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"

Classification of and cytoreductive surgery for low-grade appendiceal mucinous neoplasms

BACKGROUND

Low-grade appendiceal mucinous neoplasm (LAMN) is a precursor lesion for pseudomyxoma peritonei (PMP), which, if treated suboptimally, may later disseminate throughout the abdominal cavity. The role of cytoreductive surgery for these relatively early lesions is unclear.

METHODS

Clinicopathological details and treatment outcomes of patients with a LAMN and disease limited to the appendix or immediate periappendiceal tissues, referred to a national treatment centre between 2002 and 2009, were evaluated prospectively.

RESULTS

Of 379 patients with a diagnosis of PMP, 43 (median age 49 years) had LAMNs localized to the appendix and periappendiceal tissue. Thirty-two patients initially presented with symptoms of acute appendicitis or right iliac fossa pain. Two distinct lesions were identified: type I (disease confined to the appendiceal lumen) and type II (mucin and/or neoplastic epithelium in the appendiceal submucosa, wall and/or periappendiceal tissue, with or without perforation). Type I lesions were managed by a watch-and-wait surveillance policy with serial measurement of tumour markers and computed tomography in 14 of 16 patients. Seventeen of 27 patients with type II lesions underwent risk-reducing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with low morbidity. After a median follow-up of 40 months, there was no disease progression in either treatment pathway.

CONCLUSION

This study identified two LAMN subtypes. Type II lesions have pathological features of increased risk for dissemination and should be considered for risk-reducing cytoreductive surgery.

Intraductal papillary mucinous neoplasm (IPMN) with extra-pancreatic mucin: a case series and review of the literature

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is an increasingly recognized pancreatic neoplasm characterized by excessive mucin secretion by ductal epithelial cells resulting in a cystic dilation of the pancreatic duct.

AIM

The objective of this study was to review Thomas Jefferson University's experience and the literature to determine the significance of extra-pancreatic mucin when associated with an IPMN.

RESULTS

A retrospective analysis at our institution revealed only two cases of IPMN associated with extra-pancreatic mucin, which were classic IPMNs with rupture of the pancreatic duct and peritoneal mucin spillage. This specific finding is not previously described, although is assumed as five cases were reported in the literature with IPMN and mucin extension demonstrated by pseudomyxoma peritonei (PMP). We propose IPMN of the pancreas may be grossly compared to a mucocele of the appendix, as both are characterized by excessive secretion of mucin by ductal epithelial cells. A morbid complication of a mucocele is PMP. The presence of extra-pancreatic mucin with an IPMN could present a rare but important marker of the eventual seeding of tumor outside the primary IPMN. This has been documented with cases of iatrogenic spilling of pancreatic mucin, as well as multiple cases of IPMN associated with pseudomyxoma peritonei.

CONCLUSIONS

At this time, there is scant reporting and consensus for the treatment of IPMN with extra-pancreatic mucin.

[Peritoneal pseudomyxoma presenting as ascites in a patient with cirrhosis]

We present the case of a cirrhotic patient with ascites and an albumin gradient of less than 1.1 g/dl. After endoscopic tests, including upper gastrointestinal endoscopic ultrasound-guided fine-needle aspiration, exploratory laparoscopy was performed to provide the diagnosis, revealing mucin throughout the peritoneal cavity and nodules on the parietal and visceral peritoneum. Histopathological analysis established the diagnosis as peritoneal pseudomyxoma. This uncommon entity, which has a poor prognosis without treatment, is most frequently associated with mucinous tumors of the appendix, and secondly, with tumors of the ovary.

Early postoperative intraperitoneal chemotherapy following cytoreductive surgery for appendiceal mucinous neoplasms with isolated peritoneal metastasis

BACKGROUND

Although cytoreductive surgery and intraperitoneal chemotherapy have been advocated as standard treatment for appendiceal neoplasms with isolated peritoneal metastasis, the optimal method of chemotherapy administration has not been established. At our institution, patients undergoing complete cytoreduction in this setting typically receive multiple cycles of early postoperative intraperitoneal chemotherapy.

