Incidence of incisional hernia in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: an observational clinical study from a tertiary oncology referral care center in India.

BACKGROUND: An incisional hernia (IH) after major abdominal surgery is an unwanted complication particularly following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC). The frequency of IH among patients treated with CRS and HIPEC remains unexpectedly high in various studies. This study aimed to analyze the incidence, determine the factors contributing to the occurrence of IH, and develop methods to reduce the incidence of IH. METHODS: We retrospectively analyzed data from a prospectively maintained structured computerized comprehensive database of 360 patients who had undergone CRS and HIPEC after January 2013 and completed two years of follow-up before December 2023. All patients were followed for a minimum period of two years with physical examination and radiological imaging when required and the occurrence of IH was documented. We used SPSS software version 24 to analyze the data using appropriate statistical tests. We set a significance threshold of p < 0.05. RESULTS: Within two years of undergoing CRS and HIPEC, 25 patients (6.9%) out of 360 developed IH, indicating an annual incidence rate of 3.5%. The mean duration of hospitalization for the CRS/HIPEC procedure was 8.4 ± 4.13 days. Fifty-two (14.4%) patients experienced early post-operative surgical complications. The development of IH in our series was significantly associated with obesity (76% vs. 8.4%, P = 0.001), the occurrence of early post-operative surgical complications (48% vs. 12%, P = 0.001), mainly category III complications (44% vs. 7.1%), category IV complications (24% vs. 2.9%) according to Clavien-Dindo classification, post neoadjuvant chemotherapy status (72% vs. 87%, P = 0.045) and need for bowel anastomosis (32% vs. 11%, P = 0.002). CONCLUSION: The lower incidence of IH following CRS and HIPEC in our patient cohort than in the literature can be attributed to a combination of factors, including the use of meticulous surgical techniques and the use of an abdominal binder postoperatively, particularly in obese patients.

Pediatric, Adolescent and Young Adult (AYA) Peritoneal and Pleural Mesothelioma: A National Cancer Database Review.

PURPOSE: Malignant peritoneal and pleural mesothelioma are rare in young patients, with a paucity of data regarding clinical characteristics and outcomes. We aimed to describe the clinical characteristics, treatment strategies, and outcomes for pediatric and adolescent/young adult (AYA) patients. METHODS: The National Cancer Database (NCDB) was queried for malignant peritoneal and pleural mesothelioma in pediatric and AYA patients (ages 0-39) from 2004 to 2019. Stratification was performed for pediatric (age 0-21) and young adult (age 22-39) patients. Chi-squared, multivariable cox regression, and Kaplan-Meier analyses were performed. RESULTS: We identified 570 total patients, 46 pediatric and 524 young adult, with mesothelioma (363 peritoneal and 207 pleural). There were significant differences in sex distribution as patients with peritoneal mesothelioma were more frequently female (63.1%). Patients with peritoneal mesothelioma were more likely to have radical surgery compared to pleural mesothelioma (56.7% v. 24.6%, respectively). A majority of patients with peritoneal and pleural mesothelioma received chemotherapy (66.4% and 61.4%, respectively). For peritoneal mesothelioma, surgical resection was associated with improved overall survival, whereas male sex, neoadjuvant chemotherapy, and radiation were associated with worse overall survival. For pleural mesothelioma, intraoperative chemotherapy was associated with improved overall survival, whereas Black race was associated with worse overall survival. Mean overall survival was greater for patients with peritoneal mesothelioma (125 months) compared to those with pleural mesothelioma (69 months), which remained significant after stratification of pediatric and young adult patients. CONCLUSION: By analyzing a large cohort of pediatric and AYA mesothelioma, this study highlights clinical, prognostic, and survival differences between peritoneal and pleural disease. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Retrospective.

Peritoneal malignancy in the global COVID-19 pandemic: experience of recovery and restoration in a high-volume centre through NHS and independent sector collaboration.

INTRODUCTION: Treatment of peritoneal malignancy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) requires substantial critical care, theatre and nursing resources. The COVID-19 pandemic caused challenges in providing a high volume, tertiary referral service. METHODS: We reviewed data on referrals and operations performed in a tertiary referral centre in both NHS and independent sector settings. The impact of COVID-19 on activity was assessed using 2019 as a benchmark. RESULTS: New patient referrals were similar, with 891 in 2019 compared with 833 in 2020. Delivery of CRS and HIPEC operations were initially impacted by COVID-19. NHS and independent sector collaboration facilitated recovery, with 284 patients treated in 2020 compared with 280 in 2019. CONCLUSIONS: Close collaboration and structural organisation between the clinical and management teams in the NHS and independent sectors facilitated recovery and restoration of a complex tertiary referral service for peritoneal malignancy during the COVID pandemic.

