Pancreatic cancers are known to have a tendency to invade and wrap around nearby veins and arteries in the abdomen. When those vessels become involved, surgery to remove the cancer, which is typically the standard treatment, becomes significantly more difficult and sometimes impossible. According to a study now online ahead of print in Practical Radiation Oncology (doi.org/10.1016/j.prro.2015.04.004), researchers at Fox Chase Cancer Center have identified a way to safely downstage the tumor, pulling it away from these vessels and allowing the possibility of potentially curative surgery.
As explained in a news release, Lora Wang, MD, a resident in the Department of Radiation Oncology, and colleagues found that giving extra boosts of radiation therapy to the tumor areas that are dangerously involved with the major vessels improved the rate of surgical resection.
“In patients with non-metastatic pancreatic cancer, the tumor's involvement with the nearby vessels is what determines whether or not a tumor is resectable,” Wang said. “Some small vessels can be removed surgically without issue, but there are many important veins and arteries in the abdomen that cannot be removed easily or at all. Our practice is to give patients with borderline resectable or unresectable cancer chemotherapy and/or radiation therapy first in hopes that their tumor will shrink so they can proceed to surgery.”
The researchers evaluated patients with borderline resectable and locally advanced pancreatic cancer who were treated with neoadjuvant chemotherapy and radiation therapy to determine if the “vessel boost” improved the rate of curative surgery.
The study included 104 patients: 23 received a vessel boost and the remaining 81 did not. The median standard dose of radiation was 50.4 Gy. All patients also received concurrent chemotherapy. Patients who received the vessel boost received a median dose of 56 Gy, with the extra delivered to the areas involved with the vessels.
Patients who received the vessel boost were more likely to be able to undergo surgical resection compared with the patients who received only the standard dose of radiation. In addition, there was no difference in side effects between the two groups.
Wang also said that patients who show evidence of disease progression or metastatic disease during upfront chemotherapy and/or radiation therapy can be spared a major surgery.
The other coauthors of the study, which was earlier presented in part as a poster abstract at the American Society for Radiation Oncology 2014 Annual Meeting, are Talha Shaikh, MD; Elizabeth Handorf, PhD; John Hoffman, MD; Steven Cohen, MD; and Joshua Meyer, MD.