Survival Analysis of Patients with Breast Cancer
Total Page:16
File Type:pdf, Size:1020Kb
ANTICANCER RESEARCH 37 : 5813-5820 (2017) doi:10.21873/anticanres.12024 Survival Analysis of Patients with Breast Cancer Undergoing a Modified Radical Mastectomy With or Without a Thoracic Paravertebral Block: a 5-Year Follow-up of a Randomized Controlled Trial MANOJ KUMAR KARMAKAR 1, WINNIE SAMY 1, ANNA LEE 1, JIA WEI LI 1, WING CHEONG CHAN 2, PHOON PING CHEN 3 and BAN C.H. TSUI 4 1Department of Anesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, P.R. China; 2Department of Surgery, North District Hospital, Sheung Shui, New Territories, Hong Kong, P.R. China; 3Departments of Anesthesiology and Operating Services, North District Hospital, Sheung Shui, New Territories, Hong Kong, P.R. China; 4Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, U.S.A. Abstract. Aim: This 5-year prospective follow-up of women nor from that with GA plus c-TPVB (HR=0.79, 95% CI=0.21- randomized to general anesthesia (GA) with or without a 2.96) (p=0.88). Compared to the GA-only group, the risk of thoracic paravertebral block (TPVB) examined the risk of mortality was similarly not different from that of the two other local recurrence, metastasis and mortality after breast cancer groups (HR=2.57, 95% CI=0.66-9.92; and HR=0.66, 95% surgery. Patients and Methods: A total of 180 patients CI=0.11-3.97, respectively, p=0.15). Conclusion: Although undergoing modified radical mastectomy were randomized to the original study was underpowered to properly address one of three study groups: standardized GA only; GA with a long-term outcomes, the results of this analysis suggest that single-injection TPVB (s-TPVB) and placebo paravertebral TPVB, administered whether as a single-injection or infusion after surgery for 72-h; and GA plus with continuous continuous infusion during the perioperative period, had little TPVB (c-TPVB) for 72-h postoperatively. Cox proportional to no appreciable effect on local recurrence, metastasis or models were used to assess the effect of TPVB on long-term mortality after breast cancer surgery. outcomes. Equivalence testing was used to help interpret the results. Results: The incidence [95% confidence interval (CI)] Surgery offers the best prognosis for all excisable tumors. of cancer recurrence, metastatic spread and all-cause However, all general anesthetics (GAs) affect immune mortality was 2.3% (0.7-5.4%), 7.9% (4.6-12.6%) and 6.8% responses by depressing bone marrow activity, altering (3.6-11.2%), respectively. Four women had cancer recurrence phagocytosis by macrophages, and inducing immuno- and had metastatic spread. Compared to the GA-only group, suppression during surgery and in the postoperative period (1). the risk of metastatic spread was not different from that of GA Such immune compromise could affect the postoperative with s-TPVB [hazard ratio (HR)=1.11, 95% CI=0.32-3.83) infection rate, healing, and rate and extent of tumor dissemination during surgery (2). Anesthesia and surgical procedures have also been reported to suppress natural killer cell activity and other immune functions for a few days after Correspondence to: Ban C. H. Tsui, Dip Eng, BSc (Math), BSc surgery (2). Surgery-induced immunosuppression is also (Pharm), MSc (Pharm), MD, FRCP(C), PG Dip. Echo, Professor of associated with increased risk of tumor development and Anesthesia, Department of Anesthesiology, Perioperative and Pain metastasis in laboratory studies (2, 3). Medicine, Stanford University School of Medicine, 300 Pasteur Regional anesthesia and analgesia has been suggested to Drive, H3582, Stanford, CA 94305-5640, U.S.A. Tel: +1 6507236412, Fax:+ 1 6507258544, e-mail: [email protected] have a potentially important role in preserving immune function by attenuating or preventing the immunosuppressive Key Words: Breast cancer, radical mastectomy, paravertebral block, effect of surgery (2). A retrospective study suggested that randomized controlled trial, survival . patients given regional anesthesia for breast cancer have 5813 ANTICANCER RESEARCH 37 : 5813-5820 (2017) better prognosis than those given GA alone (4). When patients and from the Clinical Management System database, a regional anesthesia and GA are combined, the amount of GA computer database of the Hong Kong Hospital Authority, for the 5- required is significantly reduced, as is, presumably, immune year period after surgery. The study randomized 180 women into three groups (Figure 1) as suppression. Furthermore, regional analgesia provides follows: control: standardized general anesthesia (GA) using total excellent pain relief, essentially reducing or obviating the intravenous anesthesia with propofol; sTPVB: GA with single- need for postoperative opioids