Disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis. A clinicopathologic analysis of 109 cases with emphasis on distinguishing pathologic features, site of origin, prognosis, and relationship to "pseudomyxoma peritonei"

The histopathological classification, diagnosis and differential diagnosis of mucinous appendiceal neoplasms, appendiceal adenocarcinomas and pseudomyxoma peritonei

The vermiform appendix is the primary site of several distinctive benign and malignant neoplasms. Some can produce the clinical syndrome of pseudomyxoma peritonei (PMP). A consensus on their terminology was reached by an international panel of pathologists and clinicians working under the auspices of the Peritoneal Surface Oncology Group International (PSOGI), and this review discusses the application of the PSOGI classification to routine reporting. We discuss diagnosis and differential diagnosis together with implications for patient management, covering low-grade appendiceal mucinous neoplasms, high-grade appendiceal mucinous neoplasms, serrated polyps, adenomas and adenocarcinomas. We do not cover goblet cell tumours or neuroendocrine neoplasms in this paper.

Stratification of outcomes for mucinous appendiceal adenocarcinoma with peritoneal metastasis by histological grade

AIM

To investigate the importance of a three-tiered histologic grade on outcomes for patients with mucinous appendiceal adenocarcinoma (MAA).

METHODS

Two hundred and sixty-five patients with MAA undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were identified from a prospective database from 2004 through 2014. All pathology was reviewed by our gastrointestinal subspecialty pathologists and histological grade was classified as well-differentiated, moderately differentiated, and poorly differentiated. Survival analysis was performed using Cox proportional hazards regression.

RESULTS

There were 201 (75.8%) well-, 45 (16.9%) moderately- and 19 (7.2%) poorly-differentiated tumors. Histological grade significantly stratified the 5-year overall survival (OS), 94%, 71% and 30% respectively (P < 0.001) as well as the 5-year disease-free survival (DFS) 66%, 21% and 0%, respectively (P < 0.001). Independent predictors of DFS included tumor grade (HR = 1.78, 95%CI: 1.21-2.63, P = 0.008), lymph node involvement (HR = 0.33, 95%CI: 0.11-0.98, P < 0.02), previous surgical score (HR = 1.31, 95%CI: 1.1-1.65, P = 0.03) and peritoneal carcinomatosis index (PCI) (HR = 1.05, 95%CI: 1.02-1.08, P = 0.002). Independent predictors of OS include tumor grade (HR = 2.79, 95%CI: 1.26-6.21, P = 0.01), PCI (HR = 1.10, 95%CI: 1.03-1.16, P = 0.002), and complete cytoreduction (HR = 0.32, 95%CI: 0.11-0.92, P = 0.03). Tumor grade and PCI were the only independent predictors of both DFS and OS. Furthermore, histological grade and lymphovascular invasion stratified the risk of lymph node metastasis into a low (6%) and high (40%) risk groups.

CONCLUSION

Our data demonstrates that moderately differentiated MAA have a clinical behavior and outcome that is distinct from well- and poorly-differentiated MAA. The three-tier grade classification provides improved prognostic stratification and should be incorporated into patient selection and treatment algorithms.

Urachal mucinous adenocarcinoma with pseudomyxoma peritonei: A case report

RATIONALE

Pseudomyxoma peritonei is an unusual clinical condition, and the appendix and ovaries are reported as the primary sites.

PATIENT CONCERNS

A 44-year-old man who was reported a 3-month history of lower abdominal pain and distention, along with increased abdominal girth, was admitted with a palpable tender mass in the central lower abdomen.

DIAGNOSIS

Ultrasonography showed a large well-circumscribed cystic-solid mass with lobulated margin, extending from the anterosuperior dome of the urinary bladder to the anterior abdominal wall. A computed tomography (CT) scan revealed a midline heterogeneous, hypodense, irregular polycystic-solid mass adjacent to the anterior wall of the abdomen and anterior to the dome of the urinary bladder. fluorodeoxyglucose positron-emission tomography/CT showed intense fluorodeoxyglucose uptake in the thickened wall of the mass. Intraperitoneal laparoscopic exploration also revealed a midline abdominal mass adjacent to the dome of the urinary bladder. Laparotomy showed that the mass originated from the dome of the urinary bladder and was disconnected with the urinary bladder lumen. The final histopathological diagnosis was urachal mucinous adenocarcinoma associated with high-grade pseudomyxoma peritonei.

INTERVENTIONS

The patient underwent surgical cytoreductive procedure and the perioperative intraperitoneal chemotherapy.

OUTCOMES

The patient made an uneventful recovery, and 7 months later had no recurrence.

LESSONS

The urachus is a tubular structure, which extends medially from the apex of the bladder to the allantoid during fetal development, and it usually obliterates after birth. Urachal remnants can cause urachal carcinoma or bladder cancers. Pseudomyxoma peritonei originating from mucinous neoplasm of the urachus is extremely rare.

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 of the appendix with extra-appendicular spread: Clinico-surgical and histologic analysis of 27 cases

BACKGROUND AND OBJECTIVES

Appendiceal neoplasms with extra-appendiceal spread may show different clinical patterns with pseudomyxoma peritonei (PMP) being one of them. We analyse the results in a series of patients treated in our centre.

MATERIAL AND METHODS

Retrospective study of patients operated on for appendiceal peritoneal carcinomatosis from January 2012 to May 2015.

RESULTS

Twenty-seven consecutive patients were included. Median age 63 years (26-73); 14 were men. Peritoneal carcinomatosis index=16±8 (3-31). The suspected preoperative origins were appendix in 23, ovary in 3 and urothelial in one. Postoperative mortality in 2 patients (7.4%). The remaining 36% presented morbidity. Major morbidity (Clavien-Dindo grades 3 and 4) occurred in 3 patients (12%).

CONCLUSIONS

Mucinous adenocarcinomas with extra-appendiceal spread may present as PMP with mucinous ascites, jelly-nodular carcinomatosis without ascites, nodular or desmoplasic plates carcinomatosis without jelly mass/nodules. Histology is not correlated to clinical picture. Preoperative diagnosis of mucinous ovarian cancer in peritoneal carcinomatosis scenario may increase the doubt of their ovarian origin and force an appendiceal origin to be ruled out.

