Biopsies are the only way to confirm a mesothelioma diagnosis. The most common biopsy methods range in invasiveness depending on where the tumor is located in a patient’s body.
The findings of a recent study may lead to an improvement in using fluid biopsy samples to diagnose mesothelioma. With continued research, it could lead to a more effective, less invasive biopsy method to diagnose pleural mesothelioma.
Researchers Test Fluid Samples of Mesothelioma Patients
In 2021, Japanese researchers published a study aimed at improving the efficacy of fluid biopsies for pleural mesothelioma. They looked at using fluid tissue samples to reliably diagnose mesothelioma and distinguish it from lung conditions with similar symptoms.
Mesothelioma presents with nonspecific symptoms, such as cough and chest pain, that can be mistaken for the flu and other common illnesses. This combined with other factors, including a long latency period, can make it challenging for doctors to diagnose mesothelioma.
Currently, fluid biopsy samples aren’t sufficient enough to confirm a mesothelioma diagnosis. Instead, doctors typically rely on needle biopsies or surgical biopsies to diagnose mesothelioma. However, if fluid tissue samples could be used to accurately diagnose pleural mesothelioma, it would offer many patients a less invasive diagnostic method.
In the study, researchers used pleural effusion samples taken from study participants. These are samples of fluid buildup around the lungs. Pleural effusions are a common symptom of pleural mesothelioma.
The fluid samples in this study came from patients with:
- Malignant pleural mesothelioma
- Reactive mesothelial hyperplasia (RMH)
RMH is a benign condition that may be difficult to distinguish from mesothelioma.
Between 2010 and 2019, researchers collected fluid tissue samples from 54 patients with mesothelioma and 18 patients with RMH.
Study Sample Demographics
Gender: 46 men, 8 women
Average age: 71.5 years
Gender: 10 men, 8 women
Average age: 71.1 years
For quality control purposes, the researchers ensured the samples they collected had at least 100 mesothelial cells per sample. In a patient with mesothelioma, the cancer develops within the mesothelial cells.
By ensuring each fluid tissue sample included at least 100 of these cells, the researchers established a large sample size to test. These larger sample sizes increased the likelihood that researchers would identify and diagnose cancerous cells during the study.
The researchers used a diagnostic method known as fluorescence in situ hybridization (FISH) to test the fluid tissue samples. FISH tests are used to identify the presence or absence of certain genes or groups of genes.
FISH Tests Offer Promising Results
The research team ran multiple FISH tests looking at several pieces of DNA that can signal cancer development or disease. The results of the study are promising for future advancements in diagnostic methods.
One FISH test identified mesothelioma in 51.9% of mesothelioma cases. The same test identified RMH in 100% of RMH cases. A combination of additional FISH tests identified 98.1% of mesothelioma cases correctly.
If improved upon, these results could help doctors narrow diagnosis options for patients. This could lead to quicker diagnoses. It could also potentially help doctors diagnose mesothelioma earlier in patients.
However, more research is needed before fluid biopsies can become a more widely used diagnostic test for mesothelioma. For instance, 25.9% of mesothelioma cases in the study required additional testing on top of the FISH test for accurate diagnosis. This extra testing was necessary due to issues with the fluid tissue samples.
There are still challenges to solve before doctors can use fluid biopsies to accurately and consistently diagnose pleural mesothelioma.
Study Findings May Lead to Earlier Mesothelioma Diagnosis
Mesothelioma can be difficult to diagnose early. Doctors currently use biopsies to definitively confirm mesothelioma diagnoses in patients. Biopsies may come after various other tests, such as imaging scans and blood tests.
There are four types of biopsies commonly used for mesothelioma diagnosis. The least invasive of these is fluid drainage. But, in most cases, a fluid sample is insufficient for a concrete mesothelioma diagnosis.
However, this recent study laid the groundwork for improvements in fluid biopsies to diagnose pleural mesothelioma. If researchers continue to build on the work of this recent study, patients may have a more accessible, less invasive diagnosis option in the future. This could someday also lead to earlier diagnoses of pleural mesothelioma in patients.