Hyperthermic Intraperitoneal Chemotherapy Following Cytoreductive Surgery Improves Outcome in Patients With Primary Appendiceal Mucinous Adenocarcinoma: A Pooled Analysis From Three Tertiary Care Centers

Right Hemicolectomy and Appendicectomy as Treatments for Goblet Cell Adenocarcinoma: A Comparative Analysis of Two Large National Databases

INTRODUCTION

Right hemicolectomy (RHC) remains the treatment standard for goblet cell adenocarcinoma (GCA), despite limited evidence supporting survival benefit. This study aims to explore factors influencing surgical management and survival outcomes among patients treated with RHC or appendicectomy using NCRAS (UK) and SEER (USA) data.

METHODS

A retrospective analysis was conducted using 998 (NCRAS) and 1703 (SEER) cases. Factors influencing procedure type were explored using logistic regression analyses. Overall survival (OS) probabilities and Kaplan-Meier (KM) plots were generated using KM analysis and the log-rank test compared survival between groups. Cox regression analyses were performed to assess hazard ratios.

RESULTS

The NCRAS analysis revealed that age and regional stage disease were determinants of undergoing RHC, with all age groups showing similar odds of receiving RHC, excluding the 75+ age group. The SEER analysis revealed tumour size > 2 cm, and receipt of chemotherapy were determinants of undergoing RHC, unlike the distant stage, which was associated with appendicectomy. Surgery type was not a significant predictor of OS in both analyses. In NCRAS, age and stage were significant predictors of OS. In SEER, age, stage, and Black race were significant predictors of worse OS.

CONCLUSIONS

The study shows variations in the surgical management of GCA, with limited evidence to support a widespread recommendation for RHC.

Appendiceal adenocarcinoma, diagnosed after acute perforated appendicitis: Potential contribution of HIPEC

INTRODUCTION

Treatment of peritoneal metastasis from appendicular adenocarcinoma consists of cyto-reductive surgery (CRS) and Hyperthermic IntraPEritoneal Chemotherapy (HIPEC). In case of acute appendicular syndrome (AAS) the tumor is likely to be perforated. In that case, there is no treatment recommendation. We propose CRS and HIPEC.

MATERIALS AND METHOD

We listed 21 consecutive patients who were addressed for discovery of appendiceal adenocarcinoma. The emergency surgery was performed in a primary-care hospital. We evaluated the therapeutic algorithms, per operative decision, survival and recurrent rate.

RESULTS

Among the 21 patients, 4 patients were diagnosed as synchronous appendicular peritoneal metastasis, and underwent CRS and HIPEC. The other 17 patients with diagnosis of adenocarcinoma on anatomopathological samples, without peritoneal metastasis during appendectomy, were addressed. Between them 2 patients were denied CRS. Among the 15 operated patients, 8 patients had no peritoneal metastasis discovery during surgery, and therefore underwent prophylactic CRS and HIPEC. Peritoneal metastasis were discovered for the other 7 patients, who also underwent CRS and HIPEC. For the prophylactic group, the recurrence rate is 12,5 %, overall survival (OS) is 100 %. The rate of grade III-IV surgical complications after CRS and HIPEC was 36 % among the 19 patients who underwent surgery.

CONCLUSION

In case of appendectomy in emergency situations for perforated adenocarcinoma, half of the patients may have peritoneal metastasis. In case of non-identified peritoneal metastasis during CRS, performing a prophylactic HIPEC seems to be associated with an encouraging rate of peritoneal disease free situation at 5 years.

