Impact of Primary Tumor Location and Genomic Alterations on Survival Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Colorectal Peritoneal Metastases.

BACKGROUND: Colorectal cancer leads to peritoneal metastases (CRPM) in 10% of cases. Cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) improves survival. Primary tumor location and abnormalities in RAS, BRAF, and mismatch repair/microsatellite stability (MMR/MSI) may affect post-CRS-HIPEC survival, but studies have not been consistent. We estimated the effects of primary tumor site and genomic alterations on post-CRS-HIPEC survival. METHODS: This retrospective cohort study included CRS-HIPEC cases for CRPM at a high-volume center from 2001 to 2020. Next-generation sequencing and microsatellite testing defined the RAS, BRAF, and MMR/MSI genotypes. Adjusted effects of tumor sidedness and genomics on survival were evaluated using a multivariable Cox proportional hazards model. We analyzed these variables' effects on progression-free survival and the effects of immune checkpoint-inhibitors. RESULTS: A total of 250 patients underwent CRS-HIPEC with testing for RAS, BRAF, and MMR/MSI; 50.8% of patients were RAS-mutated, 12.4% were BRAF-mutated, and 6.8% were deficient-MMR/MSI-high (dMMR/MSI-H). Genomic alterations predominated in right-sided cancers. After adjustment for comorbidities and oncological and perioperative variables, rectal origin [hazard ratio (HR) 1.9, p = 0.01], RAS mutation (HR 1.6, p = 0.01), and BRAF mutation (HR 1.7, p = 0.05) were associated with worse survival. RAS mutation was also associated with shorter progression-free survival (HR 1.6, p = 0.01 at 6 months post-operatively), and dMMR/MSI-H status was associated with superior survival (HR 0.3, p = 0.01 at 2 years). dMMR/MSI-H patients receiving immune checkpoint-inhibitors trended toward superior survival. CONCLUSIONS: Rectal origin, RAS mutations, and BRAF mutations are each associated with poorer survival after CRS-HIPEC for CRPM. Patients with CRPM and dMMR/MSI-H status have superior survival. Further research should evaluate benefits of immune checkpoint-inhibitors in this subgroup.

Appendectomy Is Oncologically Equivalent to Right Hemicolectomy for Well-Differentiated T1 Appendiceal Adenocarcinoma.

