Penn Surgeons “Light Up” Tumors to Boost Mesothelioma Survival

University of Pennsylvania surgeons are experimenting with a new technology that could vastly improve survival for patients with malignant pleural mesothelioma by ensuring that more of their cancer can be  removed.

Complete resection of mesothelioma tumors can be the difference between life and death; even a few cancer cells left behind can quickly grow into new tumors.

But macroscopic complete resection, as it is called, is not easy. Not only are mesothelioma tumors irregularly-shaped and located close to critical organs like the lungs and heart, but surgeons say it is often hard to distinguish tiny metastatic tumors from inflammation or scar tissue.

In addition, traditional scanning techniques like PET can’t usually show nodules smaller than a centimeter and can’t distinguish cancerous ones from benign ones.

To improve their odds of removing as many mesothelioma cells as possible, researchers at the Abramson Cancer Center at the University of Pennsylvania are using TumorGlow®, a form of intraoperative imaging that makes even tiny clusters of cancer cells glow under near-infrared light.

Making Mesothelioma Tumors Glow

TumorGlow® is a type of molecular imaging designed to be used during cancer surgery. It utilizes an injectable dye specifically engineered to accumulate in higher amounts in malignant tissue.

According to the Penn Medicine website, the technique has the potential to improve precision and accuracy during cancer surgery and even facilitate early detection of small tumors for better cancer outcomes.

To test how safe or feasible TumorGlow® would be for patients with malignant pleural mesothelioma, the Penn team recruited 20 patients who were scheduled to have either a pleural biopsy or pleurectomy with decortication (P/D) mesothelioma surgery.

Twenty-four hours before their operation, patients were injected with the dye. During surgery, doctors used a light to guide them to as many clusters of mesothelioma cells as possible. These samples, and any other tissue that looked suspicious, were removed and sent to pathology for testing.

Light Identifies Pleural Mesothelioma

Of the 203 surgical specimens submitted for evaluation, dye had accumulated in high amounts in all 113 of the ones that proved to be mesothelioma. There were no mesothelioma specimens removed in which there were not high levels of dye.

Just as importantly, the benign tissues that were removed for testing had much lower levels of dye and casted a much dimmer glow.

The results, published recently in the Annals of Thoracic Surgery, convinced the surgeons that the TumorGlow® technology could indeed increase the odds of finding and removing more pleural mesothelioma tumors during P/D.

“Surgically removing tumors still leads to the best outcomes in cancer patients, and this study shows intraoperative molecular imaging can improve the surgeries themselves,” said the study’s lead author Jarrod D. Predina, MD, MS, a post-doctoral research fellow in the Thoracic Surgery Research Laboratory and the ACC’s Center for Precision Surgery in a Penn Medicine news release. “The more we can improve surgeries, the better the outcomes for these patients will be.”

Sources:

Predina, Jarrod, “A Clinical Trial of TumorGlow® to Identify Residual Disease during Pleurectomy and Decortication”, July 17, 2018, Annals of Thoracic Surgery, Epub ahead of print

“Glowing Tumor Technology Helps Surgeons Remove Hidden Cancer Cells”, July 26, 2017, News Release, Penn Medicine News