PIPAC for Gastrointestinal Malignancies

The peritoneum is a common site of metastases for gastrointestinal tumors that predicts a poor outcome. In addition to decreased survival, peritoneal metastases (PMs) can significantly impact quality of life from the resulting ascites and bowel obstructions. The peritoneum has been a target for regional therapies due to the unique properties of the blood-peritoneum barrier. Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) have become accepted treatments for limited-volume peritoneal disease in appendiceal, ovarian, and colorectal malignancies, but there are limitations. Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) improves drug distribution and tissue penetration, allowing for a minimally invasive application for patients who are not CRS/HIPEC candidates based on high disease burden. PIPAC is an emerging treatment that may convert the patient to resectable disease, and may increase survival without major morbidity, as indicated by many small studies. In this review, we discuss the rationale and benefits of PIPAC, as well as sentinel papers describing its application for gastric, colorectal, appendiceal, and pancreatobiliary PMs. While no PIPAC device has yet met FDA approval, we discuss next steps needed to incorporate PIPAC into neoadjuvant/adjuvant treatment paradigms, as well as palliative settings. Data on active clinical trials using PIPAC are provided.

Defining a role for systemic chemotherapy in local and advanced appendix adenocarcinoma

BACKGROUND

Appendix adenocarcinomas (AAs) are rare tumours that often present late, with a propensity for peritoneal metastases (PMs). This study aimed to evaluate outcomes of AA patients undergoing cytoreductive surgery (CRS) with curative intent and determine the role of systemic chemotherapy.

MATERIALS AND METHODS

Data were collected from a prospective database and classified according to World Health Organization (WHO) 2019 classification. Tumour clearance from CRS was described using a completeness of cytoreduction (CC) score ranging from 0 [no residual disease (RD)] to 3 (>2.5 cm RD). Patients with CC0-2 CRS received hyperthermic intraperitoneal chemotherapy (HIPEC). Systemic chemotherapy was categorised as 'prior' (>6 months before), 'neoadjuvant' (<6 months before), 'adjuvant' (<6 months after CC0-1 CRS) or 'palliative' (after CC2-3 CRS). Analyses used Kaplan-Meier and Cox regression methods.

RESULTS

Between January 2005 and August 2021, 216 AA patients were identified for inclusion. Median age was 59 years (21-81 years). CRS/HIPEC was carried out in 182 (84%) patients, of whom 164/182 (76%) had mitomycin C HIPEC. CC0-1 was achieved in 172 (80%) patients. Systemic chemotherapy was given to 97 (45%) patients from the whole cohort and to 37/46 (80%) patients with positive nodes. Median overall survival (OS) was 122 months (95% confidence interval 61-182 months). After multivariate analysis, patients with acellular and lower-grade PM had similar OS to those with localised (M0) disease (P = 0.59 and P = 0.19). For patients with positive nodes, systemic chemotherapy was associated with reduced risk of death compared to no chemotherapy (P < 0.0019).

CONCLUSION

This study identifies AA patients with positive lymph nodes derive the most benefit from systemic chemotherapy. We confirm the prognostic importance of stage and peritoneal grade, with excellent outcomes in patients with acellular mucin and lower-grade PM.

The role of chemotherapy in the treatment of advanced appendiceal cancers: summary of the literature and future directions

Appendiceal cancer is rare and encompasses a diverse group of tumours ranging from low-grade appendiceal mucinous neoplasms to high-grade adenocarcinomas. Appendiceal cancers often spread to the peritoneal cavity causing extensive mucinous dissemination and peritoneal metastases. Prognosis varies with histological subtype. Cytoreductive surgery and heated intraperitoneal chemotherapy is well-established as the most effective treatment achieving long-term survival in some patients. Chemotherapy regimens used to treat appendiceal cancer are extrapolated from the colorectal cancer setting, but disease biology differs and outcomes are inferior. The role of chemotherapy in the treatment of appendiceal cancer remains poorly defined. There is an urgent need to develop novel tailored treatment strategies in the perioperative and unresectable setting. This review aims to evaluate the literature for patients who received intraperitoneal and systemic chemotherapy for appendiceal cancers.

Appendiceal tumors and pseudomyxoma peritonei: French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (RENAPE, RENAPATH, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of appendicular epithelial tumors (AT) and pseudomyxoma peritonei (PMP) published in March 2020, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org).

