Clinical impact of high-quality testing for peritoneal lavage cytology in pancreatic cancer.

In pancreatic ductal adenocarcinoma (PDAC) patients, the importance of peritoneal lavage cytology, which indicates unresectability, remains controversial. This study sought to determine whether positive peritoneal lavage cytology (CY+) precludes pancreatectomy. Furthermore, we propose a novel liquid biopsy using peritoneal lavage fluid to detect viable peritoneal tumor cells (v-PTCs) with TelomeScan F35, a telomerase-specific replication-selective adenovirus engineered to express green fluorescent protein. Resectable cytologically or histologically proven PDAC patients (n = 53) were enrolled. CY was conducted immediately following laparotomy. The resulting fluid was examined by conventional cytology (conv-CY; Papanicolaou staining and MOC-31 immunostaining) and by the novel technique (Telo-CY; using TelomeScan F35). Of them, 5 and 12 were conv-CY+ and Telo-CY+, respectively. All underwent pancreatectomy. The two double-CY+ (conv-CY+ and Telo-CY+) patients showed early peritoneal recurrence (P-rec) postoperatively, despite adjuvant chemotherapy. None of the three conv-CY+ Telo-CY- patients exhibited P-rec. Six of the 10 Telo-CY+ conv-CY- patients (60%) relapsed with P-rec. Of the remaining 38 double-CY- [conv-CY-, Telo-CY-, conv-CY± (Class III)] patients, 3 (8.3%) exhibited P-rec. Although conv-CY+ status predicted poor prognosis and a higher risk of P-rec, Telo-CY was more sensitive for detecting v-PTC. Staging laparoscopy and performing conv-CY and Telo-CY are needed to confirm the indication for pancreatectomy.

Single-incision laparoscopic surgery for benign multicystic mesothelioma of the peritoneum in a young man: A case report.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, particularly in men, and the preoperative diagnosis poses a challenge. Here, we present a case involving single-incision laparoscopic surgery (SILS) for BMPM in a 24-year-old man with a pelvic mass and a history of ulcerative colitis. Pelvic imaging revealed multifocal cysts, prompting the performance of SILS. The tumor was successfully resected with no residual lesions, and pathology confirmed the diagnosis of BMPM. This case represents the first documented instance of SILS being employed for BMPM in a man. BMPM, characterized by pelvic multifocal cysts, is a differential diagnosis, and SILS emerges as a viable option for both diagnosis and treatment.

Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report.

BACKGROUND: The greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient. CASE PRESENTATION: A 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up. DISCUSSION AND CONCLUSION: We encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

Neoadjuvant chemotherapy does not improve survival for patients with high volume colorectal peritoneal metastases undergoing cytoreductive surgery.

BACKGROUND: Colorectal peritoneal metastases (CRPM) affects 15% of patients at initial colorectal cancer diagnosis. Neoadjuvant chemotherapy (NAC) prior to cytoreductive surgery (CRS) has been demonstrated to be a safe and feasible option, however there is limited data describing its efficacy in advanced peritoneal disease. This study evaluated the effect of NAC on survival in patients with high volume CRPM undergoing CRS with or without HIPEC. METHODS: A retrospective review of all patients who underwent CRS with or without HIPEC for CRPM from 2004 to 2019 at our institution was performed. The cohort was divided based on peritoneal carcinomatosis index (PCI) at surgery: Low Volume (PCI ≤ 16) and High Volume (PCI > 16). RESULTS: A total of 326 patients underwent CRS with HIPEC for CRPM. There were 39 patients (12%) with High Volume disease, and 15 of these (38%) received NAC. Patients with High Volume disease had significantly longer operating time, lower likelihood of complete macroscopic cytoreduction (CC-0 score), longer intensive care unit length of stay and longer hospital stay compared to Low Volume disease. In High Volume disease, the NAC group had a significantly shorter median survival of 14.4 months compared to 23.8 months in the non-NAC group (p = 0.046). CONCLUSION: Patients with High Volume CRPM achieved good median survival following CRS with HIPEC, which challenges the current PCI threshold for offering CRS. The use of NAC in this cohort did not increase perioperative morbidity but was associated with significantly shorter median survival compared to upfront surgery.

