Prevalence of post-mastectomy pain syndrome and associated risk factors: a cross-sectional cohort study.

This study was designed to determine the prevalence of post-mastectomy pain and its associated risk factors in women submitted to surgical treatment for breast cancer. A cross-sectional cohort study was conducted involving 250 women treated surgically for breast cancer. The variables evaluated were (a) post-mastectomy pain syndrome (PMPS) (as a dependent variable or outcome) and (b) the patients' social characteristics (schooling, marital status), biological characteristics (body mass index, skin color, age), prior history of headache and dysmenorrhea, occurrence of acute postoperative pain, and type of surgery (mastectomy or quadrantectomy) (as independent or predictive variables). The prevalence ratios (PR) and their respective 95% confidence intervals (95% CI) were calculated as a measure of the risk of PMPS. Multivariate analysis was performed using a hierarchical model of stepwise logistic regression that included possible explanatory variables, calculating the adjusted risk of PMPS from the odds ratio (OR) and the 95% CI at a significance level of 5%. PMPS was found in 44.4% of patients. The variables that remained strongly associated with PMPS following multiple logistic regression analysis were quadrantectomy with axillary lymphadenectomy (OR = 2.83; 95% CI: 1.60-5.02), prior history of headache (OR = 1.92; 95% CI: 1.10-3.34), and age <50 years (OR = 4.37; 95% CI: 2.43-7.86). PMPS is a common condition, particularly in women submitted to quadrantectomy with axillary lymphadenectomy, those under 50 years of age, and those with a prior history of headache. Attention should be paid to these factors at preoperative evaluation and counseling, and they should be taken into consideration in postoperative management.