Mucinous appendiceal neoplasms: Incidence, diagnosis and surgical treatment

INTRODUCTION

Mucinous tumors of the appendix are a rare pathology, with a prevalence below 0.5%. Clinical presentation usually occurs during the sixth decade of life, and mucinous tumors can clinically mimic acute appendicitis. The aim of this study is to describe the clinical and demographic variables, therapeutic procedure and diagnosis of these tumors. We analyze the association between mucinous tumors and pseudomyxoma peritonei (PP), as well as the association with colorectal and ovarian tumors.

METHODS

A retrospective study was performed including patients who underwent an appendectomy between December 2003 and December 2014.

RESULTS

Seventy-two mucinous tumors of the appendix were identified among 7.717 patients reviewed, resulting in a prevalence of 0.9%. Mean age at presentation was 64 years, 62% patients were female and 38% males. An incidental diagnosis was made in 43% of patients. Mucinous tumors of low malignant potential were significantly related to the presence of pseudomyxoma peritonei, identified in 16 (22%) of the cases. We also observed an increased risk of ovarian mucinous tumors in patients with a diagnosis of appendiceal mucinous neoplasm. In our sample, 22 (30.5%) patients showed a synchronous or metachronous colorectal cancer.

CONCLUSIONS

Appendiceal mucinous tumors are frequently an incidental finding. The diagnosis of mucinous tumors of low malignant potential is a factor associated with the development of pseudomyxoma peritonei. Histologic tumor grade and the presence of peritoneal dissemination will determine surgical treatment that can vary, from appendectomy to cytoreductive surgery.

Pseudomyxoma peritonei due to low-grade appendiceal mucinous neoplasm with symptoms of inguinal hernia and uterine prolapse: a case report and review of the literature

Pseudomyxoma peritonei (PMP) is an unusual condition in which massive amounts of mucinous ascites in conjunction with mucinous peritoneal and omental implants occur. We herein report a case of PMP due to low-grade appendiceal neoplasm (LAMN) and a literature review to clarify the clinical features of PMP. A 68-year-old female suffered from anorexia and abdominal distension and was referred to the emergency department of our hospital. Right-side inguinal hernia and uterine prolapse were revealed by a physical examination. Abdominal computed tomography at admission indicated massive ascites and a ruptured cystic mass in the lower-right abdomen. We diagnosed the patient with a ruptured appendiceal mucinous adenoma and PMP and scheduled a laparotomy. We performed an appendectomy containing the cystic mass, bilateral oophorectomy, and a biopsy for the peritoneum. We irrigated the abdominal cavity using 3000 ml of dextran solution. The macroscopic findings showed a ruptured cystic mass measuring 5 × 4 cm arising from the middle of the appendix. The bilateral ovaries and peritoneum were also covered with yellow mucin. The pathologic findings revealed the presence of low-grade atypical cells inside the capsule. However, no tumor cells were found on the surface of the ovary or peritoneum. A literature review revealed that the prognosis of PMP due to LAMN is relatively good, with a 5-year survival rate of 80%, and hernia is occasionally caused by PMP. According to this literature review, we knew this case might be a typical case. However, PMP is very rare; we need further follow-up data to select an optimal treatment for preventing the relapse of PMP.

Diagnosis of Pseudomyxoma peritonei via endoscopic ultrasound guided fine needle aspiration: a case report and review of literature

INTRODUCTION

Pseudomyxoma peritonei (PMP) is a rare condition caused by mucinous adenocarcinoma cancerous cells that produce abundance of mucin or gelatinous ascites. This cancer can cause tissue fibrosis and can impair normal organ function. Diagnosis can involve multiple imaging modalities including CT scan. There have been few cases of endoscopic ultrasound (EUS) being used as a means for diagnosis of this condition. Here we report a second case of PMP with a previous history of appendectomy diagnosed with EUS guided fine needle aspiration (FNA) biopsy.

CASE STUDY

A 66-year-old male with a history of an appendectomy presented with intermittent abdominal pain for two years and weight loss of 40 pounds over two months. EGD and colonoscopy performed at an outside hospital was unremarkable. CT abdomen revealed perigastric ascities and lesions of the liver. ESR was elevated at 75. At our facility, EUS was performed revealing a peri-gastric and omental mass measuring 36.6 mm × 25.5 mm. FNA performed of both mass and ascetic fluid revealed low grade mucinous adenocarcinoma with mucinous deposits in the peritoneum consistent with PMP.

CONCLUSIONS

Endoscopic ultrasound guided FNA, although very rarely used, can be a reliable and safe technique in diagnosis of PMP.

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.

Acute appendicitis, inflammatory appendiceal mass and the risk of a hidden malignant tumor: a systematic review of the literature

Introduction

Acute appendicitis is significantly common. Despite the increased use of computed tomography, the number of perforated cases has been stable in the past three decades. Between 2% and 6% of patients with acute appendicitis present appendiceal mass, often described as inflammatory phlegmon or abscess. Malignant tumors are confirmed by pathological analysis in 0.9–1.4% of all appendectomies performed to treat acute appendicitis. However, recent series demonstrate an elevated incidence of malignancies, ranging from 5.9 to 12%, in patients with inflammatory appendiceal mass.

Methods

The analysis was based on a systematic review of the literature. The articles were searched in PubMed for the period from 1987 to 2016. Articles presenting the incidence of the hidden malignancy among patients with appendiceal inflammatory mass were selected. Variables as age, interval appendectomy rate, the incidence of neoplasm, time to surgery, minimally invasive assessment, histology, right colectomy rate and morbidity were analyzed.

Results

A total of 13.244 patients were described as presenting acute appendicitis. Appendiceal tumor is present in approximately 1% of the appendectomies, while the rate of neoplasm varies from 10 to 29% in patients presenting appendiceal inflammatory mass. Interval appendectomies, despite been the minority of the procedures, disregard the higher morbidity associated with right sided colectomies. The review of literature also describes oncologic, histologic and clinical aspects of patients presenting appendiceal neoplasm, describing the most frequent histologic subtypes of this illness.

Conclusion

Hidden appendiceal neoplasm in acute appendicitis are rare, fortunately. However, its incidence is much higher in patients presenting appendiceal inflammatory mass. Hence, interval appendectomy should be considered in this subgroup of patients.

