Study Finds Unique Cell Surface Proteins to Identify Pleural Mesothelioma

Enlarged photo of cell surfaces

Early detection and diagnosis are essential to maximizing a mesothelioma patient’s life expectancy. Mesothelioma is difficult to diagnose due to several factors, including a long latency period and nonspecific symptoms. As a result, the disease is often misdiagnosed, which can impact treatment and prognosis. One study estimated the rate of misdiagnosis for pleural mesothelioma is as high as 41%.

However, a recent study examines how immunohistochemistry may be a useful tool in the mesothelioma diagnostic process. Researchers were able to identify several cell surface proteins unique to malignant pleural mesothelioma cells.

The Challenge of Obtaining an Accurate Mesothelioma Diagnosis

Doctors and treatment specialists have trouble diagnosing mesothelioma for many reasons. For instance, many other illnesses share common mesothelioma symptoms.

Pleural mesothelioma patients often present with vague symptoms, such as chest tightness, shortness of breath, coughing and weight loss. These symptoms may be misattributed to other types of cancer or less serious diseases, such as influenza, bronchitis and asthma.

Because early symptoms can be attributed to other health issues, malignant pleural mesothelioma is often diagnosed in later stages. Identifying mesothelioma at an earlier stage can improve a patient’s prognosis.

Doctors study mesothelioma cell pathology to make diagnoses. However, cancer cells can be difficult to distinguish from each other. Therefore, new methods of detecting and diagnosing mesothelioma cells are important research topics.

In this study, researchers compared the characteristics of pleural mesothelioma cells to metastatic lung carcinoma cells.

Pleural Mesothelioma and Metastatic Lung Carcinoma Have Microscopic Differences

This study focused on finding unique visual differences on the surfaces of cancer cells. From 2009 to 2013, researchers at the Imam Reza Hospital in Tabriz, Iran studied cell differences in two cancer types. Researchers compared malignant pleural mesothelioma cells to metastatic lung carcinoma cells. Metastatic lung carcinoma is a type of cancer that affects fluid-secreting cells in the lungs.

Cells have proteins on their outer surface. The study theorized these proteins may help distinguish between the different cancer cells.

Researchers used a technique known as immunohistochemistry to visually identify the cell surface proteins. Under a regular microscope, proteins are not visible. However, immunohistochemistry uses special dyes that stain proteins, making them visible.

In this study, researchers analyzed tissue samples belonging to patients with confirmed diagnoses of either malignant pleural mesothelioma or metastatic lung carcinoma. The authors used immunohistochemistry to test these samples for the following surface proteins: CEA, CK7, TTF1, calretinin and HBME1.

Researchers confirmed some of these five proteins are found exclusively on either pleural mesothelioma or metastatic lung carcinoma cells, but not both. Therefore, these proteins can be used to distinguish between the two cancers.

Cell Surface Proteins Can Distinguish Between Pleural Mesothelioma and Metastatic Lung Carcinoma

The study confirmed the two cancers had unique cell surface proteins.

Malignant Pleural Mesothelioma Cell Surface Proteins

  • HBME1
  • Calretinin

Metastatic Lung Carcinoma Cell Surface Proteins

  • TTF1
  • CEA
  • CK7

As a result, specialists can use immunohistochemistry to test for these five proteins and differentiate between the two cancers. It can also help specialists diagnose pleural mesothelioma more quickly.

Early diagnosis is important for mesothelioma patients to increase life expectancy. In early stages of cancer, patients typically have less advanced tumor statuses. Due to the cancer being more localized in these stages, patients are often eligible for a wider variety of treatment options.

Research is important to understanding rare cancers like mesothelioma. Scientists continue to study diagnostic methods for mesothelioma.