OBJECTIVES

The aim of this study was to describe patients with appendiceal neoplasms and peritoneal dissemination treated with complete cytoreductive surgery and early postoperative intraperitoneal chemotherapy and to document associated time to progression and morbidity.

DESIGN

This is a retrospective study at a single specialty institution. Hospital and departmental databases were searched for patients presenting with primary appendiceal neoplasms undergoing cytoreductive surgery, placement of intraperitoneal port, and subsequent intraperitoneal chemotherapy from June 1995 to September 2009.

SETTINGS

This study was conducted at Memorial Sloan-Kettering Cancer Center.

PATIENTS

We identified 50 patients (30 female), median age 48 (range, 26-66) who met the criteria.

INTERVENTIONS

Cytoreductive surgery, placement intraperitoneal port, and intraperitoneal chemotherapy were performed.

RESULTS

All patients underwent intraperitoneal catheter placement after complete cytoreductive surgery, followed by a median of 4 cycles (range, 1-9) intraperitoneal 5-fluoro-2'-deoxyuridine (1000 mg/m daily for 3 days) plus leucovorin (240 mg/m). The median hospital length of stay was 9 days (maximum, 29). Thirty-four percent of the patients experienced complications; 12% experienced major complications (3 abdominal abscesses, 1 deep vein thrombosis, 1 abdominal hemorrhage, and 1 intraperitoneal port malfunction). There were no 30-day mortalities. Five-year recurrence-free interval was observed in 43%. Among 23 patients with recurrence, 18 had a recurrence only within the peritoneum. The median overall survival was 9.8 years.

LIMITATIONS

This is a retrospective study. Many patients had surgery first at other institutions; therefore, pathologic examination of resected material was not possible in every case. Other factors possibly impacting time to recurrence (ie, preoperative chemotherapy, duration between onset of disease and presentation to our institution) varied among patients and were not controlled for. In the absence of a control arm undergoing complete cytoreduction without early postoperative intraperitoneal chemotherapy, we did not ascertain whether intraperitoneal chemotherapy confers additional benefit.

CONCLUSIONS

Cytoreductive surgery plus multiple cycles of early postoperative intraperitoneal chemotherapy is safe, achieving survival results similar to published outcomes of other protocols (including hyperthermic intraperitoneal chemotherapy). Prospective trials are warranted to compare various methods of intraperitoneal chemotherapy in this setting.

Critical role of hyperthermic intraperitoneal chemoperfusion in the treatment of a patient with Pseudomyxoma peritonei

The role of hyperthermic intraperitoneal chemoperfusion (HIPEC) in the treatment of Pseudomyxoma peritonei is debated by clinicians. We report the case of a patient who had multiple episodes of short-interval disease recurrence following debulking surgery, and only achieved long-term remission with the addition of HIPEC. A review of the relevant literature is presented.

Systemic chemotherapy and surgical cytoreduction for poorly differentiated and signet ring cell adenocarcinomas of the appendix

BACKGROUND

Poorly differentiated and signet ring cell adenocarcinomas of the appendix represent a subset with aggressive tumor biology and poor outcomes with few studies evaluating the impact of systemic chemotherapy and cytoreductive surgery (CRS).

PATIENTS AND METHODS

A retrospective chart review of patients with either poorly differentiated and signet ring cell appendiceal adenocarcinomas was completed from 1992 to 2010.

RESULTS

One hundred forty-two patients were identified. Seventy-eight patients with metastatic disease received chemotherapy. Radiographic response was 44%, median progression-free survival (PFS) was 6.9 months, and median overall survival (OS) was 1.7 years. In multivariate analysis, response to chemotherapy [hazard ratio (HR) 0.5; P = 0.02] predicted improved PFS, and complete CRS (HR 0.3; P = 0.004) predicted improved OS. Patients who underwent complete CRS (n = 26) had a median relapse-free survival (RFS) of 1.2 years and a median OS of 4.2 years. In multivariate analysis for this subset, complete cytoreduction score of 0 was significantly correlated with improved RFS (HR 0.07; P = 0.01) and OS (HR 0.02; P = 0.01).