Transhepatic Bromelain and Acetylcysteine for Treatment of Posterior Gastric Pseudomyxoma Peritonei: A Case Report.

BACKGROUND/AIM: Pseudomyxoma peritonei (PMP) is a rare condition characterized by diffuse spread of mucinous tumors within the peritoneal cavity. Traditional treatment modalities, such as cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are challenging in cases of recurrent disease, owing to anatomical complexities and increasing morbidity and mortality risk. BromAc® has emerged as a novel, targeted therapy for PMP with evidence for intra-tumoral administration to break down mucin deposits. CASE REPORT: We present a 70-year-old female with confirmed diagnosis of symptomatic appendiceal PMP situated behind the stomach, refractory to prior CRS and HIPEC. Transhepatic intra-tumor injection of BromAc® was performed, guided by imaging, with catheter placement into the posterior gastric mucinous tumor. The procedure was well-tolerated, and post-treatment imaging revealed a significant 40% reduction in tumor burden. The patient had fever on cycle days two and three, which self-resolved and septic screen performed was negative. Following BromAc® administration, the patient demonstrated improvement in symptoms and quality of life. CONCLUSION: This case highlights the potential efficacy and safety of transhepatic administration of BromAc® for the treatment of recurrent PMP behind the stomach. The targeted delivery of BromAc® directly into a mucinous tumor via the transhepatic route offers a minimally invasive alternative for cases where traditional surgical interventions pose challenges. However, further research and clinical trials are warranted to validate the broader applicability of this novel approach, assess long-term outcomes, and optimize procedural parameters for enhanced therapeutic outcomes in PMP treatment.

The role of cytoreductive surgery and HIPEC for the treatment of primary and secondary peritoneal malignancies-experience from a tertiary care center in Germany.

PURPOSE: Peritoneal surface malignancies (PSM) are commonly known to have a dismal prognosis. Over the past decades, novel techniques such as cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC) have been introduced for the treatment of PSM which could improve the overall survival and quality of life of patients with PSM. The decision to proceed with CRS and HIPEC is often challenging due the complexity of the disease, the extent of the procedure, associated side effects, and potential risks. Here, we present our experience with CRS and HIPEC to add to the ongoing discussion about eligibility criteria, technical approach, and expected outcomes and contribute to the evolution of this powerful and promising tool in the multidisciplinary treatment of patients with primary and secondary PSM. METHODS: A single-center retrospective chart review was conducted and included a total of 40 patients treated with CRS and HIPEC from April 2020 to September 2022 at the University Hospital Münster Department of Surgery. All patients had histologically confirmed primary or secondary peritoneal malignancies of various primary origins. RESULTS: Our study included 22 patients with peritoneal metastases from gastric cancer (55%), 8 with pseudomyxoma peritonei (20%), 4 with mesothelioma of the peritoneum (10%), and 6 patients with PSM originating from other primary tumor locations. Median PCI at time of cytoreduction was 4 (0-25). Completeness of cytoreduction score was 0 in 37 patients (92.5%), 1 in two patients (5%), and 2 in one patient (2.5%). Median overall survival across all patients was 3.69 years. CONCLUSION: Complete cytoreduction during CRS and HIPEC can be achieved for patients with low PCI, for patients with high PCI in low-grade malignancies, and even for patients with initially high PCI in high-grade malignancies following a significant reduction of cancer burden due to extensive preoperative treatment with PIPAC and systemic chemotherapy.

Diagnosis and treatment of malignant retroperitoneal mesothelioma: A case report.

