Multi-institutional assessment of the prevalence of neuroendocrine tumors in children undergoing laparoscopic appendectomy for acute appendicitis in the United States.

As non-operative management of acute appendicitis in children has become more common, missed incidental appendiceal pathology can be an unintended consequence. We assessed the prevalence of neuroendocrine tumors in appendectomy specimens from eight US children's hospitals from 2012 to 2021. The prevalence of neuroendocrine tumors (NET) was found to be 1:271, with a median age of 14 years and 62% female. Most tumors were small (median 6 mm; interquartile range [IQR]: 3-10), and no recurrence was noted during the follow-up period (median 22.5 months; IQR: 3-53). The possibility of delayed diagnosis of these tumors should be part of the discussion for non-operative management of pediatric acute appendicitis.

A Novel Assessment of Metabolic Pathways in Peritoneal Metastases from Low-Grade Appendiceal Mucinous Neoplasms.

BACKGROUND: There is a paucity of targeted therapies for patients with pseudomyxoma peritonei (PMP) secondary to low-grade appendiceal mucinous neoplasms (LAMNs). Dysregulated metabolism has emerged as a hallmark of cancer, and the relationship of metabolomics and cancer is an area of active scientific exploration. We sought to characterize phenotypic differences found in peritoneal metastases (PM) derived from LAMN versus adenocarcinoma. METHODS: Tumors were washed with phosphate-buffered saline (PBS), microdissected, then dissociated in ice-cold methanol dried and reconstituted in pyridine. Samples were derivatized in tert-butyldimethylsilyl (TBDMS) and subjected to gas chromatography-coupled mass spectrometry. Metabolites were assessed based on a standard library. RNA sequencing was performed, with pathway and network analyses on differentially expressed genes. RESULTS: Eight peritoneal tumor samples were obtained and analyzed: LAMNs (4), and moderate to poorly differentiated adenocarcinoma (colon [1], appendix [3]). Decreases in pyroglutamate, fumarate, and cysteine in PM from LAMNs were found compared with adenocarcinoma. Analyses showed the differential gene expression was dominated by the prevalence of metabolic pathways, particularly lipid metabolism. The gene retinol saturase (RETSAT), downregulated by LAMN, was involved in the multiple metabolic pathways that involve lipids. Using network mapping, we found IL1B signaling to be a potential top-level modulation candidate. CONCLUSIONS: Distinct metabolic signatures may exist for PM from LAMN versus adenocarcinoma. A multitude of genes are differentially regulated, many of which are involved in metabolic pathways. Additional research is needed to identify the significance and applicability of targeting metabolic pathways in the potential development of novel therapeutics for these challenging tumors.

Oncological Safety and Potential Cost Savings of Routine vs Selective Histopathological Examination After Appendectomy: Results of the Multicenter, Prospective, Cross-Sectional FANCY Study.

OBJECTIVE: To investigate the oncological safety and potential cost savings of selective histopathological examination after appendectomy. BACKGROUND: The necessity of routine histopathological examination after appendectomy has been questioned, but prospective studies investigating the safety of a selective policy are lacking. METHODS: In this multicenter, prospective, cross-sectional study, inspection and palpation of the (meso)appendix was performed by the surgeon in patients with suspected appendicitis. The surgeon's opinion on additional value of histopathological examination was reported before sending all specimens to the pathologist. Main outcomes were the number of hypothetically missed appendiceal neoplasms with clinical consequences benefiting the patient (upper limit two-sided 95% confidence interval below 3:1000 considered oncologically safe) and potential cost savings after selective histopathological examination. RESULTS: Seven thousand three hundred thirty-nine patients were included. After a selective policy, 4966/7339 (67.7%) specimens would have been refrained from histopathological examination. Appendiceal neoplasms with clinical consequences would have been missed in 22/4966 patients. In 5/22, residual disease was completely resected during additional surgery. Hence, an appendiceal neoplasm with clinical consequences benefiting the patient would have been missed in 1.01:1000 patients (upper limit 95% confidence interval 1.61:1000). In contrast, twice as many patients (10/22) would not have been exposed to potential harm due to re-resections without clear benefit, whereas consequences were neither beneficial nor harmful in the remaining seven. Estimated cost savings established by replacing routine for selective histopathological examination were €725,400 per 10,000 patients. CONCLUSIONS: Selective histopathological examination after appendectomy for suspected appendicitis is oncologically safe and will likely result in a reduction of pathologists' workload, less costs, and fewer re-resections without clear benefit.

