Impact of Perioperative Systemic Chemotherapy on Survival for Patients Who have Diffuse Malignant Peritoneal Mesothelioma Treated with CRS-HIPEC.

BACKGROUND: The available data on the role of perioperative systemic chemotherapy (SC) for diffuse malignant peritoneal mesothelioma (DMPM) patients undergoing (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is heterogeneous and unstandardized. This study aimed to evaluate the impact of SC on the survival outcomes of DMPM patients undergoing CRS-HIPEC and to identify prognostic factors that affect the decision to administer SC. METHODS: Patients who underwent CRS-HIPEC in the National Cancer Institute Milan (1995-2020) were retrospectively analyzed using propensity score-matching of known covariates. The patients were grouped into three groups: group A (neoadjuvant chemotherapy [NACT] and no-SC), group B (no-SC and adjuvant chemotherapy [ACT]), and group C (NACT and ACT). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meir method, and prognostic factors were calculated using the Cox-regression method. RESULTS: After a median follow-up period of 45 months (95% confidence interval [CI], 6.348-83.652 months) for group A, 115 months (95% CI, 44.379-185.621 months) for group B, and 88 months (95% CI, 3.296-172.704 months) for group C, the study analyzed 154 DMPM patients consisting of matched group A (NACT: 60 + no-SC: 52 = 112), group B (ACT: 38 + no-SC: 38 = 76), and group C (NACT: 31 + ACT: 31 = 62). The patients undergoing ACT had better 5-year OS and PFS than the patients undergoing NACT. In the multivariate analysis, ACT was significantly associated with improved OS by 48% (hazard ratio [HR], 0.52; 95% CI, 0.280-0.965, p = 0.038). For PFS, the association of ACT did not reach statistical significance (HR, 0.531; 95% CI, 0.266-1.058; p = 0.072). CONCLUSION: The optimum treatment sequence for DMPM is CRS-HIPEC followed by adjuvant chemotherapy for high-risk patients. Upfront surgery appears preferable to NACT for patients amenable to complete CRS.

Relapse of Pseudomyxoma Peritonei After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Pattern of Failure, Clinical Management and Outcomes.

INTRODUCTION: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) have dramatically improved pseudomyxoma peritonei (PMP) prognosis, but treatment failures are still a concern. We investigated the pattern of failure, treatment and outcomes of progressing disease. METHODS: A prospective database of 374 PMP patients was reviewed, and 152 patients relapsing after complete CRS/HIPEC were identified. PMP was graded according to the Peritoneal Surface Oncology Group International (PSOGI) classification. Hematogenous metastases and non-regional lymph node involvement were considered as systemic metastases. RESULTS: Median follow-up was 78.3 months (95% confidence interval [CI] 66.7-90.4). PMP relapse involved the peritoneum in 112 patients, pleural cavity in 8, both peritoneum and pleura in 8, systemic sites in 11, and both peritoneum and systemic sites in 13 patients. Systemic metastases involved the lung (n = 14), liver (n = 4), distant nodes (n = 3), bone (n = 2), and both lung and distant nodes (n = 1). Survival after diagnosis of PMP relapse was independently associated with curative versus palliative treatment (hazard ratio [HR] 0.52, 95% CI 0.36-0.75; p = 0.001) and PSOGI histology (HR 1.80, 95% CI 1.19-2.74; p = 0.005), but was not influenced by site of failure (p = 0.444). Ten-year overall survival was 77.5% for 62 patients who had curative-intent surgery for PMP relapse, compared with 83.0% for 192 patients who had no recurrences (p = 0.154) and 26.1% for 90 patients who underwent palliative treatments (p = 0.001). CONCLUSIONS: Relapse after CRS/HIPEC most commonly involves the peritoneum, but pleural recurrences and systemic metastases occur in a small but clinically relevant number of patients. In selected patients, surgical resection of recurrent disease can result in long survival, irrespective of sites of failure.

Force Sensing on Cells and Tissues by Atomic Force Microscopy.