BACKGROUND: Right hemicolectomy is recommended for appendiceal adenocarcinoma but may not be needed for early stage disease. OBJECTIVE: This study aimed to determine whether appendectomy offers adequate oncologic outcomes for T1 appendiceal adenocarcinoma from a national cohort of patients. DESIGN: Patients with T1 appendiceal adenocarcinoma (mucinous and nonmucinous histology) treated with either a right hemicolectomy or appendectomy between 2004 and 2016 were retrieved. Multivariate Cox regression analysis was used to identify predictors of overall survival. SETTING: The study was conducted using a national cancer database. PATIENTS: A total of 320 patients (median age, 62 y; 47% women) were identified: 69 (22%) underwent an appendectomy and 251 (78%) underwent a right hemicolectomy. MAIN OUTCOME MEASURE: Overall survival was measured. RESULTS: Nonmucinous adenocarcinoma was identified in 194 (61%), whereas 126 (39%) had mucinous adenocarcinoma. Of the overall cohort, 43% had well-differentiated histology, 39% had moderately differentiated disease, and 4% had poorly differentiated tumors. The rate of lymph node metastasis was lower in well-differentiated tumors (3%) compared with moderately (10%) or poorly differentiated tumors (25%). On univariate survival analysis, right hemicolectomy was associated with improved 1-, 3-, and 5-year overall survival in patients with moderately/poorly differentiated disease ( p < 0.001) but not for well-differentiated disease ( p = 1.000). After adjustment, right hemicolectomy was associated with overall survival improvement for moderately/poorly differentiated T1 adenocarcinoma (HR = 0.26 [95% CI, 0.08-0.82]; p = 0.02) but not for well-differentiated disease. LIMITATIONS: This study was limited by its retrospective nature. CONCLUSIONS: The current analysis from the National Cancer Database demonstrates that appendectomy is associated with equivalent survival to right hemicolectomy for well-differentiated T1 adenocarcinoma, whereas for moderately and poorly differentiated disease, right hemicolectomy is oncologically superior to appendectomy. See Video Abstract at http://links.lww.com/DCR/B689 . LA APENDICECTOMA ES ONCOLGICAMENTE EQUIVALENTE A LA HEMICOLECTOMA DERECHA PARA EL ADENOCARCINOMA APENDICULAR T BIEN DIFERENCIADO: ANTECEDENTES:La hemicolectomía derecha se recomienda para el adenocarcinoma apendicular, pero puede no ser necesaria para la enfermedad en estadio temprano.OBJETIVO:Este estudio tuvo como objetivo determinar si la apendicectomía ofrece resultados oncológicos adecuados para el adenocarcinoma apendicular T1 de una cohorte nacional de pacientes.DISEÑO:Se recuperaron pacientes con adenocarcinoma apendicular T1 (histología mucinoso y no mucinoso) tratados con hemicolectomía derecha o apendicectomía entre 2004-2016. Se utilizó un análisis de regresión de Cox multivariante para identificar los predictores de la supervivencia global.ENTORNO CLÍNICO:Base de datos nacional sobre cáncer.PACIENTES:Se identificaron un total de 320 pacientes (mediana de edad 62 años, 47% mujeres): 69 (22%) se sometieron a una apendicectomía y 251 (78%) se sometieron a una hemicolectomía derecha.PRINCIPAL MEDIDA DE RESULTADO:Sobrevida global.RESULTADOS:Se identificó adenocarcinoma no mucinoso en 194 (61%) mientras que 126 (39%) tenían adenocarcinoma mucinoso. De la cohorte general, el 43% tenía una histología bien diferenciada, el 39% tenía una enfermedad moderadamente diferenciada y el 4% tenía tumores poco diferenciados. La tasa de metástasis en los ganglios linfáticos fue menor en los tumores bien diferenciados (3%) en comparación con los tumores moderadamente (10%) o pobremente diferenciados (25%). En el análisis de sobrevida univariante, la hemicolectomía derecha se asoció con una mejor sobrevida general a 1, 3, y 5 años en pacientes con enfermedad moderada / pobremente diferenciada ( p < 0,001) pero no para la enfermedad bien diferenciada ( p = 1,000). Después del ajuste, la hemicolectomía derecha se asoció con una mejora de la sobrevida general para el adenocarcinoma T1 moderadamente / poco diferenciado (HR = 0,26, IC del 95%: 0,08-0,82, p = 0,02) pero no para la enfermedad bien diferenciada.LIMITACIONES:Este estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES:El análisis actual de la base de datos nacional de cáncer demuestra que la apendicectomía se asocia con una sobrevida similar a la hemicolectomía derecha para el adenocarcinoma T1 bien diferenciado, mientras que para la enfermedad moderada y pobremente diferenciada, la hemicolectomía derecha es oncológicamente superior a la apendicectomía. Consulte Video Resumen en http://links.lww.com/DCR/B689 . (Traducción-Dr. Yazmin Berrones-Medina ).

Omission of Right Hemicolectomy May be Safe for Some Appendiceal Goblet Cell Adenocarcinomas: A Survival Analysis of the National Cancer Database.

BACKGROUND: Appendiceal goblet cell adenocarcinomas (GCC) are rare tumors with clinical behavior between classic carcinoids and adenocarcinomas. Current guidelines recommend right hemicolectomy for all GCCs. PATIENTS AND METHODS: The National Cancer Database was retrospectively queried for appendiceal GCCs undergoing appendectomy or right hemicolectomy between 2004 and 2016. Demographics, tumor characteristics, and post-operative outcomes were collected. The primary outcome was overall survival, which was examined by surgical type and tumor T stage. Multivariate logistic regression was utilized to identify predictors of survival. RESULTS: In total, 1083 GCCs were included, and 81.8% underwent right hemicolectomy. Mean age was 57 years, and 89% were White. Patients undergoing hemicolectomy had higher T-stage tumors (66.6%/14.4% T3/T4 vs. 55.8%/8.1%, p < 0.001). Lymph node positivity increased with T stage (1.1%, 2.1%, 9.9%, and 29.1% for T1-T4). GCCs undergoing colectomy were more frequently moderately or poorly differentiated (16.7%/9.0% vs. 12.2%/6.6%, p = 0.011). Appendectomy surgical margins were positive in 17.3% (3.4% hemicolectomy, p < 0.001). In T3/T4 tumors, a significant survival benefit at 5 years was observed in patients undergoing colectomy as compared with appendectomy (85.4% vs. 82.0%, p = 0.028). On multivariate analysis, lymph node positivity markedly decreased survival overall for the entire cohort (HR 7.58, p < 0.001) and for T3/T4 tumors (HR 7.63, p < 0.001). In patients with T3/T4 tumors, there was a trend towards improved survival with right hemicolectomy (HR 0.42, p = 0.068). CONCLUSION: Omitting right hemicolectomy can be considered for select T1/T2 appendiceal GCCs with negative appendectomy margins, given low rates of lymph node metastases and lack of survival benefit with right hemicolectomy.