METHODS

All French medical societies specialized in the management of AT and PMP collaboratively established these recommendations based on literature until December 2019 and the results of a Delphi vote carried out by the Peritoneal Surface Oncology Group International experts, and graded into 4 categories (A, B, C, Expert Agreement) according to their level of evidence.

RESULTS

AT and PMP are rare but represent a wide range of clinico-pathological entities with several pathological classification systems and different biological behaviors. Their treatment modalities may vary accordingly and range from simple surveillance or laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) and / or systemic chemotherapy. The prognosis of these neoplasms may also largely vary according to their pathological grade and spreading at diagnosis or during the follow-up. Given the rarity of certain situations, the therapeutic strategy adapted to each patient, must be discussed in a specialized multidisciplinary meeting after a specialized pathological and radiological pre-therapeutic assessment and a clinical examination by a surgeon specializing in the management of rare peritoneal malignancies.

CONCLUSION

These recommendations are proposed to achieve the most beneficial strategy in a daily practice as the wide range and the rareness of these entities renders their management challenging. These guidelines are permanently being reviewed.

Celecoxib and Myrtol: A Novel Therapy for Recurrent Appendiceal Mucinous Neoplasms With Extensive Peritoneal Dissemination

BACKGROUND

Unresectable appendiceal mucinous neoplasms (AMNs) with extensive peritoneal dissemination cause significant morbidity and have limited treatment options. We evaluated a novel combination of Celecoxib and Myrtol in treating such AMNs.

METHODS

Patients with recurrent AMNs with extensive peritoneal disease treated with a daily regimen of 200 mg Celecoxib and 1200 mg Myrtol Standardized were included. Progression-free survival (PFS) and overall survival (OS) were calculated, and carcinoembryonic antigen (CEA) trends were compared pretreatment and post-treatment in terms of percentage change.

RESULTS

Thirteen patients with extensive, recurrent disease (median peritoneal carcinomatosis index of 36) were included between 2017 and 2020. The median age was 63 years (interquartile range: 55 to 67) and 7 (54%) were male. A total of 85% had undergone prior cytoreductive surgery while 15% underwent cytoreductive surgery >2 times. 54% had received multiple cycles of systemic chemotherapy before starting Celecoxib-Myrtol. After a median follow-up of 8 months, median PFS and OS were 16 months (interquartile range: 5 to 17) and 27 months, respectively. Nine (69.2%) showed improvement in CEA values 3 months after treatment compared with 3-month pretreatment CEA trends. None had adverse events attributable to Celecoxib-Myrtol.

CONCLUSIONS

Our feasibility study suggests that a regimen of Celecoxib-Myrtol is well tolerated and may prolong PFS and OS in patients with recurrent AMNs with peritoneal spread.

Defining stage in mucinous tumours of the appendix with peritoneal dissemination: the importance of grading terminology: systematic review

Background

Mucinous appendiceal neoplasms with peritoneal dissemination (PD) show a wide spectrum of clinical behaviour. Histological grade has been correlated with prognosis, but no universally accepted histological grading has been established. The aim of this systematic review was to provide historical insight to understand current grading classifications, basic histopathological features of each category, and to define which classification correlates best with prognosis.

Methods

MEDLINE and the Cochrane Library were searched for studies that reported survival across different pathological grades in patients with mucinous neoplasm of the appendix with PD treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. PRISMA guidelines were followed.

Results

Thirty-eight studies were included. Ronnett’s classification was the most common (9 studies). Classifications proposed by the Peritoneal Surface Oncology Group International (PSOGI) (6 studies) and the seventh or eighth edition of the AJCC (7 studies) are gaining in popularity. Nine studies supported a two-tier, 12 a three-tier, and two a four-tier classification system. Three studies demonstrated that acellular mucin had a better prognosis than low-grade pseudomyxoma peritonei in the PSOGI classification or M1bG1 in the eighth edition of the AJCC classification. Four studies demonstrated that the presence of signet ring cells was associated with a worse outcome than high-grade pseudomyxoma peritonei in the PSOGI classification and M1bG2 in the eighth edition of the AJCC.