Biosensors are aimed at detecting tiny physical and chemical stimuli in biological systems. Physical forces are ubiquitous, being implied in all cellular processes, including cell adhesion, migration, and differentiation. Given the strong interplay between cells and their microenvironment, the extracellular matrix (ECM) and the structural and mechanical properties of the ECM play an important role in the transmission of external stimuli to single cells within the tissue. Vice versa, cells themselves also use self-generated forces to probe the biophysical properties of the ECM. ECM mechanics influence cell fate, regulate tissue development, and show peculiar features in health and disease conditions of living organisms. Force sensing in biological systems is therefore crucial to dissecting and understanding complex biological processes, such as mechanotransduction. Atomic Force Microscopy (AFM), which can both sense and apply forces at the nanoscale, with sub-nanonewton sensitivity, represents an enabling technology and a crucial experimental tool in biophysics and mechanobiology. In this work, we report on the application of AFM to the study of biomechanical fingerprints of different components of biological systems, such as the ECM, the whole cell, and cellular components, such as the nucleus, lamellipodia and the glycocalyx. We show that physical observables such as the (spatially resolved) Young's Modulus (YM) of elasticity of ECMs or cells, and the effective thickness and stiffness of the glycocalyx, can be quantitatively characterized by AFM. Their modification can be correlated to changes in the microenvironment, physio-pathological conditions, or gene regulation.

Impact of Previous Gynecologic Surgical Procedures on Outcomes of Non-Gynecologic Peritoneal Malignancies Mimicking Ovarian Cancer: Less Is More?

BACKGROUND: Non-gynecologic rare peritoneal surface malignancies (PSMs) often are misdiagnosed as disseminated ovarian cancer and initially treated by gynecologic surgeons. This study aimed to assess whether these previous maneuvers (i.e., full surgical staging and/or cytoreductive attempts) affect outcomes after the definitive surgery performed in a tertiary center. METHODS: The study reviewed 298 women affected by non-gynecologic PSM who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) after previous gynecologic surgery. Prior surgery was categorized as limited surgery (pLS: abdominal exploration with biopsy plus adnexectomy and/or appendectomy) or extended surgery (pES: full surgical staging or cytoreductive attempts including hysterectomy with bilateral salpingo-oophorectomy). RESULTS: Of the 298 patients, 143 had pLS and 153 had pES. Morbidity was similar between the groups (P = 0.143), but the pES group had more severe urinary tract injuries (19 vs. 3; P < 0.001), longer operating time (585.9 vs. 506.7; P = 0.027), and more patients needing more than two anastomoses (41 vs. 26; P = 0.033). Age older than 55 years (odds ratio [OR] 2.42; P = 0.009) and number of anastomoses (OR 3.17; P = 0.002) correlated with severe morbidity; pES correlated with urinary tract grades 3 and 4 injuries (OR 7.9; P = 0.001). The 5-year cumulative incidence of locoregional relapse was significantly higher in the pES group (0.41 vs. 0.27; P = 0.012; median follow-up period, 69 months). The multivariate analysis identified a Peritoneal Carcinomatosis Index (PCI) higher than 20 and pES as independent risk factors. CONCLUSION: For women undergoing CRS±HIPEC for non-gynecologic PSM, the risk for locoregional relapse and severe postsurgical urinary tract complications is increased by pES. Therefore, prior full surgical staging or cytoreductive attempts without definitive gynecologic histology should be avoided. Prophylactic ureteral stenting and stricter oncologic follow-up assessment must be considered in this scenario.

Prognostic Impact of Primary Side and RAS/RAF Mutations in a Surgical Series of Colorectal Cancer with Peritoneal Metastases.