Appendiceal Incidentalomas: Prevalence, Radiographic Characteristics, Management, and Outcomes.

BACKGROUND: Radiographically detected incidental appendiceal abnormalities, in this report termed "appendiceal incidentalomas" (AIs), are an ill-defined entity with an unknown prevalence of neoplasm. This study aimed to describe the prevalence, radiographic characteristics, and outcomes of patients with a diagnosis of AI. METHODS: The study reviewed the electronic health records for patients at a single institution undergoing abdominopelvic computed tomography and magnetic resonance imaging (MRI) from 2000 to 2020 for non-appendix-related complaints with mention of appendix abnormality in the radiology report. The suggested diagnosis at the index imaging was recorded. Outcomes were compared between the operative and non-operative patients. RESULTS: Of 5197 records, 484 were identified as reports of AIs (9 % of screened patients). Neoplasms were suggested radiographically in 16 % (n = 79) of the records, 59 % (47/79) of which were resected. Pathologically, 32 of the abnormalities were confirmed as neoplasms, yielding a diagnostic accuracy of 68 %. Compared with the non-operative patients, the operative patients had AIs with a larger mean diameter (22.7 ± 13.0 vs. 17.8 ±7.7 mm; p = 0.04), a higher colonoscopy rate (51 % vs. 22 %; p = 0.01), and diagnosis at a younger age (55.8 ± 15.6 vs. 67.2 ± 16.0 years; p = 0.003). The postoperative complications were minor (Clavien-Dindo grade 1 or 2) in 26 % and major (grades 3-5) in 4 % of the cases. During a median follow-up period of 28.3 months, 94 % of the patients were alive without disease, and 6 % died of other causes. The 32 non-operative suggested neoplastic AIs had a median follow-up period of 20.9 months. At this writing, 59 % of the operative patients are alive with a stable abnormal appendix, 13 % had no appendix abnormality at last follow-up visit, and 28 % have died of other causes. CONCLUSION: Neoplastic AIs are an uncommon finding and radiographically diagnosed with relatively high accuracy. Larger appendiceal diameter and younger age predict operative intervention. Although surgery is associated with favorable outcomes and minimal risk of postoperative complications, observation of suspected neoplastic AIs may be a safe alternative for select patients undergoing follow-up longitudinal imaging.

The 2019 World Health Organization Classification of appendiceal, colorectal and anal canal tumours: an update and critical assessment.

The recently published 5th edition 2019 World Health Organization (WHO) Classification of Tumours of the Digestive System brings significant changes from the 2010 4th edition. An emphasis on uniformity in nomenclature and grading for tumours across all organ systems is a particular feature of the 5th edition blue book series that is reflected in the gastrointestinal tract (GIT) classification. For example, simplified two tiered grading is reinforced for preinvasive lesions throughout the GIT, with dysplasia at all sites now being considered either low or high grade. Similarly, a uniform approach to classification and grading of GIT neuroendocrine neoplasms has been consolidated, with an emphasis on distinguishing grade 3 neuroendocrine tumours from neuroendocrine carcinomas. In this review, we discuss and critically assess the important and sometimes controversial changes made to the classification of tumours of the lower GIT, comprising the colorectum, vermiform appendix and anal canal. The particularly controversial decision to endorse the term 'sessile serrated lesion' for lesions previously termed 'sessile serrated polyp/adenoma' is explored. The morphological, molecular, and clinical insights behind the substitution of the term 'goblet cell adenocarcinoma' for 'goblet cell carcinoid' are assessed. The evolution of the classification of appendiceal mucinous neoplasms is considered. Inflammatory bowel disease related dysplasia and its evolving subtypes, with major implications for pathologists in routine practice, is explained.

