Anesthetic choices and breast cancer recurrence: a retrospective pilot study of patient, disease, and treatment factors.

The purpose of this work was to investigate differences in patient, disease, and treatment factors between women who received outpatient surgical treatment of breast cancer with paravertebral and general anesthesia compared with women who received general anesthesia alone. A total of 358 patients with stage 0-III disease received a partial or total mastectomy without axillary node dissection at a large academic cancer center. Study median follow-up time was 28.8 months. Patient demographic characteristics were equally represented across anesthesia groups. Mean body mass index (kg/m) was greater in those who received general anesthesia alone (mean = 29, SD = 6.8) than in those who received paravertebral regional block with general anesthesia (mean = 28, SD = 5.1) (P = .001). The paravertebral regional block with general anesthesia group contained advanced stages of disease (P = .01) and had longer surgical procedures (P = .01) than the general anesthesia alone group. Breast cancer recurrence was detected in 1.7% of the study population (paravertebral regional block with general anesthesia: n = 4; and general anesthesia alone: n = 2). Overall, no association between anesthesia type and recurrence was detected (P = .53), with an unadjusted estimated hazard ratio of 1.84 (95% confidence interval, 0.34-10.08). The overall rate of recurrence was very small in this population. A larger study is needed to detect significant differences in rates of recurrence attributable to type of anesthesia.