RATIONALE: Malignant peritoneal mesothelioma (MPM) is a rare clinical disease. Although there are several reports describing intraperitoneal mesothelioma of the lung, liver, and intestine, retroperitoneal mesothelioma is, to our knowledge, very rare and rarely reported. In recent years, our best clinical protocols for the treatment and diagnosis of retroperitoneal mesothelioma have not been proven and the diagnosis and treatment are challenging. PATIENT CONCERNS: A 37-year-old Chinese woman complained of bilateral low back pain for a month, with obvious symptoms of low back pain on the left side. To treat low back pain, retroperitoneal masses were found during physical examination. The patient consulted a urological specialist for further treatment. DIAGNOSIS: After the operation, pathological biopsy confirmed retroperitoneal epithelioid diffuse mesothelioma. INTERVENTIONS: After exclusion of surgical contraindications, the patient underwent laparoscopic retroperitoneal lesion resection under tracheal intubation and general anesthesia, and the operation was successful. OUTCOMES: On the tenth day after surgery, the patient vital signs were stable, and he was discharged. LESSONS: Patients with malignant peritoneal mesothelioma may have no typical clinical symptoms, and the diagnosis is based on pathological and immunohistochemical examination. In selected patients, surgical cell reduction and intraoperative intraperitoneal heat chemotherapy have become the first choice of treatment, which can achieve ideal therapeutic effects and prolong survival.

Doxorubicin as Risk Factor for Fascial Dehiscence After CRS-HIPEC for Peritoneal Metastases.

BACKGROUND/AIM: Among postoperative complications, fascial dehiscence (FD) is registered in up to 10% of patients after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). This study aimed to evaluate the risk factors related to FD after CRS-HIPEC. PATIENTS AND METHODS: A retrospective analysis of a prospectively maintained database of consecutive patients who underwent CRS-HIPEC between 2015 and 2023 was performed. For each patient, risk factors for postoperative fascial dehiscence were identified using multivariate analysis. RESULTS: During the study period (2018-2023), 217 patients were treated with CRS-HIPEC. The incidence of FD was observed in seven cases (3.2%), which were reoperated with direct fascial closure. In three cases, FD was associated with other grade III-IV complications. Body mass index, (BMI; p=0.024), doxorubicin-based HIPEC (p=0.005), and open technique (p=0.004) were identified as risk factors for FD in univariate analysis. Systemic chemotherapy, prior surgical score, and peritoneal cancer index (PCI) were not associated with an increased risk of FD. In multivariable regression analysis, doxorubicin-based HIPEC and open technique were confirmed as risk factors for FD. CONCLUSION: Although FD is a relatively rare event after CRS-HIPEC, open technique and doxorubicin-based HIPEC were significant predictors of this complication. Specific fascial closure techniques and proper wound care should be considered in high-risk patients.

Ruptured Ovarian Cystic Teratoma: A Rare Diagnosis, Easily to Be Confused with Peritoneal Carcinomatosis.

Although ovarian cystic teratoma is the most common ovarian tumor, complications are quite rare. However, it is important to be recognized by the radiologist in order to avoid inaccurately diagnosing them as malignant lesions. This case report describes a 61-year-old postmenopausal woman, who presented to the emergency room with abdominal pain following a minor blunt abdominal trauma. In this context, a CT scan was performed, which showed the presence of round, hypodense masses randomly distributed in the peritoneum, with coexisting ascites in moderate amount; ovarian carcinoma with peritoneal carcinomatosis was suspected. The patient was hospitalized and an MRI of the abdomen and pelvis was recommended for a more detailed lesion characterization. Following this examination, the patient was diagnosed with mature cystic ovarian teratoma complicated by rupture. Surgery was performed, and the outcome was favorable. The cases of ruptured cystic teratomas are rare, and to our knowledge, this is the first occurrence described in literature. Special attention must be paid when confronting with such a case in medical practice, since it can easily misdiagnosed as peritoneal carcinomatosis.

Complexity of surgery and treatment burden in patients with peritoneal malignancy is not determined by addition of hyperthermic intraperitoneal chemotherapy.