Temporal trends in incidence, evaluation and management of neuroendocrine neoplasms of the appendix: 14 years' experience.

BACKGROUND: Information regarding temporal trends in appendiceal neuroendocrine neoplasms (ANEN) is limited. This retrospective study evaluated temporal trends in ANEN incidence and management over a 14-year period. METHODS: Appendectomy pathology reports from a single tertiary center were reviewed. RESULTS: During 2005-2018, 8327 appendectomies were performed and 57 ANENs were diagnosed (average age 31.7 ± 17 years; 70.2% women; 17.5% Arab ethnicity; and 22.8% < 18 years of age). The cohort was divided according to year of diagnosis (Period A 2005-2011; Period B 2012-2018). No differences were found in ANEN incidence (0.75% and 0.62%, respectively, p = 0.104), epidemiologic or pathologic characteristics between periods. In period B, pathology reports were more comprehensive and use of specific imaging and biochemical studies was more prevalent. Hemicolectomy rates and results were similar (8 in Period A, 7 in Period B, p = 0.925). All patients remained alive for the duration of follow-up. CONCLUSIONS: No temporal changes in epidemiological, clinical or pathological features of ANENs were noted. Although clinico-pathological evaluation was more detailed after 2011, there was no change in rates of hemicolectomy or disease prognosis.

Macroscopic and microscopic characteristics of low grade appendiceal mucinous neoplasms (LAMN) on appendectomy specimens and correlations with pseudomyxoma peritonei development risk.

Low grade appendiceal mucinous neoplasm (LAMN) is the primary source of pseudomyxoma peritonei (PMP). PMP may develop after seemingly complete resection of primary tumor by appendectomy, which is unpredictable due to lack of reliable prognostic indicators. We retrospectively reviewed 154 surgically resected LAMNs to explore if any of the macroscopic and microscopic characteristics may be associated with increasing risk of PMP development. Our major findings include: (1) As compared to those without PMP, the cases that developed PMP were more frequent to have (a) smaller luminal diameter (<1 cm) and thicker wall, separate mucin aggregations, and microscopic perforation/rupture, all suggestive of luminal mucin leakage; (b) microscopic acellular mucin presenting on serosal surface and not being confined to mucosa; and (c) neoplastic epithelium dissecting outward beyond mucosa, however, with similar frequency of neoplastic cells being present in muscularis propria. (2) Involvement of neoplastic cells or/and acellular mucin at surgical margin did not necessarily lead to tumor recurrence or subsequent PMP, and clear margin did not absolutely prevent PMP development. (3) Coexisting diverticulum, resulted from neoplastic or non-neoplastic mucosa being herniated through muscle-lacking vascular hiatus of appendiceal wall, was seen in a quarter of LAMN cases, regardless of PMP. The diverticular portion of tumor involvement was often the weakest point where rupture occurred. In conclusion, proper evaluation of surgical specimens with search for mucin and neoplastic cells on serosa and for microscopic perforation, which are of prognostic significance, should be emphasized.

Cost analysis of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy and the risk factors for their increased cost in a public insurance health care system - Single centre study.