and consequent adverse injection TPVB (ropivacaine 2 mg/kg with 5 μg/ml epinephrine) and effects on immune function and promotion of tumor growth a paravertebral infusion of 0.9% saline (0.1 ml/kg/h); and c-TPVB: (5). Regional analgesia also reduces the release of general anesthesia with a single-injection TPVB as above and endogenous opioids (6), which exert a negative effect on the continuous paravertebral infusion of 0.25% ropivacaine at 0.1 ml/kg/h immune system. Certain GA regimens have been suggested for 72 h (8). to have potential in influencing cancer recurrence and Outcome measures . The primary outcome measure was the metastasis; for example, a propofol thoracic paravertebral incidence of local cancer recurrence or metastatic spread among the block (TPVB) technique was found to significantly reduce three groups. There was no direct patient contact or intervention the concentrations of endogenous factors associated with during the follow-up. Data on the tumor, including tumor location, angiogenesis in breast cancer (7). type, size, stage, and histological grading; resection margin; We previously examined chronic pain and quality of life estrogen receptor status; progesterone receptor status; expression of outcomes in a cohort of patients who underwent modified human epidermal growth factor receptor ( HER2 ); any radical mastectomy for breast cancer who were randomized lymphoangioinvasive growth; nodal status; adjuvant therapy received; immediate postoperative wound complications and to receive a standardized GA regimen with or without a treatment; and complications after receiving chemotherapy/ TPVB (8). In the current investigation, we prospectively radiotherapy; and the data of recurrence or metastatic spread were assessed the same cohort for local cancer recurrence, recorded from the Clinical Management System database (4, 9). metastasis and mortality for the 5-year period after surgery. Mammograms, ultrasound, biopsy results, and follow-up records were also retrieved from the Clinical Management System database Patients and Methods to review patient’s progress and confirm any recurrence or metastasis. If there was any uncertainty on the patient’s progress, This trial was registered with the Centre for Clinical Trials of The consultation with the surgeons was initiated. Chinese University of Hong Kong, http://www.cct.cuhk.edu.hk/ Registry/publictriallist.aspx, under the unique trial registration Statistical analysis. Data were analyzed using SPSS for windows number CUHK_CCT00301. Research Ethics Committee approval (Version 22; IBM Corp, Armonk, NY, USA) and STATA 13.1 was obtained (CRE-2011.286) from the Joint Chinese University of (StataCorp, College Station, TX, USA). Normality of the data was Hong Kong–New Territories East Cluster Clinical Research Ethics tested using Shapiro–Wilk’s test. Data are presented as median and Committee to conduct the 5-year follow up. Since there was no interquartile range (IQR) or frequency (%). Kruskal–Wallis test was direct patient contact during the 5-year follow-up period informed used to compare the medians between the study groups. The chi- consent was waived. square test was used to compare categorical data between groups. The time from treatment allocation to first recurrence of breast Population and sample size. This study was a follow-up study to a cancer; metastasis to bone, liver, brain, or lung; or end of follow- prospective, randomized, double-blinded controlled study on 180 up was recorded in months for the primary outcome. Similarly, time women undergoing modified radical mastectomy with TPVB and from treatment allocation to all-cause mortality or end of follow-up GA (8). Details of the inclusion and exclusion criteria, was estimated for the secondary outcome. The incidences of randomization procedure, anesthetic technique and the paravertebral primary and secondary outcomes were estimated with 95% infusion regimen (72-h postoperatively) used are presented in detail confidence intervals (95% CI). As the follow-up durations were in our previous report (8). different between groups, we also report the incidence rate (per Briefly, adult patients American Society of Anesthesiologists 10,000 months) and 95% CI. Cox regression was used to estimate (ASA) 1-3 under the age of 70 years undergoing major breast cancer the hazard ratio (HR) for comparing the outcomes between groups surgery (which included axillary lymph node dissection) were after checking the proportional hazards assumption with scaled recruited for this study. Patients with following conditions were Schoenfeld residuals. The Harrell’s c-statistic was estimated to excluded from the study: history of chronic pain, history of regular assess the overall discrimination of the survival