Peritoneal metastases from gastric cancer in a nationwide cohort: Incidence, treatment and survival.

The aims of this study were to investigate incidence, risk factors and treatment of synchronous or metachronous peritoneal metastases (PM) from gastric cancer and to estimate survival of these patients using population-based data. Patients diagnosed with gastric cancer in 2015 to 2016 were selected from the Netherlands Cancer Registry. The incidence of synchronous and metachronous PM were calculated. Multivariable regression analyses were performed to identify factors associated with the occurrence of PM. Treatment and survival were compared between patients with synchronous and metachronous PM. Of 2206 patients with gastric cancer, 741 (34%) were diagnosed with PM. Of these, 498 (23%) had synchronous PM. The cumulative incidence of metachronous PM in patients who underwent potentially curative treatment (n = 675) was 22.8% at 3 years. A factor associated with synchronous and metachronous PM was diffuse type histology. Patients diagnosed with synchronous PM more often received systemic treatment than patients with metachronous PM (35% vs 18%, respectively, P < .001). Median overall survival was comparable between synchronous and metachronous PM (3.2 vs 2.3 months, respectively, P = .731). Approximately one third of all patients with gastric cancer are diagnosed with PM, either at primary diagnosis or during 3-year follow-up after potentially curative treatment. Patients with metachronous PM less often received systemic treatment than those with synchronous PM but survival was comparable between both groups. Future trials are warranted to detect gastric cancer at an earlier stage and to examine strategies that lower the risk of peritoneal dissemination. Also, specific treatment options for patients with gastric PM should be further investigated.

Increased Incidence of Liver Metastases in Colorectal Versus Appendiceal Adenocarcinoma Peritonectomy Patients Despite Equivocal Survival.

BACKGROUND/AIM: Colorectal adenocarcinoma (CRAdenoCa) and appendiceal adenocarcinoma (AAdenoCa) are diseases of the same histopathological type that metastasise to the liver and peritoneum. In selected subgroups, peritonectomy and heated intraperitoneal chemotherapy (HIPEC) may be indicated as part of the multimodal treatment plan. However, literature comparing the survival outcomes and preoperative tumour activity and burden of CRAdenoCa and AAdenoCa peritonectomy patients without synchronous liver metastases (sLM) is scarce. Little is also known about the comparative incidence of sLM and metachronous LM (mLM) between CRAdenoCa and AAdenoCa peritonectomy patients. This study aimed to clarify the above. PATIENTS AND METHODS: A retrospective cohort study of 684 CRAdenoCa and AAdenoCa primary peritonectomy patients between 2001-2021 was conducted at St George Hospital in Sydney, Australia. RESULTS: Median overall survival (years) was equivocal between CRAdenoCa and AAdenoCa peritonectomy patients (1.7 vs. 1.9, p=0.35). Peritoneal cancer index and preoperative carcinoembryonic antigen (CEA) were significantly elevated (25 vs. 9, p<0.0001 and 7.9 vs. 5, p=0.0080) in AAdenoCa versus CRAdenoCa peritonectomy patients without sLM. The incidence of sLM and mLM was increased in CRAdenoCa peritonectomy patients (24% vs. 3.1%, p<0.0001 and 26% vs. 10%, p=0.0001). CONCLUSION: This study demonstrates similar survival outcomes between CRAdenoCa and AAdenoCa peritonectomy patients. Despite elevated preoperative tumour burden and biological activity in AAdenoCa patients, CRAdenoCa patients had higher rates of sLM and mLM. Further studies are warranted to validate and identify cellular and molecular targets that increase CRAdenoCa's ability to metastasise to the liver.

Pathological findings and long-term prognosis in Korean BRCA1/2 mutation carriers undergoing risk-reducing salpingo-oophorectomy.