Low-Grade Appendiceal Mucinous Neoplasm Presenting as an Adnexal Mass

Appendiceal tumors are rare, late diagnosed neoplasms that may not be differentiated from adnexal masses even by advanced imaging methods and other diagnostic procedures. They may be asymptomatic and remain undiagnosed until surgery. We report a case of an 80-year-old postmenopausal woman presenting with a pelvic mass and a history of weight loss. The patient underwent laparotomy which revealed an appendiceal mucocele, for which she received a full oncological procedure. The histology report showed a low-grade appendiceal mucinous neoplasm, and the patient underwent six cycles of chemotherapy. Appendiceal tumors should be kept in mind in patients with adnexal mass.

Radical appendectomy as an alternative to right colon resection in patients with epithelial appendiceal neoplasms

OBJECTIVE

Appendectomy is an extremely common surgical procedure usually performed for an inflammatory process within this organ. Upon occasion, the pathology within the appendix is a neoplastic process which requires definitive oncologic management.

METHODS

The optimal management strategies for appendiceal neoplasms were reviewed and pertinent literature critically evaluated. The technology for appendectomy for an inflammatory process and an appendectomy for a neoplastic process were compared and contrasted.

RESULTS

A new surgical procedure called "radical appendectomy" was described and its merits for optimizing the management of an appendiceal neoplasm enumerated. The technology of radical appendectomy was described. The possible shortcomings that may be encountered in performing a new surgical methodology for appendectomy was presented and the results of a technically perfect radical appendectomy enumerated. The integration of a radical appendectomy with perioperative hyperthermic chemotherapy was described.

CONCLUSIONS

When a malignancy exists as the cause of appendiceal pathology, the radical appendectomy will provide the maximal amount of information required for optimal decisions regarding patient management.

Management of an inguinal hernia in patients with pseudomyxoma peritonei

BACKGROUND

Pseudomyxoma peritonei is a disease that results from a perforated mucinous neoplasm of the appendix so that mucinous ascites and mucin-producing tumor cells are widely disseminated in a characteristic pattern throughout the abdomen and pelvis. The intraabdominal mucus can accumulate in the inguinal canal and by physical examination be indistinguishable from the usual inguinal hernia.

METHODS

A database of patients with pseudomyxoma peritonei was used to identify patients who had an inguinal hernia prior to or at the time of cytoreductive surgery (CRS) and perioperative hyperthermic chemotherapy (HIPEC). At the time of CRS, care was taken in all patients to remove the peritoneal lining of the inguinal canal. Patients who had the inguinal hernia repaired prior to definitive treatment with CRS and HIPEC had all tissue and mesh associated with prior herniorrhaphy resected.

RESULTS

In 178 pseudomyxoma peritonei patients, 17 had a new onset or previously repaired inguinal hernia that required extraction of mucus and mucinous tumor from the hernia site. No repair of the open inguinal canal was attempted at the time of CRS. No recurrent inguinal hernias were recorded and no patients required an inguinal incision at a later time to resect progressive disease within the inguinal canal.

CONCLUSIONS

Inguinal hernias caused by mucinous ascites and tumor were definitively treated by cytoreductive surgery plus HIPEC. Extraction of tumor and peritoneum from the inguinal canal facilitates fibrous closure of the hernia defect so that hernia recurrence was not observed.

Role of Imaging in Peritoneal Surface Malignancies

Imaging plays a vital role in the evaluation of peritoneal malignancies. The presence of peritoneal metastases (PM) alters tumor staging, with direct implications in treatment choice and prognosis. Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC) as a combined modality treatment have led to prolonged survival and even cure in selected patients with PM. Better outcomes are seen in patients with limited disease spread. Therefore, early diagnosis of peritoneal tumor seeding is essential. Despite significant advancement of technology, assessment of the origin of PM is often difficult, due partly to the complex peritoneal anatomy and partly due to the complex overlap of imaging features. Multidetector CT (MDCT) is the main stay due to its wide availbility, rapid evaluation, robust technique and good resolution. Imaging plays a vital role in selecting patients for the combined modality treatment. MRI is not as popular as CT due to limited availability, time required for the study and lack of experience with interpreting the results. PET-CT is useful in ruling out extra peritoneal disease and it is the CT component that is more reliable for predicting the disease extent. This article reviews the current use of various imaging modalities in various stages of treatment of patients with PM especially those undergoing CRS and HIPEC.

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.

Outcome and surgical strategy in critical sites in cases of psuedomyxoma peritonei

BACKGROUND

For a long time peritoneal neoplasms were considered beyond surgical intervention and beyond cure, till the concept of cytoreductive surgery (CRS) and adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC) was introduced. However this surgical intervention is technically demanding and associated with considerable postoperative morbidity.

OBJECTIVE

To describe the surgical strategy in resection of critical sites loaded by heavy tumor deposits and to evaluate short and long term results of CRS and HIPEC, in a cohort of Egyptian patients with pseudomyxoma peritonei (PMP) from appendiceal origin.

PATIENTS AND METHODS

21 patients with PMP, age ranged from 40 to 63years, 12 males and 9 females. All were recruited from the department of surgery at the National Cancer Institute (NCI), Cairo University over the period from February 2011 to February 2016. They were subjected to CRS and HIPEC with mitomycin-C.

RESULTS

The median peritoneal carcinoma index (PCI) was 22 (range: 10-39). Optimal cytoreduction (CCR-0/1) was achieved in 19 patients (90.4%) of whom 17 patients (80.9%) had a complete cytoreduction (CCR-0). The median follow up period was 51.5months (range: 0.07-82.3months). The cumulative overall survival was 85.7% while the cumulative disease free survival was 76.9%.

CONCLUSION

To the best of our knowledge, this is the first study reporting five years postoperative outcome of CRS and HIPEC in Egyptian patients with PMP from appendiceal origin. Our results support that although technically demanding this treatment modality is safe and associated with favorable outcome.

Early identification of DPAM in at-risk low-grade appendiceal mucinous neoplasm patients: a new approach to surveillance for peritoneal metastasis

Background

Disseminated peritoneal adenomucinosis (DPAM) patients often have a history of appendectomy with identification of an incidental mucinous neoplasm (low-grade appendiceal mucinous neoplasm (LAMN)). The rate of developing DPAM is not well established.

