Improved Imaging, Classification Advance Sarcoma Care

Kiran K. Turaga, MD

The field of sarcoma may have reached a turning point, according to Kiran K. Turaga, MD.

“There are many, many exciting things that are happening in the field of sarcoma, said Turaga, associate professor of Surgery, vice chief, Section of General Surgery and Surgical Oncology, the University of Chicago Medicine. “When thinking about the advancements in the management of sarcomas, I think we are reaching a time where, finally, we are able to overcome just simple surgery and radiation concepts, and we are getting into this phase where we are able to understand these tumors for what they are.”

OncLive: What are you most excited about right now within sarcoma?

In an interview with OncLive, Turaga discusses advancements in classification, surgical techniques, imaging modalities, and therapeutics that are moving the field of sarcoma in a positive direction, as well as the challenges that still remain within the treatment landscape.Turaga: We now realize that, both phylogenetically and evolutionarily, sarcomas can now be classified into broad groups. There is some very exciting work that came out of Dana-Farber Cancer Institute, which helped us understand certain groups of sarcomas. Usually, we would look at them under histology—are they more like muscles, or rhabdomyosarcoma, or are they more like fats, or liposarcomas?

How has new technology advanced the field of sarcoma?

We are finding that there are certain groups of sarcomas that are closer to each other versus certain groups of sarcomas that are further apart. That is important because, traditionally, sarcomas were always considered with a very standard paradigm—which is surgery—and maybe radiation. Adjuvant chemotherapy has always been a little bit of a plus or minus, in terms of thinking about how well it works for sarcomas. By trying to clump these tumors together, we are able to understand how to better treat them.There are amazing advances in imaging, especially diffusion-weighted imaging for retroperitoneal sarcomas, where we can actually use diffusion characteristics. Diffusion-weighted imaging relies on the water content of cells and it is remarkable for our ability to detect some areas of malignancy versus not within sarcomas, and potentially guide biopsies and pretreatment paradigms.

Are there barriers to implementing some of these new imaging advancements?

The standard of surgical resection remains paramount for patients with retroperitoneal sarcomas, but what is exciting is the fact that the concept of compartmental resections is being re-explored and certainly appears to be attractive for preventing recurrences for patients with retroperitoneal sarcomas. The concept that was abandoned in the extremity is now being re-explored in the retroperitoneum. That is a very exciting surgical development where we are actually resecting more than just the sarcoma mass alone.There are numerous barriers in getting these imaging modalities utilized across the board. Most big to mid-sized cancer centers have this technology; they have the ability to do the MRI. The software that is necessary to do diffusion-weighted imaging is not as widely understood or applied, even if it is available to certain groups.

Even today, sarcomas remain a mystery and they just sort of look like this mass that needs to be resected. This may be okay, but we need the ability to apply these imaging modalities. The setting of neoadjuvant treatment in sarcoma is when we choose to do either radiation or systemic chemotherapy, and we do know that pathological response is predictive of the overall survival of our patients.

Are there any particular agents that you see a lot of potential for in sarcoma?

Diffusion-weighted imaging might give us insight into that in a noninvasive way and help us understand how these patients will do. The technology is getting there and the software is available, but the understanding as to how to apply it in the world of sarcomas is evolving.Recent drugs such as trabectedin (Yondelis) as well as pazopanib (Votrient) are 2 new interesting agents that have shown some promise. There are also numerous clinical trials that are going on right now, including TKIs and multireceptor TKIs. For some reason, the immune-modulating agents have not shown much promise in sarcomas, but that would also go against the lack of significant androgen expression that we see in melanomas or bladder cancers. There is certainly some excitement about some of the new drugs, but the responses are still a bit underwhelming compared with where we would want them to be.