Mesothelioma is a rare and aggressive form of cancer that affects the protective lining (mesothelium) of the body’s internal organs, primarily the lungs. Biphasic malignant mesothelioma is a subtype of this disease that is characterized by the presence of two distinct cell types: epithelioid and sarcomatoid. This unique combination of cell types can present a unique set of challenges when it comes to diagnosis and treatment.
What is Biphasic Malignant Mesothelioma?
Biphasic malignant mesothelioma is a type of mesothelioma that is characterized by the presence of both epithelioid and sarcomatoid cell types within the same tumor. Epithelioid cells are the more common and typically less aggressive cell type, while sarcomatoid cells are less common and generally more aggressive.
The Causes of Biphasic Malignant Mesothelioma
The primary cause of biphasic malignant mesothelioma, as well as other types of mesothelioma, is exposure to asbestos. Asbestos is a naturally occurring mineral that was widely used in a variety of industrial and construction applications due to its heat-resistant and durable properties. When asbestos fibers are inhaled or ingested, they can become lodged in the mesothelial lining of the lungs, abdomen, or heart, eventually leading to the development of mesothelioma.
The Prevalence of Biphasic Malignant Mesothelioma
Biphasic malignant mesothelioma is relatively rare, accounting for only about 10-20% of all mesothelioma cases. The exact prevalence of this subtype is difficult to determine, as it can be challenging to accurately diagnose and distinguish from other types of mesothelioma.
The Prognosis of Biphasic Malignant Mesothelioma
The prognosis for individuals with biphasic malignant mesothelioma is generally poorer than for those with the epithelioid subtype, but better than for those with the sarcomatoid subtype. The presence of both cell types can make the tumor more aggressive and resistant to treatment, leading to a shorter median survival time.
Symptoms of Biphasic Malignant Mesothelioma
The symptoms of biphasic malignant mesothelioma can vary depending on the location of the tumor and the stage of the disease at the time of diagnosis. However, there are some common symptoms that are often associated with this subtype of mesothelioma.
Difficulty Breathing
One of the most common symptoms of biphasic malignant mesothelioma is difficulty breathing, or dyspnea. This can be caused by the buildup of fluid in the pleural cavity (the space between the lungs and the chest wall), which can put pressure on the lungs and make it difficult to breathe.
Chest Pain
Chest pain is another common symptom of biphasic malignant mesothelioma. This pain can be caused by the tumor itself, as it grows and puts pressure on the surrounding tissues, or by the buildup of fluid in the pleural cavity.
Coughing and Hoarseness
Some individuals with biphasic malignant mesothelioma may experience persistent coughing or hoarseness of the voice. This can be caused by the tumor’s impact on the nerves or structures in the chest.
Abdominal Pain and Swelling
If the tumor is located in the abdominal cavity, individuals with biphasic malignant mesothelioma may experience abdominal pain and swelling. This can be caused by the buildup of fluid in the abdominal cavity, or by the tumor putting pressure on the surrounding organs.
Weight Loss and Fatigue
Biphasic malignant mesothelioma can also cause weight loss and fatigue, as the body struggles to cope with the demands of the disease. This can be exacerbated by the side effects of treatment.
Diagnosis of Biphasic Malignant Mesothelioma
Diagnosing biphasic malignant mesothelioma can be a complex and challenging process, as the presence of both epithelioid and sarcomatoid cell types can make it difficult to distinguish from other types of mesothelioma or other lung and abdominal cancers.
Medical History and Physical Examination
The diagnosis of biphasic malignant mesothelioma often begins with a thorough medical history and physical examination. The healthcare provider will ask about the individual’s symptoms, any history of asbestos exposure, and any other relevant medical information.
Imaging Tests
Imaging tests, such as chest X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans, are often used to help diagnose biphasic malignant mesothelioma. These tests can help identify the location and size of the tumor, as well as any signs of metastasis (the spread of the cancer to other parts of the body).
Biopsy
A biopsy is the definitive way to diagnose biphasic malignant mesothelioma. During a biopsy, a small sample of the tumor is removed and examined under a microscope to determine the specific cell types present. This can help confirm the diagnosis and distinguish biphasic malignant mesothelioma from other types of cancer.
Pathological Analysis
Once a biopsy sample has been obtained, it will be analyzed by a pathologist, who will examine the cells under a microscope to determine the specific cell types present. This analysis can help confirm the diagnosis of biphasic malignant mesothelioma and provide information about the tumor’s characteristics, which can inform the treatment plan.