The Role of Adjuvant Chemotherapy in Non-Metastatic Goblet Cell Carcinoid of the Appendix: An 11-Year Experience from the National Cancer Database.

BACKGROUND: Goblet cell carcinoids (GCC) are an aggressive, albeit rare, subtype of appendiceal tumors that exhibit distinct histologic features and lack clear treatment guidelines. We aimed to ascertain the impact of adjuvant chemotherapy (AC) for GCC in a national cohort of patients. METHODS: Patients who underwent a right hemicolectomy for stage I-III GCC of the appendix between 2006 and 2016 were selected from the National Cancer Database (NCDB). Stratification based on AC receipt was performed. Kaplan-Meier survival estimates and Cox proportional hazard regression were used to identify predictors of overall survival (OS). RESULTS: A total of 867 patients were identified, of whom 124 (14%) received AC. Patients in the AC group were significantly younger (54 vs. 57 years; p = 0.006) and were predominantly of male sex (60 vs. 48%; p = 0.012). On histopathology, patients in the AC group had a higher proportion of poorly/undifferentiated grade (27 vs. 5%; p < 0.001), T4 disease (35 vs. 11%; p < 0.001), and lymph node-positive disease (45 vs. 7%; p < 0.001) than patients who did not receive AC. After excluding patients diagnosed in 2016 due to a lack of follow-up data (n = 162), a survival advantage for the AC group was detected only after stratification for lymph node-positive disease (p = 0.007). On Cox proportional hazard regression, AC demonstrated an independent association with improved OS (hazard ratio 0.24, 95% confidence interval 0.084-0.683; p = 0.007). CONCLUSION: The current analysis from the NCDB supports the role of AC for GCC of the appendix, chiefly for patients with lymph node metastatic disease.

KRAS amplification in metastatic colon cancer is associated with a history of inflammatory bowel disease and may confer resistance to anti-EGFR therapy.

Mutations in RAS occur in 30-50% of metastatic colorectal carcinomas (mCRCs) and correlate with resistance to anti-EGFR therapy. Consequently, mCRC biomarker guidelines state RAS mutational testing should be performed when considering EGFR inhibitor treatment. However, a small subset of mCRCs are reported to harbor RAS amplification. In order to elucidate the clinicopathologic features and anti-EGFR treatment response associated with RAS amplification, we retrospectively reviewed a large cohort of mCRC patients that underwent targeted next-generation sequencing and copy number analysis for KRAS, NRAS, HRAS, BRAF, and PIK3CA. Molecular testing was performed on 1286 consecutive mCRC from 1271 patients as part of routine clinical care, and results were correlated with clinicopathologic findings, mismatch repair (MMR) status and follow-up. RAS amplification was detected in 22 (2%) mCRCs and included: KRAS, NRAS, and HRAS for 15, 5, and 2 cases, respectively (6-21 gene copies). Patients with a KRAS-amplified mCRC were more likely to report a history of inflammatory bowel disease (p < 0.001). In contrast, mutations in KRAS were associated with older patient age, right-sided colonic origin, low-grade differentiation, mucinous histology, and MMR proficiency (p ≤ 0.017). Four patients with a KRAS-amplified mCRC and no concomitant RAS/BRAF/PIK3CA mutations received EGFR inhibitor-based therapy, and none demonstrated a clinicoradiographic response. The therapeutic impact of RAS amplification was further evaluated using a separate, multi-institutional cohort of 23 patients. Eight of 23 patients with KRAS-amplified mCRC received anti-EGFR therapy and all 8 patients exhibited disease progression on treatment. Although the number of KRAS-amplified mCRCs is limited, our data suggest the clinicopathologic features associated with mCRC harboring a KRAS amplification are distinct from those associated with a KRAS mutation. However, both alterations seem to confer EGFR inhibitor resistance and, therefore, RAS testing to include copy number analyses may be of consideration in the treatment of mCRC.

Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are tumors that often present with widespread mucin in the peritoneal cavity (pseudomyxoma peritonei [PMP]). Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective treatment, but no published recommendations exist regarding surveillance. METHODS: Data from prospective databases of patients who underwent CRS-HIPEC from 2001 to 2017 at two high-volume institutions were retrospectively analyzed. Patients who underwent complete CRS-HIPEC for PMP secondary to LAMN were included in the analysis. Pathologic examination confirmed the diagnosis of LAMN. Cases of mucinous adenocarcinomas and neuroendocrine tumors (goblet cell carcinoids) were excluded. RESULTS: The study enrolled 156 patients. The median peritoneal cancer index (PCI) was 18 (interquartile range IQR1-3, 12-23), and 125 patients (80.1%) had a CC0 cytoreduction. According to American Joint Committee on Cancer (AJCC) grading, 152 patients (97.4%) presented with acellular mucin or G1 implants, 2 patients (1.3%) presented with G2 disease, and 2 patients (1.3%) presented with G3 disease. During the follow-up period (median, 45 months; IQR1-3 23-76 months), 23 patients (14.7%) experienced recurrence. All the recurrences were peritoneal and occurred within 5 years. The 1-, 3-, and 5-year disease-free survival (DFS) rates were respectively 95.5%, 83.4%, and 78.3%. Univariate Cox regression analysis showed that higher PCI scores (p < 0.001), a CC1 cytoreduction (p = 0.005), and higher preoperative levels of carcinoembryonic antigen (CEA) (p = 0.012) and CA-125 (p = 0.032) correlated with a shorter DFS. Only higher PCI scores independently predicted earlier recurrences (p < 0.001). CONCLUSION: Most patients had recurrence within 3 years after CRS-HIPEC, and none after 5 years. High PCI was the only independently significant variable. The study findings support intensive surveillance (every 3-6 months) with tumor markers and imaging methods during the first 3 years, and annual surveillance thereafter, with follow-up assessment after 5 years yielding limited benefit.

Ferroptosis-inducing agents enhance TRAIL-induced apoptosis through upregulation of death receptor 5.

Ferroptosis is considered genetically and biochemically distinct from other forms of cell death. In this study, we examined whether ferroptosis shares cell death pathways with other types of cell death. When human colon cancer HCT116, CX-1, and LS174T cells were treated with ferroptotic agents such as sorafenib (SRF), erastin, and artesunate, data from immunoblot assay showed that ferroptotic agents induced endoplasmic reticulum (ER) stress and the ER stress response-mediated expression of death receptor 5 (DR5), but not death receptor 4. An increase in the level of DR5, which is activated by binding to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and initiates apoptosis, was probably responsible for synergistic apoptosis when cells were treated with ferroptotic agent in combination with TRAIL. This collateral effect was suppressed in C/EBP (CCAAT-enhancer-binding protein)-homologous protein (CHOP)-deficient mouse embryonic fibroblasts or DR5 knockdown HCT116 cells, but not in p53-deficient HCT116 cells. The results from in vitro studies suggest the involvement of the p53-independent CHOP/DR5 axis in the synergistic apoptosis during the combinatorial treatment of ferroptotic agent and TRAIL. The synergistic apoptosis and regression of tumor growth were also observed in xenograft tumors when SRF and TRAIL were administered to tumor-bearing mice.

Discrimination of low- and high-grade appendiceal mucinous neoplasms by targeted sequencing of cancer-related variants.

DNA was obtained from matching micro-dissected, primary tumor cells, paired metastases, and peripheral blood mononuclear cells (germline) from patients with appendiceal mucinous neoplasms. We compared specimens from patient cohorts comprising low-grade adenomucinous neoplasm versus high-grade mucinous adenocarcinoma using a targeted, amplicon sequencing panel of 409 cancer related genes (Ion Torrent Comprehensive Cancer Panel, Thermo-Fisher, Waltham, MA). Copy number variants, single nucleotide variants and small insertions/deletions were identified using a multiplex algorithm pipeline (GATK, VarScan2, MuTect2, SIFT, SIFT-INDEL, PolyPhen-2, Provean). There were significantly more damaging variants in high-grade versus low-grade tumor cohorts. Both cohorts contained damaging, heterozygous germline variants (catenin ß1; notch receptor 1 and 4) in pathways associated with cell-lineage specification (WNT, NOTCH). Damaging, somatic KRAS proto-oncogene, GTPase mutations were present in both cohorts, while somatic GNAS complex locus mutations were confined to low-grade neoplasms. Variants predominantly affected transcription factors, kinases, and stem cell signaling molecules in canonical pathways including epithelial to mesenchymal transition, stem cell pluripotency, p53, PTEN, and NF-қB signaling pathways. High-grade tumors demonstrated MYC proto-oncogene, bHLH transcription factor (MYC) and death domain associated protein (DAXX) amplification and damaging somatic variants in tumor protein p53 (TP53), likely to amplify an aggressive phenotype. Damaging APC, WNT signaling pathway regulator (APC) deletions were identified in metastatic tissue of both cohorts suggesting a role in invasive disease. Our data suggest that germline dysregulation of WNT and/or NOTCH pathways predisposes patients toward a secretory cell phenotype (i.e., goblet-like cells) upon acquisition of somatic KRAS mutations. Additional somatically acquired variants activating oncogenes MYC and DAXX and inhibiting the critical tumor suppressor, tumor protein TP53, were consistent with manifestation of a high-grade phenotype. These additional changes within the epithelial to mesenchymal transition signaling network (WNT, NOTCH, RAS/ERK/PI3K, PTEN, NF-қB), produce aggressive high-grade tumor characteristics by actively driving cells towards dedifferentiation, proliferation, and migration.

