A biphasic, or mixed, mesothelioma tumor is made of epithelioid cells and sarcomatoid cells. If the biphasic tumor contains more epithelioid cells, a patient has more treatment options, because epithelioid cells are more responsive to treatment than sarcomatoid cells. The more epithelioid cells in a biphasic tumor, the better a patient’s prognosis.
Things to Know About Biphasic Mesothelioma
Prognosis varies: Two people diagnosed with a biphasic cell type may have drastically different prognoses. This is because biphasic tumors with a majority of epithelioid cells are more treatable.
Second opinions are important: A proper diagnosis is important to secure the best treatment possible for biphasic mesothelioma. Sometimes even doctors make mistakes, so consider getting a second opinion if your treatment options are limited.
There are several key characteristics of this cell type:
- How well a biphasic tumor responds to treatment depends on which type of cell, epithelioid or sarcomatoid, is more prevalent.
- Biphasic tumors with more epithelioid cells grow faster than biphasic tumors with more sarcomatoid cells. They do not, however, spread to other parts of the body as quickly.
- Epithelioid and sarcomatoid cells tend to grow in separate parts of the same biphasic tumor. This makes diagnosing biphasic mesothelioma difficult.
The first step specialists take to diagnose biphasic mesothelioma is an imaging test, such as a CT scan or MRI. Imaging tests are mainly used to locate growths in the chest and abdominal cavities. Determining the cell type of a tumor is not possible using scans obtained from imaging tests alone.
Epithelioid and sarcomatoid cells tend to grow in separate parts of the same biphasic tumor, making visual diagnosis a nearly impossible task. Both cell types also look very similar to the cells of other cancers. A biphasic tumor may be misdiagnosed as a carcinoma or a synovial sarcoma, a cancer that grows in the arm, leg or neck joints.
The only method by which specialists can confirm a biphasic mesothelioma diagnosis is a biopsy.
To perform a biopsy, a surgeon takes a tissue sample directly from the tumor mass they located with an imaging scan. Common biopsies used to confirm a biphasic mesothelioma diagnosis include fine needle aspiration or a standard surgical biopsy, such as a thoracotomy or laparotomy.
Specialists then use a diagnostic technique called immunohistochemistry to obtain an accurate biphasic diagnosis. Pathologists, doctors who specialize in identifying cells, stain samples obtained from a biopsy with a dye that helps distinguish cancer cells.
A correct diagnosis is essential for doctors to determine the right course of treatment. Misdiagnosed biphasic patients may not be considered for aggressive treatment options or curative chemotherapy.
The availability of treatment options for a biphasic patient depends on the location of the tumor and the stage of cancer.
Early-stage patients may be eligible for an aggressive combination of curative surgeries.
Advanced-stage patients may only be eligible for palliative treatments designed to ease symptoms. A qualified mesothelioma specialist can determine which course of treatment can provide the most improved prognosis.
The ratio of epithelioid and sarcomatoid cells also plays a role in the aggressiveness of a treatment plan. A tumor containing mostly epithelioid cells will be more receptive to aggressive treatments and than a tumor containing more sarcomatoid cells.
The prognosis for patients diagnosed with biphasic mesothelioma is less favorable than those diagnosed with epithelioid mesothelioma, but more favorable than those with sarcomatoid mesothelioma.
Biphasic mesothelioma patients have a median survival rate of 12 months, compared with 12 to 24 months for epithelioid type and 6 months for sarcomatoid type.