Conclusion

There is a great need for a common language in describing mucinous neoplasms of the appendix with PD. Evolution in terminology as a result of pathological insight turns the four-tiered PSOGI classification system into a coherent classification option.

Incidentally found mucinous epithelial tumors of the appendix with or without pseudomyxoma peritonei: diagnostic and therapeutic algorithms based on current evidence

Mucinous appendiceal tumors with or without the pseudomyxoma peritonei (PMP) syndrome are rare, but often present as an incidental finding. The confusing histology and lack of large prospective trials result in a considerable diagnostic and therapeutic challenge in these patients. We propose treatment algorithms in patients with incidentally found mucinous epithelial appendiceal tumors, with or without PMP, based on the currently available evidence. The therapeutic approach should take into account the histology and grade of the primary appendix tumor, as well as those of the associated peritoneal disease.

Appendiceal Mucinous Neoplasm: Nurse Education About a Rare and Complex Disease

BACKGROUND

Appendiceal mucinous neoplasms (AMNs) are a rare and complex spectrum of disease involving a mucinous tumor within the appendix, which can range from benign to malignant. If not limited to the appendix, the mucinous tumor can spread diffusely throughout the peritoneum.

OBJECTIVES

Because of the low incidence of AMN, this study describes the diagnosis and treatment process for this disease, which is not well known to most care providers.

METHODS

An extensive analysis of the current literature, including incidence, diagnosis, and surgical treatment, was performed. A review of the pre- and postoperative needs for patients undergoing surgery was also conducted.

FINDINGS

There is minimal information in the nursing literature about AMN and the complexity of surgical management. Nurses play an important role in caring for these patients and their unique needs both before and after surgery.

Incidence and survival trends for appendiceal mucinous adenocarcinoma: an analysis of 3237 patients in the Surveillance, Epidemiology, and End Results database

Aim: To characterize the epidemiology of appendiceal mucinous adenocarcinoma. Methods: Prognostic factors were evaluated with univariate and multivariate analyses. The results were used to generate a nomogram. Results: The incidence of appendiceal mucinous adenocarcinoma showed a significant upward trend. Multivariate Cox analysis identified 11 independent prognostic factors. The nomogram was based on independent risk factors that were significant in multivariate Cox analysis, and the concordance-index for overall survival and cancer-specific survival were 0.76 (95% CI: 0.71-0.79) and 0.74 (95% CI: 0.70-0.79), respectively. Conclusion: Advanced age, single relationship status, male sex, black race, the presence of distant and regional lymph node metastases, poor differentiation or lack of differentiation, advanced SEER extent of disease, cancer-directed surgery and chemotherapy were independently associated with prognosis.

ΔNp73 status in peritoneal and ovarian dissemination of appendicular adenocarcinoids (goblet cells)

INTRODUCTION

Goblet cell carcinoma (GCC) is an appendicular neoplasia representing less than 5% of all appendicular tumors, found in 0.3-0.9% of the appendectomies, 35-58% of all appendicular neoplasms, and less than 14% of malign appendix tumors. The most frequent clinical presentation is abdominal pain associated with a picture of acute appendicitis.

MATERIALS AND METHODS

We present 3 clinical cases of appendix GCC, 2 subjected to cytoreductory surgery plus intraperitoneal hyperthermic chemotherapy and a third, who is currently receiving neoadjuvant treatment with a good response to chemotherapy and who will be offered the same treatment as the first two patients. Given the unpredictable behavior of these tumors, the use of molecular markers could help us to predict their behavior and prognosis. In this context, the TP73 gene would make an interesting putative marker. ∆Np73 has been described as overexpressed in a great variety of tumor types including colon cancer and this up-regulation is associated with a poor prognosis. To evidence its role in this malignancy, we evaluate here the status of ∆Np73 in the primary tumor and normal counterpart tissues, in the metastatic implants and in healthy areas of the peritoneum from the appendicular GCC patients. In addition, we checked the expression levels of this p73 variant in the tumor and normal tissue of 26 patients with colon cancer.