INTRODUCTION: This study aimed to evaluate the costs of CRS and HIPEC and treatment of the related postoperative complications in the public healthcare system. We also aimed to identify the risk factors that increase the cost of CRS and HIPEC. MATERIALS AND METHODS: We retrospectively evaluated 80 patients who underwent CRS and HIPEC between February 2016 and November 2018 in the Department of Surgery, University Hospital of Olomouc, Czech Republic. Intraoperative factors and postoperative complications were assessed. The treatment cost included the surgery, hospital stay, intensive care unit (ICU) admission, pharmaceutical charges including medication, hospital supplies, pathology, imaging, and allied healthcare services. RESULTS: The postoperative morbidity rate was 50%, and the mortality rate was 2.5%. The mean length of hospitalisation and ICU admission was 15.44 ± 8.43 and 6.15 ± 4.12 for all 80 patients and 10.73 ± 2.93 and 3.73 ± 1.32, respectively, for 40 patients without complications, and 20.15 ± 13.93 and 8.58 ± 6.92, respectively, for 40 patients with complications. The total treatment cost reached €606,358, but the total reimbursement was €262,931; thus, the CRS and HIPEC profit margin was €-343,427. Multivariate analysis showed that blood loss ≥1.000 ml (p = 0.03) and grade I-V Clavien-Dindo complications (p < 0.001) were independently associated with increased costs. CONCLUSION: The Czech public health insurance system does not fully compensate for the costs of CRS and HIPEC. Hospital losses remain the main limiting factor for further improving these procedures. Furthermore, treatment costs increase with increasing severity of postoperative complications.

Optimal Surveillance Frequency After CRS/HIPEC for Appendiceal and Colorectal Neoplasms: A Multi-institutional Analysis of the US HIPEC Collaborative.

BACKGROUND: No guidelines exist for surveillance following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for appendiceal and colorectal cancer. The primary objective was to define the optimal surveillance frequency after CRS/HIPEC. METHODS: The U.S. HIPEC Collaborative database (2000-2017) was reviewed for patients who underwent a CCR0/1 CRS/HIPEC for appendiceal or colorectal cancer. Radiologic surveillance frequency was divided into two categories: low-frequency surveillance (LFS) at q6-12mos or high-frequency surveillance (HFS) at q2-4mos. Primary outcome was overall survival (OS). RESULTS: Among 975 patients, the median age was 55 year, 41% were male: 31% had non-invasive appendiceal (n = 301), 45% invasive appendiceal (n = 435), and 24% colorectal cancer (CRC; n = 239). With a median follow-up time of 25 mos, the median time to recurrence was 12 mos. Despite less surveillance, LFS patients had no decrease in median OS (non-invasive appendiceal: 106 vs. 65 mos, p < 0.01; invasive appendiceal: 120 vs. 73 mos, p = 0.02; colorectal cancer [CRC]: 35 vs. 30 mos, p = 0.8). LFS patients had lower median PCI scores compared with HFS (non-invasive appendiceal: 10 vs. 19; invasive appendiceal: 10 vs. 14; CRC: 8 vs. 11; all p < 0.01). However, on multivariable analysis, accounting for PCI score, LFS was still not associated with decreased OS for any histologic type (non-invasive appendiceal: hazard ratio [HR]: 0.28, p = 0.1; invasive appendiceal: HR: 0.73, p = 0.42; CRC: HR: 1.14, p = 0.59). When estimating annual incident cases of CRS/HIPEC at 375 for non-invasive appendiceal, 375 invasive appendiceal and 4410 colorectal, LFS compared with HFS for the initial two post-operative years would potentially save $13-19 M/year to the U.S. healthcare system. CONCLUSIONS: Low-frequency surveillance after CRS/HIPEC for appendiceal or colorectal cancer is not associated with decreased survival, and when considering decreased costs, may optimize resource utilization.

