In studying the mesothelioma survival rate, the anatomy is divided into two classifications: Gross anatomy is the study of the anatomy that can be seen with the naked eye, and histology, which is the study of tissues.
In order to study the microscopic anatomies of the cells within tissues, a thin slice of tissue, called a sample, is stained with special dyes, which make the cells more visible under a microscope.
Histopathology is the study of diseased tissue. Pathologists examine the cells in samples of diseased tissue in order to help diagnose the nature of the disease.
Histology of the Mesothelium
When you have a mesothelioma diagnosis, in order to comprehend the statistics that make up the mesothelioma survival rate and totality, a better understanding of what makes up mesothelioma is not only practical, but necessary. Mesothelioma gets its name because the cells of this disease originate in the mesothelium. It is a membrane made up of a single layer of flat shaped cells that creates the lining of body cavities like the thoracic cavity, the abdominal cavity, the sac surrounding the heart, and the male and female reproductive organs
The part of the mesothelium that covers viscera or internal organs is called the visceral mesothelium. The part that lines the walls of the body is called the parietal mesothelium.
Histology of Mesothelioma Cells
Mesothelioma cells are divided into three different types:
- Epithelioid – This is the most common of the three different cell types, making up about half of all mesotheliomas. The cells appear as elongated nipple-like projections; however, when viewed under an electron microscope, they are multi-sided, with a distinct nucleus, and long hair-like projections along the surface. All of these cells are fairly uniform in shape. Epithelioid cells are connected to each other by dense structures made of protein plaques.
- Sarcomatoid – These are the rarest of the three types. A sarcomatoid cell is spindle-shaped with an elongated nucleus. When looked at under an electron microscope, the extensive membrane network that connects these cells is visible.
- Biphasic – These cells have features of both epithelioid and sarcomatoid cells.
Patients with epithelioid mesothelioma have the best prognosis. Those with sarcomatoid tumors have a much poorer prognosis because these cells are considered to be more aggressive.
Study demonstrates the Poor Mesothelioma Survival Rate of Patients with Sarcomatoid Mesothelioma
It is no coincidence that once insurance companies were made aware of the risk of asbestos to workers as early as 1908, they began decreasing their benefits. The Occupational Safety and Health Administration (OSHA) in the 1970’s along with other federal regulatory authorities began the regulation of asbestos. Today, strict laws protect workers from asbestos exposure. In a study about the mesothelioma survival rate titled “Therapeutic Surgery for Nonepithelioid Malignant Pleural Mesothelioma: Is it Really Worthwhile?” published March 2010 in The Annals of Thoracic Surgery, researchers analyzed the outcomes of 312 patients with pleural mesothelioma who underwent surgery.
Of these patients, 218 had epithelioid mesothelioma, 66 had biphasic and 28 had sarcomatoid. One hundred ninety-five patients had radical surgery, and 117 had non-radical surgery. The average survival was a little over 15 months in the epithelioid group, approximately 10 months in the biphasic group, and 5 months in the sarcomatoid group.
The researchers also made some other surprising discoveries about the mesothelioma survival rate:
- In the epithelioid group, the stage of the cancer, depending on the mesothelioma treatment options and whether the patient underwent radical/non-radical surgery and whether the patient had pre-operative or post-operative chemotherapy were factors that influenced the length of survival.
- In the biphasic group, the only real factor influencing a positive mesothelioma survival rate was whether or not the patient developed anemia.
- In the sarcomatoid group, only the stage of the cancer was a factor in the patient’s survival. The type of surgery the patient underwent had no effect on survival rates.
Read more about what the EPA has to say about asbestos and mesothelioma here.