BACKGROUND: This study describes surgical and quality of life outcomes in patients with peritoneal malignancy treated by cytoreductive surgery (CRS) alone compared with a subgroup treated with CRS and hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: Peritoneal malignancy patients undergoing surgery between 2017 and 2023 were included. The cohort was divided into patients treated by CRS and HIPEC and those treated by CRS without HIPEC (including CRS only or maximal tumour debulking (MTB)). Main outcomes included surgical outcomes, survival, and quality of life. Groups were compared using non-parametric tests and log-rank test was used to compare survival curves. RESULTS: 403 had CRS and HIPEC, 25 CRS only and 15 MTB. CRS and HIPEC patients had a lower peritoneal carcinomatosis index (12.0 vs. 17.0 vs. 35.0; P < 0.001) and longer surgical operative time (9.3 vs. 8.3 vs. 5.2 h; P < 0.001), when compared to CRS only and MTB, respectively. No other significant difference between groups was observed. CONCLUSIONS: The optimal management of selected patients with resectable peritoneal malignancy incorporates a combined strategy of CRS and HIPEC. When HIPEC is not utilized, due to significant residual disease or comorbidity precluding safe delivery, CRS alone is associated with good outcomes. Hospital stay and complications are acceptable but not significantly different to the CRS and HIPEC group. CRS alone is a complex intervention requiring comparable resources with good outcomes. In view of our findings 'intention to treat' with CRS and HIPEC should be the basis for resource allocation and funding.

Peritoneal carcinomatosis in mouse models.

Peritoneal carcinomatosis (PCa) represents a metastatic stage of a disease with unmet therapeutic options. Malignant cells from primary tumors (gastrointestinal or gynecologic malignancies) invade the peritoneal cavity and eventually seed onto peritoneal surfaces, with the omentum being the most common nest area. With a median survival of less than 6 months, PCa has a dismal prognosis that can be improved with treatments only available to a select few individuals with low tumor burden. Thus, the discovery of novel and effective therapies for this disease depends on reliable animal models. Here, we describe a method to generate syngeneic PCa mouse models based on intraperitoneal (i.p.) administration of tumor cells. This model allows to follow-up cancer progression in PCa models from ovarian and colorectal origins monitoring mice bodyweight changes, ascites development and overall survival. Moreover, luciferase-expressing tumor cells can also be used to assess tumor growth after i.p. injection through in vivo bioluminescence quantification. The establishment of reliable, easy-to-monitor and reproducible intraperitoneal syngeneic tumors models, as described here, is the first step to develop cutting-edge therapies against PCa.

Senolytic drugs dasatinib and quercetin combined with Carboplatin or Olaparib reduced the peritoneal and adipose tissue metastasis of ovarian cancer.

Chemotherapy and targeted drugs-induced senescent ovarian cancer cells that accumulate in peritoneal adipose tissue contribute significantly to chronic inflammation, disrupt homeostasis, and may fuel various aspects of cancer progression. However, the pro-senescence effects of chemotherapy and targeted drugs on adipose derived stem cells (ADSCs) within peritoneal adipose tissue remain poorly understood. In this study, we show that the first-line chemotherapy and targeted drugs can induce the cellular senescence of ADSCs in vitro and increase the aging of peritoneal adipose tissue in vivo. These treatments significantly promoted the dysregulation of glucose and lipid metabolism, including insulin resistance and liver lipid accumulation. Our study shows that dasatinib and quercetin, as senolytics, effectively restore glucose homeostasis in mice with ovarian cancer and significantly reduce adipose tissue aging. Importantly, combining these drugs with Carboplatin or Olaparib results in a marked decrease in both peritoneal and adipose tissue metastasis of ovarian cancer cells. Mechanistically, we revealed that there is crosstalk between ovarian cancer cells and senescent ADSCs. The crosstalk increases inflammatory cytokines and chemokines production in ADSCs and notably upregulates chemokine receptors on cancer cells. Collectively, these data indicate that senescent ADSCs induced by chemotherapy and targeted therapy drugs impair adipose tissue function. However, the senolytic drugs dasatinib and quercetin, can significantly ameliorate organ aging and damage induced by these treatments. Notably, dasatinib and quercetin combined with Carboplatin or Olaparib reduced the peritoneal and adipose tissue metastasis of ovarian cancer, ultimately benefiting the mice undergoing chemotherapy and targeted therapy.

Safety and efficacy of sirolimus in recurrent intravenous leiomyomatosis, pulmonary benign metastatic leiomyomatosis, and leiomyomatosis peritonealis disseminata: a pilot study.