Repeat Cytoreductive Surgery-Hyperthermic Intraperitoneal Chemoperfusion is Feasible and Offers Survival Benefit in Select Patients with Peritoneal Metastases.

INTRODUCTION: We hypothesized that repeat cytoreductive surgery-hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) for peritoneal metastases (PM) may be associated with suboptimal resection, more frequent postoperative complications, and worse oncologic outcomes. METHODS: Using a prospectively maintained database, we compared clinicopathologic, perioperative, and oncologic outcome data in patients undergoing single or repeat CRS-HIPEC procedures. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with perioperative and oncologic outcomes. RESULTS: Of the 1294 patients undergoing CRS-HIPEC procedures at our institution, only one CRS-HIPEC procedure (single HIPEC cohort) was performed in 1169 patients (90.3%), whereas 125 patients (9.7%) underwent repeat CRS-HIPEC procedures (repeat HIPEC cohort). Of the 1440 CRS-HIPEC procedures at our institution, a first CRS-HIPEC procedure was performed in 1294 patients (89.9%), whereas subsequent second, third, and fourth CRS-HIPEC procedures were performed in 125 patients (8.7%), 18 patients (1.3%), and 3 patients (0.2%), respectively. Progression-free survival (PFS) following the second CRS-HIPEC procedure was negatively impacted by shorter PFS following the first CRS-HIPEC procedure, independent of other significant variables related to the second procedure, including completeness of cytoreduction and postoperative complications. Patients undergoing multiple CRS-HIPEC procedures were not at higher risk for suboptimal resection or postoperative complications and demonstrated equivalent PFS following each successive procedure compared to the first procedure. CONCLUSIONS: Repeat CRS-HIPEC procedures for PM were not associated with suboptimal perioperative and oncologic outcomes. Our data confirmed our ability to select patients appropriately for repeat CRS-HIPEC procedures.

Discordant Diagnostic Terminology and Pathologic Grading of Primary Appendiceal Mucinous Neoplasms Reviewed at a High-Volume Center.

BACKGROUND: Diagnostic terminology and grading of primary appendiceal mucinous neoplasms lacks uniformity. We sought to identify discordance in pathologic reporting by reviewing pathology slides for cases referred to our institution. METHODS: Using guidelines from Peritoneal Surface Oncology Group International (PSOGI) and American Joint Committee on Cancer 8th edition (AJCC8), we compared diagnostic terminology/grading of primary appendiceal mucinous neoplasms (n = 115) between pathology reports from referring institutions and review of slides by pathologists at our high-volume institution. RESULTS: There was discordance in pathologic terminology and grading of primary appendiceal mucinous neoplasms between referring institutions and our institution in 28% and 50% of patients, respectively. In particular, 24% of patients referred with mucinous adenocarcinoma (MACA) had LAMN on our review, and a higher grade MACA was found in 48% of patients referred with low-grade (G1) MACA and 16% of patients referred with high-grade (G2) MACA following our review. Discordance in tumor grade between primary and metastatic disease was seen in 19% of cases based on referred primary tumor grading compared with only 4% following our review. Systemic chemotherapy was unnecessarily administered to four cases of LAMN (6%) and inappropriately not administered to four cases of MACA (6%) before referral due to inaccurate diagnosis/grading by referring institutions. CONCLUSIONS: We found significant discordance in diagnostic terminology/grading of primary appendiceal mucinous neoplasms following review of referred cases. Inaccurate pathologic assessment was associated with overtreatment or undertreatment with chemotherapy. These data highlight the need for pathologic review of such rare cases at high-volume centers.

