The National Comprehensive Cancer Network (NCCN) guidelines include three possible treatments for early (Stage IA) non-small cell lung cancer (NSCLC). Surgery is listed as first-line therapy, with radiation therapy—preferably stereotactic body radiation therapy (SBRT)—recommended for patients who are not candidates for surgery. Image-guided thermal ablation (IGTA) “may be an option for select patients not receiving radiation therapy,” according to the guidelines.
However, a new study shows that one type of IGTA—microwave ablation (MWA)—appears to be a safe, effective and non-inferior option when compared to either resection or SBRT as a primary therapy for early NSCLC.
Ericson John Torralba, a fourth-year medical student at Wright State University Boonshoft School of Medicine, who is planning to become an IR, will present the research team’s findings as a featured abstract, “Microwave Ablation versus Surgical Resection versus Stereotactic Body Radiation Therapy of Stage IA Non-small Cell Lung Cancer in U.S. Veterans,” during Sunday’s Scientific Session 8, Thoracic Interventions, from 3 to 4:30 p.m. MT.
“Thanks go to the current leadership of SIR, who continue to advocate for the presence of IR therapies within treatment guidelines like the NCCN guidelines, thus allowing patients to be able to consider minimally invasive alternatives for treatment,” Torralba said.
Lung cancer is the leading cancer killer worldwide, and U.S. veterans are disproportionally affected by lung cancer. Lung cancer kills more patients every year than breast, prostate and colon cancer combined, according to Robert F. Short, MD, PhD, section chief of interventional radiology, associate professor of surgery and biomedical engineering, and director of the Minimally Invasive Nodule Therapy Clinic at the Dayton, Ohio, Veterans Affairs Medical Center (VAMC).
Many patients diagnosed with early lung cancer are poor surgical candidates. Lung cancer screening programs with low-dose chest CT are starting to take off, Dr. Short said, and as these programs are implemented, more early (potentially curable) lung cancers will be identified. Having more options for treating these cancers based on specific patient scenarios is the hope, he said.
Dr. Short is senior author on the retrospective study of patients at the Dayton VAMC, which compared outcomes of the three options for curative treatment of Stage 1A lung cancer: surgical resection, SBRT and IGTA, specifically with MWA.
Dr. Short has been treating lung cancer with MWA for more than 7 years. “Image-guided thermal ablation therapy is not exactly new,” he said. “People have been treating cancers with ablation for decades. Lung ablation is slightly more recent. Techniques and technology have evolved to the point that allow us to perhaps begin to challenge current treatment paradigms as data continue to emerge.”
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Treatment of Stage IA NSCLC occurred in 178 patients with a mean tumor size of 18 mm + 0.9 mmm; the tumors were 100 adeno, 69 squamous cell and nine unspecified carcinomas. Patients in the resection group underwent lobar, sublobar/subanatomic resection based on the surgeon’s preference. All-cause 90-day mortality for the surgical group was 6.81% (six patients) and 3.33% in the radiation group. For the MWA group, technical success was 100% with one prolonged air leak that resolved at 20 days. All-cause 90-day mortality for the MWA group was 1.6% (one patient). A single, small-bore chest tube was placed in 22 patients with MWA (37%), and two, large-bore chests tubes were employed in 88 patients (100%) with resection.
Patients who were admitted after therapy (100% of resection patients; 37% of MWA patients) stayed longer after a resection than an MWA (4.1 days versus 1.0). A shorter stay with MWA both saves money and allows a patient to get back to their life faster, Torralba said. He also pointed out that the patients in the study receiving MWA tended to be medically sicker overall—they weren’t candidates for surgery—and yet they still responded as well as surgical candidates, as evidenced by no significant difference in length of progression-free survival.
In the Dayton study, most patients were offered IGTA or SBRT and allowed to participate in a shared decision-making process to determine which therapy met their treatment goals. As reflected in the data, patients tended to choose IGTA over radiation. Dr. Short and Torralba agreed that more prospective studies are warranted that include IGTA to show which methods are most effective for which patients.
“We need to look at not just what is most effective against the cancer but also incorporate patient quality of life and what is compatible with the patient’s goals for therapy,” Dr. Short said. “What’s best for some may not be best for all. I think what we’ll see is that there are three good, likely comparable, options for early-stage lung cancer, each with pros and cons. When patients know they have options, they will be more likely to get screening. And early detection through low-dose CT lung cancer screening will lead to better outcomes, no matter the treatment modality.”