Staging and Grading
After a diagnosis of biphasic malignant mesothelioma has been made, the next step is to determine the stage and grade of the tumor. The stage of the tumor refers to the extent of the disease, while the grade refers to the aggressiveness of the tumor. This information can help guide treatment decisions and provide a better understanding of the prognosis.
Treatment Options for Biphasic Malignant Mesothelioma
The treatment of biphasic malignant mesothelioma can be complex and may involve a combination of different approaches, depending on the stage and characteristics of the tumor, as well as the individual’s overall health and preferences.
Surgery
Surgery is a common treatment option for biphasic malignant mesothelioma, particularly in the early stages of the disease. The goal of surgery is to remove as much of the tumor as possible, while preserving the surrounding healthy tissues.
Extrapleural Pneumonectomy
One type of surgery used to treat biphasic malignant mesothelioma is the extrapleural pneumonectomy, which involves the removal of the entire affected lung, along with the lining of the chest cavity (the pleura), the diaphragm, and sometimes a portion of the pericardium (the sac surrounding the heart).
Pleurectomy and Decortication
Another surgical option is the pleurectomy and decortication, which involves the removal of the pleural lining and the tumor, while leaving the lung intact. This procedure is generally less invasive than the extrapleural pneumonectomy and may be preferred for individuals with more advanced disease or who are not suitable candidates for the more extensive surgery.
Chemotherapy
Chemotherapy is often used in the treatment of biphasic malignant mesothelioma, either alone or in combination with other treatments, such as surgery or radiation therapy.
Cisplatin and Pemetrexed
The most commonly used chemotherapy regimen for biphasic malignant mesothelioma is a combination of the drugs cisplatin and pemetrexed. This combination has been shown to improve survival and quality of life for individuals with this disease.
Other Chemotherapy Drugs
In some cases, other chemotherapy drugs, such as carboplatin, gemcitabine, or vinorelbine, may be used, either alone or in combination with other treatments.
Radiation Therapy
Radiation therapy may also be used in the treatment of biphasic malignant mesothelioma, either as a primary treatment or in combination with other therapies, such as surgery or chemotherapy.
External Beam Radiation Therapy
One type of radiation therapy used for biphasic malignant mesothelioma is external beam radiation therapy, which uses high-energy beams of radiation to target and destroy the tumor cells.
Intensity-Modulated Radiation Therapy
Another type of radiation therapy is intensity-modulated radiation therapy (IMRT), which uses computer-controlled linear accelerators to deliver precisely targeted radiation beams to the tumor, while minimizing the exposure to surrounding healthy tissues.
Targeted Therapy and Immunotherapy
In recent years, there have been advancements in the development of targeted therapies and immunotherapies for the treatment of biphasic malignant mesothelioma.
Targeted Therapy
Targeted therapies, such as tyrosine kinase inhibitors or angiogenesis inhibitors, are designed to target specific molecular pathways that are involved in the growth and development of the tumor.
Immunotherapy
Immunotherapy, which uses the body’s own immune system to fight the cancer, is also being explored as a treatment option for biphasic malignant mesothelioma. This includes the use of checkpoint inhibitors, which can help to activate the immune system to recognize and attack the tumor cells.
Prognosis and Survival Rates
The prognosis and survival rates for individuals with biphasic malignant mesothelioma can vary depending on a number of factors, including the stage of the disease, the individual’s overall health, and the response to treatment.
Median Survival Time
The median survival time for individuals with biphasic malignant mesothelioma is generally shorter than for those with the epithelioid subtype, but longer than for those with the sarcomatoid subtype. The median survival time can range from 6 to 18 months, depending on the stage of the disease and the individual’s response to treatment.
5-Year Survival Rates
The 5-year survival rate for individuals with biphasic malignant mesothelioma is generally low, with estimates ranging from 5% to 10%. This is due to the aggressive nature of the disease and the difficulty in achieving long-term remission or cure.
Factors Affecting Prognosis
Several factors can affect the prognosis for individuals with biphasic malignant mesothelioma, including the stage of the disease, the individual’s overall health and fitness, the response to treatment, and the availability of new and emerging therapies.
Conclusion
Biphasic malignant mesothelioma is a rare and aggressive form of cancer that can present unique challenges when it comes to diagnosis and treatment. While the prognosis for individuals with this disease is generally poorer than for those with the epithelioid subtype, there are several treatment options available that can help to improve the quality of life and potentially extend the survival time.
It is important for individuals who have been exposed to asbestos to be vigilant about monitoring their health and seeking medical attention if they experience any symptoms that may be related to mesothelioma. Early detection and prompt treatment are crucial in the management of this disease, and ongoing research and advancements in treatment options may help to improve the outlook for individuals with biphasic malignant mesothelioma in the future.
