Postmastectomy pain syndrome is a "major clinical challenge," but four treatment modalities have been found to have a "significant effect" on the pain, conclude the authors of a new review systematic review of the subject.
However, another expert laid emphasis elsewhere, saying there is "no magic drug" and that some patients feel their ongoing, intractable pain is a "lost cause."
Postmastectomy pain syndrome is neuropathic pain in and around the area of surgery that lasts more than 3 months and can persist indefinitely, say the authors, led by Inga Magdalena Larsson, MD, a surgeon at the Odense University Hospital in Denmark.
Their review of treatments was published as a short communication on December 30, 2017, in the Breast Journal.
Estimates of prevalence of the pain syndrome range from 25% to 60% of all mastectomy patients. What causes the pain is unknown, but surgical injury to peripheral nerves in the axilla or chest wall is the main explanation.
Despite its commonness, the pain syndrome has been little researched, and there is no consensus on treatment, the review authors say.
So the team performed a PubMed database search, which yielded 88 publications through 2014, but only six fulfilled criteria — only randomized or controlled trials and comparative studies were included.
In the end, four modalities were found to yield a statistically significant reduction in pain, as measured by various scales. The list consisted of antidepressants (amitriptyline, venlafaxine), an antiepileptic (levetiracetam), topical treatment (capsaicin), and autologous fat grafting. However, none of the studies were large, and most had enough limitations that the review authors called for larger, higher-quality confirmatory trials for each modality.
Still, the authors conclude brightly: "There is a palette of effective treatment modalities of post-mastectomy pain syndrome."
But Liz Ball, MBChB, PhD, an oncoplastic breast surgeon in Suffolk, United Kingdom, thinks a bit differently, especially about drug treatment.
As a physician, Dr Ball admits that she "never really took much notice" of this pain problem in mastectomy patients. (In the United Kingdom, breast cancer patients present to surgeons only 1 year and 5 years after undergoing surgery.)
"That all changed when I had a left mastectomy myself, and suddenly I now had postmastectomy pain syndrome," she told Medscape Medical News. (Dr Ball, who underwent mastectomy in 2015, has tweeted and written about experience under her married name, O'Riordan.)
Her postsurgery symptoms included a burning sensation on the left side and sharp shooting pains on the chest wall that "make me swear out loud." Also, Dr Ball has long-term shoulder stiffness resulting from axillary lymph node surgery and the effects of radiation on the pectoral muscle that covers an implant.
"Treating it is hard, as the review article says," Dr Ball said in an email.
"Most people, like me, are given antidepressants and antiepileptics to try, and they do work for some people, but the side effects can be disabling," she emphasized.
Amitriptyline left Dr Ball with "a dreadful hangover." She took it every night at 9:00 pm before sleep. "If I took it any later, I would be groggy and muggy-headed in the morning. I stopped taking it because it didn't fit in with my lifestyle," she said.
Also, the daily experience of pain and taking drugs that have side effects makes having cancer a "never ending" experience, said Dr Ball. So, she gave up drug therapy: "Like a lot of women, I learned to live with the pain. You feel like you're a lost cause and are expected to cope."
Dr Ball, who is a triathlete who bikes, runs, and swims, eventually decided to visit a physiotherapist.
The treatment, which she underwent twice a month for 2 years, was mainly for her stiff shoulder, which her clinician treated by stretching the chest and back muscles to encourage movement. "That's what helped me," she said.
With the physiotherapist, Dr Ball also underwent "an experiment," she said.
The pair visited the Neuro Orthopedic Institute (NOI) website, which provides evidence-based pain treatment information, and Dr Ball performed a quick exercise.
"You are shown pictures of left and right hands in various positions — upside down, twisted around, facing you or facing away from you. Your job is to say whether the hand is a left hand or a right hand, as fast as you can. I thought this would be really easy, and it was. Until I saw the results. It took me 10 times longer to identify a left hand," she explained, adding that her mastectomy was performed on the left breast.
New research has proven this phenomenon among larger groups of patients, she said.
"If you have chronic pain in one of your limbs, it alters the brain's perception of left and right, and it takes you longer to associate with the side you have pain," she explained.
But, as with other neurologic injuries, the brain can be trained back into shape. "I have the NOI app on my phone and use it to practice, and my responses for 'left' things do get faster. You can train your brain to recognize both sides equally," she said.
The training is more than an academic exercise, inasmuch as Dr Ball needs to be able to differentiate left and right hand sides on a regular basis, such as when reading mammograms or prepping a breast for surgery.
Fat Grafting and Other Ideas
Autologous fat grafting is the only nondrug treatment modality on the new review's list of effective treatments. It is relatively new compared to the other treatment options, with research undertaken in the past decade.
The idea is that the injections may result in a softening of scar tissue and a reduction in inflammation, say the review authors. Two studies "showed a highly significant clinical result on women with post-mastectomy pain syndrome," they observe.
However, Dr Ball was cautious.
"Fat grafting is a new approach that I hadn't heard of, and there may be promise in this," she said.
However, it represents "yet another operation, and bruised and sore thighs or tummy for several weeks," depending on the donor site from which the fat is taken. "We know that up to 30% of fat grafted can die because it doesn't get a good enough blood supply, so the operation may need doing again," she also pointed out.
Other research for this pain syndrome is ongoing. For example, Emory University, in Atlanta, Georgia, is now undertaking a 22-patient pilot study to examine the effectiveness of cryoablation on postmastectomy chronic pain syndrome.
Participants will be randomly assigned to receive cryoablation or a therapeutic peripheral nerve block injection, which is another modality that was recently shown to have efficacy. Cryoablation uses extreme cold to destroy or damage tissue — in this case, the intercostobrachial nerve.
"Some patients may have experienced trauma to the intercostobrachial nerve during surgery, formed scar tissue or neuroma causing them persistent pain," said Janice Newsome, MD, an Emory radiologist, in a statement.
"We use a CT scan to help guide the needle during cryoablation to accurately target the problem area," said Dr Newsome. "Then, we freeze the nerve for over five minutes, unthaw, and freeze again."
The authors and Dr Ball have disclosed no relevant financial relationships.
Breast J. 2017;23:338-343. Abstract
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Cite this: Nick Mulcahy. Four Treatments for Mastectomy Pain, but 'No Magic Drug' - Medscape - Jan 26, 2018.