BACKGROUND: Intravenous leiomyomatosis (IVL), pulmonary benign metastatic leiomyomatosis (PBML), and leiomyomatosis peritonealis disseminata (LPD) are leiomyomas with special growth patterns and high postoperative recurrence rates. We report the safety and efficacy of a pilot study of sirolimus in the treatment of recurrent IVL, PBML, and recurrent LPD. METHODS: This was a pilot study to evaluate the safety and efficacy of sirolimus in the treatment of leiomyomatosis (ClinicalTrials.gov identifier NCT03500367) conducted in China. Patients received oral sirolimus 2 mg once a day for a maximum of 60 months or until disease progression, intolerable toxicity, withdrawal of consent, or investigator decision to stop. The primary end point of this study was the objective response rate. Secondary end points included safety and tolerability, disease control rate, and progression-free survival. RESULTS: A total of 15 patients with leiomyomatosis were included in the study, including five with recurrent IVL, eight with PBML and two with recurrent LPD. The median follow-up time was 15 months (range 6-54 months), nine patients (60%) had treatment-related adverse events (including all levels), and two patients had treatment-related grade 3 or 4 adverse events. The objective response rate was 20.0% (95% CI, 7.1-45.2%), and the disease control rate was 86.7% (95% CI, 62.1-96.3%). Partial response was achieved in three patients. The median response time in the three partial response patients was 33 months (range 29-36 months), and the sustained remission time of these three patients reached 0, 18, and 25 months, respectively. CONCLUSIONS: Sirolimus was safe and effective in the treatment of recurrent IVL, PBML, and recurrent LPD. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03500367. Registered on 18 April 2018.

TGF-ß-driven LIF expression influences neutrophil extracellular traps (NETs) and contributes to peritoneal metastasis in gastric cancer.

Gastric cancer (GC), notorious for its poor prognosis, often advances to peritoneal dissemination, a crucial determinant of detrimental outcomes. This study intricately explores the role of the TGFß-Smad-LIF axis within the tumor microenvironment in propagating peritoneal metastasis, with a specific emphasis on its molecular mechanism in instigating Neutrophil Extracellular Traps (NETs) formation and encouraging GC cellular functions. Through a blend of bioinformatics analyses, utilizing TCGA and GEO databases, and meticulous in vivo and in vitro experiments, LIF was identified as pivotally associated with GC metastasis, notably, enhancing the NETs formation through neutrophil stimulation. Mechanistically, TGF-ß was substantiated to elevate LIF expression via the activation of the Smad2/3 complex, culminating in NETs formation and consequently, propelling peritoneal metastasis of GC. This revelation uncovers a novel potential therapeutic target, promising a new avenue in managing GC and mitigating its metastatic propensities.

Correlation between peritoneal cancer index and survival in advanced epithelial ovarian cancer with complete resection.

OBJECTIVE: The aim of this study was to investigate the relation between the peritoneal cancer index, overall survival, and recurrence free survival, in patients with epithelial ovarian cancer. METHODS: Patients treated at the Gustave-Roussy Institute between December 2004 and November 2017 for advanced epithelial ovarian cancer in complete resection were included. The correlation between the peritoneal cancer index and survival was studied using statistical modeling. Multivariate analysis was performed with a logistic regression model. RESULTS: Of the 351 patients included, 94 (27%) had initial surgery and 257 (73%) had interval surgery. Median follow-up was 52.7 months (range 47.6-63.9). Median peritoneal cancer index was 10 (range 0-32). The linear model best represented the relationship between peritoneal cancer index and overall survival. Patients with neoadjuvant chemotherapy had a greater instantaneous risk of baseline death than those with initial surgery, as well as a more rapid increase in this risk as the peritoneal cancer index increased. Overall survival and recurrence free survival were better in the initial surgery group (103.4 months (79.1-not reached (NR)) vs 66.5 months (59.1-95.3) and 31.8 months (23.7-48.7) vs 25.9 months (23.2-29), respectively). Risk factors for death were body mass index, peritoneal cancer index, and need for neoadjuvant chemotherapy. CONCLUSION: The peritoneal cancer index is a prognostic indicator, but its linear relationship with survival precluded setting a unique peritoneal cancer index cut-off. Moreover, the prognostic impact of peritoneal cancer index was stronger in the setting of neoadjuvant chemotherapy.

Outcomes following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal malignancies: 10 ​Year experience.