Methods

Twenty-two patients with incidental LAMN were identified and monitored with cancer markers and CT every 4–6 months. Laparoscopy with peritoneal washing was performed in patients either in the event of radiographic disease or after 12 months in absence of radiographic disease. The rate of detecting peritoneal metastasis was determined for CT scan and laparoscopy.

Results

Peritoneal metastasis was detected in 5 (23 %) patients. Occult disease was detected in four patients at laparoscopy without a detectable disease on CT scan. One patient developed radiographic progression at 6 months confirmed with laparoscopy. Four patients were treated with cytoreductive surgery (CRS)/HIPEC and one with CRS only. The 17 patients with negative laparoscopy remain disease free with a median follow-up of 50 months.

Conclusions

The rate of peritoneal metastasis in incidental LAMN patients was 23 %. Laparoscopy was the primary screening tool identifying occult metastasis. The median PCI of 7 was low, and all the patients underwent R0/R1 resections. This study revealed 1 in every 4.4 patients with LAMN may develop PMP. Longer follow-up and further patient surveillance is warranted.

Pseudomyxoma Peritonei of Extra-Appendiceal Origin: A Comparative Study

BACKGROUND

Pseudomyxoma peritonei (PMP) usually originates from appendiceal neoplasms and, less commonly, from extra-appendiceal lesions. To date, the clinical and therapeutic implications of extra-appendiceal origin are largely unknown.

METHODS

A prospective database of 225 PMP patients uniformly treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) was reviewed to identify cases with extra-appendiceal primaries. Histologically, negative appendix defined extra-appendiceal origin. Clinical, pathological, and immunohistochemical features (cytokeratin [CK]-20, CK-7, CDX-2, MUC-2, MUC-5A) were correlated with the site of origin. PMP was categorized into low or high grade, according to the 2010 World Health Organization (WHO) classification. The main independent variable for survival analysis was appendiceal versus extra-appendiceal primary.

RESULTS

In 19 patients (8.4 %), PMP origin was the ovary (n = 9), uterine cervix (n = 1), mature cystic teratomas (n = 4), and unknown (n = 5). Appendiceal and extra-appendiceal PMP groups were comparable for all characteristics, except for a prevalence of females in the latter. Median follow-up was 64.1 months (95 % confidence interval [CI] 53.9-80.1), and 10-year overall survival was 63.4 % (median 148.2 months; 95 % CI 131.2-165.2) for appendiceal PMP, and 62.0 % (median not reached) for extra-appendiceal PMP. The difference was not significant at univariate ( p = 0.297) and multivariate analysis (hazard ratio 1.51, 95 % CI 0.78-3.14; p = 0.278). High-grade peritoneal histology (p = 0.007), prior systemic chemotherapy (p = 0.003), more than four visceral resections (p = 0.011), and incomplete cytoreduction (p = 0.021) independently correlated with poorer survival.

CONCLUSIONS

Clinical-pathological features of PMP, and outcome after CRS/HIPEC, did not differ according to the primary site, thus suggesting that PMP is a relatively homogeneous disease that can be produced by a range of histopathologic entities. Extra-appendiceal origin does not contraindicate CRS/HIPEC.

Pathology of Mucinous Appendiceal Tumors and Pseudomyxoma Peritonei

Neoplasms of the appendix are rare, but because of their unusual presentation and unpredictable biologic behavior, it is important to diagnose them correctly. Mucinous tumors account for 58 % of malignant tumors of appendix in SEER database and the remaining are carcinoids. The mucinous appendiceal tumors have a potential to spread to the peritoneum and viscera in the form of gelatinous material with or without neoplastic cells resulting in Pseudomyxoma peritonei. (PMP) PMP is a clinical entity that has a unique biological behavior and can arise from seemingly benign tumors to frankly malignant ones. Several classifications exist for PMP of which Ronnet's classification has been the most popular. In 2010, the WHO proposed a 2 tier classification that classified PMP as either low grade or high grade based on the presence of mucin, cytological and architectural features. According to this classification when the underlying cause for PMP is an appendiceal tumor it is always a mucinous adenocarcinoma rather than a mucocoele or adenoma and these terms should no longer be used. This system of classification helps in predicting the behavior of the tumor and proper treatment strategies. The understanding of the pathogenesis of the disease has also improved with identification of newer biomarkers and molecular genetic alterations. IHC markers CK 20, CDX2 and MUC2 are found to be positive in these tumors in addition to KRAS mutation and loss of heterozygosity in some gene loci. Proper histopathologic classification and predicting the tumor behavior requires a close interaction between the pathologist and the surgeon. The use of the combined modality treatment of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has led to a 5-year survival ranging from 62.5 % to 100 % for low grade, and 0 %-65 % for high grade disease. This article focuses on the etiopathogenesis, clinical behavior, diagnosis and classification of mucinous tumors of the appendix and pseudomyxoma peritonei.

Preoperative Preparation and Patient Selection for Cytoreductive Surgery and HIPEC

Peritoneal dissemination is a significant variable affecting long term survival of abdominal cancer patients. A generally accepted clinical point of view is that peritoneal dissemination is tantamount to distant organ metastases. This implies it to be a terminal condition. Current practice dictates that if peritoneal dissemination is observed intraoperatively, the curative therapeutic options are deferred and comprehensive systemic chemotherapy remains the only option with a dismal prognosis. The past few years have generated lot of interest in management of peritoneal carcinomatosis. Prof Paul Sugarbaker has researched, validated and fine-tuned the concept of cytoreductive surgery with peritonectomy procedure (Sugarbaker technique) and perioperative chemotherapy as HIPEC & EPIC. Recognition of a HIPEC centre is based on an infrastructure equipped with basic knowledge of the tumor biology, oncosurgical techniques, technical knowhow for HIPEC administration, intensive care unit etc. There are some aspects which need to be accorded special consideration. Comprehensive therapy of Cytoreduction surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is initiated with exploration and cytoreductive surgery and includes visceral resections and peritonectomy procedure when achieved optimally results in complete, visible resection of all cancer within the abdomen and pelvis. Subsequent to CRS, HIPEC forms an integral part of the surgical procedure. This approach involves conceptual changes in both the route and timing of chemotherapy administration. Patient selection is of utmost importance. The greatest impediment to lasting benefits from intraperitoneal chemotherapy remains an improper patient selection. Currently, there are four important clinical assessments of peritoneal metastasis that need to be used to select patients ie; histopathological type of tumour, radiological distribution of disease, peritoneal cancer index and completeness of cytoreduction. Patients undergoing HIPEC surgery face the usual physiological insults of a major surgery in addition to the thermal stress secondary to intraperitoneal administration of heated chemotherapy agent. A team approach of everyone involved in care of these patients is known to improve patient outcomes. It has also been observed that with the necessary preoperative & perioperative steps, the morbidity and mortality for this treatment can be brought down as comparable to any other major abdominal surgeries.