Pleuropulmonary Recurrence Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Appendiceal Pseudomyxoma Peritonei.

BACKGROUND: The aim of this study was to identify factors associated with pleuropulmonary disease recurrence following cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) for appendiceal pseudomyxoma peritonei (PMP) and to evaluate the oncologic impact of pleuropulmonary disease recurrence compared with isolated peritoneal recurrence. METHODS: From a prospective database, we identified patients who developed pleuropulmonary recurrence, isolated peritoneal recurrence, or no recurrence following CRS/HIPEC for appendiceal PMP. Clinicopathologic, perioperative, and oncologic data associated with the index CRS/HIPEC procedure were reviewed. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with recurrence and survival. RESULTS: Of 382 patients undergoing CRS/HIPEC, 61 (16%) developed pleuropulmonary recurrence. Patients who developed a pleuropulmonary recurrence were more likely to have high-grade (American Joint Committee on Cancer [AJCC] grade 2/3) tumors (74% vs. 56%, p = 0.02) and increased operative blood loss (1651 vs. 1201 ml, p = 0.05) and were more likely to have undergone diaphragm stripping/resection (79% vs. 48%, p < 0.01) compared with patients with an abdominal recurrence. In a multivariate analysis, pleuropulmonary recurrence after CRS/HIPEC was associated with diaphragm stripping/resection, incomplete cytoreduction, and higher AJCC tumor grade. There was a trend towards reduced survival in patients with pleuropulmonary recurrence compared with patients with isolated peritoneal recurrence (median overall survival 45 vs. 53 months, p = 0.87). CONCLUSION: Pleuropulmonary recurrence of appendiceal PMP following CRS/HIPEC is common and may negatively impact survival. Formal protocols for surveillance and therapeutic intervention need to be studied and implemented to improve oncologic outcomes.

Correction to: Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience.

In the original version of the article, Margaret Hofstedt's last name was misspelled.

Impact of Cellularity on Oncologic Outcomes Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Pseudomyxoma Peritonei.

BACKGROUND: The Peritoneal Surface Oncology Group International (PSOGI) recommends pathologic reporting of tumor cellularity in patients with pseudomyxoma peritonei (PMP) undergoing cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC). We investigated the prognostic significance of PMP cellularity, or lack thereof (acellular mucin), following CRS-HIPEC. METHODS: We reviewed clinical data for 310 CRS-HIPEC procedures in low-grade (American Joint Committee on Cancer grade G1) PMP with acellular mucin (n = 19), scant cellularity (n = 30), or moderate cellularity (n = 242). Kaplan-Meier survival curves and multivariate Cox regression models identified prognostic factors affecting oncologic outcomes. RESULTS: Compared with patients with acellular mucin, those with scant and moderate cellularity had higher PCI and less-frequent complete macroscopic resection. After an estimated median follow-up of 49 months, 4 patients (14%) with scant cellularity and 127 patients (56%) with moderate cellularity progressed, while none of the patients with acellular mucin progressed. While the median progression-free survival (PFS) was not reached for patients with acellular mucin or scant cellularity (estimated 5-year PFS probability of 100 and 83%, respectively), patients with moderate cellularity demonstrated a median PFS of 32 months (estimated 5-year PFS probability of 27%). In a multivariate model, degree of disease cellularity, or lack thereof (acellular mucin), was an independent predictor of PFS but not overall survival. CONCLUSIONS: Early disease progression is unlikely in patients with acellular mucin undergoing CRS-HIPEC, as opposed to a 14% recurrence rate with scant cellularity. Thorough pathologic assessment for cellularity, or lack thereof (acellular mucin), is vital for accurate prognostication of disease progression for patients with low-grade PMP undergoing CRS-HIPEC.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion in Adolescent and Young Adults with Peritoneal Metastases.

