This study showed an imposing increase in laparoscopic treatment of early-stage EC from 11% of the procedures in 2006 to 85% in 2015, reflecting that LH was well implemented in the past decade in the studied clinical oncology network in the Netherlands. The introduction of TLH was frequently preceded by LAVH. The only predictive factor for a laparoscopic approach was treatment in a teaching hospital.
To the best of our knowledge, this is the first study that reports upon the implementation of LH in the treatment of EC over a 10-year period since the publication of the LACE trial in 2006. In a recently published study, results over a 4-year time span demonstrated an increase in minimally invasive hysterectomy of 22% in 2007 to 51% in 2011 in the USA [
22]. Data are in line with results from Bogani et al. who compared the type of surgical approach for gynecological malignancies during the years 2000–2003 with 2008–2011 and showed a comparable increase from 10 to 82%. Yet, these data were from a single center and included large numbers that might explain a faster increase in implementation [
17]. In comparison, the implementation of LH in the Netherlands was relatively late when compared to that in other countries, possibly due to the lack of centralization of EC treatment resulting in many hospitals treating small numbers [
23]. Implementation in the Netherlands might have been facilitated by the Dutch RCT, published in 2010 [
7].
The observed conversion rate changed over time and was 6.9% in the last year of our study, quite in line with the previous Dutch RCT that reported conversion rates of 10.8%, but higher than the reported 2.4% in the LACE trial [
6,
7]. Even in 2015, this number is still relatively high. Possible explanations are as follows: (1) variations in the time of the start of LH between hospitals that may not have reached the optimal surgical performance at the time of analysis, (2) relatively small numbers per hospital, and (3) a substantial proportion of obese patients (40.6%), since these are associated with increased conversion rate [
23,
24]. The overall comparable complication rates support our assumption that laparoscopic surgeons in the GOCS region were sufficiently trained to perform a LH. The absence of a decrease in the rate of complications with the implementation of LH during the 10-year period can be explained by the fact that more surgeons started to perform LH for endometrial cancer, each going through their individual learning curve. Analyses of an
overall learning curve are thus a mixture of several
individual learning curves. The observed trend towards an increased duration of surgery with less LH cases per year suggests that surgical volume might be relevant. However, since surgeons that perform LH of endometrial cancer also perform LH for benign indications, these numbers should be included for a proper analysis. The observation that the introduction of a TLH was frequently preceded by a LAVH approach may illustrate a step-wise adaptation of laparoscopic surgery. Although we hypothesized, according to previous findings, that patient-related factors such as BMI and previous abdominal surgery were predictive for the type of surgical approach, we could not confirm this in our study [
24,
25]. In our study cohort, 72.6% of the patients were overweight, with 40.6% being obese. The Dutch RCT was conducted between 2007 and 2009, and training of the surgical team including the anesthesiologist may have improved in recent years, resulting in reduced conversion rate. Interestingly, the type of hospital was related to the implementation of a laparoscopic approach. In 2015, all hospitals had implemented the LH, but implementation was faster in teaching hospitals compared to that in non-teaching hospitals. This is in line with the study of Pijnenborg and ter Haar who demonstrated the important contribution of residents in teaching hospitals in the implementation of LH in clinical practice [
12]. We did not observe a relation between the age or gender of surgeon and the type of primary surgical approach in line with previous data [
13,
14]. The safety of laparoscopy in the treatment of EC is established in eight RCTs that included mainly early-stage, low-grade EC [
11]. There is strong evidence for the role of laparoscopy in the management of low-grade EC, yet for high-grade EC, data are still limited. In a recently published study, it was shown that LH and laparoscopic lymph node dissection were equally safe when compared to open procedures in high-grade EC [
26]. Although numbers are relatively small, these data illustrate the shift of the indication towards the laparoscopic approach in high-grade EC treatment. This is supported by a follow-up date of the Gynecologic Oncology Group (GOG) LAP2 trial, which demonstrated that the outcome of patients with high-risk histology, including grade 3 endometrioid-type, serous, and clear cell carcinosarcoma, was not related to the type of surgical approach [
27]. In our study cohort, only 10 EC patients underwent a LH with lymphadenectomy, since surgical staging was implemented from 2015 onward. Yet, since numbers of high-grade EC with laparoscopic surgery are limited, there is still a need to continue monitoring whether a laparoscopic approach can be extended to high-grade EC patients. This switch from open to laparoscopic surgery has great impact on the costs for healthcare. Even robotic-assisted laparoscopic hysterectomy was shown to be 17% cheaper when compared to AH, mainly due to a shorter hospital stay [
28]. This benefit may be even more when conventional laparoscopic hysterectomy is performed and dependent on the use of expensive disposable supplies [
29]. Whether advanced-stage EC can be treated by a minimal invasive procedure equally safe has not been studied so far.
This study has some limitations that need to be addressed. The surgical treatment of EC in the Netherlands is not centralized, and consequently, the current data reflect the clinical practice in one clinical oncology network in the Netherlands [
23]. Since 2015, the surgical approach for EC is documented in the Netherlands Cancer Registry, demonstrating that 79% (66–83%) of the patients in 2015 with early-stage, low-grade EC were operated by a LH (data not shown). Based on our findings, we recommend to add the conversion rate and BMI to this Netherlands Cancer Registry database to monitor these in relation to annual cases in order to further improve the quality of care. Both the years of experience of individual surgeons with laparoscopic hysterectomy for benign indication and the experience of the surgical team have not been taken into account, while this may have influenced our data.