CONCLUSIONS

Systemic chemotherapy appears to be a viable treatment option for patients with metastatic poorly differentiated and signet ring cell appendiceal adenocarcinomas. Complete CRS is associated with improved RFS and OS, though part of this benefit likely reflects the selection of good tumor biology.

Early recurrence of pseudomyxoma peritonei following treatment failure of cytoreductive surgery and perioperative intraperitoneal chemotherapy is indicative of a poor survival outcome

BACKGROUND

The aim of this study was to identify predictors of early recurrence to optimize outcomes.

METHODS

A comparison of clinicopathological factors between patients who developed early recurrence (≤12 months) and late recurrence (>12 months) was performed to identify predictors of treatment failure through univariate and multivariate analyses. Survival parameters were estimated using the Kaplan-Meier method.

RESULTS

A total of 113 patients with a median PCI of 24 (range, 2-39) underwent cytoreductive surgery. The median progression-free and overall survival was 48 and 104 months, respectively. Multivariate analysis identified prior operations >1, ≥10 units of fresh frozen plasma (FFP) transfusion, incomplete cytoreduction and not undergoing definitive cytoreductive surgery within 12 months of diagnosis as predictors for disease recurrence. Twenty of 41 patients (49%) developed early recurrence. The median overall survival of patients who developed early recurrence was 38 months and in patients who did not develop early recurrence was 97 months (P = 0.002). Subgroup analysis of patients with recurrence identified the male gender (P = 0.028), elevated CA 125 (P = 0.037), having elevated carcinoembryonic antigen (CEA), CA 125 and CA 19-9 (P = 0.029), peritoneal cancer index >25 (P = 0.020), incomplete cytoreduction (P = 0.020), >6 units of blood transfusion (P = 0.020) and >10 units of FFP transfusion (P = 0.009) as factors associated with early recurrence.

CONCLUSION

Early recurrence of pseudomyxoma peritonei occurs despite achieving high rates of oncologically optimal cytoreduction. The clinicopathologic factors associated with early recurrence identified in this study may inform us about patients at greatest risk of treatment failure during the post cytoreduction follow-up.

Morphological subtypes of ovarian carcinoma: a review with emphasis on new developments and pathogenesis

Ovarian carcinomas comprise a heterogeneous group of neoplasms, the four most common subtypes being serous, endometrioid, clear cell and mucinous. In recent years, our understanding of the underlying pathogenesis and initiating molecular events in the different tumour subtypes has greatly increased, and although ovarian carcinoma is often considered clinically as one disease, there is now a much greater realisation that the various subtypes have a different natural behaviour and prognosis. At present, adjuvant therapy is mainly dependent upon tumour stage and grade rather than type; however, this is likely to change in the future with the development of new chemotherapeutic agents and targeted therapies and clinical trials are necessary to evaluate the efficacy of different agents in clear cell, mucinous and low grade serous carcinomas, neoplasms which are considered relatively resistant to traditional chemotherapeutic regimes. In this review, the major subtypes of ovarian carcinoma are discussed. It is now firmly established that there are two distinct types of ovarian serous carcinoma, low grade and high grade, the former being much less common and arising in many cases from a serous borderline tumour. Low grade and high grade serous carcinoma represent two distinct tumour types with a different underlying pathogenesis rather than low grade and high grade variants of the same neoplasm. Both are usually advanced stage (stage III or IV) at diagnosis. B-raf and k-ras mutations are important molecular events in low grade serous carcinomas while high grade serous carcinomas are almost always associated with TP53 mutation. There is now emerging and compelling evidence that many high grade serous carcinomas (by far the most common subtype of ovarian carcinoma) actually arise from the epithelium of the distal fallopian tube. Future studies regarding the initiating molecular events in the development of this aggressive neoplasm should concentrate on this site. Primary ovarian mucinous carcinomas are uncommon, almost always unilateral and stage I, and largely of so-called intestinal or enteric type. Most arise in a stepwise manner from a pre-existing mucinous cystadenoma and mucinous borderline tumour. Endometrioid and clear cell carcinomas typically present as low stage neoplasms and in many, or most, cases arise from endometriosis; the former are usually well differentiated and there is now evidence that the majority of neoplasms reported in the past as high grade endometrioid carcinoma are of serous type. WT1 is useful in this regard since it is a relatively specific marker of a serous phenotype. It is recommended that different subtypes of ovarian carcinoma are graded using different systems rather than employing a universal grading system.

