One In Four Breast Biopsies May Be Inaccurate

Being told that you need a breast biopsy is guaranteed to send a jolt of nervous electricity through your system. With the potential of a diagnosis of breast cancer hanging over your head, it's vital you get the correct diagnosis.

But can you bet your life on the accuracy of the biopsy? A new study in the JAMA says maybe not.

Researchers tested 115 pathologists who routinely interpret the tissue samples of breast biopsies as part of their practices. Each pathologist reviewed 60 samples, some negative, some positive for cancer. Only the researchers knew the correct diagnoses.

When it came to active and invasive cancers, the pathologists were pretty much on the mark. They hit a 96 percent rate of accuracy. You'd obviously like to see 100 percent.

But when it came to subtle cancers -- or pre-cancers, the scorecard wasn't as good.

Up to one out of every five pathologists misdiagnosed ductal cancers (DSIC), which are cancers that are confined to the milk ducts, and haven't invaded true breast tissue. These typically do not require as aggressive a treatment as invasive breast cancer such as mastectomy or radiation.

When it came to "atypia," the pathologists only hit the nail on the head half the time. Atypia means cells that are not cancerous, but one day may turn into a cancer. Some doctors said there was no problem -- when there was … others said there was a problem when there was none.

So what's the takeaway? It's called a second opinion.

First remember -- this was a study designed to trick the pathologist with extra hard cases. In the real world, most if not all pathologists will get another two cents on a sample that just may not look right -- or even one that looks okay, but they want to be sure. Pathologists tend to be an extra cautious bunch -- which is good.

That means you're probably okay from an accuracy standpoint, but it's vital you speak up and ask to make sure that second opinion was done. You don't want overtreatment. You don't want under-treatment.

All biopsies need two sets of eyes.

All.

Dr. Dave Hnida is CBS4's Medical Editor. He blogs about the latest studies and trends in the health world. Read his latest blog entries, check out his bio or follow him on Twitter @drdavehnida