In our study there was no difference in disease-free survival or cancer-specific survival between patients undergoing minimally invasive versus open pelvic exenteration. No significant difference was found in peri-operative morbidity in our patients (apart from the higher incidence of intra-operative transfusions in the group treated with the open approach). The lack of difference in morbidity in our series may be explained by the relatively low incidence of major complications in both groups. Nevertheless, even if not significant, the minimally invasive group reported a lower incidence of peri-operative complications (Table 2).

Different studies have previously reported the feasibility and the better peri-operative outcomes of minimally invasive pelvic exenteration.10 11 However, few studies have reported the survival outcomes of patients undergoing the minimally invasive approach, particularly compared with the open approach.12 A recent study by Matsuo et al showed that the minimally invasive approach was associated with a decreased incidence of sepsis and thromboembolism compared with an open approach in a retrospective population-based analysis of the National Inpatient Sample.11 In the present series, the incidence of post-operative complications is comparable to other series of pelvic exenteration for gynecologic malignancies.23 No difference in post-operative morbidity was noted between the open and minimal access approach, but a trend towards a higher incidence of wound dehiscence/infection, blood transfusion, and bowel obstruction in the laparotomy group has to be mentioned.

Our survival rate is comparable to those reported in other pelvic exenteration series.6 9 12 In particular, we report a median disease-free survival and cancer-specific survival of 17 and 26 months, respectively, in the entire population. Although this might appear to be a limited survival rate, one must note that this is in a group of non-selected consecutive patients including 12.0% of palliative procedures, which are usually not included in other published series6 12 23 (deemed a contraindication to pelvic exenteration for poor survival outcomes24), and 20.5% of laterally extended disease, which was considered a contraindication to radical surgery until recently.25 Laterally extended endopelvic resection has been shown to be a feasible procedure with interesting surgical and oncological outcomes,26 but different series have shown that lateral disease represents a worse prognostic factor per se.6 25 The high number of lateral involvements in the present series might have also contributed to impaired survival of our cohort.

As shown in previous studies, involvement of the surgical margin and tumor size at recurrence are the most important prognostic factors affecting disease-free survival and cancer-specific survival in patients with gynecological malignancies undergoing pelvic exenteration.6 12 27 For this reason, patient selection and surgery planning with updated pre-operative imaging is crucial to obtain free surgical margins at final histology. All baseline characteristics were equalized in our population by propensity match analysis. This gave us the opportunity to compare patients with similar tumor diameter. In this context, we consider that tumor diameter together with pelvic sidewall involvement should be an important criterion in selecting patients for an open versus a minimally invasive approach. In fact, even though some reports have shown the feasibility of laterally extended pelvic resection by laparoscopy, this approach should be used with caution as achievement of free surgical margins cannot be compromised.13 28

When analyzing the surgical approach in gynecological cancer surgery, the results of the well-known randomized Laparoscopic Approach to Cervical Cancer (LACC) trial should always be noted.29 However, this trial included patients with newly diagnosed early-stage cervical cancer while, in our series, most of the included patients (95.7%) had recurrent/persistent pelvic disease. Nevertheless, it is always crucial to follow the basic principles of oncological surgery, avoiding cancer cell spillage, careful specimen manipulation and resection of tumor-free tissues.

The results of the present study may be considered in a larger context of surgical oncology, including rectal and bladder cancer. In these settings, minimally invasive exenteration could be performed in highly selected cases with favorable patient anatomy and tumor characteristics, as it was associated with reduced intra-operative blood loss, shorter length of hospital stay, and reduced morbidity with no survival difference from the open approach in rectal and bladder cancer.30–32

Our study represents one of the largest series comparing oncologic outcomes in patients undergoing open versus minimally invasive pelvic exenteration. However, it does have some limitations: first, the retrospective nature of the study may have led to selection bias; second, the heterogeneity of primary origin of the included gynecological cancers makes survival comparison with other studies less reliable; and last, selection to open versus minimally invasive exenteration was performed according to the surgeon’s preference and this may represent a further important selection bias.