RESULTS

Remarkably, 2 patients showed significant ∆Np73 down-regulation in both the primary tumor and the implants. Case 1 presented a fourfold decrease of levels in the primary tumor and 20-fold decrease in the implants. Case 2 showed a seven- and fourfold down-regulation in the primary tumor and implants, respectively. However, Case 3 showed an up-regulation of 53- and threefold in the primary tumor and implants, respectively.

CONCLUSION

Goblet cell carcinoma of the appendix is very rate. It tends to seed throughout the peritoneum, making aggressive surgical cytoreduction and chemotherapy viable treatment options. Investigation into the molecular basis of these tumors may improve the diagnosis, prognosis and therapeutic decisions regarding these patients. ∆Np73 seems a good candidate for further analysis in longer series.

Systemic chemotherapy and survival in patients with metastatic low-grade appendiceal mucinous adenocarcinoma

BACKGROUND

Appendiceal cancer is a rare malignancy that exhibits a wide range of histology and treatment response. Given the rarity and heterogeneous nature of the disease, it has been difficult to define optimal treatment strategies. Our goal is to examine the association between use of systemic chemotherapy and survival in patients with metastatic low-grade mucinous appendiceal adenocarcinoma.

METHODS

The National Cancer Database (2004-2015) was queried, and patients with mucinous, grade 1, stage IV appendiceal adenocarcinoma were identified. The Kaplan-Meier method was used to calculate survival, and a Cox regression model was used to identify predictors of survival.

RESULTS

Six hundred and thirty-nine patients were identified. Five-year overall survival (OS) for patients undergoing no chemotherapy vs chemotherapy was 52.9% and 61.3%, respectively. After adjusting with Cox proportional hazards model, chemotherapy was not associated with OS (HR:1.1, 95% CI:0.82-1.40, P = 0.61). Patients who underwent surgical resection (HR:0.40, 95% CI:0.28-0.57, P < .001) or were female (HR:0.61, 95% CI:0.5-0.8, P < .001) had improved survival in adjusted analysis.

CONCLUSIONS

There is no association between undergoing chemotherapy and OS in this cohort of patients with stage IV low-grade mucinous appendiceal adenocarcinoma. Development of national treatment guidelines is urgently needed for more consistency in the management of patients with appendiceal cancers.

Optimizing outcomes for patients with gastric cancer peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) from gastric cancer has traditionally been considered a terminal progression of the disease and is associated with poor survival outcomes. Positive peritoneal cytology similarly worsens the survival of patients with gastric cancer and treatment options for these patients have been limited. Recent advances in multimodality treatment regimens have led to innovative ways to care for and treat patients with this disease burden. One of these advances has been to use neoadjuvant therapy to try and convert patients with positive cytology or low-volume PC to negative cytology with no evidence of active peritoneal disease. These strategies include the use of neoadjuvant systemic chemotherapy alone, using neoadjuvant laparoscopic heated intraperitoneal chemotherapy (NLHIPEC) after systemic chemotherapy, or using neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) in a bidirectional manner. For patients with higher volume PC, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been mainstays of treatment. When used together, CRS and HIPEC can improve overall outcomes in properly selected patients, but overall survival outcomes remain unacceptably low. The extent of peritoneal disease, commonly measured by the peritoneal carcinomatosis index (PCI), and the completeness of cytoreduction, has been shown to greatly impact outcomes in patients undergoing CRS and HIPEC. The uses of NLHIPEC and NLHIPEC plus NIPS have both been shown to decrease the PCI and thus increase the opportunity for complete cytoreduction. Newer therapies like pressurized intraperitoneal aerosol chemotherapy and immunotherapy, such as catumaxomab, along with improved systemic chemotherapeutic regimens, are being explored with great interest. There is exciting progress being made in the management of PC from gastric cancer and its' treatment is no longer futile.