OBJECTIVE: Our study aimed to evaluate the incidence of pathological findings in asymptomatic Korean patients with BRCA1/2 pathogenic variants who underwent risk-reducing salpingo-oophorectomy and to assess their long-term prognosis. METHODS: We retrospectively analyzed the medical records of patients with a germinal BRCA1/2 pathologic variant who had undergone risk-reducing salpingo-oophorectomy at Asan Medical Center (Seoul, Korea) between January 2013 and December 2020. All pathologic reports were made based on the sectioning and extensively examining the fimbriated end of the fallopian tube (SEE/FIM) protocol. RESULTS: Out of 243 patients who underwent risk-reducing salpingo-oophorectomy, 121 (49.8%) had a BRCA1 mutation, 119 (48.9%) had a BRCA2 mutation, and three (1.2%) had both mutations. During the procedure, four (3.3%) patients with a BRCA1 mutation were diagnosed with serous tubal intraepithelial carcinoma (STIC) or serous tubal intraepithelial lesion (STIL), and another four patients (3.3%) were diagnosed with occult cancer despite no evidence of malignancy on preoperative ultrasound. In the BRCA2 mutation group, we found one (0.8%) case of STIC, but no cases of STIL or occult cancer. During the median follow-up period of 98 months (range, 44-104) for STIC and 54 months (range, 52-56) for STIL, none of the patients diagnosed with these precursor lesions developed primary peritoneal carcinomatosis. CONCLUSIONS: Risk-reducing salpingo-oophorectomy, in asymptomatic Korean patients with BRCA1/2 pathogenic variants, detected ovarian cancer and precursor lesions, including STIC or STIL. Furthermore, our follow-up period did not reveal any instances of primary peritoneal carcinomatosis, suggesting a limited body of evidence supporting the imperative need for adjuvant treatment in patients diagnosed with these precursor lesions during risk-reducing salpingo-oophorectomy.

A call for standardized reporting of early-onset colorectal peritoneal metastases.

BACKGROUND: The incidence of colorectal cancer (CRC) in patients under 50 years of age, i.e., early-onset CRC, has increased in the past two decades. Colorectal peritoneal metastases (CPM) will develop in 10-30% of CRC patients. CPM traditionally had a dismal prognosis, but surgery and novel systemic treatments appear to increase survival. Determining potential age-associated risk and prognostic factors is optimized when analyses use standardized age groupings. METHODS: We performed a review of early-onset CPM studies and compared variables used, e.g., age stratification and definitions of synchronous and metachronous CPM. We included studies published in PubMed up to November 2022 if results were stratified by age. RESULTS: Of 114 screened publications in English, only 10 retrospective studies met inclusion criteria. Incidence of CPM was higher in younger CRC patients (e.g. 23% vs. 2% for <25 vs. ≥25 years, P < 0.0001; and 57% vs. 39% vs. 4% for <20 vs. 20-25 vs. >25 years, P < 0.001); two studies reported higher proportion of younger African American CPM patients (e.g. 16% vs. 6% for <50 vs. ≥50 years). Studies used seven different age-stratification methods, presenting comparison challenges. CONCLUSION: Studies showed a higher proportion of CPM in younger patients, but directly comparing results was not possible due to inconsistent reporting. To better address this issue, CRC and CPM studies stratified by standard age groups (e.g. <50 vs. ≥50) are needed.

Epidemiology, oncologic results and risk stratification model for metachronous peritoneal metastases after surgery for pT4 colon cancers: results from an observational retrospective multicentre long-term follow-up study.