BACKGROUND: Several studies suggest that young patients may derive less oncologic benefit from surgical resection of cancers compared with older patients. We hypothesized that young patients may have worse outcomes following cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) for peritoneal metastases. METHODS: Perioperative and oncologic outcomes in adolescent and young adults (AYA), defined as younger than age 40 years (n = 135), undergoing CRS/HIPEC between 2001 and 2015 were reviewed and compared with middle-aged adults, defined as aged 40-65 years (n = 684). RESULTS: The two groups were similar with regards to perioperative characteristics except that AYA were more likely to be symptomatic at presentation (65.2 vs. 50.9%, p = 0.003), had lower Charleson comorbidity index (median 6 vs. 8, p < 0.001), were less likely to receive neoadjuvant chemotherapy (32.8 vs. 42.5%, p = 0.042), and had longer operative times (median 543 vs. 493 min, p = 0.010). Postoperative Clavien-Dindo grade 3-4 morbidity was lower in AYA (17 vs. 26%, p = 0.029), and they required fewer reoperations for complications (3.7 vs. 10.4%, p = 0.014). AYA had longer median overall survival (103.6 vs. 73.2 months, p = 0.053). In a multivariate Cox regression analysis, age was an independent predictor of improved overall survival [hazard ratio 0.705; 0.516-0.963, p = 0.028]. CONCLUSIONS: Young patients with peritoneal metastases derive similar benefits from CRS/HIPEC as middle-aged patients. Young age should not be a deterrent to consideration of CRS/HIPEC for peritoneal metastases.

Institutional Experience with Ostomies Created During Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) is a complex procedure that often requires ostomy creation to protect high-risk anastomoses. This study aimed to evaluate the authors' institutional experience with CRS-HIPEC-associated ostomies, determine predictors of ostomy creation and reversal, and assess their impact on survival. METHODS: The study analyzed clinicopathologic, perioperative, and oncologic data from a prospective database of 1435 CRS-HIPEC procedures for peritoneal metastases. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with ostomy creation/reversal and survival. RESULTS: Ostomies were created in 34% of the patients, most commonly loop ileostomies (82%). Loop ileostomies were reversed in the majority of patients (83%), whereas non-loop ileostomies were infrequently reversed (< 10% reversal rate). In a multivariate logistic regression model, intermediate or high tumor grade, colectomy/proctectomy, longer operative time, and lower Charlson comorbidity index were associated with loop ileostomy creation, whereas incomplete macroscopic resection, colorectal histology, and major postoperative complications were associated with non-reversal of loop ileostomy. In a multivariate Cox proportional hazards model, intermediate or high tumor grade and non-reversal of loop ileostomy were associated with worse overall survival. CONCLUSIONS: Loop ileostomies were almost always reversed, whereas non-loop ileostomies were almost always permanent. Hospital readmissions for loop ileostomy-related complications were common. Therefore, formal outpatient protocols for prevention and management should be implemented. Non-reversal of loop ileostomy was associated with very poor survival.

Safety and efficacy of combined resection of colorectal peritoneal and liver metastases.

BACKGROUND: To determine if a select subgroup of patients with combined liver and peritoneal colorectal metastases would derive oncologic benefit from surgical resection as a component of multimodality treatment. MATERIALS AND METHODS: We retrospectively compared 32 patients with combined colorectal peritoneal and liver metastases (CRLM) and 173 patients with peritoneal metastases only (CRPM) undergoing cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC). Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting survival. RESULTS: Major postoperative complications (Clavien-Dindo grades 3-5) occurred in 32% (CRLM) and 17% (CRPM) of patients (P = 0.08). After an estimated median follow-up from surgery of 57 mo, propensity score-adjusted median progression-free survival was 5.1 mo (CRLM) and 7.6 mo (CRPM), whereas median overall survival was 13 mo (CRLM) and 21 mo (CRPM). Multivariate Cox-regression analysis of the CRLM group identified number of liver metastases to be the only independent predictor of poor survival (hazard ratio: 2.3, P = 0.03), with a dramatic decrease in survival in patients with more than three liver metastases. CONCLUSIONS: Simultaneous resection of colorectal liver metastases at the time of cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion for peritoneal metastases may be associated with worse survival, especially in patients with more than three liver metastases.

Hyperthermic intraperitoneal chemoperfusion as a component of multimodality therapy for ovarian and primary peritoneal cancer.

BACKGROUND AND OBJECTIVES: The role of hyperthermic intraperitoneal chemoperfusion (HIPEC) in the multimodality treatment of ovarian peritoneal metastases (OPM) and primary peritoneal cancer (PPC) remains controversial. We hypothesized that cytoreductive surgery (CRS) and HIPEC would provide meaningful survival benefit without excessive morbidity. METHODS: We reviewed clinicopathologic and perioperative data following 96 CRS-HIPEC procedures for primary or recurrent OPM and PPC. Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting oncologic outcomes. RESULTS: CRS-HIPEC was mostly performed for recurrent disease (56.3%) and high-grade serous carcinoma (72.9%). Platinum-based systemic chemotherapy was administered to 89.5% of patients, with 75.5% having platinum-sensitive disease at CRS-HIPEC. Complete macroscopic resection was achieved in 70.8% of patients. Clavien-Dindo grade 3/4 morbidity occurred in 23.4% of patients; three patients died within 60-days postoperatively. Median overall survival from diagnosis of peritoneal metastases and CRS-HIPEC was 78 and 38 months, respectively. Completeness of cytoreduction, pathologic subtype, and 30-day morbidity were independent predictors of survival in multiple regression analysis. CONCLUSIONS: Our study demonstrates promising survival data and supports the role of HIPEC in the multimodality treatment algorithm for primary or recurrent OPM and PPC. However definite indications and timing of HIPEC need to be clarified by prospective studies.

