A fine needle aspiration can spread cancer

How dangerous is the biopsy?

JACKSONVILLE. In recent years there have been indications from case reports that fine needle aspiration biopsies in patients with pancreatic carcinoma are spreading cancer cells and causing metastases, for example in the stomach wall.

Subsequently, however, smaller studies had shown that the use of this endoscopic ultrasound-guided diagnosis to examine suspicious pancreatic lesions was not associated with an increased rate of gastric or peritoneal carcinomas.

However, due to the small number of participants, the studies are not conclusive enough, as gastroenterologists led by Dr. Saowanee Ngamruengphong from the Mayo Clinic in Jacksonville, Florida, reported (Gut 2015; online January 9).

Their hypothesis: If cancer cells were to be carried over with fine needle biopsies, the survival rate after a complete resection should be reduced.

To test this, the doctors evaluated data from Medicare insured persons in the USA who had been diagnosed with pancreatic cancer with a localized region.

Findings from 2034 patients

The results of 2034 patients aged 65 and over, available up to 2010, could be evaluated for the study, most of whom (90 percent) had adenocarcinoma of the pancreas.

A preoperative fine-needle biopsy had been performed in 498 patients - roughly one in four - but not in 1536 patients. The mean follow-up time was 21 months, with a maximum of 140 months.

Only 2.2 percent of the biopsied patients developed pancreatitis as a result of the procedure.

In the group of patients with a biopsy, 285 patients (57 percent) died in the follow-up period, in the group without a biopsy 1,167 patients (76 percent).

During the period, 251 patients (50 percent) in the biopsy group and 980 patients (65 percent) in the comparison group died of complications from pancreatic cancer.

For the parameter "cancer-specific survival" there was no significant difference between the two groups in the statistical multivariate analysis if several confounding factors such as age, gender, tumor histology as well as radiation and chemotherapy were taken into account.

In contrast, for the parameter "overall survival", the doctors calculated a trend towards a better survival rate in the group in which a fine needle biopsy was performed before the operation (hazard ratio, HR: 0.84). This is reflected in the fact that patients in the biopsy group lived for another 22 months, compared with only 15 months in the comparison group with a biopsy.

Since there are no randomized controlled trials on the safety of fine needle aspiration biopsy in pancreatic cancer patients and probably will not be, results from large population-based cohort studies are the best available for clarification, as the US doctors emphasize.

Her study assures doctors that this diagnostic procedure for assessing suspicious pancreatic lesions is a safe procedure.

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