What Mesothelioma Studies Don’t Tell You Could Be Costly

One deficiency of existing research that is investigating how mesothelioma responds to various forms of systemic treatment is the failure of most of those studies to tell you which mesothelioma subtypes were tested.

Researchers from Mayo Clinic and Levine Cancer Institute Carolinas HealthCare System, Charlotte, North Carolina, have caught onto this shortcoming.

In a recent study of their own, they imply that leaving this information out makes it harder to identify innovative mesothelioma treatments that merit being advanced to the head of the Research & Development funding line.

By routinely not specifying, for instance, how a particular therapy works against sarcomatoid mesothelioma in comparison to epithelioid mesothelioma, many sarcomatoid mesothelioma patients end up assuming a treatment will work for them when in actuality it might not.

Had they known that the treatment wasn’t viable for them, they would never have wasted time and money pursuing it.

Mesothelioma Research Shortcoming Wasn’t on Radar

The researchers’ findings were published in the journal Lung Cancer.

The study, “Systematic Review of Response Rates of Sarcomatoid Malignant Pleural Mesotheliomas in Clinical Trials” identifies Aaron S. Mansfield of the Mayo Clinic as the lead author.

Interestingly, the researchers didn’t set out to identify this shortcoming common to mesothelioma studies.

They said they simply wanted to examine the reported response rates of mesothelioma subtypes to treatment with a chemotherapy combination of cisplatin and pemetrexed.

They indicated that the idea for such a study arose from their clinical impressions that this type of chemotherapy delivers different response rates for sarcomatoid mesothelioma patients than it does for those with either the epithelioid or biphasic forms of the disease.

The researchers hinted that they wanted to see if other mesothelioma clinicians and researchers had also noticed the difference and, if so, to what extent the results for sarcomatoid mesothelioma patients varied.

“Our objective was to compare the response rates of sarcomatoid mesotheliomas to the overall response rates in published clinical trials,” they wrote.

The authors searched 544 publications for articles published between 2000 and March 20, 2014.

It was in the course of this exploration that the researchers began to notice response rates by mesothelioma cell-type were not usually reported.

They found 41 trials that satisfied their requirement of being about first- or second-line systemic therapy for malignant pleural mesothelioma.

Eleven of the studies — or more than one-fourth of the total — had to be tossed out because they didn’t include patients with sarcomatoid mesothelioma.

The 30 studies they were able to use involved a grand total of 1,475 subjects.

Mesothelioma Researchers Made Estimate

The authors of those 30 studies did offer a breakdown of how many participants had each mesothelioma subtype.

However, Mansfield and his team noted it was unusual to run across a study that further broke down the differences in results by mesothelioma subtype.

So what the Mayo Clinic researchers had to do was estimate the therapy’s effectiveness by mesothelioma subtype based on the percentage of representation of each subtype in the study.

By their reckoning, cisplatin and pemetrexed delivers a response rate of nearly 14 percent when administered to mesothelioma patients with the sarcomatoid subtype of the disease.