BACKGROUND: Selecting patients with colorectal cancer peritoneal metastases (CRC-PMs) for surgery is still a concern. Biological features have the potential to improve prognostic stratification, but their significance in this clinical setting is still unclear. We assessed the prognostic impact of primary side and KRAS/NRAS/BRAF/PIK3CA mutations in patients treated with either cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) or CRS alone. METHODS: We reviewed a prospective database of 152 CRC-PM patients selected to undergo perioperative systemic chemotherapy and CRS with or without HIPEC. Extensive mutational analysis of KRAS, NRAS, BRAF, and PIK3CA was performed by polymerase chain reaction (PCR). In 68 patients, Ion Torrent next-generation sequencing technology was used to characterize the hotspot regions of 50 genes. RESULTS: The primary tumor was right-sided in 61 patients (40.1%) and left-sided in 91 patients (59.9%). Right-sided primaries were associated with mutated KRAS (p = 0.01) and normal carcinoembryonic antigen (CEA; p = 0.03). KRAS was mutated in 71/152 patients (46.7%), NRAS in 7/152 patients (4.6%), BRAF in 10/152 patients (6.6%), PIK3CA in 17/78 patients (25.0%), TP53 in 37/68 patients (54.4%), APC in 25/68 patients (36.7%), SMAD4 in 13/68 patients (19.1%), and FBXW7 in 5/68 patients (7.4%). Median follow-up was 54.9 months and median survival from PM diagnosis was 45.1 months. The right-sided primary (hazard ratio [HR] 1.62, 95% confidence interval [CI] 0.43-0.89; p = 0.011), BRAF mutations (HR 2.21, 95% CI 1.05-4.63; p = 0.038), and Peritoneal Cancer Index (HR 1.47, 95% CI 1.03-2.10; p = 0.036) independently correlated with poorer survival, while APC mutations univariately correlated with better survival (p = 0.03). CONCLUSIONS: BRAF mutations and right-sided primary are adverse prognostic factors that may be used to optimize therapeutic strategies. APC may be involved in CRC-PM development and progression.

Colorectal Peritoneal Metastases Treated by Perioperative Systemic Chemotherapy and Cytoreductive Surgery With or Without Mitomycin C-Based HIPEC: A Comparative Study Using the Peritoneal Surface Disease Severity Score (PSDSS).

BACKGROUND: The Prodige-7 trial has questioned the role of hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal metastases from colorectal cancer (CRC-PM). PATIENTS AND METHODS: We compared a prospectively collected group of 48 patients undergoing oxaliplatin/irinotecan-based perioperative systemic chemotherapy (s-CT) with targeted agents, and cytoreductive surgery (CRS) (no-HIPEC group) with 48 controls undergoing the same perioperative s-CT and CRS/HIPEC (HIPEC group). Patients were matched (1:1) according to the Peritoneal Surface Disease Severity Score, completeness of cytoreduction, history of extraperitoneal disease (EPD), and Peritoneal Cancer Index. RESULTS: The groups were comparable, except for a higher number of patients in the HIPEC group with World Health Organization performance status 0, pN2 stage primary tumor, and treated with preoperative s-CT. Forty-one patients in the no-HIPEC group and 43 patients in the HIPEC group had optimal comprehensive treatment (P = 0.759), defined as complete cytoreduction of PM and margin-negative EPD resection. Median follow-up was 31.6 months in the no-HIPEC group and 39.9 months in the HIPEC group. Median overall survival was 39.3 months in the no-HIPEC group and 34.8 months in the HIPEC group (P = 0.702). In the two groups, severe morbidity occurred in 14 (29.2%) and 13 (27.1%) patients, respectively (P = 1.000), with no operative deaths. On multivariate analysis, left-sided primary and curative treatment independently correlated with better survival while HIPEC did not (hazard ratio 0.73; 95% confidence interval 0.47-1.15; P = 0.178). CONCLUSIONS: Our results confirmed that, in selected patients, perioperative s-CT and surgical treatment of CRC-PM resulted in unexpectedly high survival rates. Mitomycin C-based HIPEC did not increase morbidity but did not impact prognosis.

Neoadjuvant chemo-radiotherapy for cT3N0 rectal cancer: any benefit over upfront surgery? A propensity score-matched study.

