with other cancers —including lung, ovarian, endometrial, and pancreatic cancers - can have apparent elevated test levels as a result of their cancers producing substances that interfere with the test.
• some patients with epithelial mesothelioma, a form of the disease that affects the cavity lining or membranes, do not produce SMRP.

When used in investigation planning for someone with a possible diagnosis of mesothelioma but when high resolution CT scanning is difficult to access, if SMRP is elevated then referral for such scanning may be expedited.

This test is not used to diagnose mesothelioma but is usually used to monitor progression or recurrence. The diagnosis of this disease is often difficult and involves many steps. It usually begins with a review of the patient’s medical history, including a history of exposure to asbestos, and with a complete physical examination. These may be followed by imaging studies of the chest and abdomen, including X-rays and computed tomography (CT) scans, and with lung function tests. Diagnosis may be confirmed by examining tissue from a biopsy or fluid from the affected area for malignant cells.