INTRODUCTION: The treatment of peritoneal malignancies has evolved and select patients can undergo effective surgical therapies. Access to innovative oncology procedures can be improved if programs are developed within and outside of academic cancer centers. We report the creation of a high volume, comprehensive peritoneal malignancy program developed in a community center. METHODS: A retrospective single-site study was conducted using registry data comprising all patients who underwent Cytoreductive Surgery (CRS) and Heated Intraperitoneal Chemotherapy (HIPEC) between October 2011-December 2021. RESULTS: 353 patients underwent CRS and HIPEC. 208 patients experienced in-hospital morbidity (58.9 â€‹%). Group comparison by disease site, PCI, and the completeness of cytoreduction demonstrated survival differences in mean overall survival and disease-free survival in 1-, 3- and 5-year ranges. CONCLUSIONS: This study demonstrates that with a standardized protocol and a surgeon-led multidisciplinary team it is possible to offer safe outcome driven, complex oncologic surgery in a community-based cancer program.

Real-world study of lymphadenectomy in patients with advanced epithelial ovarian cancer.

BACKGROUND: The evidence on the role of retroperitoneal lymphadenectomy is limited to less common histology subtypes of epithelial advanced ovarian cancer. METHODS: This retrospective cohort study utilized data from the Surveillance, Epidemiology, and End Results Program from January 1, 2010, to December 31, 2019. Patients with stage III-IV epithelial ovarian cancer were included and divided into two groups based on whether they received retroperitoneal lymphadenectomy. The primary outcomes are overall survival (OS) and cause-specific survival (CSS). RESULTS: Among the 10 184 included patients, 5472 patients underwent debulking surgery with retroperitoneal lymphadenectomy, while 4712 patients only underwent debulking surgery. No differences were found in the baseline information between the two groups after propensity score matching. Retroperitoneal lymphadenectomy during debulking surgery was associated with improved 5-year OS (43.41% vs. 37.49%, p < 0.001) and 5-year CSS (46.43% vs. 41.79%, p < 0.001). Subgroup analysis further validate the retroperitoneal lymphadenectomy increased the 5-year OS and CSS in patients with high-grade serous cancer. Although the results were not validated in the less common ovarian cancer (including endometrial cancer, mucinous cancer, low-grade serous cancer, and clear cell cancer), the tendency showed patients with the above four subtypes may benefit from the lymphadenectomy which is restricted for small sample size after propensity score matching. CONCLUSIONS: This study revealed that retroperitoneal lymphadenectomy could further improve the survival outcome during debulking surgery in patients with advanced epithelial ovarian cancer. The conclusion was affected by the histology subtypes of ovarian cancer and further studies are needed to validate the conclusion in less common ovarian cancer.

Feasibility of Robot-Assisted Cytoreductive Surgery With Upper-Abdominal Peritonectomy for Pseudomyxoma Peritonei With Low Peritoneal Carcinomatosis Index: A Pilot Study.

INTRODUCTION: Our study's objective was to provide the method for, and preliminary findings from, robot-assisted cytoreductive surgery (r-CRS) combined with upper-abdominal peritonectomy in pseudomyxoma peritonei (PMP) with limited peritoneal surface malignancy (PSM). MATERIALS AND METHODS: We conducted a retrospective pilot study on consecutive patients with PSM secondary to pseudomyxoma peritonei with a peritoneal cancer index (PCI) of under 10 who were indicated for r-CRS combined with upper-abdominal peritectomy. Perioperative and 30-day major morbidity and mortality characteristics were analyzed and compared with cases in which laparoscopic CRS (l-CRS) was performed under the same conditions. RESULTS: Six patients underwent r-CRS combined with an upper-abdominal partial peritonectomy. Their mean PCI was 4.83. Complete cytoreduction was achieved in all patients. The mean duration of the operation was 156.8 minutes. There was no major complication and no mortality. The mean length of hospital stay after surgery was 6.33 days. r-CRS resulted in less blood loss, a lower C-reactive protein level, and a shorter length of hospital stay that were significantly different compared with those of l-CRS. CONCLUSIONS: This is the initial technical report of a robotic approach for CRS combined with upper-abdominal peritonectomy. r-CRS with a combined upper-abdominal peritonectomy was shown to be safe and feasible for PMP with limited PSM.