Significance of epithelial cell clusters in pseudomyxoma peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare clinical syndrome characterised by distension of the peritoneum by jelly-like ascites. Cytological evaluation of peritoneal fluid is often an initial diagnostic test for possible ovarian and/or appendiceal primary tumours.

AIMS AND OBJECTIVES

The present work was conducted to study the usefulness of peritoneal fluid cytomorphology in the early diagnosis of PMP and to evaluate the significance of the presence of epithelial cell (EC) clusters and their prognostic implications.

MATERIALS AND METHODS

We evaluated the detailed cytological features of 21 cases of PMP retrospectively. Both conventional and liquid-based cytology smears of peritoneal fluid were reviewed, cytological features were compared with histological findings and cases were classified into disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA).

RESULTS

In our study, the common causes of PMP were primary gastrointestinal malignancies (appendix and colorectal, 57.14%), followed by primary ovarian mucinous neoplasms (28.57%) and synchronous ovarian and appendicular tumours (14.28%). Thick mucinous material was present in all cases (100%). ECs were present in 18 of 21 (85.17%) patients, with mild nuclear atypia in the majority of cases. Histiocytes, mesothelial cells and fibroblast-like, spindle-shaped cells with entrapped mucin were also noted in the background. The cases of PMCA showed greater numbers of EC clusters in cytology smears and these patients had recurrent episodes of PMP.

CONCLUSION

On cytomorphology, high-grade tumours were more cellular and frequently showed EC clusters with moderate to severe atypia, prominent nucleoli and mitosis, and were more prone to PMCA.

Pathologic diagnosis, origin, and natural history of pseudomyxoma peritonei

Mucinous ascites and pools of mucin within the peritoneal cavity associated with neoplastic, mucinous epithelium are the characteristic features of pseudomyxoma peritonei (PMP). Clinically, PMP presents with abdominal distension and gelatinous ascites. In female patients, pelvic masses can be seen. Radiologic findings on computed tomography include scalloping of the hepatic and splenic margins and dense ascites. Surgically, PMP is encountered as grossly visible mucin in the peritoneal cavity. The presence of mucin outside of the appendix, in the right lower quadrant, and beyond is an important diagnostic finding. The appendix may be distended or ruptured. In women, there is often bilateral surface involvement of the ovaries, raising the differential diagnosis of primary ovarian neoplasms; however, these are extremely rare causes of PMP. Because of the association between appendiceal lesions and metastatic mucinous neoplasms of the ovary, appendectomy in the setting of any mucinous peritoneal or ovarian process may be prudent, even if the appendix is grossly normal. The gastrointestinal tract, especially the hepatopancreato biliary system, also needs to be assessed by the surgeon. Pathologically, PMP arises almost exclusively from low- or high-grade mucinous neoplasms of the appendix. These neoplasms must be distinguished both from rare benign causes of mucinous ascites and from nonappendiceal primary tumors. PMP has a protracted clinical course with progressive fibrous adhesions and obstructive disease; aggressive surgical and cytoreductive therapy with hyperthermic intraperitoneal chemotherapy has been reported to improve clinical outcomes.

A Consensus for Classification and Pathologic Reporting of Pseudomyxoma Peritonei and Associated Appendiceal Neoplasia: The Results of the Peritoneal Surface Oncology Group International (PSOGI) Modified Delphi Process

Pseudomyxoma peritonei (PMP) is a complex disease with unique biological behavior that usually arises from appendiceal mucinous neoplasia. The classification of PMP and its primary appendiceal neoplasia is contentious, and an international modified Delphi consensus process was instigated to address terminology and definitions. A classification of mucinous appendiceal neoplasia was developed, and it was agreed that "mucinous adenocarcinoma" should be reserved for lesions with infiltrative invasion. The term "low-grade appendiceal mucinous neoplasm" was supported and it was agreed that "cystadenoma" should no longer be recommended. A new term of "high-grade appendiceal mucinous neoplasm" was proposed for lesions without infiltrative invasion but with high-grade cytologic atypia. Serrated polyp with or without dysplasia was preferred for tumors with serrated features confined to the mucosa with an intact muscularis mucosae. Consensus was achieved on the pathologic classification of PMP, defined as the intraperitoneal accumulation of mucus due to mucinous neoplasia characterized by the redistribution phenomenon. Three categories of PMP were agreed-low grade, high grade, and high grade with signet ring cells. Acellular mucin should be classified separately. It was agreed that low-grade and high-grade mucinous carcinoma peritonei should be considered synonymous with disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis, respectively. A checklist for the pathologic reporting of PMP and appendiceal mucinous neoplasms was also developed. By adopting the classifications and definitions that were agreed, different centers will be able to use uniform terminology that will allow meaningful comparison of their results.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in 1000 patients with perforated appendiceal epithelial tumours

PURPOSE

To report early and long term outcomes following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in 1000 patients with perforated appendiceal epithelial tumours, predominantly with pseudomyxoma peritonei (PMP).

METHODS

Retrospective analysis of a prospective database of 1000 consecutive patients undergoing CRS and HIPEC for perforated appendiceal tumours between 1994 and 2014 in a UK National Peritoneal Malignancy unit.

