Mesothelioma is often treated with multimodal therapy, a combination of standard treatments. Researchers continuously test multimodal therapy approaches to determine the most beneficial combinations.
In a recent study, researchers tested the efficacy of surgery for mesothelioma after radiation therapy, also known as SMART.
What Is SMART Protocol?
SMART stands for surgery for mesothelioma after radiation therapy. This treatment type was developed by researchers at the Princess Margaret Cancer Centre in Toronto, Canada.
In a recently published study, researchers tested the SMART protocol on 96 pleural mesothelioma patients. The patients were treated in Toronto from 2008 to 2019.
The study’s approach consisted of two steps:
- Patients were given intensity modulated radiation therapy (IMRT) on one-half of the chest cavity. The radiation therapy was directed at their tumors.
- Within one week after radiation, patients underwent an extrapleural pneumonectomy.
This is a new multimodal approach for mesothelioma. Most commonly, surgery occurs before chemotherapy or radiation.
An extrapleural pneumonectomy (EPP) is a mesothelioma surgery that removes the diseased lung, lung lining, part or all of the diaphragm and any visible tumors.
Pleural mesothelioma patients with lymph node metastasis also had the option of undergoing three cycles of chemotherapy after surgery.
How Does SMART Work?
Through the SMART approach, researchers use radiation to help limit tumor progression. Radiation therapy is used before EPP to limit potential cancer spread during surgery.
Researchers hypothesize this may decrease distant recurrences of mesothelioma.
Researchers Tested Safety and Efficacy of SMART
The overall goal of the SMART protocol is to decrease the speed and severity of tumor growth. During the Canadian study, researchers analyzed:
- Clinical feasibility: The acceptable number of adverse health events patients experienced
- Therapeutic effect: The effectiveness of SMART on median survival
An EPP is an invasive surgery that has a high incidence of adverse events. In the study, researchers graded adverse events on a 0 – 5 scale. A grade of 5 event is a treatment-related fatality.
Researchers found within 30 days of EPP:
- 49 patients experienced grade 0 – 2 adverse events
- 47 patients experienced grade 3 – 4 adverse events
The researchers set a maximum acceptable level of adverse events. They decided the treatment would be “successful” if 35% of patients or less experienced grade 3 – 4 adverse events. The study did not meet this threshold.
SMART Improved Survival for Some Patients
Among all patients, regardless of cell type, median survival was 24.4 months, including:
- 42.8 months for patients with epithelioid mesothelioma
- 18 months for patients with biphasic mesothelioma
The current overall median survival for pleural mesothelioma is about a year and a half.
Is SMART Protocol Effective for Mesothelioma Patients?
Based on the Canadian study, the SMART approach was effective for some pleural mesothelioma patients.
The results showed 50% of pleural mesothelioma patients lived longer than two years. Overall, patients in the study experienced above-average median survival.
However, 49% of patients experienced a grade 3 – 4 adverse event. Mesothelioma recurrence also occurred in 72% of patients.
Although the study results are promising, SMART needs to be tested on a larger patient group before conclusions can be drawn. Additional clinical trials may provide more insight into treatment efficacy.
New Clinical Trial Will Continue SMART Research
To further test the SMART approach, researchers at the Princess Margaret Cancer Centre are beginning a second trial. The researchers are currently enrolling patients in the new trial. This clinical trial allows mesothelioma patients to undergo EPP or extended pleurectomy-decortication.
Extended pleurectomy-decortication (eP/D) is a more tolerable surgery than EPP. Studies show eP/D has a lower rate of serious adverse events than EPP. So, it may be accessible to more mesothelioma patients.
Patients who are interested in a clinical trial should contact a mesothelioma doctor. This specialist can help patients understand their treatment options.