PURPOSE: Benefits of neoadjuvant chemo-radiotherapy (CRT) are well known for locally advanced and/or node-positive rectal cancer, but the best timing for CRT has been less explored for cT3N0 patients. The aim of the present study was to compare the 5-year disease-free survival (DFS) probability between neoadjuvant CRT and upfront surgery in patients affected by cT3N0 rectal cancer. METHODS: A retrospective review of 105 patients affected by cT3N0 rectal cancer, staged by pelvic magnetic resonance imaging and treated at the National Cancer Institute of Milan between 2011 and 2017, was performed: 42 (40.0%) were treated by neoadjuvant CRT and 63 (60.0%) by upfront surgery. Propensity score matching was performed to avoid selection bias, and Cox multivariate regression was used to analyze outcomes. RESULTS: The 5-year DFS probability was 87.5% in neoadjuvant CRT patients vs. 90.0% in upfront surgery cases (Log-rank p = 0.76). The 5-year loco-regional recurrence-free survival probability was respectively 96.8% vs. 96.3% (Log-rank p = 0.954). On multivariate analysis, neoadjuvant CRT had no impact on DFS when compared to upfront surgery (adjusted HR 0.71, 95%CI 0.18-2.70, p = 0.613), but 61.9% of upfront surgery cases were treated by adjuvant chemo-radiation (adjusted HR 0.41, 95%CI 0.11-1.57, p = 0.196). The only independent predictor of improved DFS was age at diagnosis (adjusted HR 0.95, p = 0.017). CONCLUSION: CRT should be considered for cT3N0 patients, but its timing (neoadjuvant vs. adjuvant) seems not to affect the disease-free survival in the present cohort of patients.

Molecular Signatures for Combined Targeted Treatments in Diffuse Malignant Peritoneal Mesothelioma.

Background-There are currently no effective therapies for diffuse malignant peritoneal mesothelioma (DMPM) patients with disease recurrence. In this study, we investigated the biology of DMPM by analyzing the EGFR family, Axl, and MET, in order to assess the presence of cross-talk between these receptors, suggesting the effectiveness of combined targeted treatments in DMPM. Method-We analyzed a series of 22 naïve epithelioid DMPM samples from a single institute, two of which showed higher-grade malignancy ("progressed"). EGFR, HER2, HER3, Axl, and MET activation and expression were investigated by biochemical analysis, real-time PCR immunofluorescence, immunohistochemistry, next-generation sequencing, miRNA, and mRNA in situ hybridization. Results-In most DMPMs, a strong EGFR activation was associated with HER2, HER3, Axl, and MET co-activation, mediated mainly by receptor heterodimerization and autocrine-paracrine loops induced by the expression of their cognate ligands. Axl expression was downregulated by miRNA34a. Mutations in MET Sema domain were exclusively found in two "progressed" DMPMs, and the combined Axl and MET inhibition reduced cellular motility in a DMPM cell line obtained from a "progressed" DMPM. Conclusion-The results indicate that the coordinated activity of multiple cross-talks between RTKs is directly involved in the biology of DMPM, suggesting the combined inhibition of PIK3 and mTOR as an effective strategy that may be easily implemented in clinical practice, and indicating that the combined inhibition of EGFR/HER2 and HER3 and of Axl and MET deserves further investigation.

Dose-Dependent Effect of Red Blood Cells Transfusion on Perioperative and Long-Term Outcomes in Peritoneal Surface Malignancies Treated with Cytoreduction and HIPEC.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are associated with increased red blood cell transfusion (RBT) demand. Although the deleterious effects of RBT are documented in various settings, its effect in this setting is obscure. In this study, we evaluated the effects of different-grade RBT on the short- and long-term outcomes of CRS and HIPEC. METHODS: We analyzed 231 patients with diffuse malignant peritoneal mesothelioma (DMPM) and 273 patients with pseudomyxoma peritonei (PMP) operated in our unit. RBT was categorized according to the amount of packed red blood cell units (PRBCs) administered (0, 1-2, 3-5, > 6). The effects of RBT on long-term oncological outcomes [progression-free survival (PFS) and overall survival (OS)] were assessed by using multivariate analysis. RESULTS: Overall, 74% of the patients were transfused with a median of 2 PRBCs (range 0-37). Transfusion level correlated with operative time, surgical extent (as measured by the peritoneal carcinomatosis index), and age. Postoperatively, patients with major transfusion (> 6 PRBCs) had increased mortality rate (11.1%, p = 0.01) and length of hospital stay (31.2 ± 16.8 days, p = 0.01) compared with other levels of RBT. RBT was dose-dependently associated with oncological outcomes in both DMPM and PMP for both PFS [hazard ratio (HR) = 1.40, 95% confidence interval (CI) 1.12-1.74, p = 0.003; HR = 1.44, 95% CI 1.15-1.81, p = 0.001, respectively] and OS (HR = 1.57, 95% CI 1.21-2.03, p = 0.001; HR = 1.43, 95% CI 1.15-1.90, p = 0.01, respectively). CONCLUSIONS: Our data show a dose-dependent relationship between RBT and oncological outcomes. Further research to develop transfusion sparing protocols is needed in this extensive surgical procedure.