Mucinous Neoplasms of the Appendix and Peritoneum

Context.—Appendiceal mucinous neoplasms are considered enigmatic tumors of unpredictable biologic potential. Their importance lies in their potential to spread to the peritoneum and viscera in the form of gelatinous mucin deposits. Extra-appendiceal spread of these tumors is the most common etiology of pseudomyxoma peritonei, which is a descriptive term encompassing a number of neoplastic and nonneoplastic peritoneal disorders. Many studies aimed at evaluating the biologic importance of appendiceal mucinous neoplasms and pseudomyxoma peritonei have employed inconsistent histologic criteria for their diagnosis and descriptive terminology for their classification. As a result, appendiceal mucinous neoplasms and associated peritoneal disease represents one of the most confusing and controversial areas in gastrointestinal pathology.

Objectives.—To summarize the literature regarding the biologic potential of appendiceal mucinous neoplasms and pseudomyxoma peritonei and to discuss the similarities and differences between proposed systems for their classification.

Data Sources.—Literature review and case-derived material.

Conclusions.—Many studies have contributed to an increased understanding of the natural progression of mucinous neoplasms of the appendix and peritoneum, and the adoption of a uniform reporting system, as advocated by the American Joint Committee on Cancer and the World Health Organization, will facilitate clear communication among pathologists and clinical colleagues.

CT, MRI and PET imaging in peritoneal malignancy

Imaging plays a vital role in the evaluation of patients with suspected or proven peritoneal malignancy. Nevertheless, despite significant advances in imaging technology and protocols, assessment of peritoneal pathology remains challenging. The combination of complex peritoneal anatomy, an extensive surface area that may host tumour deposits and the considerable overlap of imaging appearances of various peritoneal diseases often makes interpretation difficult. Contrast-enhanced multidetector computed tomography (MDCT) remains the most versatile tool in the imaging of peritoneal malignancy. However, conventional and emerging magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT techniques offer significant advantages over MDCT in detection and surveillance. This article reviews established and new techniques in CT, MRI and PET imaging in both primary and secondary peritoneal malignancies and provides an overview of peritoneal anatomy, function and modes of disease dissemination with illustration of common sites and imaging features of peritoneal malignancy.

Pseudomyxoma peritonei treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: results from a single centre

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare, slowly progressive disease whose prognosis depends primarily on the completeness of cytoreduction. The value of intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) and of additional factors predicting long-term outcome and disease-free survival (DFS) remains poorly understood. This study aims to analyse survival rates and prognostic factors in patients undergoing maximal cytoreduction and HIPEC.

METHODS

Thirty patients were selected from a prospective database of records for patients undergoing cytoreduction and HIPEC with mitomycin C or paclitaxel. Overall survival (OS), DFS, and the prognostic factors influencing them, were examined using multivariate analysis.

RESULTS

Median follow-up was 44 months (range, 8-144). Histological classification of PMPs was DPAM in 6/30 of cases, PMCA-I in 10/30 and PMCA in 14/30. Complete cytoreduction (CC-0 and CC-1) was achieved in 28/30 of patients and CC-2 in 2/30. Median OS was 111 months (range 0-230) and five-year OS rate was 67%. Median DFS was 53.5 months (range 0-120) and 5-year DFS rate was 44%. Incomplete cytoreduction, lymph node involvement and PCI>20 were associated with poor prognosis for OS, while lymph node involvement, elevated CA-125 levels, unfavourable histology and previous chemotherapy were associated with poor outcomes for DFS. There was morbidity of Grade 3 or higher in 9/30. Post-operative mortality occurred in 1 case.