PURPOSE: Metachronous peritoneal metastases (MPM) following a curative surgery procedure for pT4 colon cancer is a challenging condition. Current epidemiological studies on this topic are scarce. METHODS: A retrospective multicentre trial was designed. All consecutive patients who underwent operations to treat pT4 cancers between 2015 and 2017 were reviewed. Demographic, clinical, operative, pathological and oncological follow-up variables were included. MPM were described as any oncological disease at the peritoneum, clearly different from a local recurrence. Univariate and multivariate Cox regression models were constructed. A risk stratification model was created on a cumulative factor basis. According to the calculated hazard ratio (HR), a scoring system was designed (HR < 3, 1 point; HR > 3, 2 points) and a scale from 0 to 6 was calculated for peritoneal disease-free rate (PDF-R). A risk stratification model was also created on the basis of these calculations. RESULTS: Fifty different hospitals were involved, which included a total of 1356 patients. Incidence of MPM was 13.6% at 50 months median follow-up. The strongest independent risk factors for MPM were positive pN stage [HR 3.72 (95% CI 2.56-5.41; p < 0.01) for stage III disease], tumour perforation [HR 1.91 (95% CI 1.26-2.87; p < 0.01)], mucinous or signet ring cell histology [HR 1.68 (95% CI 1.1-2.58; p = 0.02)], poorly differentiated tumours [HR 1.54 (95% CI 1.1-2.2; p = 0.02)] and emergency surgery [HR 1.42 (95% CI 1.01-2.01; p = 0.049)]. In the absence of additional risk factors, pT4 tumours showed 98% and 96% PDF-R in 1-year and 5-year periods based on Kaplan-Meier curves. CONCLUSIONS: Cumulative MPM incidence was 13.6% at 5-year follow-up. The sole presence of a pT4 tumour resulted in high rates of PDF-R at 1-year and 5-year follow-up (98% and 96% respectively). Five additional risk factors different from pT4 status itself were identified as possible MPM indicators during follow-up.

Insights into synchronous peritoneal metastases from hepatobiliary origin: Incidence, risk factors, treatment, and survival from a nationwide database.

INTRODUCTION: - This population-based study aimed to investigate incidence, risk factors, treatment, and survival of synchronous peritoneal metastases (PM) of hepatobiliary origin. METHODS: - All Dutch patients diagnosed with hepatobiliary cancer between 2009 and 2018 were selected. Factors associated with PM were identified with logistic regression analyses. Treatments for patients with PM were categorized into local therapy, systemic therapy, and best supportive care (BSC). Overall survival (OS) was investigated using log-rank test. RESULTS: - In total, 12 649 patients were diagnosed with hepatobiliary cancer of whom 8% (n = 1066) were diagnosed with synchronous PM (12% [n = 882/6519] in biliary tract cancer [BTC] vs. 4% [n = 184/5248] in hepatocellular carcinoma [HCC]). Factors that were positively associated with PM were the female sex (OR 1.18, 95% CI 1.03-1.35), BTC (OR 2.93, 95% CI 2.46-3.50), diagnosis in more recent years (2013-2015: OR 1.42, 95% CI 1.20-1.68; 2016-2018: OR 1.48, 95% CI 1.26-1.75), T3/T4 stage (OR 1.84, 95% CI 1.55-2.18), N1/N2 stage (OR 1.31, 95% CI 1.12-1.53) and other synchronous systemic metastases (OR 1.85, 95% CI 1.62-2.12). Of all PM patients, 723 (68%) received BSC only. Median OS was 2.7 months (IQR 0.9-8.2) in PM patients. CONCLUSION: - Synchronous PM were found in 8% of all hepatobiliary cancer patients and occurred more often in BTC than in HCC. Most patients with PM received BSC only. Given the high incidence and dismal prognosis of PM patients, extended research in hepatobiliary PM is needed to achieve better outcome in these patients.

Clinical epidemiology of peritoneal metastases in China: The construction of professional peritoneal metastases treatment centers based on the prevalence rate.

OBJECTIVE: To understand the tumor burden of peritoneal metastases (PM) in China, and to guide the construction of professional PM treatment centers in China. METHODS: Based on the cancer statistics by the National Cancer Center of China published in 2016, the prevalence of PM in 2020 was calculated according to the population statistics in China and the survival and mortality rates of various PM. RESULTS: The prevalence rates of PM in China were as follows: gastric cancer PM 371.0/million, absolute number 523,937; colorectal cancer PM 47.1/million, absolute number 66,482; ovarian cancer PM 97.1/million, absolute number 137,083; pseudomyxoma peritonei 25.1/million, absolute number 35,425; malignant peritoneal mesothelioma 2.6/million, absolute number 3737; the above total was 766,664. According to the annual high-quality treatment volume of 365 cases in each professional PM treatment center, China needs to establish 1194 specialized PM treatment centers. At present, there are 1580 tertiary first-class hospitals in China. Therefore, for every 3 first-class tertiary hospitals in China there should be at least 2 PM treatment centers in full operation. CONCLUSIONS: Considering the large number of PM patients in China and the relatively small number of professional PM treatment centers, more resources should be devoted to the promotion and construction of PM treatment centers.

Incidence of gastrointestinal perforation associated with bevacizumab in combination with neoadjuvant chemotherapy as first-line treatment of advanced ovarian, fallopian tube, or peritoneal cancer: analysis of a Japanese healthcare claims database.