RESULTS

Overall 1000/1444 (69.2%) patients treated for peritoneal malignancy had appendiceal primary tumours. Of these 738/1000 (73.8%) underwent complete cytoreductive surgery (CCRS), 242 (24.2%) had maximal tumour debulking (MTD) and 20 (2%) had laparotomy and biopsies only. Treatment related 30-day mortality was 0.8% in CCRS and 1.7% in MTD group with major postoperative morbidity rates of 15.2% (CCRS) and 14.5% (MTD). Five- and 10-year overall survival was 87.4% and 70.3% in the 738 patients who had CCRS compared with 39.2% and 8.1% respectively in the MTD group. On multivariate analysis, significant predictors of reduced overall survival were male gender (p = 0.022), elevated CEA (p = 0.001), elevated CA125 (p = 0.001) and high tumour grade or adenocarcinoma (p = 0.001).

CONCLUSIONS

Perforated epithelial appendiceal tumours are rare, though may be increasing in incidence and can present unexpectedly at elective or emergency abdominal surgery, often with PMP. CRS and HIPEC results in good long term outcomes in most patients.

Diagnosis and Treatment of Mucinous Appendiceal Neoplasm Presented as Acute Appendicitis

Appendiceal mucocele is a rare cause of acute abdomen. Mucinous appendiceal neoplasms represent 0.2-0.7% of all appendix specimens. The aim of this study is to report a case of a mucinous appendiceal neoplasm presented as acute appendicitis, discussing the clinical and surgical approach in the emergency setting. A 72-year-old female patient was admitted to the emergency department with a clinical examination indicative of acute abdomen. The patient underwent abdominal computed tomography scan which revealed a cystic lesion in the right iliac fossa measuring 8.3 × 5.2 × 4.1 cm, with calcified walls, and a mean density indicative of high protein content. The patient was taken to the operating room and a right hemicolectomy was performed. The postoperative course was unremarkable. The histopathological examination revealed a low-grade mucinous appendiceal neoplasm with negative regional lymph nodes. Ultrasound and CT are useful in diagnosing appendiceal mucocele and synchronous cancers in the emergency setting. The initial operation should include appendectomy and resection of the appendicular mesenteric fat along with any fluid collection for cytologic examination. During urgent appendectomy it is important to consider every mucocele as malignant in order to avoid iatrogenic perforation causing pseudomyxoma peritonei. Although laparotomy is recommended, the laparoscopic approach is not contraindicated.

Repeat cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: review of indications and outcomes

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is an established treatment option in selected patients with peritoneal dissemination from a variety of epithelial primaries. Even though a small proportion will be alive and potentially cured at 10 years, the majority will eventually develop recurrent disease. Repeat CRS/HIPEC is a valid consideration in a selected subpopulation of patients with isolated peritoneal recurrence. This review summarizes the data on patient selection, feasibility, limitations and outcomes of repeat CRS/HIPEC.

Pathophysiology and classification of pseudomyxoma peritonei

Background: The term pseudomyxoma peritonei (PMP) was first described in 1884 and there has been much debate since then over the term. A recent consensus of world experts agreed that PMP should be thought of as a clinical entity characterised by the presence of mucinous ascites, omental cake, peritoneal implants and possibly ovarian involvement. It generally originates from mucinous appendiceal tumours. Content: This review details the clinical presentation of this unusual condition, presents the new classification system and how this relates to outcome. The pathophysiology of this disease is also explored with a special reference to the relationship of the disease to tumour markers. Summary: A classification system has been agreed upon by the leading experts in PMP which is now divided into low and high grade mucinous carcinomatosis peritonei. This distinction correlates with clinical outcome as does the presence of raised tumour markers preoperatively. Outlook: Research needs to be focused on understanding the factors associated with poor prognosis through well designed multi-centred prospective studies. This will allow us to identify patients with bad tumour biology so that targeted treatment based on likely prognosis may then become a reality.

Patient-derived xenograft mouse models of pseudomyxoma peritonei recapitulate the human inflammatory tumor microenvironment

Pseudomyxoma peritonei (PMP) is a neoplastic syndrome characterized by peritoneal tumor implants with copious mucinous ascites. The standard of care for PMP patients is aggressive cytoreductive surgery performed in conjunction with heated intraperitoneal chemotherapy. Not all patients are candidates for these procedures and a majority of the patients will have recurrent disease. In addition to secreted mucin, inflammation and fibrosis are central to PMP pathogenesis but the molecular processes that regulate tumor-stromal interactions within the peritoneal tumor microenvironment remain largely unknown. This knowledge is critical not only to elucidate PMP pathobiology but also to identify novel targets for therapy. Here, we report the generation of patient-derived xenograft (PDX) mouse models for PMP and assess the ability of these models to replicate the inflammatory peritoneal microenvironment of human PMP patients. PDX mouse models of low- and high-grade PMP were generated and were of a similar histopathology as human PMP. Cytokines previously shown to be elevated in human PMP were also elevated in PDX ascites. Significant differences in IL-6 and IL-8/KC/MIP2 were seen between human and PDX ascites. Interestingly, these cytokines were mostly secreted by mouse-derived, tumor-associated stromal cells rather than by human-derived PMP tumor cells. Our data suggest that the PMP PDX mouse models are especially suited to the study of tumor-stromal interactions that regulate the peritoneal inflammatory environment in PMP as the tumor and stromal cells in these mouse models are of human and murine origins, respectively. These mouse models are therefore, likely to be useful in vivo surrogates for testing and developing novel therapeutic treatment interventions for PMP.

Cytoreductive surgery and intraperitoneal chemotherapy: an evidence-based review-past, present and future

Peritoneal carcinomatosis (PC) has historically been considered a terminal condition with merely palliative treatment achieving a survival rate measured in months. Cytoreductive surgery (CyRS) and intraperitoneal chemotherapy (IPC) have emerged as potentially effective regional treatments with the potential for long-term survival in well-selected patients. The fundamentals of CyRS and IPC are patient selection and complete cytoreduction. Since there is now sufficient evidence for the superiority of CyRS and IPC to systemic chemotherapy alone in a highly select group of patients, surgeons and oncologists should be aware of this modality as a potential benefit for patients with PC. The aim of this report is to highlight cancer-specific evidence in the context of ongoing studies regarding the outcome of this treatment.