CONCLUSION

Cytoreduction plus peritonectomy procedures combined with HIPEC is a safe treatment and could improve survival rates. Since the optimal cytoreduction is the primary prognostic factor, patients should be centralised under the care of experienced teams.

Long-term follow-up in the treatment of peritoneal carcinomatosis

BACKGROUND

The objective of this study was to report a long-term survival analysis of a phase II protocol of cytoreductive surgery (CS) and heated intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal carcinomatosis (PCs).

METHODS

Between 2000 and 2008, 101 consecutive patients were treated with CS, HIPEC and early postoperative intraperitoneal chemotherapy using a standardized protocol. Disease recurrence and mortality data were collected prospectively. Primary outcomes were median, 3-year, and 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

The median age was 49 years (range, 18-77 years), and the majority (82%) had complete CS with no gross residual cancer. Tumor types included appendiceal (n = 58), colorectal (n = 31), and other (n = 12). Median follow-up was 28 months (range, 0-119 months), with minimum of 24 months among survivors. For appendiceal tumors, median DFS was 34 months (range, 0-119 months) and OS has not yet been defined. Three-year and 5-year DFS was 48% and 42%, respectively, and 3-year and 5-year OS was 76% and 62%, respectively. For colorectal carcinomatosis, median disease-free and OS was 9 months (range, 0-87 months) and 27 months (range, 0-87 months), respectively. Three-year and 5-year DFS was 34% and 26%, respectively, and 3-year and 5-year OS was 38% and 34%, respectively.

CONCLUSIONS

Long-term survival with regional treatment of PC from appendiceal or colorectal primary tumors with CS and HIPEC is achievable.

Immunohistochemistry in the distinction between primary and metastatic ovarian mucinous neoplasms: Table 1

The distinction between a primary and metastatic mucinous carcinoma within the ovary may be problematic. In most cases, the distinction can be made by careful pathological examination encompassing both the gross and microscopic findings and taking into account the distribution of the disease. However, immunohistochemistry may be of value in certain scenarios. In this review, I discuss the value of markers in the distinction between primary ovarian mucinous neoplasms and metastatic mucinous carcinomas from the colorectum, appendix, pancreas, biliary tract, stomach and cervix, the most common primary sites which give rise to metastatic mucinous carcinoma within the ovary. There is a significant degree of immunophenotypic overlap between primary ovarian mucinous neoplasms and metastatic mucinous carcinomas from the gastrointestinal tract, especially the upper gastrointestinal type; this is because most primary ovarian mucinous carcinomas and borderline tumours are of so-called intestinal or enteric type and exhibit some degree of positivity with enteric markers. Mullerian type primary ovarian mucinous neoplasms also exist and exhibit distinct immunohistochemical differences to the more common intestinal type.

Pseudomyxoma peritonei: An uncommon tumor

Pseudomyxoma peritonei is a poorly understood and uncommon tumor that is known for its production of mucin in the abdominal cavity and mucinous implants, diffusely involving the peritoneal surfaces. A 60-year-old female presented to us with post-op complaints of diffuse abdominal pain and distension. On work-up, she was diagnosed as a case of Pseudomyxoma peritonei (with residual disease). She received chemotherapy in the form of oral capecitabine for residual disease. She was totally asymptomatic till the last follow-up. This case is being reported on account of its rarity and to emphasize a simple alternative treatment option as compared to the standard one.

Psuedomyxoma peritonei secondary to adenocarcinoma of the cecum

Pseudomyxoma peritonei is a rare progressive disease. Patients commonly present with a picture of acute appendicitis or with increasing abdominal girth. We present a case of a 71 year old man who presented with right iliac fossa pain, fever and vomiting. His abdominal examination revealed right iliac fossa mass which was confirmed radiologically. Diagnostic laparoscopy showed jelly like material along with a right iliac fossa mass. The aspirate was negative for malignancy initially. Due to persistance and progression of his disease he underwent right hemicolectomy. Histopathological diagnosis showed moderately differentiated adenocarcinoma of the cecum Duke’s C2.