OBJECTIVE: To assess the incidence of bevacizumab-associated gastrointestinal (GI) perforation during first-line treatment of patients with ovarian, fallopian tube, or peritoneal cancer receiving neoadjuvant chemotherapy (NAC) in Japanese real-world clinical practice. METHODS: A retrospective study was conducted using a healthcare claims database owned by Medical Data Vision Co., Ltd. (study period, 2008-2020). Patients who initiated first-line treatment of ovarian, fallopian tube, or peritoneal cancer were identified and divided into NAC and primary debulking surgery (PDS) groups. The incidence of bevacizumab-associated GI perforation was compared within the NAC group and between the groups. RESULTS: Paclitaxel + carboplatin (TC) was most commonly used as first-line treatment (39.5% and 59.6% in the NAC and PDS groups, respectively). TC + bevacizumab was used in 9.3% and 11.6% of patients in the NAC and PDS groups, respectively. In the NAC group receiving TC, the proportion of patients with risk factors for GI perforation was lower among patients with versus without concomitant bevacizumab. The incidence of GI perforation in the NAC group was 0.38% (1/266 patients) in patients receiving TC + bevacizumab and 0.18% (2/1,131 patients) in patients receiving TC without bevacizumab (risk ratio=2.13; 95% confidence interval [CI]=0.19 to 23.36; risk difference=0.20; 95% CI=-0.58 to 0.97). None of the 319 patients in the PDS group receiving TC + bevacizumab had GI perforation. CONCLUSION: No notable increase was observed in GI perforation associated with NAC containing bevacizumab. We conclude that bevacizumab is prescribed with sufficient care in Japan to avoid GI perforation.

Comparison between signet-ring cell carcinoma and non-signet-ring cell carcinoma of the stomach: clinicopathological parameters, epidemiological data, outcome, and prognosis-a cohort study of 123 patients from a non-endemic country.

BACKGROUND: Signet-ring cell carcinoma of the stomach (SRCC) is a particular gastric cancer entity. Its incidence is increasing. Its diagnosis is pathological; it corresponds to adenocarcinoma with a majority of signet-ring cells component (> 50%). These histological features give it its aggressiveness characteristics. This has repercussions on the prognostic level and implications for the alternatives of therapy, especially since some authors suggest a potential chemoresistance. This survey aimed to identify the epidemiological, pathological, therapeutic, and prognostic characteristics of SRCC as a separate disease entity. METHODS: This was a retrospective study of 123 patients admitted for gastric adenocarcinoma to Habib Thameur Hospital in Tunis over 11 years from January 2006 to December 2016. A comparative study was performed between 2 groups: the SRCC group with 62 patients and the non-SRCC (non-signet-ring cell carcinoma of the stomach) with 61 patients. RESULTS: The prevalence of SRCC in our series was 50%. SRCC affected significantly younger patients (55 vs 62 years; p = 0.004). The infiltrative character was more common in SRCC tumors (30.6 vs 14.8%; p = 0.060), whereas the budding character was more often noted in non-SRCC tumors (78.7 vs 58.1%; p = 0.039). There was no significant difference in tumor localization between both groups. Linitis plastica was noted in 14 patients with SRCC against a single patient with non-SRCC (p = 0.001). The tumor size was more important in the non-SRCC group (6.84 vs 6.39 cm; p = 0.551). Peritoneal carcinomatosis was noted in 4.3% of cases in the SRCC group versus 2.2% of cases in the NSRCC group (p = 0.570). Total gastrectomy was more often performed in the SRCC group (87 vs 56%; p = 0.001). Resection was more often curative in the non-SRCC group (84.4 vs 78.3%; p = 0.063). Postoperative chemotherapy was more commonly indicated in the SRCC group (67.4 vs 53.3%; p = 0.339). Tumor recurrence was more common in the non-SRCC group (35.7 vs 32%; p = 0.776). The most common type of recurrence was peritoneal carcinomatosis in the SRCC group (62.5%) and hepatic metastasis in the non-SRCC group (60%; p = 0.096). The overall 5-year survival in the SRCC group was lower than in the non-SRCC group, with no statistically significant difference (47.1 vs 51.5%; p = 0.715). The overall survival was more important for SRCC in early cancer (100 vs 80%; p = 0.408), whereas it was higher for non-SRCC in advanced cancer (48.1 vs 41.9%; p = 0.635). CONCLUSION: Apart from its epidemiological and pathological features, SRCC seems to have a worse prognosis. Indeed, it is diagnosed at a more advanced stage and has a worse prognosis in advanced cancer than non-SRCC. It is therefore to be considered as a particular entity of gastric adenocarcinoma requiring a specific therapeutic protocol where the place of chemotherapy remains to be more investigated.

