For many years, lumpectomy has been the most common surgical procedure to treat breast cancer. In a 2014 study in the Journal of the American Medical Association, researchers examined medical records of more than 132,000 women undergoing treatment for early-stage breast cancer, “defined as having a tumor size of 4 centimeters or smaller with 3 or less positive lymph nodes.” Their finding: 70 percent of the patients elected to have a lumpectomy, also sometimes referred to as “breast conservation therapy.”
During a lumpectomy, the breast surgeon removes only the tumor and a perimeter of cells surrounding it — the margin. The intention is to remove all of the tumor plus a thin rim of healthy tissue to be sure that all the cancer has been extracted. The surgery is often followed with radiation therapy to ensure that any cancer cells that could have been left behind are killed before they can multiply or develop into a new tumor.
[See: Breast Pain? Stop Worrying About Cancer.]
Lumpectomy is a common and effective means of treating breast cancer, especially early-stage cancers. Another 2014 JAMA study found that 83.2 percent of the patients who’d undergone a lumpectomy plus radiation treatments survived for 10 years after the procedure. In many cases, it’s considered a better option because a lumpectomy procedure usually takes less than an hour to complete and the recovery period is much shorter than what a patient would experience after a mastectomy, in which the entire breast (or both breasts in a contralateral or bilateral mastectomy) is removed.
Although lumpectomy is considered the best option for many breast cancer patients, it’s not perfect and one of the trickiest parts is ensuring that all of the cancer has been removed. Dr. Mary Gemignani, attending surgeon at Memorial Sloan Kettering Cancer Center in New York and the program director for surgical fellowship, says that being sure that all the cancerous cells have been removed is something of an “art” that requires the skills of an experienced surgeon.
Once the tumor has been removed, the surgeon will send the tissue to a pathology lab for testing. There, a pathologist examines the edges of the tumor and the perimeter of cells to determine whether it’s a “clean margin,” meaning that there’s a full perimeter of noncancerous cells around the tumor. If so, it’s usually safe to assume that all the cancerous cells have been extracted, but radiation treatment is still typically prescribed as a precaution.
Results from the pathology report can take a week to come back, which can create stress for the patient waiting to know whether all the cancer has been removed. “When you’re done and it goes to pathology, you have a good idea but you don’t know that you’ve got clean margins,” Gemignani says.
If the surgeon wasn’t able to get a clean margin — which can be especially difficult to do when dealing with a nonpalpable tumor (one that can’t easily be seen or felt) — you may need to have a second surgery, called a re-excision, to remove more tissue. According to a 2012 JAMA study, nearly 23 percent of all lumpectomy patients end up having subsequent surgery because cancer cells were found at the edge of the removed tissue.
These rates of re-excision vary depending on the surgeon’s skill, experience level and the type and location of the patient’s cancer. But some new technologies now entering operating rooms could help reduce the chances of re-excision and help patients deal with the uncertainty of having to wait a week or longer for confirmation that the cancer was completely removed.
[See: 7 Innovations in Cancer Therapy.]
Lori Chmura, CEO of Dune Medical Devices, which makes a device called the MarginProbe, says that this handheld, pen-shaped instrument helps doctors determine whether the tumor’s margin is clean while still in the operating room. The doctor holds the device, which was approved by the FDA for use in patients in 2013, to the removed tissue and presses a button. The device then sends radio waves into the tissue and reads what happens next in a process called radio-frequency spectroscopy. “The characteristics of the cells are reflected back to the console,” she says. The device then compares the data it receives to an internal algorithm and displays either a red bar, which means the cells being analyzed are cancerous, or a blue bar, which means they’re not. If the results come back red, “there’s likely cancer left in the breast, and the surgeon can go back in right then and take a directed shave,” to remove additional cells and recheck for whether all the cancer has been extracted, she says.
“The biggest benefit is that [surgeons are] able to see the result in real time,” and it takes some of the subjectivity out of guessing where the cancer ends and normal breast tissue begins, Chmura says. This can help doctors preserve more healthy tissue in patients — meaning that the breast could be less disfigured by the surgery — while still ensuring that the cancer has been removed. Chmura says the company tested the device “in 12,000 patients in the U.S., Israel and the U.K. and were able to reduce re-excisions by 79 percent.”
Dr. Stephanie Akbari, a dedicated breast surgeon in the Inova Breast Care Program in Fairfax, Virginia, was part of the clinical trial for the MarginProbe and uses the device in her practice. She says that after removing the tumor, “you actually place the device onto the tissue itself. It has to connect with the tissue,” after it’s been removed, so the device is not used on the patient directly. The results come back in just a few moments, and Akbari says the process adds about two or three minutes to the surgery. Akbari says before using the device, her re-excision rate “was already low at nine percent but it enabled me to lower it by half to four or five percent.”
Akbari notes that one drawback to the device is that it has a financial cost associated with it, “but the amount of money for a re-excision is more than 20 times the cost of the device, so it depends on how you look at that question.” False positives are also a potential issue. “You might [check a side of the tumor] and determine you need to take more tissue, but when you get the final pathology report, sometimes it will say that the original side that came back as positive on the device actually does not have cancer in it.” Despite this potential, which could result from the pathologist sampling a slightly different area than the surgeon, Akbari says it’s still preferable to having to re-excise a patient.
[See: A Tour of Mammographic Screenings During Your Life.]
Dr. Dennis Holmes, a breast surgical oncologist and principal investigator on the trial for the probe, notes that no medical device is perfect. “The MarginProbe doesn’t guarantee that there couldn’t be a positive margin, but it performed much better than the traditional tools we use,” he says.
The appeal of devices that can give surgeons real-time feedback on their performance is strong, and researchers at the University of Texas at Austin announced this week that they’d also “invented a powerful tool that rapidly and accurately identified cancerous tissue during surgery, delivering results in 10 seconds.” This device, called the MasSpec Pen, is a separate device developed by a different team from the MarginProbe and uses a somewhat different approach to analyzing the cells. The MasSpec Pen reportedly uses molecules called metabolites present in cancer to determine whether the cells are healthy or cancerous.
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Improving Margin Assessment in Lumpectomy originally appeared on usnews.com
