The Impact of Paravertebral Block Analgesia on Breast Cancer Survival After Surgery.
Cata JP, Chavez-MacGregor M, Valero V et al.
Reg Anesth Pain Med. 2016 Nov/Dec;41(6):696-703.

Seven hundred ninety-two women with nonmetastatic breast cancer were included in this retrospective study. Patients were divided based on the administration of PVB analgesia for mastectomy surgeries. One hundred ninety-eight (25%) were given a PVB, the remainder were treated with opioid-based analgesia. Propensity score matching was developed using several variables. Univariate and multivariate analyses were used to assess the impact of PVB analgesia on Recurrance Free Survival (RFS) and Overall Survival (OS).

The median follow-up times for RFS and OS were 5.8 and 6 years, respectively. In the propensity score matching model, a total of 396 women were included in each group of treatment (non-PVB group, n = 198 vs PVB group, n = 198). As expected, the fentanyl consumption was significantly lower in PVB  patients than non-PVB subjects. Other variables were not statistically significant.

After adjusting for several important covariates, the analysis indicated that the use of PVB is not associated with a significant change in RFS [1.60 (0.81-3.16), P = 0.172] or OS [1.28 (0.55-3.01)] survival.

This retrospective study does not support the hypothesis that the use of regional analgesia is associated with longer survival after surgery for breast cancer.