Preoperative Radiographic Assessment Predicts Incomplete Cytoreduction in Patients with Low Grade Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for patients with low-grade mucinous adenocarcinoma (LGMA) is most effective when complete cytoreduction is achieved. We externally validated two radiographic scoring systems to predict resectability and assessed radiographic response to systemic chemotherapy (SCT). METHODS: Patients with LGMA who received preoperative SCT followed by CRS/HIPEC from 2013 to 2016 were identified. CT scans were graded by six physicians using the simplified radiologic score (SRS) and simplified preoperative assessment of appendiceal tumor (SPAAT) systems. Positive and negative predictive values (PPV, NPV) were calculated by comparing to completeness of cytoreduction. Inter-rater agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: Twenty-four patients had preoperative SCT followed by CRS/HIPEC. Thirteen patients underwent incomplete CRS and 11 patients complete CRS. Scoring of the preoperative CT had a PPV of complete cytoreduction of 75% and 66.7% for SRS and SPAAT, respectively. NPV was 83.4% and 88.9% for SRS and SPAAT, respectively. ICC for the preoperative SRS and SPAAT score was 0.826 (95% confidence interval [CI]: 0.720-0.910] and 0.788 [0.667-0.888). Comparison of CT scans before and after SCT recorded an increase in calculated scores in 45.8% (SRS) and 50% (SPAAT) of patients. CONCLUSIONS: External validation of two radiographic scoring systems to predict complete cytoreduction showed that inter-rater agreement for both systems was good. Both scoring systems predicted incomplete cytoreduction. Applying a systematic approach to preoperative imaging review is recommended to improve treatment selection by minimizing morbidity associated with incomplete CRS and help to set patient expectations.

Appendiceal cancer masked as inflammatory appendicitis in the elderly, not an uncommon presentation (Surveillance Epidemiology and End Results (SEER)-Medicare Analysis).

BACKGROUND: The misdiagnosis of appendiceal cancer as inflammatory appendicitis is becoming of greater clinical concern because of the rise of nonoperative management especially in the elder population. To quantify this rate of misdiagnosis, we retrospectively reviewed SEER-Medicare data. METHODS: The SEER-Medicare database was reviewed from 2000 to 2014. We identified patients older than 65 years old who were diagnosed with appendiceal cancer and then cross-referenced them for a diagnosis of inflammatory appendicitis. Demographic data and oncologic stage were collected. RESULTS: Our results showed that 28.6% of appendiceal cancer patients received an incorrect initial diagnosis of inflammatory appendicitis. Patients older than 75 years of age were more likely to be misdiagnosed than those between ages 65 and 75 (risk ratio [RR]: 0.81; 95% confidence interval: 0.70-0.93; P = .003). We found that 42% of patients within the misdiagnosis group presented with an earlier stage of disease (stage 1 or 2) compared to 26% of those primarily diagnosed with appendiceal cancer (P < .001). CONCLUSION: A significant proportion of patients older than 65 years old with appendiceal cancer were initially misdiagnosed with acute appendicitis. We suggest caution when considering a nonoperative approach for appendicitis in the elderly and follow-up imaging or an interval appendectomy should be part of the treatment plan.

Diagnostic and therapeutic laparoscopy in assessment and management of patients with appendiceal neoplasms.

INTRODUCTION: Radiological imaging often underestimates the extent of low volume peritoneal disease. The benefit of laparoscopy in assessing peritoneal metastases from colorectal and gastric cancer is accepted, but is inconclusive for appendiceal malignancy. We report our experience of diagnostic (DL) and therapeutic laparoscopy (TL) in patients with appendiceal tumours to determine indications and role in assessment and management. METHODS: A retrospective review of a National Peritoneal Malignancy Centre's prospectively maintained database was performed. All patients with appendiceal neoplasms who underwent DL or TL between September 2011 and January 2016 were included. The indications and outcomes of the laparoscopy, complications and interval to laparotomy were evaluated. RESULTS: Six hundred and eighty-five patients underwent surgery for appendiceal neoplasms during the study period, of which 73 (10.6%) underwent laparoscopy (50 DL, 23 TL). The main indications for DL were to clarify imaging and stage patients with high-risk histology. Indications for TL were an abnormal appendix without gross pseudomyxoma peritonei (PMP) or with low volume PMP, and concerns for fertility in the presence of PMP. DL resulted in 16 patients (32%) avoiding laparotomy because of extensive disease or no tumour found. Overall, 28 patients were assessed to have resectable disease and at laparotomy, 25/28 had complete cytoreduction with three patients unresectable. In the TL group, appendicectomy and peritoneal lavage was achieved in all four women with fertility concerns, allowing them to conceive thereafter. There were no complications. CONCLUSIONS: Patients with high-risk appendiceal neoplasm may benefit from DL, and potentially avoid unnecessary laparotomy. TL is useful in patients with low volume PMP and may aid fertility in selected patients.

