Main Menu

Unexpected Outcome in Hysterectomy Study

With regard to the retrospective analysis, Uppal encouraged continued monitoring of survival data for the more recent years of the study period, looking for potential alternative explanations for the declining survival and to confirm the association with MIS.

He also presented data in response to his rhetorical question: “What will happen if we abandoned minimally invasive surgery?” Referring to the National Inpatient Sample for 2015, he noted that a return to open surgery for all patients would result in 85 additional complications, 70 transfusions, and approximately two deaths per 1,000 cases per year. Another recent analysis of uptake of minimally invasive hysterectomy suggested that an additional six lives per 1,000 cases per year would be saved by increased uptake versus open surgery.

Using the lower estimate for deaths would result in 2.60 lives saved per 1,000 cases with open surgery versus a net loss of 1.25 lives with the higher estimate, as LACC data suggested 4.75 lives would be saved per 1,000 cases if minimally invasive surgery were abandoned.

Randomized Trial

The LACC trial had a primary endpoint of DFS at 4.5 years. The study was statistically powered as a noninferiority trial, and the investigators tested the hypothesis that MIS would lead to a DFS rate within 7.2% of that associated with open surgery. To help ensure standardization of care, participating centers submitted 10 MIS cases to a central review committee in advance, as well as two unedited videos of MIS procedures. MIS included total laparoscopic and robotic-assisted procedures.

Eligible patients had stage IA1 to IB1 squamous, adenocarcinoma, or adenosquamous cervical cancer. Enrollment started in June 2008 and ended in June 2017 when the data and safety monitoring committee performed an interim analysis and identified a safety issue associated with one of the still-blinded treatment arms. Martinez noted that the data for the primary outcome were about 40% complete at the time of the analysis, and that the data for overall survival were 37% complete.

The intention-to-treat analysis showed a 4.5-year DFS rate of 96.5% in the open-surgery arm and 86.0% in the MIS group, representing a 13% difference in the hazard ratio in favor of open surgery. A per-protocol analysis showed 4.5-year DFS rates of 97.6% and 87.1% — a 12% HR advantage in favor of open surgery.

Martinez reported 27 recurrences in the MIS arm versus seven with open surgery. The difference translated into a DFS hazard ratio of 3.74 (95% CI 1.63 to 8.58, P=0.002). The MIS group had 19 locoregional recurrences — a sixfold difference versus the three that occurred in the open-surgery group (95% CI 1.77 to 20.3, P=0.004). The hazard ratio for disease-specific survival was 6.74 for MIS versus open surgery (95% CI 1.48 to 29.0, P=0.013).

Retrospective Analysis

Rauh-Hain reported findings from an analysis of all-cause mortality with MIS versus open hysterectomy. He and his colleagues also evaluated whether adoption of MIS into clinical practice influenced trends in 4-year survival.

The analysis involved patient records included in the National Cancer Database, which covers 70% of new cancer diagnoses in the United States. Eligible patients had surgery during 2010-2012 for stage IA2 or IB1 cervical cancer of any histology, and a procedure that included radical hysterectomy and pelvic lymph-node dissection. The investigators used propensity-score analysis to help ensure the similarity of the two treatment arms.

Rauh-Hain and colleagues also performed an interrupted time series analysis using data from the NCI Surveillance, Epidemiology, and End Results (SEER) registry program. The objective was to determine how adoption of MIS for radical hysterectomy affected survival, and the analysis showed a 1% decrease in 4-year survival for each year after 2006.

The team identified 2006 as the first year of MIS adoption, and 2000-2006 provided data to estimate pre-existing trends. The objective was to determine whether trends in 4-year relative survival differed significantly after 2006.

The analysis included 2,221 patients, 47.5% of whom underwent MIS procedures, which were robotic-assisted in 79% of cases.

The analysis produced a hazard ratio of 1.48 (95 CI 1.10 to 1.98) for MIS versus open surgery and an adjusted probability of death within 4 years of 8.4% with MIS and 5.8% with open surgery. An increased mortality risk persisted in sensitivity analyses of:

  • Adjuvant therapy — HR 1.44, 95% CI 1.07 to 1.93
  • Robotic assistance — HR 1.39, 95% CI 1.01 to 1.91
  • Traditional laparoscopy — HR 1.42, 95% CI 0.93 to 2.18
  • Exclusion of hospitals without MIS — HR 1.33, 95% CI 1.05 to 1.6

Leave a Reply

Your email address will not be published. Required fields are marked *