The prognostic significance of BAP1, NF2, and CDKN2A in malignant peritoneal mesothelioma.

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for patients with malignant peritoneal mesothelioma has resulted in improved disease control and increased survival. Despite these results, there are significant perioperative risks associated with this aggressive procedure that necessitate consideration of prognostic markers during patient selection. The molecular pathogenesis of peritoneal mesothelioma remains relatively unknown, but extrapolation of findings from their pleural counterpart would suggest frequent alterations in CDKN2A, NF2, and BAP1. Homozygous deletions in CDKN2A portend a worse overall survival in peritoneal mesothelioma. However, the prevalence and prognostic significance of NF2 and BAP1 abnormalities has not been studied. Dual-color fluorescence in situ hybridization using CDKN2A and NF2 locus-specific probes and BAP1 immunohistochemistry identified homozygous CDKN2A deletions (n=25, 29%), hemizygous NF2 loss (n=30, 35%), and/or loss of BAP1 protein expression (n=49, 57%) in 68 of 86 (79%) peritoneal mesotheliomas. Homozygous CDKN2A deletions or hemizygous NF2 loss correlated with shorter progression-free survival (P<0.02) and poor overall survival (P<0.03). Moreover, the significance of these findings was cumulative. Patients harboring both homozygous CDKN2A deletions and hemizygous NF2 loss had a 2-year progression-free survival rate of 9% with a median of 6 months (P<0.01) and overall survival rate of 18% with a median of 8 months (P<0.01). By multivariate analysis, combined homozygous CDKN2A deletions and hemizygous NF2 loss was a negative prognostic factor for both progression-free survival and overall survival, independent of patient age, peritoneal cancer index, completeness of cytoreduction, and extent of invasion. In contrast, loss of BAP1 was not associated with clinical outcome. In summary, homozygous deletions in CDKN2A and hemizygous loss of NF2 as detected by fluorescence in situ hybridization would confer a poor clinical outcome and may guide future treatment decisions for patients with peritoneal mesothelioma.

Curative Surgical Resection as a Component of Multimodality Therapy for Peritoneal Metastases from Goblet Cell Carcinoids.

BACKGROUND: The impact of histopathologic features on oncologic outcomes for patients with peritoneal metastases from goblet cell carcinoid (GCC) undergoing multimodality therapy, including cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC), is unknown. METHODS: This study prospectively analyzed 43 patients with GCC undergoing CRS-HIPEC between 2005 and 2013. Pathology slides were re-reviewed to classify GCC into histologic subtypes according to the Tang classification. Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting oncologic outcomes. RESULTS: The 43 patients in this study underwent 50 CRS-HIPEC procedures for peritoneal metastases from GCC, and the majority received neoadjuvant and/or adjuvant systemic chemotherapy. The GCC demonstrated an aggressive phenotype with frequent lymph node and peritoneal metastases without systemic dissemination. The majority of the patients had Tang B GCC. The estimated median overall survival times after surgery for the patients with Tang A, B, and C GCC were respectively 59, 22, and 13 months. In a multivariate Cox-regression analysis, poor survival was associated with patients who had Tang B or C GCC, those undergoing incomplete macroscopic resection, and those with symptoms at the time of CRS-HIPEC. The patients with Tang A GCC demonstrated oncologic outcomes similar to those with intermediate-grade (American Joint Committee on Cancer [AJCC] grade 2) disseminated mucinous appendiceal neoplasms, whereas the patients with Tang B and C GCC demonstrated survival rates similar to or worse than those with high-grade (AJCC grade 3) disseminated mucinous appendiceal neoplasms. CONCLUSIONS: Tang classification is an independent prognostic factor for poor survival after multimodality therapy for GCC. Patients with Tang C GCC demonstrate limited survival and are not ideal candidates for a surgical approach.