Computed Tomography Follow-Up Assessment of Patients with Low-Grade Appendiceal Mucinous Neoplasms: Evaluation of Risk for Pseudomyxoma Peritonei.

BACKGROUND: Low-grade appendiceal mucinous neoplasms are rare. Both classification and management vary. This study aimed to follow up on patients with a diagnosis of LAMN after primary surgery with computer tomography (CT) scans to examine the risk for the development of pseudomyxoma peritonei (PMP). METHODS: This population-based prospective study investigated patients who underwent appendectomy between 2007 and 2013 and had histology results demonstrating the presence of LAMN. The patients were followed up with a CT scan every 6 months for 2 years, until December 2015. RESULTS: The study investigated 41 patients (20 females) with a median age of 65 years (range 20-87 years). The entire appendix was processed and examined, with results showing that 12 were perforated, and 3 had a positive margin. Extra-appendiceal mucin on the surface of the appendix was found in ten cases, and in two cases, extra-mucinous epithelial cells were detected. During a median follow-up period of 5.1 years (range 2-8.6 years), none of the patients experienced the development of PMP. CONCLUSIONS: These data suggest that for patients with LAMN confined to the appendix, involvement of the appendectomy margin or perforation with mucin locally, even with epithelial cells, did not predict the development of PMP, and a conservative approach seems justified. No reoperation was needed, and regular follow-up evaluation with CT scans was sufficient.

External Validation of the Simplified Preoperative Assessment for Low-Grade Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: MD Anderson Cancer Center developed a computed tomography (CT)-based preoperative assessment tool simplified preoperative assessment for appendix tumor (SPAAT) for predicting incomplete cytoreduction (IC) in low-grade mucinous adenocarcinoma (LGMA) of the appendix, based on preoperative CT scans. This study independently evaluates the tool's performance. METHODS: Seventy-six preoperative CT scans of LGMA patients were evaluated by two surgeons unfamiliar with the patients' medical history. Scores were assigned based on SPAAT criteria, with a SPAAT ≥3 predictive of IC. Binary regression analyses and area under the receiver operating characteristic (AUROC) curve analyses were performed. Patients with splenic resection were excluded due to the structure of the SPAAT assessment tool. RESULTS: Seventy-six LGMA patients underwent attempted cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). Of 68 patients, 58 had complete cytoreduction and 10 had IC; 8 patients were ineligible due to prior splenectomy. The mean SPAAT score was 0.8, with six patients having SPAAT scores ≥3. SPAAT scores ≥3 were predictive of IC, with a hazard ratio (HR) of 19 (95% confidence interval 2.8-124.1) (p = 0.002). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 40, 97, 50, and 90%, respectively. A SPAAT score ≥3 was not associated with worse survival prognosis. Median follow-up was 2.4 years and AUROC curve was 71%. SPAAT components with respective HR and p-values were foreshortening of the bowel mesentery (29.5; p = 0.004), and scalloping of the pancreas (9; p = 0.008), spleen (4.3; p = 0.04), portal vein (3.1; p = 0.4), and liver (2.1; p = 0.3). CONCLUSION: A SPAAT score ≥3 predicted IC based on a binary regression model. The clinical value of this score is controversial due to low sensitivity and PPV.

