Although epithelial ovarian cancers (EOCs) have been thought to arise from the simple epithelium lining the ovarian surface or inclusion cysts, the major subtypes of EOCs show morphologic features that resemble those of the müllerian duct-derived epithelia of the reproductive tract. We found that HOX genes, which normally regulate mullerian duct differentiation, are not expressed in normal ovarian surface epithelium (OSE), but are expressed in different EOC subtypes according to the pattern of mullerian-like differentiation of these cancers. Ectopic expression of Hoxa9 in tumorigenic mouse OSE cells gave rise to papillary tumors resembling serous EOCs. In contrast, Hoxa10 and Hoxa11 induced morphogenesis of endometrioid-like and mucinous-like EOCs, respectively. Hoxa7 showed no lineage specificity, but promoted the abilities of Hoxa9, Hoxa10 and Hoxa11 to induce differentiation along their respective pathways. Therefore, inappropriate activation of a molecular program that controls patterning of the reproductive tract could explain the morphologic heterogeneity of EOCs and their assumption of müllerian-like features.

Dissemination of ovarian cancer is a major clinical challenge and is poorly understood at the molecular level due to a lack of suitable experimental models. During normal development of the Drosophila ovary, a dynamic process called border cell migration occurs that resembles the migratory behavior of human ovarian cancer cells. In this study, we found that myosin VI, a motor protein that regulates border cell migration, is abundantly expressed in high-grade ovarian carcinomas but not in normal ovary and ovarian cancers that behave indolently. Inhibiting myosin VI expression in high-grade ovarian carcinoma cells impeded cell spreading and migration in vitro. Optical imaging and histopathologic studies revealed that inhibiting myosin VI expression reduces tumor dissemination in nude mice. Therefore, using genetic analysis of border cell migration in Drosophila is a powerful approach to identify novel molecules that promote ovarian cancer dissemination and represent potential therapeutic targets.

Objective: The aim of the study was to analyze the outcomes of patients who have undergone laparoscopic pancreaticoduodenectomy (LPD) in China. Summary Background Data: LPD is being increasingly used worldwide, but an extensive, detailed, systematic, multicenter analysis of the procedure has not been performed. Methods: We retrospectively reviewed 1029 consecutive patients who had undergone LPD between January 2010 and August 2016 in China. Univariate and multivariate analyses of patient demographics, changes in outcome over time, technical learning curves, and the relationship between hospital or surgeon volume and patient outcomes were performed. Results: Among the 1029 patients, 61 (5.93%) required conversion to laparotomy. The median operation time (OT) was 441.34 minutes, and the major complications occurred in 511 patients (49.66%). There were 21 deaths (2.43%) within 30 days, and a total of 61 (5.93%) within 90 days. Discounting the effects of the early learning phase, critical parameters improved significantly with surgeons’ experience with the procedure. Univariate and multivariate analyses revealed that the pancreatic anastomosis technique, preoperative biliary drainage method, and total bilirubin were linked to several outcome measures, including OT, estimated intraoperative blood loss, and mortality. Multicenter analyses of the learning curve revealed 3 phases, with proficiency thresholds at 40 and 104 cases. Higher hospital, department, and surgeon volume, as well as surgeon experience with minimally invasive surgery, were associated with a lower risk of surgical failure. Conclusions: LPD is technically safe and feasible, with acceptable rates of morbidity and mortality. Nonetheless, long learning curves, low-volume hospitals, and surgical inexperience are associated with higher rates of complications and mortality.