Another study is out and there is still no clear answer about the value of the SMART protocol for mesothelioma.
SMART stands for surgery for mesothelioma after radiotherapy. After studying nearly a hundred patients, doctors in Toronto say radical surgery after RT can be effective. But they also say it is still very hard to prevent serious complications, even in an experienced center like theirs.
The team at Princess Margaret Cancer Center tested the SMART protocol on previously-untreated pleural mesothelioma patients.
As with previous studies of the SMART protocol for mesothelioma, some of the patients did very well. Many lived longer than they would normally expect to live. But there was also a high incidence of serious surgery-related complications.
The SMART Protocol for Pleural Mesothelioma
Pleural mesothelioma is a rare but often deadly cancer caused by asbestos. It affects the membrane around the lungs. When asbestos fibers get into the tissue, they cause damage and cancer in some people.
Most patients have a combination of treatments for mesothelioma. These may include chemotherapy, radiotherapy, immunotherapy, surgery, and others. Even with combination treatment, the prognosis for mesothelioma is poor.
Researchers developed the SMART protocol for mesothelioma to improve the odds. It relies on high doses of targeted radiotherapy prior to surgery. The RT may help make tumors easier and safer to remove. This is followed by EPP surgery to remove one lung and surrounding tissue.
With the SMART protocol for mesothelioma, patients get RT over just a few days. Then they go right to surgery. It is a faster approach to treatment than chemotherapy. This is important because mesothelioma tumors grow quickly.
Effective but Risky
EPP surgery is a radical treatment. Patients can have serious complications and may even die. This is one reason many surgeons now prefer lung-sparing PD surgery for pleural mesothelioma instead.
The SMART protocol for mesothelioma aims to improve survival after EPP. Clinical trials show a median overall survival time of 51 months. This is better than any other single treatment.
But the new Canadian study shows it is not easy to achieve these kinds of results. The study included 96 patients treated between 2008 and 2019. Patients got five doses of IMRT over a week. They had surgery within the next week.
Half of the patients on this SMART protocol for mesothelioma had serious (grade 3 – 4) complications in the first 30 days. One patient died of pneumonia. The good news is that it took years for cancer to recur in some cases. But after a median follow-up of 47 months, 63% percent of patients had signs of mesothelioma again.
“Results from this study suggest that extrapleural pneumonectomy after radiotherapy can be done with good early and long-term results,” concludes the report in The Lancet Oncology.
But there was also a caveat: “Minimising grade 4 events on the protocol is technically demanding and might affect survival beyond the post-operative period.”
Patients with good overall health, small tumors, and the epithelial subtype typically get the best results from the SMART protocol for mesothelioma.
Cho, BCJ, et al, “Surgery for malignant pleural mesothelioma after radiotherapy (SMART): final results from a single-centre, phase 2 trial”, January 2021, Lancet Oncology, Online ahead of print, https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(20)30606-9/fulltext
De Perrot, M, et al, “Accelerated hemithoracic radiation followed by extrapleural pneumonectomy for malignant pleural mesothelioma”, February 2016, The Journal of Thoracic and Cardiovascular Surgery, https://www.sciencedirect.com/science/article/pii/S0022522315019868