Biopsies don't spread cancer, Mayo research shows

Volume 4, Issue 2, 2015

Summary

Having a biopsy can actually improve outcomes in cancer.

Photograph of Michael B. Wallace, M.D.

Michael B. Wallace, M.D.

A study of more than 2,000 patients by researchers at the Mayo Clinic Cancer Center in Florida dispels the myth that cancer biopsies cause cancer to spread.

In the Jan. 9, 2015, online issue of the journal Gut, researchers show that patients who had a biopsy had a better outcome and longer survival than did patients who didn't have a biopsy.

The researchers studied pancreatic cancer, but the findings likely apply to other cancers because the diagnostic technique used in this study — fine-needle aspiration — is commonly used across tumor types, said the study's senior investigator, Michael B. Wallace, M.D., a gastroenterologist at Mayo Clinic Cancer Center in Jacksonville, Florida, and a professor of medicine at Mayo Clinic College of Medicine.

Patients and even some physicians have long believed that a biopsy can cause some cancer cells to spread.

"This study shows that physicians and patients should feel reassured that a biopsy is very safe," Dr. Wallace said. "We do millions of biopsies of cancer a year in the U.S., but one or two case studies have led to this common myth that biopsies spread cancer."

Biopsies offer "very valuable information that allows us to tailor treatment. In some cases, we can offer chemotherapy and radiation before surgery for a better outcome, and in other cases, we can avoid surgery and other therapy altogether," Dr. Wallace said.

Dr. Wallace and his team have conducted two separate studies to examine the risk of having a cancer biopsy.

In a 2013 study published in the journal Endoscopy, the researchers examined outcomes in 256 patients with pancreatic cancer treated at the Mayo Clinic Cancer Center in Florida. They found no difference in cancer recurrence between 208 patients who had ultrasound-guided fine-needle aspiration (EUS-FNA) and the 48 patients who didn't have a biopsy.

In the current study, they examined 11 years (1998-2009) of Medicare data on patients with nonmetastatic pancreatic cancer who underwent surgery. The researchers examined overall survival and pancreatic cancer-specific survival in 498 patients who had ultrasound-guided fine-needle aspiration and 1,536 patients who didn't have a biopsy.

During a mean follow-up time of 21 months, 285 patients (57 percent) in the EUS-FNA group and 1,167 patients (76 percent) in the non-EUS-FNA group died. Pancreatic cancer was identified as the cause of death for 251 patients (50 percent) in the EUS-FNA group and 980 patients (64 percent) in the non-EUS-FNA group.

Median overall survival in the EUS-FNA group was 22 months compared with 15 months in the non-EUS-FNA group.