MarginProbe System is Effective Tool in Assessing Margins During Breast Cancer Surgery

For patients with breast cancer, surgery is the most common treatment. They can undergo either of the two main types of surgeries: a lumpectomy — part of the breast containing the cancer is removed, or a mastectomy — all of the breast is removed.

The surgeon performing the operation looks for clear margins, meaning that no cancer cells are seen at the outer edges of the tissue that was removed. However, in some cases, a positive margin — cancer at the edge of the removed tissue — occurs, and that can lead to a second operation for the patient and an increased risk of cancer recurrence.

To assist surgeons in assessing margins in the operating room, The MarginProbe System was created by Dune Medical Devices. Using the tool, surgeons can get immediate information about the presence of cancer cells on the margins of a tumor.

How would you explain the use of the MarginProbe system to a patient?

Are there any statistics on how much MarginProbe has improved the success of lumpectomies overall?

In a study recently published online in the Annals of Surgical Oncology, a team of researchers gave a systematic review of the device. Richard Gray, M.D., general surgeon, co-director of the Breast Clinic at the Mayo Clinic in Phoenix, Arizona, and lead author on the study, spoke about the MarginProbe’s usefulness and limitations in an interview with CURE.It’s a device that is designed to detect abnormal cells at the edge of tissue that’s removed during breast cancer surgery. The goal of that is to make sure that all the cancerous cells are removed at the time of the first operation, so patients don’t have to go back for a second operation.Among the various studies there is some variability. MarginProbe has largely been used in lumpectomies, and that’s where the evidence resides. In terms of the statistics for patients undergoing lumpectomies, the use of the MarginProbe has decreased the rate of having cancer cells at the edge of the lumpectomy. That’s good because, most of the time, finding cancer cells at the margin means there is at least a question of whether all the cancer has been removed, and therefore the woman has to undergo a second operation.

When was the MarginProbe first introduced in the operating room, and how has the product changed lumpectomies?

One of the most reliable studies showed that the rate of positive margins went down from 42 percent to 31 percent. So, that means that 11 out of 100 women had clear margins because of the MarginProbe device. And, in that same study, there were six out of 100 women who were able to avoid a second operation because of the use of the MarginProbe device.The MarginProbe received approval from the Food and Drug Administration in late 2012. But it has been adopted in relatively small numbers. One reason for this is that it is somewhat expensive. It is reported that it costs the hospitals around $20,000 for the system, and then the probe that is used in each procedure is about $1,000.

It is also important to know that the MarginProbe was designed to let the surgeon know if something was abnormal at the edge, and whenever you set something to be very good at finding something it can sometimes be overly sensitive and make even normal cells register as abnormal. In the studies where MarginProbe was used, more than half the time when the probe said there was something abnormal and the surgeon should remove a little more tissue, it turned out there wasn’t actually anything abnormal there.

So, I guess the reasons why it hasn’t been adopted everywhere is that it is still expensive, many times it gives false-positive results and some institutions have other methods for detecting cancer at the margins, such as pathologists being available during surgery.

Can removing too much good tissue cause harm to the patient?

Is the device better for some patients?

As a surgeon, why is it important to know that you have achieved clear margins?

When we did our study of whether doctors should use the MarginProbe, our recommendation was, “Hey, if you have quite a few positive margins, if your rates are pretty high, then it is probably reasonable to use this to bring them down.” But because of the false positives, if your rates are already low, then those false positives are going to likely make you remove tissue that you don’t need to.Possibly, but the harm is largely cosmetic. So, when we are doing a lumpectomy, if we remove too much tissue there can be abnormalities in the appearance of the woman’s breast afterwards. There can be contour changes or indentations of the skin, which we want to avoid. This is a case where you want to use the tool, in this case MarginProbe, in the right circumstances. For a lot of places that don’t have resources like some of the bigger cancer centers do, the MarginProbe can be a very effective tool.No. It appears to be useful for a broad array of patients with breast cancer undergoing lumpectomies.We have to get clear margins to get the recurrence risk the lowest that we can for our patients. If we do a lumpectomy and we don’t get clear margins, most of the time we are doing a second operation to get those clear margins. Nobody likes that. The surgeon doesn’t want to have to do it and the patient certainly doesn’t want to have to have a second operation. And, health care costs are significant for second operations. I mentioned the cost of the MarginProbe — $1,000 per procedure — well, it costs a lot more than $1,000 to do a second operation.