Validation of the Recent PSOGI Pathological Classification of Pseudomyxoma Peritonei in a Single-Center Series of 265 Patients Treated by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Controversies still persist regarding the terminology and pathologic classification of appendiceal mucinous neoplasms and associated pseudomyxoma peritonei (PMP). We assessed reproducibility and prognostic significance of the classification recently proposed by the Peritoneal Surface Oncology Group International (PSOGI). METHODS: A prospective database of 265 PMP patients uniformly treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) from 1995 to 2017 was reviewed. According to the PSOGI, peritoneal disease was retrospectively classified into three categories: low-grade (LG-PMP), high-grade (HG-PMP), and signet-ring cells (SRC-PMP). Acellular mucin (AC) was classified separately. The extent of peritoneal involvement was quantified by the peritoneal cancer index (PCI). RESULTS: Twenty-six patients were diagnosed with AC (9.8%), 197 with LG-PMP (74.4%), 38 with HG-PMP (14.3%), and 4 with SRC-PMP (1.5%). In the overall series, median follow-up was 65.5 months (95% confidence interval 53.7-78.8) and 10-year overall survival was 62.9% (median 148.7 months). Operative death occurred in 10 patients (3.8%) and major complications occurred in 89 patients (33.6%). Ten-year survival was 89.6% for AC, 63.2% for LG-PMP, 40.1% for HG-PMP, and 0 for SRC-PMP. In a multivariate model, the World Health Organization (WHO) pathological classification independently correlated with survival (p = 0.028). In a separate model, the PSOGI classification did not reach statistical significance (p = 0.149). Completeness of cytoreduction and PCI > 22 correlated with prognosis in both models. CONCLUSIONS: AC and SRC-PMP pathological categories of the PSOGI classification identified two subsets of patients with favorable and exceedingly dismal prognosis, respectively. It remains unclear whether the PSOGI classification might provide better prognostic stratification than the current WHO classification. Further studies in larger prospective series are needed.

Correction to: Clinical Surveillance After Macroscopically Complete Surgery for Low-Grade Appendiceal Mucinous Neoplasms (LAMN) with or Without Limited Peritoneal Spread: Long-Term Results in a Prospective Series.

In the original article Massimo Milione's last name was spelled incorrectly. It is correct as reflected here. The original article has also been updated.

Clinical Surveillance After Macroscopically Complete Surgery for Low-Grade Appendiceal Mucinous Neoplasms (LAMN) with or Without Limited Peritoneal Spread: Long-Term Results in a Prospective Series.

