Ultrasound-guided aspiration safe for suspected pancreatic cancer

Last Updated: 2015-01-15

By Megan Brooks

NEW YORK (Reuters Health) - It's safe to perform endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the work-up of suspicious pancreatic lesions, despite lingering concerns to the contrary, a new study shows.

Preoperative EUS-FNA was not associated with increased risk of overall or cancer-specific mortality in a large study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database.

"The advantage of doing preoperative biopsies has become more important in this era of genetic testing and targeted chemotherapy. We wanted to try to dispel the myth that biopsy causes the cancer to spread," Dr. Michael Wallace of the Mayo Clinic in Jacksonville, Florida, who worked on the study, noted in an interview with Reuters Health.

EUS-FNA is a well-established technique for studying suspicious pancreatic lesions, the authors note. Its main objective is to accurately identify malignant lesions and spare the patient with a benign condition an unnecessary resection, they wrote January 9 online in Gut.

"Although EUS-FNA of pancreatic lesions is generally regarded as a safe procedure, there have been concerns of tumor cell seeding along the needle track or within the peritoneum caused by EUS-FNA," they point out. As a result, many physicians avoid EUS-FNA.

"There have been a couple of case reports of someone doing a biopsy and then the cancer recurring at the point of entry of the needle," Dr. Wallace noted. "We know it does happen; it's just exceedingly rare, really just a handful of case reports, despite the millions of biopsies that are done. When we looked at it systematically . . . there was no untoward effect of the biopsy."

Using the SEER-Medicare database, the researchers identified 2034 patients with surgically resected locoregional pancreatic cancer and compared long-term outcomes in the 498 (24%) who underwent EUS-FNA and the 1536 who did not. EUS-FNA was more likely in patients with multiple comorbidities and more recent diagnosis.

In multivariate analysis controlling for a variety of factors including age, race, gender, and tumor histology, stage, grade, location, comorbidity, radiation and chemotherapy, EUS-FNA was marginally associated with improved overall survival (hazard ratio 0.84), with no overall effect on cancer-specific survival (HR 0.87).

In addition, when the researchers compared patients who had EUS both with and without FNA and those who did not have EUS, EUS was independently associated with improved overall survival in multivariate analysis.

"This finding was in line with a previous population-based study that showed that EUS evaluation was an independent predictor of improved survival in patients with locoregional pancreatic cancer, most probably as a result of improved stage-appropriate management, including more selective performance of curative intent surgery and perioperative adjuvant therapy," the researchers note.

"In summary," they write, preoperative EUS-FNA does not appear to increased the risk of cancer-specific or overall mortality after surgery for pancreatic cancer.

Furthermore, "gastric recurrence or peritoneal seeding of cancer cells from EUS-FNA does not appear to have clinical significance or affect long-term outcomes in these patients."

Doctors can be reassured, they continue, "that tissue diagnosis by EUS-FNA is safe for the work-up of suspicious pancreatic lesions."

But, they add, whether or not EUS-FNA is actually worthwhile needs to be confirmed in randomized trials of staging with and without it.

Dr. Wallace receives research funding (unrelated to this study) from COSMO pharmaceuticals, Olympus, Boston Scientific and Ninepoint and US Endoscopy. The study had no commercial funding.

SOURCE: http://bmj.co/1AU8w5A

Gut 2015.