Pseudomyxoma peritonei with endometrial mucinous carcinoma and appendicular mucinous tumor: An unusual association

The association between pseudomyxoma peritonei and appendicular or ovarian mucinous tumors is usually reported in the literature, while the association with endometrial carcinoma is exceptional. Although there has been always a continuous debate regarding its primary origin, tumors of the appendix and ovary remain the most common primary sites for this disease. The association of pseudomyxoma peritonei with two primaries from endometrial mucinous adenocarcinoma and appendicular mucinous tumor is very rare. So, we report this case to raise awareness among clinicians about this rare tumor association.

Prognostic Molecular Subtypes of Low-Grade Cancer of the Appendix

BACKGROUND

Appendiceal cancer (AC) patients treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) often demonstrate an unpredictable variability in their survival outcomes. Biomarkers predictive of CRS/HIPEC efficacy could better guide treatment decisions. We hypothesized that variation in the transcriptional programming of AC tumors might distinguish molecular subtypes with differential outcomes after CRS/HIPEC.

STUDY DESIGN

Gene expression profiles of 2 AC cohorts were analyzed using Affymetrix whole-genome expression microarrays. Hierarchical clustering methods, Kaplan-Meier analysis, and Cox regression models were used to discover and validate prognostic molecular subtypes of AC. Gene set enrichment analysis was used to infer pathologic attributes of the molecular subtypes.

RESULTS

Unsupervised hierarchical clustering analysis of tumor expression profiles revealed a 139-gene cassette that distinguished 2 molecular subtypes (based on low vs high expression of the gene cassette) with statistically significant survival differences (disease-specific survival, p = 0.0075; progression-free survival, p = 0.0072). In a second AC cohort, the 139-gene cassette reproducibly partitioned tumors into subtypes with significant survival differences. Tumors showing high relative expression of the genes comprising the cassette associated with poor survival outcomes (disease-specific survival, p = 0.047; progression-free survival, p = 0.0079), and exhibited gene expression patterns enriched for oncogenic processes and pathways. The prognostic value of the molecular subtypes was specific for low-grade appendiceal tumors (disease-specific survival, p = 0.028; progression-free survival, p = 0.0016), and remained significant in the presence of conventional prognostic markers, including grade, surgical resection score, Eastern Cooperative Oncology Group status, and age.

CONCLUSIONS

The 139-gene cassette can have actionable clinical utility for identifying low-grade appendiceal tumor molecular subtypes predictive of therapeutic efficacy of CRS/HIPEC.

Can a Benefit be Expected from Surgical Debulking of Unresectable Pseudomyxoma Peritonei?

PURPOSE

This study evaluated the role of surgical debulking in improving pseudomyxoma peritonei (PMP)-related symptoms if complete cytoreductive surgery (CCRS) of huge PMP is unachievable.

METHODS

This was a retrospective analysis of a prospective database of all patients in our tertiary care center treated for PMP between 1992 and 2014. All cases of surgical debulking in patients scheduled for CCRS that proved unachievable during the operation were selected for the present study.

RESULTS

Among the 338 patients operated on for PMP, 39 (11.5 %) had undergone surgical debulking because CCRS was unachievable. All of these patients were symptomatic before surgery, and the median PCI was 32 (5-39). More than 80 % of the disease burden was resected in 23 patients (59 %). Mortality and major morbidity rates were 2.5 and 23 %, respectively. After debulking surgery, symptoms gradually subsided over a median time of 23 months and 50 % of the patients no longer experienced PMP-related symptoms after a median follow-up of 24.5 months. After a median follow-up of 46.4 months (range 3-120), median overall (OS) and progression-free (PFS) survival times were 55.5 and 20 months, respectively. Five-year OS and PFS rates were 46 and 11 %, respectively.

CONCLUSIONS

Aggressive debulking surgery in case of unachievable CCRS for huge PMP can offer prolonged relief of PMP-related symptoms and long-term survival, in experienced centers that are able to be sufficiently aggressive to resect the major part of the disease, and conservative enough to achieve low mortality and good quality of life.

Clinicopathologic and Prognostic Features in Patients with Peritoneal Metastasis from Mucinous Adenocarcinoma, Adenocarcinoma with Signet Ring Cells, and Adenocarcinoid of the Appendix Treated with Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy

BACKGROUND

Tumors that show a signet ring or adenocarcinoid histomorphology have been associated with a poor prognosis. This study aimed to analyze the clinicopathologic and prognostic features in patients with peritoneal metastasis from mucinous adenocarcinoma (PMCA), adenocarcinoma with signet ring cell (PMCA-S), or adenocarcinoid (PMCA-A) of the appendix treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy.

METHODS

Retrospective analysis of a prospectively maintained database for all patients treated for appendiceal adenocarcinoma from 1989 to 2012 was performed.

RESULTS

The study cohort consisted of 494 patients including 361 patients with PMCA (73.1 %), 80 patients with PMCA-S (16.2 %), and 53 patients with PMCA-A (10.7 %). The patients comprised 273 men (55.3 %) and 221 women (44.7 %) with a mean age at presentation of 50.7 years for the PMCA-S patients, 47.3 years for the PMCA patients, and 47.5 years for the PMCA-A patients (p < 0.03). The 3- and 5-year survival rates were respectively 51 and 38 % for PMCA compared with 30 and 22 % for PMCA-S and 26 and 15 % for PMCA-A. The median survival time was 45.4 months for PMCA compared with 18.9 months for PMCA-S and 26.8 months for PMCA-A (p < 0.000). The groups did not differ significantly in the completeness of cytoreduction achieved, with 53.5 % of the PMCA patients having a CC0/1 compared with 46.2 % of the PMCA-S patients and 41.6 % of the PMCA-A patients (p < 0.20). In the multivariate analysis, the independent predictors of a reduced survival were incompleteness of cytoreduction, histomorphology of PMCA-S or PMCA-A, and distant metastasis.

CONCLUSION

The findings showed that PMCA-S or PMCA-A histomorphology contributes to the poor prognosis associated with peritoneal metastasis from appendiceal adenocarcinoma. The independent predictors for a poor overall survival included incompleteness of cytoreduction, PMCA-S and PMCA-A histomorphology, and distant metastasis.

The impact of stage, grade, and mucinous histology on the efficacy of systemic chemotherapy in adenocarcinomas of the appendix: Analysis of the National Cancer Data Base

BACKGROUND

Adenocarcinomas of the appendix represent a heterogeneous disease depending on the presence of mucinous histology, histologic grade, and stage. In the current study, the authors sought to explore the interplay of these factors with systemic chemotherapy in a large population data set.