BACKGROUND: Low-grade appendiceal mucinous neoplasm (LAMN) is the most common primary lesion of pseudomyxoma peritonei, a disease whose standard treatment is cytoreduction and hyperthermic intraperitoneal chemotherapy. The optimal management of LAMN is not well defined. This study prospectively assessed a clinical surveillance strategy for LAMN with or without limited peritoneal spread. METHODS: During 2003-2017, the study prospectively enrolled 41 patients treated by macroscopically complete surgery for LAMN with or without limited peritoneal spread (pelvis and right lower quadrant). Follow-up assessment included thoracic-abdomino-pelvic computed tomography scan and serum tumor markers scheduled after surgery, then every 6 months for 5 years, and yearly thereafter. All specimens were reviewed by a dedicated pathologist. RESULTS: Appendectomy and five right colectomies were performed for 36 patients. Nine patients also underwent macroscopically complete cytoreduction of mucinous peritoneal disease, and four patients had hysterectomy plus bilateral salphingo-oophorectomy. Appendiceal rupture was evaluable in 38 of the 41 patients, being present in 21 patients (51.2%). Mucin, cells, or both outside the appendix were observed in 24 patients (58.5%). The median follow-up period was 58 months (range 9.3-162 months). The 5-year recurrence-free survival rate was 95.1%. Only two patients experienced peritoneal recurrences (4.9%), respectively 18 and 22 months after appendectomy. Their primary lesions were LAMNs with and without appendix wall rupture or extra-appendiceal mucin, respectively. No death occurred. CONCLUSION: These findings strongly suggest that radically resected LAMN, even with limited peritoneal spread, carries a low recurrence risk. Furthermore, appendix wall perforation and the presence of mucin, cells, or both outside the appendix were not associated with a higher risk of metachronous peritoneal dissemination. In this setting, clinical and radiologic surveillance is a viable choice.

Should a History of Extraperitoneal Disease Be a Contraindication to Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Cancer Peritoneal Metastases?

BACKGROUND: Survival improvements have been reported in selected patients affected by colorectal peritoneal metastases who were undergoing cytoreductive surgery with intraperitoneal hyperthermic chemotherapy. Treatment of peritoneal metastases associated with extraperitoneal disease is still controversial. OBJECTIVE: We assessed the prognostic impact of a history of extraperitoneal disease that was curatively treated either at the same time as or before the onset of peritoneal metastases. DESIGN: We reviewed 2 prospective databases. Peritoneal involvement was scored by Peritoneal Cancer Index. SETTINGS: Our study was conducted in 2 high-volume peritoneal malignancy management institutions. PATIENTS: A total of 148 patients with peritoneal metastases were included. In 27 patients, extraperitoneal disease involving the liver (n = 23), lung (n = 1), both lung and liver (n = 2), or inguinal lymph nodes and liver (n = 1) was curatively treated either simultaneously with peritoneal metastases (n = 22) or before their onset (n = 5). INTERVENTIONS: All of the macroscopic tumors were removed by means of peritonectomy procedures and visceral resections. Microscopic residual disease was treated by mitomycin C/cisplatin-based hyperthermic intraperitoneal chemotherapy. MAIN OUTCOME MEASURES: Overall survival was the primary outcome measure. RESULTS: After a median follow-up of 34.6 months (95% CI, 22.6-65.7 mo), 5-year survival of patients treated for both peritoneal and extraperitoneal disease versus peritoneal metastases alone was 16.5% versus 52.0% (p = 0.019). After multivariate analysis, reduced survival correlated with extraperitoneal disease (p = 0.001), Peritoneal Cancer Index >19 (p = 0.004), and peritoneal residual disease >2.5 mm (p = 0.018). Three prognostic groups were defined, and median survival was not reached for group 1 (Peritoneal Cancer Index ≤19 and no extraperitoneal disease), reached in 27.0 months for group 2 (Peritoneal Cancer Index ≤9 and extraperitoneal disease), and reached in 11.6 months for group 3 (Peritoneal Cancer Index >19 and no extraperitoneal disease or Peritoneal Cancer Index >9 and extraperitoneal disease). LIMITATIONS: The main study limitation is its observational nature. CONCLUSIONS: A history of extraperitoneal disease is associated with poorer prognosis. However, survival benefit may be obtained in selected patients with limited peritoneal involvement. See Video Abstract at http://links.lww.com/DCR/A655.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) at the Time of Primary Curative Surgery in Patients with Colorectal Cancer at High Risk for Metachronous Peritoneal Metastases.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) are maximally effective in early-stage colorectal cancer peritoneal metastases (CRC-PM); however, the use of HIPEC to treat subclinical-stage PM remains controversial. This prospective two-center study assessed adjuvant HIPEC in CRC patients at high risk for metachronous PM ( www.clinicaltrials.gov NCT02575859). METHODS: During 2006-2012, a total of 22 patients without systemic metastases were prospectively enrolled to receive HIPEC simultaneously with curative surgery, plus adjuvant systemic chemotherapy (oxaliplatin/irinotecan-containing ± biologics), based on primary tumor-associated criteria: resected synchronous ovarian (n = 2) or minimal peritoneal (n = 6) metastases, primaries directly invading other organs (n = 4) or penetrating the visceral peritoneum (n = 10). A control group retrospectively included 44 matched (1:2) patients undergoing standard treatments and no HIPEC during the same period. The cumulative PM incidence was calculated in a competing-risks framework. RESULTS: Patient characteristics were comparable for all groups. Median follow-up was 65.2 months [95 % confidence interval (CI) 50.9-79.5] in the HIPEC group and 34.5 months (95 % CI 21.1-47.9) in the control group. The 5-year cumulative PM incidence was 9.3 % in the HIPEC group and 42.5 % in the control group (p = 0.004). Kaplan-Meier estimated 5-year overall survival (OS) was 81.3 % in the HIPEC group versus 70.0 % in the control group (p = 0.047). No operative death occurred. Grade 3-4 [National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4] morbidity rates were 18.2 % in the HIPEC group and 25 % in controls (p = 0.75). At multivariate analysis, HIPEC correlated to lower PM cumulative incidence [hazard ratio (HR) 0.04, 95 % CI 0.01-0.31; p = 0.002], and better OS (HR 0.25, 95 % CI 0.07-0.89; p = 0.039) and progression-free survival (HR 0.31, 95 % CI 0.11-0.85; p = 0.028). CONCLUSION: Adjuvant HIPEC may benefit CRC patients at high-risk for peritoneal failure. These results warrant confirmation in phase III trials.