Incidence and Survival of Appendiceal Mucinous Neoplasms: A SEER Analysis

OBJECTIVES

The aim of this study is to characterize the changes in the incidence, presentation, surgical treatment, and survival of patients with appendiceal mucinous neoplasm (AMN) over the past 4 decades using nationwide cancer surveillance data.

METHODS

Patients with the diagnosis of AMN were identified in the Surveillance Epidemiology and End Results (SEER) database. Information on demographics, disease characteristics, and surgical treatment was collected. Temporal changes in AMN incidence, characteristics of cases, and survival were analyzed from 1973 to 2011. Determinants of overall survival (OS) were examined using both crude and multivariable Cox proportional hazard models.

RESULTS

The overall incidence rate of AMN increased on average 3.1%/1,000,000 persons-years (P<0.001). A significant decline in the age at diagnosis was observed (P=0.014). The proportion of patients presenting with distant disease at diagnosis also significantly increased (P=0.004). Five-year survival of patients with distant stage AMN increased at a rate of 3.5%/y between 1984 and 2006 (P<0.001). Median OS was not reached for localized and regional stage disease. Median OS for distant stage disease was 42 months.

CONCLUSIONS

There has been an increase in the overall incidence of AMN with an observed increase in the proportion of younger age and distant stage at diagnosis. The OS has improved over time.

Appendiceal Mucinous Neoplasms: Diagnosis and Management

OBJECTIVE

Appendiceal mucinous neoplasms (AMNs) are a rare and heterogeneous disease for which clinical management is challenging. We aim to review the literature regarding modalities of treatment to guide the management of AMNs.

METHODS AND REVIEW CRITERIA

We conducted a PubMed search in February 2016 for English-language publications, using the terms "appendiceal," "appendix," "carcinoma," "cancer," "mucinous," "treatment," "genes," "target," "genomic," and terms listed in the articles' subheadings. Published reports and abstracts from the American Society of Clinical Oncology meetings were also searched.

RESULTS

In this review, we summarize current data and controversies in AMN classification, clinical presentation, molecular alterations, treatment outcomes with regard to cytoreductive surgery, hyperthermic intraperitoneal chemotherapy (HIPEC), and the role of systemic chemotherapy.

CONCLUSION

Appendiceal mucinous neoplasms are a heterogeneous group of tumors with a rising incidence. Treatment is based on stage and histology. Low-grade tumors are treated surgically with resection of the primary site in early stage disease, or peritoneal debulking and HIPEC in patients with advanced stage disease. Treatment of high-grade tumors requires further prospective trials, and options include debulking surgery and HIPEC with or without preoperative chemotherapy. Trials evaluating novel therapies based on the molecular profiling of AMN tumors are needed to evaluate therapeutic options in patients who are not surgical candidates.

IMPLICATIONS FOR PRACTICE

This review provides a reference to guide gastroenterologists, pathologists, surgeons, and oncologists in the management of appendiceal mucinous neoplasms (AMNs), a rare and heterogeneous disease with no consensus on histologic classification or guidelines for treatment algorithms. This review summarizes all AMN classifications and proposes a treatment algorithm based on stage and histology of disease.

