New research out of Pennsylvania suggested that not all people with metastatic mesothelioma will live longer with chemotherapy.
Although chemotherapy is the primary treatment for malignant pleural mesothelioma, some types of metastatic mesothelioma appear to be less responsive than others.
In some cases, the researchers say best supportive care may be a better option for preserving a patient’s quality of life.
Three Mesothelioma Subtypes
There are three histological subtypes of malignant pleural mesothelioma. The categories are based on how the cells look under a microscope. Cell type appears to influence how aggressive they are as metastatic mesothelioma. Cell type also factors into mesothelioma prognosis.
Epithelioid mesothelioma is the most common cell type. Epithelioid cells tend to lack uniformity and may form small tubes or clusters. Epithelioid mesothelioma is usually more responsive to treatment than other subtypes, even after metastatic mesothelioma has occurred.
The non-eipthelioid subtypes are sarcomatoid and biphasic. Sarcomatoid cells are the least common but most aggressive mesothelioma subtype. Biphasic mesothelioma contains both epithelioid and sarcomatoid cells in the same tumor.
Assessing Treatment Options for Metastatic Mesothelioma
The new mesothelioma study was conducted at several top research centers including MD Anderson, University of Pennsylvania and Yale.
It included 4655 pleural mesothelioma patients from the National Cancer Database. Forty-one percent of the patients had metastatic mesothelioma. This means that mesothelioma cells have spread to other parts of their body.
People with metastatic mesothelioma are not good candidates for surgery. Chemotherapy is often the primary treatment for these patients. About half of the study subjects had chemotherapy and the other half received best supportive care.
“Chemotherapy was associated with higher overall survival in [metastatic mesothelioma] cases with unknown histology and [metastatic] epithelioid patients,” writes lead author Vivek Verma of the Radiation Oncology department at Pittsburgh’s Allegheny Health Network Cancer Institute.
But patients with metastatic mesothelioma of the sarcomatoid or biphasic subtype did not respond nearly as well. Chemotherapy led to longer survival in this group only if the cancer had not spread.
Mesothelioma chemotherapy carries its own risks, including the risk of death. In cases where it is unlikely to help, this research suggests that best supportive care may be a better option.
The research team concludes that “careful patient selection in this population cannot be understated.”
Verma, V, et al, “Chemotherapy Versus Supportive Care for Unresected Malignant Pleural Mesothelioma”, March 26, 2019, Clinical Lung Cancer, Epub ahead of print, https://www.clinical-lung-cancer.com/article/S1525-7304(19)30076-2/fulltext