Source: DGNews  |  Posted 3 years ago

NEW YORK -- November 26, 2008 -- Administering radiation therapy prior to surgery nearly doubles survival in pancreatic cancer patients with operable tumours, according to a study in the November 15 issue of the International Journal of Radiation Oncology, Biology and Physics.

“Patients who received presurgical radiation had almost double the overall survival compared with similar patients who didn’t undergo radiation, and survived significantly longer than patients who received radiation after the tumour was removed,” said senior author David Sherr, MD, Weill Cornell Medical College and NewYork-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York.

“There are potential benefits to delivering radiation before surgery rather than after. Radiation might actually increase the number of people eligible for tumour resection, by shrinking the tumour so it no longer endangers vital structures.”

In addition, neoadjuvant radiation might render cancer cells less likely to establish metastases.

“Radiation could also provide more benefit if given prior to surgery, since radiation therapy is more effective in well-oxygenated tumour tissues. After surgery, tissue is frequently less well oxygenated due to the development of scar tissue,” said Dr. Sherr.

Finally, patients are typically more able to easily tolerate radiation therapy before surgery rather than after the operation, when they are often weak and require a prolonged convalescence period before they’re well enough to receive additional treatment.

In the retrospective analysis, Dr. Sherr and colleagues analysed data from 3,885 cases of resected pancreatic cancer, recorded between 1994 and 2003 as part of the national Surveillance, Epidemiology and End Results (SEER) registry database.

Of the cases, 2,337 (60%) of patients had received surgery alone, 1,478 (38%) received radiation after resection, and 70 (2%) received neoadjuvant radiation therapy.

The team found that the overall survival of patients who received neoadjuvant radiation was 23 months compared with 17 months for those receiving postsurgical radiotherapy, and just 12 months for patients who received surgery alone.

Controlling for variables such as patient age, sex, cancer stage, grade, and year of diagnosis, they found that neoadjuvant radiation cut the death risk for patients by 45% compared with other treatment strategies, and by 37% compared with radiation performed after surgery.

Why the improvement in outcomes? “It may be that in shrinking the tumour, preoperative radiation gives the surgeon more of a margin of healthy tissue to work with. Because of that, patients are less likely to have microscopic residual disease,” said Dr. Sherr.

He stressed that the findings do need to be verified by a randomised, prospective trial before any firm recommendations can be made. Dr. Sherr is hopeful that such a trial will be conducted in the future.

“In the meantime, this is really heartening news for patients,” he said. “It suggests that there may be a real advantage to preoperative radiation. Right now, when a pancreatic tumour is deemed operable, patients typically go straight to surgery. This suggests that, in some cases at least, we may be able to boost the odds of cure if we employ radiation first. More study is needed, but I believe this type of research has the potential to change practice.”

SOURCE: NewYork-Presbyterian Hospital/Weill Cornell Medical Center