Adenocarcinoma ex-goblet cell carcinoid (appendiceal-type crypt cell adenocarcinoma) is a morphologically distinct entity with highly aggressive behavior and frequent association with peritoneal/intra-abdominal dissemination: an analysis of 77 cases

High-grade versions of appendiceal goblet cell carcinoids ('adenocarcinoma ex-goblet cell carcinoids') are poorly characterized. We herein document 77 examples. Tumors occurred predominantly in females (74%), mean age 55 years (29-84), most with disseminated abdominal (77% peritoneal, 58% gynecologic tract involvement) and stage IV (65%) disease. Many presented to gynecologic oncologists, and nine had a working diagnosis of ovarian carcinoma. Metastases to liver (n=3) and lung (n=1) were uncommon and none arose in adenomatous lesions. Tumors had various histologic patterns, in variable combinations, most of which were fairly specific, making them recognizable as appendiceal in origin, even at metastatic sites: I: Ordinary goblet cell carcinoid/crypt pattern (rounded, non-luminal acini with well-oriented goblet cells), in variable amounts in all cases. II: Poorly cohesive goblet cell pattern (diffusely infiltrative cords/single files of signet ring-like/goblet cells). III: Poorly cohesive non-mucinous cell (diffuse-infiltrative growth of non-mucinous cells). IV: Microglandular (rosette-like glandular) pattern without goblet cells. V: Mixed 'other' carcinoma foci (including ordinary intestinal/mucinous). VI: goblet cell carcinoid pattern with high-grade morphology (marked nuclear atypia). VII: Solid sheet-like pattern punctuated by goblet cells/microglandular units. Ordinary nested/trabecular ('carcinoid pattern') was very uncommon. In total, 33(52%) died of disease, with median overall survival 38 months and 5-year survival 32%. On multivariate analysis perineural invasion and younger age (<55) were independently associated with worse outcome while lymph-vascular invasion, stage, and nodal status trended toward, but failed to reach, statistical significance. Worse behavior in younger patients combined with female predilection and ovarian-affinity raise the possibility of hormone-assisted tumor progression. In conclusion, 'adenocarcinoma ex-goblet cell carcinoid' is an appendix-specific, high-grade malignant neoplasm with distinctive morphology that is recognizable at metastatic sites and recapitulates crypt cells (appendiceal crypt cell adenocarcinoma). Unlike intestinal-type adenocarcinoma, it occurs predominantly in women, is disguised as gynecologic malignancy, and spreads along peritoneal surfaces with only rare hematogenous metastasis. It appears to be significantly more aggressive than appendiceal mucinous neoplasms.

Appendiceal Neuroendocrine, Goblet and Signet-Ring Cell Tumors: A Spectrum of Diseases with Different Patterns of Presentation and Outcome

PURPOSE

Appendiceal tumors are a heterogeneous group of diseases that include typical neuroendocrine tumors (TNET), goblet cell carcinoids (GCC), and atypical GCC. Atypical GCC are classified into signet-ring cell cancers (SRCC) and poorly differentiated appendiceal adenocarcinoids. The prognosis and management of these diseases is unclear because there are no prospective studies. The aim of this study is to assess the characteristics and outcome of appendiceal TNET, GCC, and SRCC patients.

MATERIALS AND METHODS

Appendiceal TNET, GCC, and SRCC patients diagnosed between 1973 and 2011 were identified in the Surveillance Epidemiology and End Results (SEER) database. Demographics, type of surgery, and clinicopathologic characteristics were collected. Survival functions were estimated by the Kaplan-Meier method, and log-rank test was used to assess the difference in overall survival (OS) among the three histologies.

RESULTS

The SEER database yielded 1,021 TNET patients, 1,582 with GCC, and 534 SRCC patients. TNET presented at a younger age (p < 0.001). Patients with SRCC presented with advanced stage disease (p < 0.001). The median OS (mOS) for GCC and TNET patients was not reached; mOS for SRCC was 24 months. Multivariate analysis stratified for stage revealed significantly longer survival for TNET and GCC than SRCC (p < 0.001).

CONCLUSION

This is the largest report to date for appendiceal neuroendocrine tumor patients, suggesting a spectrum of diseases with different characteristics and outcomes. In this report, we present a treatment approach for this complex spectrum of disease, based on the experience of Ohio State and Emory Universities investigators.