Laparoscopic Colectomy: A Risk Factor for Postoperative Peritoneal Metastasis.

BACKGROUND: The oncologic outcomes are generally considered equivalent for both laparoscopic and open surgery. However, our previous single-center study found a greater risk of postoperative peritoneal metastasis (PM) after laparoscopic colectomy (LC) than after open colectomy (OC) in patients with pathological T4a (pT4a) colon cancer. This multicenter study aimed to clarify if the risk of PM was increased after LC. METHODS: This study used the multicenter database of the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer, which included patients with colorectal cancer treated between 1997 and 2012 in 24 referral hospitals across Japan. The analysis included 17,323 patients with pathological stage I-III colon cancer, including 2380 patients with pT4a disease. The risk of PM was compared between the LC and OC groups. RESULTS: The cumulative incidence of PM was significantly higher after LC in patients with pT4a colon cancer (13.0% vs. 7.7%; P = .001). Multivariable analyses showed LC was a significant risk factor for PM (hazard ratio [HR]: 1.36, 95% confidence interval [CI]: 1.04-1.78, P = .023), which was confirmed by propensity score analyses (HR: 1.36, 95% CI: 1.04-1.78, P = .024). CONCLUSION: This study demonstrated a significant increase in the risk of PM after LC than after OC.

Does laparoscopy increase the risk of peritoneal recurrence after resection for pT4 colon cancer? Results of a propensity score-matched analysis from an international cohort.

BACKGROUND: Peritoneal metastases (PM) occur in 15-20% of surgically resected pT4 colon cancer (CC) and strongly affect prognosis. Since no standard treatment has been established, efforts should be addressed toward its prevention. Some literature suggests a detrimental effect of laparoscopy in pT4 CC, hence we aimed to determine its impact on the development of PM after potentially curative resection. METHODS: International multicenter retrospective cohort study including consecutive patients undergoing surgery for pT4a and pT4b CC (2014-2018) at 5 referral centers. The inclusion criteria were absence of distant metastasis, elective surgery, curative-intent resection (R0-1), and a minimum follow-up of 24 months (median, IQR: 35, 25.8-50.5 months). RESULTS: 276 patients fulfilled the inclusion criteria and were selected for analysis. After 1:1 propensity score matching (PSM), 63 patients in the laparoscopic group (LapGroup) were compared with 63 patients in the open surgery group (OpenGroup). The two groups were comparable in terms of demographic and clinical parameters, operative data, and specimen characteristics. The OpenGroup presented a higher estimated intraoperative blood loss (P < .001) and postoperative length of stay (P < .001). Overall survival, cancer-specific survival, and disease-free survival resulted comparable. The 5-year probability of developing PM was 16.2% after laparoscopy and 19.5% after open surgery (P = .686). Multivariate analysis confirmed laparoscopy not to be an independent risk factor for PM. CONCLUSIONS: Elective laparoscopic surgery for pT4 CC does not seem to increase the risk of metachronous PM after potentially curative surgery. Long-term outcomes after laparoscopy are not inferior to conventional open resections.

Occurrence of peritoneal carcinomatosis in patients with rectal cancer undergoing staging pelvic MRI: clinical observations.