Pseudomyxoma Peritonei of Extra-Appendiceal Origin: A Comparative Study.

BACKGROUND: Pseudomyxoma peritonei (PMP) usually originates from appendiceal neoplasms and, less commonly, from extra-appendiceal lesions. To date, the clinical and therapeutic implications of extra-appendiceal origin are largely unknown. METHODS: A prospective database of 225 PMP patients uniformly treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) was reviewed to identify cases with extra-appendiceal primaries. Histologically, negative appendix defined extra-appendiceal origin. Clinical, pathological, and immunohistochemical features (cytokeratin [CK]-20, CK-7, CDX-2, MUC-2, MUC-5A) were correlated with the site of origin. PMP was categorized into low or high grade, according to the 2010 World Health Organization (WHO) classification. The main independent variable for survival analysis was appendiceal versus extra-appendiceal primary. RESULTS: In 19 patients (8.4 %), PMP origin was the ovary (n = 9), uterine cervix (n = 1), mature cystic teratomas (n = 4), and unknown (n = 5). Appendiceal and extra-appendiceal PMP groups were comparable for all characteristics, except for a prevalence of females in the latter. Median follow-up was 64.1 months (95 % confidence interval [CI] 53.9-80.1), and 10-year overall survival was 63.4 % (median 148.2 months; 95 % CI 131.2-165.2) for appendiceal PMP, and 62.0 % (median not reached) for extra-appendiceal PMP. The difference was not significant at univariate ( p = 0.297) and multivariate analysis (hazard ratio 1.51, 95 % CI 0.78-3.14; p = 0.278). High-grade peritoneal histology (p = 0.007), prior systemic chemotherapy (p = 0.003), more than four visceral resections (p = 0.011), and incomplete cytoreduction (p = 0.021) independently correlated with poorer survival. CONCLUSIONS: Clinical-pathological features of PMP, and outcome after CRS/HIPEC, did not differ according to the primary site, thus suggesting that PMP is a relatively homogeneous disease that can be produced by a range of histopathologic entities. Extra-appendiceal origin does not contraindicate CRS/HIPEC.