Prognostic significance of lymph node metastases in patients with high-grade appendiceal cancer

BACKGROUND

In treating high-grade appendiceal cancer, appropriate patient selection for cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) is essential. The effect of lymph node (LN) status on survival is not clear. We hypothesize that LN metastases negatively affect long-term survival.

METHODS

Retrospective analysis of peritoneal mucinous carcinomatosis (PMCA) patients from a prospective database was conducted. Using Kaplan-Meier survival curves and Cox proportional hazards ratio analysis, the effect of LN status, completeness of cytoreduction (CC), and peritoneal cancer index (PCI) was studied.

RESULTS

Of 134 patients with appendiceal cancer who underwent CRS/HIPEC, 77 (57%) had PMCA. Mean follow-up was 22 (range, 3-90) months. Overall survival (OS) was 88, 56, and 40% for 1, 3, and 5-year, respectively. Thirty-four patients (44%) had LN metastases, 23 of whom (68%) had CC, whereas in LN negative patients 35 of 43 (81%) had CC (p = 0.191). PCI ≥ 20 was seen in 23 of 34 patients (68%) with LN metastases and 29 of 43 (67%) without metastases (p = 0.191). Five-year OS for patients with LN metastases was 11% compared with 76% for LN negative (p < 0.001). Among patients with complete cytoreduction, 5-year OS for LN positive vs. negative was 21 and 73%, respectively (p = 0.002). On multivariate regression analysis of LN status, CC score and PCI, the following hazard ratios were obtained: 3.4 (95% confidence interval (CI), 1.3-9.0), 2.6 (95% CI, 1.03-6.7), and 2.8 (95% CI, 0.8-10.4), respectively.

CONCLUSIONS

Patient selection for CRS/HIPEC should take into consideration LN status, but it should not be a contraindication if preoperative evaluation revealed a high likelihood of complete cytoreduction.

Low-grade appendiceal mucinous neoplasm with disseminated peritoneal adenomucinosis involving the uterus, mimicking primary mucinous endometrial adenocarcinoma: a case report

We present a patient with a low-grade appendiceal mucinous neoplasm, resulting in disseminated peritoneal adenomucinosis (pseudomyxoma peritonei) with uterine involvement, and mimicking primary mucinous endometrial adenocarcinoma. On immunohistochemistry, neoplastic glands were cytokeratin 7-negative and cytokeratin 20-positive, indicating a gastrointestinal origin rather than a primary ovarian mucinous neoplasm. A diagnosis of uterine metastasis of appendiceal origin was made, based on the constellation of clinicopathological findings, that is, preceding appendiceal neoplasm, peritoneal involvement, absence of coexisting prototypical endometrioid adenocarcinoma or endometrial hyperplasia. The patient underwent hysterectomy and there was no evidence of disease progression at the 12-month follow up. This suggested the indolent nature of this particular neoplasm, despite its advanced stage.

The role of cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) in patients with high-grade appendiceal carcinoma and extensive peritoneal carcinomatosis

BACKGROUND

Patients with peritoneal mucinous carcinomatosis (PMCA) of appendiceal origin and extensive disease are commonly advised against CRS/HIPEC. We hypothesize that CRS/HIPEC is a beneficial treatment for this group.

METHODS

Retrospective analysis of 134 patients with appendiceal cancer treated with CRS/HIPEC was performed from a prospective database. Extent of disease, measured by peritoneal cancer index (PCI), was related to completeness of cytoreduction (CC), lymph node (LN) status, and prior surgery score (PSS). Overall survival (OS) was estimated by Kaplan-Meier curves. Test differences were calculated using log-rank test.