OBJECTIVES: Describe the cumulative incidence (CUIN) of peritoneal carcinomatosis (PC) and survival in patients presenting with advanced rectal cancer at staging pelvic MRI. METHODS: From 2013 to 2018, clinicopathologic records of patients with pretreatment rectal MRI clinical (c)T3c, cT3d, cT4a, and cT4b primary rectal adenocarcinoma were retrospectively reviewed by two radiologists. Standard MRI descriptors and pathologic stages were recorded. Recurrence-free (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Development of PC was explored using competing risk analysis. Differences in survival were compared using the log-rank test. Gray's test was used to test for differences in CUIN of PC. RESULTS: Three hundred forty-three patients (147 women; median age, 56 years) had MRI stages cT3cd, n = 170; cT4a, n = 40; and cT4b, n = 133. Median follow-up among survivors was 27 months (0.36-70 months). For M1 patients, OS differed only by cT stage (2-year OS: cT3 88.1%, cT4a 79.1%, cT4b 64.7%, p = 0.045). For M0 patients, OS and RFS differed only by pathological (p)T stage. We observed a statistically significant difference in the cumulative incidence of PC by cT stage (2-year CUIN: cT3 3.2%, cT4a 8.5%, cT4b 1.6%, p = 0.01), but not by pT stage. Seventy-nine patients (23%) presented with metastatic disease (M1), eight with PC (2.3%). Overall, eight patients presented with PC (cT4a: n = 4, other stages: n = 4) and 22 developed PC (cT4a: n = 5, other stages: n = 17). CONCLUSIONS: PC is uncommon in rectal cancer. MRI-based T stage exhibited an overall association with the cumulative incidence of PC, and descriptively, cT4a stage appears to have the highest CUIN. KEY POINTS: • In a retrospective study of 343 patients with rectal cancer undergoing baseline MRI and clinical follow-up, we found that peritoneal carcinomatosis was rare. • We observed a significant overall association between PC at presentation and cT stage that appeared to be driven by the higher proportion of cT4a patients presenting with PC. • Among patients that did not present with PC, we observed a significant overall association between time to PC and cT stage that may be driven by the higher cumulative incidence of PC in cT4a patients.

Patterns of gastric cancer metastasis in the United States.

BACKGROUND: Literature on the epidemiology of gastric cancer metastasis is limited, although outcomes are known to be poor. We describe patterns of gastric cancer metastasis and treatment in the United States. METHODS: Patients with metastatic gastric adenocarcinoma were identified in the NCDB from 2004 to 2016. We describe univariate associations between sites of metastasis and clinicopathologic characteristics and treatment modalities, using chi-square and Kruskal-Wallis tests. Overall survival was calculated using Kaplan-Meier estimation. RESULTS: 43% (n = 2028) of patients presented with peritoneal metastases, 26% (n = 1228) with liver metastases, 20% (n = 941) with distant nodes, and 11% (n = 552) with bone, brain or lung metastases. Compared to liver metastases, peritoneal metastases were more likely from an antral primary site (28% v. 16%); associated with signet ring histology (34% v. 6%); tumor grade of III/IV (85% vs. 60%) (p < 0.0001 for all). Isolated metastasis to distant lymph nodes had the longest median overall survival (7.6 months, p < 0.0001). CONCLUSIONS: Most patients with metastatic gastric cancer in the USA present with peritoneal disease. Predictors for peritoneal metastases include primary antral site, signet ring histology and higher tumor grades.

Incidence, treatment and survival of malignant pleural and peritoneal mesothelioma: a population-based study.

INTRODUCTION: Malignant mesothelioma (MM) is an aggressive cancer that primarily arises from the pleura (MPM) or peritoneum (MPeM), mostly due to asbestos exposure. This study reviewed the Dutch population-based incidence, treatment and survival since the national ban on asbestos in 1993. MATERIALS AND METHODS: Patients with MPM or MPeM diagnosed from 1993 to 2018 were selected from the Dutch cancer registry. Annual percentage change (APC) was calculated for (age-specific and sex-specific) revised European standardised incidence rates (RESR). Treatment pattern and Kaplan-Meier overall survival analyses were performed. RESULTS: In total, 12 168 patients were included in the study. For male patients younger than 80 years, the MM incidence significantly decreased in the last decade (APC ranging between -9.4% and -1.8%, p<0.01). Among both male and female patients aged over 80 years, the incidence significantly increased during the entire study period (APC 3.3% and 4.6%, respectively, p<0.01). From 2003 onwards, the use of systemic chemotherapy increased especially for MPM (from 9.3% to 39.4%). Overall, 62.2% of patients received no antitumour treatment. The most common reasons for not undergoing antitumour treatment were patient preference (42%) and performance status (25.6%). The median overall survival improved from 7.3 (1993-2003) to 8.9 (2004-2011) and 9.3 months from 2012 to 2018 (p<0.001). CONCLUSION: The peak of MM incidence was reached around 2010 in the Netherlands, and currently the incidence is declining in most age groups. The use of systemic chemotherapy increased from 2003, which likely resulted in improved overall survival over time. The majority of patients do not receive treatment though and prognosis is still poor.

