Biphasic mesothelioma, typically, is caused by exposure to asbestos. The other name for this condition is mixed mesothelioma. In fact, this cell type is the second most common in all mesothelioma cases, contributing to about 10 – 20% of them.
If Epithelioid cells are dominant, the patients may have improved prognosis, more treatment options, and longer survival periods. Similarly, if sarcomatoid cells are dominant, patients may have a worse prognosis, fewer treatment options, and minimal life expectancies.
Due to the complexity of cells, it is difficult to diagnose this disease accurately. Some doctors, who have less experience treating biphasic mesothelioma, may mistake this disease for other cell types. Hence, medical experts recommend a second opinion for these kinds of diseases.
What Is Biphasic Mesothelioma?
Generally, the tumors associated with biphasic mesothelioma have both sarcomatoid and epithelioid cells. However, they must have at least 10% of either cell, in order to qualify as Biphasic Mesothelioma. For Example,
1.) If the tumors contain more than 90% of epithelioid cells, the disease is called epithelioid mesothelioma
2.) Likewise, If the tumors contain more than 90% of sarcomatoid cells, the disease is called sarcomatoid mesothelioma
3.) Similarly, if the tumors contain at least 10% or more of either cell, the disease is called biphasic mesothelioma.
Biphasic mesothelioma develops mostly in the peritoneum (abdominal linings) or pleura (lung linings). Sometimes, it may develop in tunica vaginalis (testes) or pericardium (heart lining) also.
Although the cell patterns differ based on the breakdown of both cells, they have distinct patterns of their own.
Patterns of Biphasic Mesothelioma Cell
Epithelioid Cell Pattern
Patterns of Biphasic Sarcomatoid Cell
What Are the Symptoms of Biphasic Mesothelioma?
Like other forms of cancer, biphasic mesothelioma may not show symptoms for decades. After a certain stage, it begins to show symptoms based on the location of its presence.
For instance, Pleural biphasic mesothelioma patients may experience lung-related symptoms. Other symptoms of this disease include the following:
Dyspnea (difficulty breathing)
Some peritoneal mesothelioma cases may also have these cells. Such patients may experience abdominal swelling, abdominal pain, and weight loss.
However, all symptoms of these types of conditions depend on some factors. They include the individual’s overall health, pre-existing conditions, age, and development stage of the associated cells.
How Is Biphasic Mesothelioma Diagnosed?
Medical experts begin diagnosing all mesothelioma diseases including biphasic mesothelioma with imaging tests. They may include CT scans and X-rays. These tests show the presence of excess fluid or tumors in the abdomen or chest cavity.
If they find any abnormalities, they may order blood tests to recognize specific biomarkers. This helps them to differentiate mesothelioma from other conditions.
After that, the pathologists may use a biopsy to diagnose the disease accurately. However, they may need multiple biopsies in biphasic mesothelioma cases. After all these tests, the medical experts determine the course of treatments required for specific cases.
Biphasic tumors may differ for different cases. For instance, the biopsy sample under study may contain only one type of cell. But the existing tumor may contain both cells.
According to a study, biopsy samples, taken for examining were inadequate in more than 50% of cases. So, the doctors mistakenly identified the tumors as epithelioid mesothelioma in the initial tests. However, the later tests confirmed the presence of both cells in most cases.
Another study indicated different types of biopsies have different initial diagnosis accuracies. For example:
1.) Thoracotomy is a surgical biopsy. It involves opening the chest cavity and examining the heart, lungs, and surrounding areas. It shows about 83% accuracy.
2.) Thoracoscopy is also a surgical biopsy. But it is not as invasive as thoracotomy. The surgeons insert a camera into the patient’s chest cavity and examine the affected areas.
They may also take tissue samples and fluids, if required, for testing. This method has shown about 74% accuracy.
3.) CT-guided biopsies are about 44 % accurate. Initially, the doctors more often use this method, as it is least invasive and less complicated. It involves imaging tests to find the abnormalities.
In fact, pathologists examine the tissue samples in many ways to confirm biphasic mesothelioma cases. They may also use immunohistochemistry for this purpose. This involves the detection of certain proteins, which may have an impact on the treatment.
What is Biphasic Mesothelioma Prognosis?
The average life expectancy of biphasic mesothelioma patients is about a year. However, it may vary depending on certain factors such as disease location and treatment method.
Modern emerging treatments may improve the survival times many folds. According to studies, the patients can survive from 8 months to about 7 years, with continuous appropriate treatments.
In fact, the prognoses of this condition vary widely. It depends on the ratio of sarcomatoid cells and epithelioid cells.
If Epithelial cells dominate tumors, the patients may have more treatment options and favorable prognoses. Similarly, if sarcomatoid cells have dominancy, the patients may have limited treatment options and poor prognoses.
Also, some other factors such as overall health and mesothelioma stage, play an important role, in the life expectancy of the patients.
How to Treat for Biphasic Mesothelioma?
Depending on the dominancy of either cell, treatment options may vary for individual patients. However, the common treatments for most mesothelioma cases are chemotherapy, surgery, and radiation.
The doctors may also use multimodal treatments in some cases. That is to say, doctors may treat the patients, with two or more forms of treatment plans combined.
In most biphasic mesothelioma cases, radiation and chemotherapy treatments have shown mixed results. They also remain largely ineffective, while treating sarcomatoid cells. However, they have improved the survival times in some epithelioid mesothelioma cases.
The treatments for biphasic mesothelioma may also depend on the following:
Location of the disease
Development stage (severity)
Overall health condition of the patients
Percentage of sarcomatoid cells
In any case, it is best to consult mesothelioma doctors, who are experienced in treating these diseases. They can diagnose the conditions easily and suggest treatments specific to individuals.
Due to the bleak prognosis, some researchers in the past have suggested palliative care treatments for this disease. However, modern studies show, appropriate treatments can increase the life expectancy of biphasic patients by years.
Treating Biphasic Peritoneal Mesothelioma
The CRS (combination cytoreductive surgery) combined with HIPEC (heated intraoperative chemotherapy) is one of the proven effective treatments for Biphasic Peritoneal Mesothelioma.
In the past, experts believed biphasic cases similar to Sarcomatoid mesothelioma. So, they thought the treatments will not show expected results. However, they found a good response when biphasic patients are treated with CRS and HIPEC combination, in 2018.
1.) The patients, with all tumors removed, have a median survival period of about 6.8 years.
2.) The patients, with most tumors removed, have a median survival period of about 2.8 years.
Nowadays, medical experts suggest this treatment combination to all biphasic patients. However, they should discuss and confirm their eligibility with doctors, before going for this procedure.
Treating Biphasic Pleural Mesothelioma
Patients with this condition, in general, show a good response to immunotherapy. Researchers conducted a study in 2019 to find the effects of immunotherapy on pleural mesothelioma patients.
According to that study, immunotherapy improved survival times of patients who underwent chemotherapy treatment, at least once. Some of them who took nivolumab (a prescription medicine) continuously, survived for more than 20 months.
How Biphasic Treatments Impact Sarcomatoid Cells?
Generally, Sarcomatoid cells show poor response to any treatment. Such patients have limited options for treatment. For example, if Sarcomatoid cells dominate tumors by more than 80%, CRS or any other aggressive treatments may not be viable options.
In such scenarios, the doctors may recommend palliative care. These types of treatments often improve comfort by reducing symptoms. Patients can also opt for clinical trials, which may improve the survival times.