The study team found that vacuum assisted biopsies were acceptable and that it should be possible to do a larger trial.
This study was open for people to join between 2013 and 2015, and the research team reported the results in 2016.
About this study
The women in this
pilot study all had
breast cancer and were due to have surgery. As part of this study they had either a core needle biopsy (CNB) or vacuum assisted biopsy (VAB) of the lymph nodes under their arm. They then had surgery to remove their breast cancer and lymph nodes.
The research team asked 95 women if they would like to take part in this study, and 81 women (85%) agreed.
Of these, 80 were able to take part and were put into 1 of 2 groups at
random:
- 40 had a core needle biopsy (CNB)
- 40 had a vacuum assisted biopsy (VAB)
Results
The research team looked at the tissue removed during the biopsies and the lymph nodes removed during surgery, to see whether they contained any cancer cells.
They compared the results from the biopsies and the operation for each woman, to see how accurate the two types of biopsy were.
Of the 40 women who had a core needle biopsy:
- 33 women had the same results from the biopsy and the operation
- 4 women had different results from the biopsy and the operation
- 1 woman didn’t have surgery
- 1 woman had surgery elsewhere and the results were not available
- 1 biopsy sample wasn’t big enough test
Of the 40 women who had a vacuum assisted biopsy:
- 28 women had the same results from the biopsy and the operation
- 4 women had different results from the biopsy and the operation
- 2 women didn’t have surgery
- 6 biopsy samples weren’t big enough to test
The research team asked the women taking part if they would, in theory, be prepared to have a biopsy in the same way again:
- 38 out of 39 women (97%) who had CNB said yes
- 33 out of 39 women (85%) who had VAB said yes
The number is a bit higher for CNB but the difference between the groups could be due to chance. It’s difficult to draw any firm conclusions about this because of the small number of people in each group.
Pain
The research team asked the women taking part to rate their pain on a scale of 0 (no pain) to 10 (worst pain they could imagine). They did this just after the biopsy, and again at their clinic appointment a week or so later.
The research team looked at the ‘median’ pain score. They work this out by putting the pain scores from all the women in numerical order. The median score is the number in the middle number in that list.
The median score for pain just after the biopsy was 1 for women in both groups.
The median score for pain at the clinic appointment was 1 for those who had CNB, and 2 for those who had VAB.
Other side effects
Very few women taking part had side effects other than pain. Two women who had VAB had some bleeding under the skin (a haematoma) after the biopsy. One was taking aspirin, which thins the blood.
The study team recommend that people who take medication to thin their blood shouldn’t have a vacuum assisted biopsy.
Conclusion
The study team concluded that a vacuum assisted biopsy is an acceptable test that women would be willing to have. VAB did cause a bit more pain than CNB, but the accuracy for diagnosing cancer was similar. But these results don’t provide enough evidence for the team to recommend that women have a VAB instead of a CNB.
Where this information comes from
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (
peer reviewed ) and published in a medical journal. The figures we quote above were provided by the team who did the research. We have not analysed the data ourselves.