METHODS

Patients in the National Cancer Data Base (NCDB) who were diagnosed with mucinous, nonmucinous, and signet ring cell-type appendiceal neoplasms from 1985 through 2006 were selected. Multivariable Cox proportional hazards regression models were developed.

RESULTS

A total of 11,871 patients met the inclusion criteria for the current study: 50.3% had mucinous neoplasms, 40.5% had nonmucinous neoplasms, and 9.2% had signet ring cell-type neoplasms. The 5-year overall survival (OS) stratified by grade was similar among patients with American Joint Committee on Cancer stage I to stage III disease but not for those with stage IV disease. The median OS for patients with stage IV mucinous and nonmucinous tumors was 6.4 years and 2.3 years, respectively, for those with well differentiated histology (P<.0001) and was 1.5 years and 0.8 years, respectively, for those with poorly differentiated histology (P<.0001). In multivariable modeling for stage I to III disease, adjuvant chemotherapy improved OS for both mucinous and nonmucinous histologies, with hazard ratios (HRs) of 0.78 (95% confidence interval [95% CI], 0.68-0.89 [P = .0002]) and 0.83 (95% CI, 0.74-0.94 [P = .002]), respectively. For patients with stage IV disease, systemic chemotherapy significantly improved OS for those with nonmucinous (HR, 0.72; 95% CI, 0.64-0.82 [P<.0001]) but not mucinous (HR, 0.95; 95% CI, 0.86-1.04 [P = .2) histologies, although this was grade-dependent. The median OS for chemotherapy versus no chemotherapy was 6.4 years versus 6.5 years (P value not significant) for patients with mucinous, well-differentiated tumors and 1.6 years versus 1.0 years (P = .0007) for patients with mucinous, poorly differentiated tumors.

CONCLUSIONS

Adjuvant chemotherapy demonstrated a significant OS benefit regardless of histology. However, for patients with stage IV disease, the benefit of systemic chemotherapy varied by tumor histology and grade, with patients with well-differentiated, mucinous, appendiceal adenocarcinomas deriving no survival benefit from systemic chemotherapy. Cancer 2016;122:213-221. © 2015 American Cancer Society.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei and Appendix Tumours

Pseudomyxoma peritonei (PMP) is the intra-peritoneal accumulation of mucus due to mucinous neoplasia, most often from a ruptured mucinous appendiceal neoplasm. A similar syndrome is caused by appendix cancer and other gastrointestinal malignancies. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) provides long-term survival in selected patients with these conditions. The management of the appendiceal neoplasm prior to development of peritoneal involvement is initially discussed. This is followed by an overview of the management of peritoneal disease caused by appendiceal neoplasms. The principles and basic techniques of CRS and intraperitoneal chemotherapy (both intraoperative and post operative) are then discussed. Survival outcomes from several large studies are summarised. Prognostic factors are also discussed. We report our basic outcome data for the 345 patients with PMP or appendix cancer treated at our institution. Finally, the promising upcoming treatment of mucolytic therapy is discussed. We conclude that appendiceal neoplasms, although rare can cause significant morbidity and mortality. With optimal management long-term survival is possible in the majority of patients. The key to treatment is complete cytoreduction and use of hyperthermic intraperitoneal chemotherapy.

Genome-wide significant risk associations for mucinous ovarian carcinoma

Genome-wide association studies have identified several risk associations for ovarian carcinomas but not for mucinous ovarian carcinomas (MOCs). Our analysis of 1,644 MOC cases and 21,693 controls with imputation identified 3 new risk associations: rs752590 at 2q13 (P = 3.3 × 10(-8)), rs711830 at 2q31.1 (P = 7.5 × 10(-12)) and rs688187 at 19q13.2 (P = 6.8 × 10(-13)). We identified significant expression quantitative trait locus (eQTL) associations for HOXD9 at 2q31.1 in ovarian (P = 4.95 × 10(-4), false discovery rate (FDR) = 0.003) and colorectal (P = 0.01, FDR = 0.09) tumors and for PAX8 at 2q13 in colorectal tumors (P = 0.03, FDR = 0.09). Chromosome conformation capture analysis identified interactions between the HOXD9 promoter and risk-associated SNPs at 2q31.1. Overexpressing HOXD9 in MOC cells augmented the neoplastic phenotype. These findings provide the first evidence for MOC susceptibility variants and insights into the underlying biology of the disease.

Drug Sensitivity Testing in Cytoreductive Surgery and Intraperitoneal Chemotherapy of Pseudomyxoma Peritonei

Background

Cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) is an established therapy for pseudomyxoma peritonei (PMP). However, the role of IPC is unclear. By ex vivo assessment of PMP tumor cell sensitivity to cytotoxic drugs, we investigated the basis for IPC drug selection and the role of IPC in the management of PMP.

Methods

Tumor cells were prepared by collagenase digestion of tumor tissue from 133 PMP patients planned for CRS and IPC. Tumor cell sensitivity to oxaliplatin, 5FU, mitomycin C, doxorubicin, irinotecan, and cisplatin was assessed in a 72-h cell-viability assay. Drug sensitivity was correlated to progression-free survival (PFS) and overall survival (OS).

Results

Samples from 92 patients were analyzed successfully. Drug sensitivity varied considerably between samples. Peritoneal mucinous carcinomatosis (PMCA), compared with PMCA intermediate or disseminated peritoneal adenomucinosis, was slightly more resistant to platinum and 5FU and tumor cells from patients previously treated with chemotherapy were generally less sensitive than those from untreated patients. Multivariate analysis showed patient performance status and completeness of CRS to be prognostic for OS. Among patients with complete CRS (n = 61), PFS tended to be associated with sensitivity to mitomycin C and cisplatin (p ≈ 0.06). At the highest drug concentration tested, the hazard ratio for disease relapse increased stepwise with drug resistance for all drugs.

Conclusions

Ex vivo assessment of drug sensitivity in PMP provides prognostic information. The results suggest a role for IPC as therapeutic adjunct to CRS and for individualization of IPC by pretreatment assessment of drug sensitivity.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-015-4675-0) contains supplementary material, which is available to authorized users.