Researchers have identified several risk factors for chronic pain after breast cancer surgery including radiation therapy, removal of lymph nodes from under the arm (axillary lymph node dissection) and younger age. Axillary lymph node dissection was found to be the greatest risk factor; women who underwent surgery to remove lymph nodes from under the arm for breast cancer were much more likely to develop chronic pain.
Even with a 10-year survival rate of about 83%, up to 60% of surviving patients who have had surgery for breast cancer experience chronic pain after surgery, which is linked to decreased quality of life and functional impairment. Being informed about risk factors could have an impact on pain management by allowing women at high risk of pain after surgery to be identified, who may then be targeted for interventions — for instance, psychotherapy. An international team of researchers conducted a study to identify risk factors for chronic pain among women who have undergone surgery for breast cancer.
The team found 77 independent risk factors for persistent pain. The study, recently published in the Canadian Medical Association Journal had shown high quality evidence that radiotherapy, greater acute postoperative pain, axillary lymph node dissection and younger age were risk factors associated with the development of chronic pain after surgery for breast cancer. Furthermore, moderate-quality evidence suggested an association with the presence of increased acute preoperative pain. Axillary lymph node dissection, a surgical procedure to remove the lymph nodes from under the arm, accounted for the largest of these associations, with a 21% increase in risk of chronic pain (among women who underwent axillary lymph node dissection). Additionally, high quality evidence showed no association between type of breast surgery, chemotherapy and endocrine therapy and body mass index (BMI) with chronic pain, suggesting that these are not important predictors for chronic pain.
The study was a systematic review on 30 observational studies exploring the association between risk factors and chronic pain (lasting at least two months) after surgery for breast cancer on 19, 813 patients who underwent breast cancer surgery.
The overall findings of this study suggest that women who undergo surgery for breast cancer are more likely to develop chronic pain if their surgery involved axillary lymph node dissection to remove their tumour. Researchers assert that the established increase in risk of pain with axillary lymph node dissection is sufficient to suggest interventions. They go on to state that future research is needed to determine the link between overall comorbidity (the simultaneous presence of two conditions in a patient), dosage of radiotherapy and chronic pain after surgery, and establish whether axillary (armpit) nerve-sparing techniques (i.e. to save the nerves near the tissues being removed) are effective for reducing chronic pain after breast surgery.
Written By: Nigar Celep, BASc