Hyperthermic intraperitoneal chemotherapy + early postoperative intraperitoneal chemotherapy versus hyperthermic intraperitoneal chemotherapy alone: assessment of survival outcomes for colorectal and high-grade appendiceal peritoneal carcinomatosis.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have improved survival for colorectal and high-grade appendiceal carcinomatosis. We compared the overall and recurrence-free survival (OS and RFS) of patients treated with HIPEC with mitomycin c and early postoperative intraperitoneal chemotherapy (EPIC) with fluorouracil versus HIPEC alone using oxaliplatin and simultaneous IV infusion of fluorouracil. METHODS: Ninety-three patients with colorectal or high-grade appendiceal carcinomatosis were treated with CRS and HIPEC + EPIC or HIPEC alone. OS and RFS were analyzed using Kaplan-Meier curves and log-rank testing. RESULTS: Survival did not differ between HIPEC regimens. The 3-year OS and RFS rates were 50% and 21% for HIPEC + EPIC and 46% and 6% for HIPEC alone (P = .72 and P = .89, respectively). HIPEC + EPIC patients experienced more grade III/IV complications (43.2% vs 19.6%, P = .01). CONCLUSIONS: There was no difference in OS and RFS between colorectal and high-grade appendiceal adenocarcinoma patients treated with CRS and HIPEC + EPIC versus HIPEC alone. However, HIPEC + EPIC patients suffered greater morbidity, making HIPEC alone the preferable regimen.

A Simplified Preoperative Assessment Predicts Complete Cytoreduction and Outcomes in Patients with Low-Grade Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: Complete cytoreduction with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has been shown to improve survival in patients with low-grade mucinous adenocarcinoma (LGMA). However, incomplete cytoreduction exposes patients to significant morbidity without a similar survival benefit. Preoperative assessment of the ability to achieve CRS is therefore a critical step in selecting patients for CRS/HIPEC. OBJECTIVE: The aim of this study was to develop and validate a preoperative scoring system to accurately predict the ability to achieve complete cytoreduction in patients with LGMA of the appendix. METHODS: A simplified preoperative assessment for appendix tumor (SPAAT) score was developed based on computed tomography scan findings thought to predict incomplete cytoreduction. We applied the SPAAT score to patients with LGMA to determine the ability of the score to predict complete cytoreduction. This scoring system was then applied to a separate cohort of patients from a different institution. Sensitivity and specificity were determined for the SPAAT score. Survival was calculated and correlated with the SPAAT score and the completeness of cytoreduction score. RESULTS: A SPAAT score of <3 is a significant predictor of complete cytoreduction in the derivation cohort. In the validation cohort, 40 of 42 patients with a SPAAT score <3 achieved a complete cytoreduction, for a positive predictive value of 95.2 % and a negative predictive value of 100 %. Additionally, the SPAAT score was a significant predictor of disease-free survival. CONCLUSIONS: The SPAAT score is a useful tool in the preoperative assessment of patients with LGMA who are under consideration for cytoreductive surgery. Prospective analysis of this scoring system is warranted to appropriately select patients who will benefit from CRS/HIPEC.

Clinicopathologic and molecular analysis of disseminated appendiceal mucinous neoplasms: identification of factors predicting survival and proposed criteria for a three-tiered assessment of tumor grade.

Previous studies have demonstrated that the prognosis of disseminated mucinous appendiceal neoplasms is highly dependent upon tumor grade. Reflecting this, the 7th edition of the American Joint Committee on Cancer (AJCC) staging system now incorporates a three-tier grading system for prognostic staging of mucinous appendiceal tumors. However, the grading criteria are not well described. In order to address this issue, we evaluated clinicopathologic and molecular features of 219 cases from 151 patients with widely disseminated appendiceal mucinous neoplasia treated at our institution between 2004 and 2012. We identified histologic features that were associated with worse overall survival on univariate analysis: destructive invasion, high cytologic grade, high tumor cellularity, angiolymphatic invasion, perineural invasion, and signet ring cell component (all with P<0.0001). We used these morphologic characteristics to classify neoplasms into three grades: AJCC grade G1 lacked all adverse histologic features; AJCC grade G2 had at least one adverse histologic feature (except a signet ring cell component); and AJCC grade G3 were defined by the presence of a signet ring cell component. Patients with AJCC grade G2 and grade G3 adenocarcinomas had a significantly worse prognosis compared with AJCC grade G1 (P<0.0001 for each). A trend toward worse overall survival was identified for patients with AJCC grade G3 adenocarcinomas compared with AJCC grade G2 adenocarcinomas (P=0.07). Our multivariate analysis found that this three-tier grading system was a significant predictor of outcome (P=0.008), independent of other prognostic variables. After controlling for other prognostic variables, AJCC grade G2 was associated with a 2.7-fold increased risk of death (95% confidence interval (CI), 1.2-6.2) and AJCC grade G3 was associated with a 5.1-fold increased risk of death (95% CI, 1.7-14) relative to grade G1 tumors. Our results indicate that evaluation of a limited set of adverse histologic features allows for the separation of disseminated mucinous neoplasms of appendiceal origin into three morphologically defined and prognostically relevant grades as advocated by the AJCC.

