Risk Factors for PMPS
A recent retrospective study evaluated risk factors for developing PMPS in women from 4r to 9 years after mastectomy with axillary node dissection. Of the 128 patients included in the study, 43.8% reported experiencing chronic pain. Multivariate logistic/linear regression identified 4 independent risk factors: recall of preoperative pain, chemotherapy, need for opioids postoperatively, and the use of halogenated anesthesia. Other than the anesthesia finding, which needs further study, the risk factors from this study support previous research that demonstrated perioperative pain and use of adjuvant therapy as risk factors for PMPS.1
Other risk factors for PMPS include radiation therapy, younger age, higher body mass index, and more invasive mastectomy procedures. 2 “The major risk factor is breast surgery, especially in the upper outer quadrant of the breast. PMPS can develop with or without axillary surgery. Other factors that may increase the risk of PMPS are radiation, chemotherapy, larger tumor size, and age. Studies show a variety of risk factors but many of these are not consistent across the studies,” says Dr Boolbol.
Management of PMPS
The recent study on risk factors suggests that better management of perioperative pain may reduce PMPS.1 It may also be possible that as breast-conserving surgical procedures become more common, there may be a gradual reduction in PMPS; these procedures now account for approximately 40% of breast surgeries.2 More studies are needed on perioperative risk reduction.1,2
A study presented at the 2014 annual meeting of the American Society of Anesthesiologists compared 33 women given intravenous lidocaine during and for 2 hours after mastectomy to 28 women administered placebo. At 6 months following surgery, women in the lidocaine group reported a 20-fold reduction in pain compared to those in the placebo group. The researchers believe that the lidocaine reduced nerve damage and inflammation.3
For now, as with other types of neuropathic pain, there is no single treatment that is effective. “We see these patients in our pain management clinic,” says Dr Danesh. “Opioids are not indicated. Physical therapy has limited benefit. We can use nerve blocks, antiseizure medications, and antidepressants. Mind-body techniques can also help. In short, we use the whole multidisciplinary approach to pain management.
“Management of the symptoms is important not only for pain management but also for the impact on daily life. Treatment of the symptoms can initially include use of nonsteroidal agents. Massage of the area and acupuncture have also been found to relieve the pain. Depending on the severity of the pain, other medications such as gabapentin may be useful. Nerve blocks have also been used to relieve the symptoms,” says Dr Boolbol.