Second-look Surgery Detects Low Volume Recurrent Disease Following Cytoreductive Surgery for Peritoneal Carcinomatosis.

BACKGROUND/AIM: Formation of stoma during cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis (PC) is often performed to reduce the risk of anastomotic leak. Subsequent stoma reversal provides a unique opportunity for second-look surgery to detect early peritoneal recurrence. Current surveillance methods often fail to detect disease early, including imaging and biochemical markers. In our study, we examined the safety and efficacy of second-look surgery for detection and treatment of disease recurrence. PATIENTS AND METHODS: We performed a retrospective analysis of prospectively collected data from 35 patients undergoing stoma reversal from 2015 to 2019 with negative pre-operative imaging. RESULTS: A total of 37% of cases had disease recurrence, with a median peritoneal cancer index of 4. Complete cytoreduction was achieved in all patients. The majority of patients (77%) suffered minor complications only. Median length of hospital stay was 12 days. CONCLUSION: Second-look surgery detects early disease recurrence and is a safe alternative to conventional screening methods post primary CRS/HIPEC for PC. Long-term, routine second-look surgery can improve survival.

Hyperthermic Intraperitoneal Chemotherapy With Cisplatin and Doxorubicin for 90 Minutes Versus 60 Minutes After Cytoreductive Surgery (CRS). Does the 30-Minute Difference Matter? A Comparative Study in a High Volume Centre.

BACKGROUND/AIM: This study compared the perioperative outcomes after the same combination of hyperthermic intraperitoneal chemotherapy (HIPEC) compounds when administered for 90 min vs. 60 min, while all other therapy variables remained constant. PATIENTS AND METHODS: A total of 120 patients were included with peritoneal surface malignancy who underwent cisplatin (75 mg/m2) and doxorubicin (15 mg/m2) closed HIPEC after cytoreductive surgery. RESULTS: Sixty-five patients (54.2%) in the 60 min and 55 patients (45.8%) in the 90 min HIPEC group were compared. Patients, tumor characteristics, and postoperative complications were comparable. The only significant difference was the rate of chest drain/pleural puncture with an incidence of 18.5% and 34.5% in the 60 min and 90 min group, respectively (p=0.045). After adjustment in a multi-variable regression analysis, the odds for patients with HIPEC 90 min of having chest drain or pleural puncture in comparison to patients with HIPEC 60 min was still higher, but not significant with an OR of 2.238 (95%CI=0.932-5.373; p=0.071). CONCLUSION: HIPEC administered for 90 min is safe and does not increase perioperative morbidity and mortality compared to the 60-min administration.

Addition of sintilimab to nanoparticle albumin-bound paclitaxel and S-1 as adjuvant therapy in stage IIIC gastric cancer.

The prognosis of stage III gastric cancer (GC) is not satisfying and the specific chemotherapy regimens for GC of stage IIIC based on the 8th edition of the UICC/AJCC TNM staging system are still inconclusive. Peritoneal recurrence is the common and severe relapse pattern. Nanoparticle albumin-bound paclitaxel (Nab-PTX) is safer and more effective than PTX in the peritoneal metastasis. Clinical trial has demonstrated the safety and efficacy of sintilimab in GC. A combination of Nab-PTX, S-1 and sintilimab could be a promising triplet regimen as adjuvant therapy for GC. The aim of this article is to describe the design of this prospective Dragon-VII trial, conducted to evaluate the safety and efficacy of the combination of Nab-PTX, S-1 and sintilimab. Clinical trial registration: NCT04781413.

Lay abstract The prognosis of stage IIIC gastric cancer is poor and the treatment for it is not satisfying. This is a clinical trial that aims to explore a more effective therapy in gastric cancer patients of stage IIIC. Patients with stage IIIC gastric cancer must meet all of the inclusion criteria and none of the exclusion criteria to be eligible for this trial. The eligible patients will be given eight cycles of combinatory therapy of albumin-bound paclitaxel, a chemotherapy (day 1 and day 8), and S-1, another chemotherapy (days 1 to 14), plus sintilimab, a type of immunotherapy called an immune checkpoint inhibitor (day 1) every 3 weeks and then sintilimab maintenance for up to 12 months.