Assessment of neoadjuvant chemotherapy on operative parameters and outcome in patients with peritoneal dissemination from high-grade appendiceal cancer.

BACKGROUND: High-grade appendiceal adenocarcinoma is a rare malignancy with propensity for peritoneal metastases (PM). The impact of neoadjuvant chemotherapy on operative cytoreduction (CRS) and intraperitoneal chemotherapy (HIPEC) and patient survival was reviewed. METHODS: A total of 45 patients with PM from high-grade appendiceal adenocarcinoma were identified from a prospective database. All patients had laparotomy with intent to undergo CRS and HIPEC. Operative parameters, complications, and survival outcomes were analyzed. RESULTS: Of the 45 patients (male: 27, female: 18; median age: 55 years), 26 received neoadjuvant chemotherapy ± bevacizumab. Of the 26, 15 (58 %) had a response based on improvement in imaging, biomarkers, or both and 9 (34 %) had stable disease. The median peritoneal cancer index (PCI) was 27. Also, 30 (67 %) had a completeness of cytoreduction score (CCR) of ≤1 and 37 (82 %) received HIPEC. There were no differences in PCI, CCR score, operative blood loss, or major organ resection between those who received or did not receive neoadjuvant chemotherapy. Operative time was significantly shorter in those who did not receive neoadjuvant chemotherapy. Major complications and length of hospital stay were similar between the groups. The median actuarial overall survival calculated from the date of initial therapeutic intervention was not different in those treated with or without neoadjuvant therapy. CONCLUSIONS: Neoadjuvant chemotherapy has marked clinical activity in patients with PM from high-grade appendiceal adenocarcinoma and does not adversely affect operative outcomes. These data support conducting a prospective clinical trial to define the role of neoadjuvant chemotherapy in this clinical setting.

Incidental appendectomy--standard or unnecessary additional trauma in surgery for colorectal cancer? A retrospective analysis of histological findings in 380 specimens.

BACKGROUND: Incidental appendectomy is a frequent but non-standard procedure during surgery for colorectal cancer. Incidental appendectomy during colorectal resections is performed at the discretion of the operating surgeon. METHOD: This retrospective study used data from 1352 consecutive patients who underwent surgery for colorectal cancer between 1993 and 2009 at the Medical University of Vienna. The authors evaluated histopathological results of appendices removed incidentally. In addition, complications and costs of the additional intervention were analyzed. RESULTS: Appendectomy had been performed in 314 (23.22%) patients because of appendicitis. Incidental appendectomy had been performed in 380 (28.11%) patients: 86 (22.63%) had a histologically completely normal appendix, a pathologic alteration was found in 289 (76.05%) and a neoplasm was found in seven (1.84%). No complications occurred from the additional surgical procedure. The costs and time effort were negligible. CONCLUSION: Incidental appendectomy is a safe procedure and can be integrated into surgery for colorectal carcinoma to avoid future complications. Pathological findings of the appendix, including neoplasm, are frequent but the clinical relevance remains questionable.