RESULTS

A total of 77 patients (57%) had PMCA. Mean follow-up was 22 months with a median of 18 months. OS was 88%, 56%, and 40% for 1, 3, and 5 years, respectively. 68% had PCI ≥ 20. LN metastasis was found in 44% of patients in PCI ≥ 20 and PCI < 20 groups. 73% and 60% of patients had PSS of 2 or 3 in PCI ≥ 20 and PCI < 20 groups, respectively (P = .196). Complete cytoreduction was achieved in 65% of PCI ≥ 20 group and 96% of PCI < 20 group (P = .004). With complete cytoreduction, the 5-year OS was 45% in PCI ≥ 20 group and 66% in PCI < 20 group (P = .139). 18 of 19 patients with incomplete cytoreduction had PCI ≥ 20, with 3- and 5-year OS of 27% and 0%. Hazard ratios (by Cox regression) were 2.8 (95% confidence interval [95% CI] 0.8-10.2) and 3.6 (95% CI 1.5-8.8) for PCI < 20 and complete cytoreduction, respectively.

CONCLUSIONS

Meaningful long-term survival could be achieved in patients with PMCA even with extensive peritoneal disease. PCI ≥ 20 should not be used as an exclusion criterion when selecting these patients for CRS/HIPEC, and every effort should be made to achieve complete cytoreduction.

Subperitoneal adenomucinosis following proctocolectomy for ulcerative colitis

Adenomucinosis is a rare condition characterized by accumulation of large volumes of mucin, typically related to mucinous neoplasms of the appendix within the peritoneal space. Extraperitoneal adenomucinosis is an uncommon variant where mucin accumulates outside the peritoneal space and usually arises following surgery for mucinous appendiceal neoplasms. This is a case of subperitoneal adenomucinosis resulting from retention of a small fragment of rectal mucosa following proctocolectomy for ulcerative colitis 16 years prior. The patient presented with a slow-growing boggy perineal mass. Contrast-enhanced magnetic resonance imaging (MRI) showed the mass to be localized to the pelvis, without solid enhancing components, and correctly facilitated local surgical excision without the risk of peritoneal dissemination and accurately predicted benignity.

Surgical cytoreduction and survival in appendiceal cancer peritoneal carcinomatosis: an evaluation of 46 consecutive patients

BACKGROUND

Surgical cytoreduction and intraperitoneal chemotherapy is increasingly accepted as an effective treatment modality for mucinous appendiceal neoplasm. For the majority of patients with low-grade histology, outcomes have been encouraging. The survival of patients with neoplasms of malignant character is protracted and this study was designed to evaluate the effectiveness of this surgical strategy on outcomes.

METHODS

Forty-six consecutive patients with mucinous and nonmucinous appendiceal cancer with peritoneal dissemination were studied. Clinicopathological and treatment related factors were obtained from a prospective database. The study's end points of disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method.

RESULTS

The median DFS and OS after cytoreduction were 20.5 and 56.4 months respectively. Five-year overall survival rate was 45%. Five independent factors associated with DFS and OS were identified through a multivariate analysis: age (DFS p = 0.001, OS p = 0.002), completeness of cytoreduction (DFS p = 0.001, OS p = 0.003), previous chemotherapy treatment (DFS p = 0.021), CA 199 levels (DFS p = 0.013), and tumor grade (OS p = 0.005).

CONCLUSIONS

Cytoreductive surgery and intraperitoneal chemotherapy may achieve long-term survival in appendiceal malignancies with peritoneal dissemination for which the predictors of outcomes identified through this study may tailor the disease management to commit patients early toward this successful surgical strategy.

Mucinous carcinomas of the ovary and colorectum: different organ, same dilemma

Mucinous carcinomas are uncommon histological types that affect several organ sites. Primary mucinous carcinomas of the ovary are distinct from other ovarian carcinoma types, but they can pose a particular challenge for correct diagnosis from metastases, which most usually originate from the colorectum. Correct diagnosis is the mainstay of treatment, because standard practice states that protocols are tailored to the primary organ site. Little is known of mutational alterations in primary and metastatic mucinous carcinomas of the ovary, and few markers exist that can discriminate between them. We reviewed commonalities between ovarian and colorectal mucinous carcinomas with respect to aetiology, molecular alterations, differential diagnosis, and implications for treatment. Although primary mucinous carcinomas of the ovary and colorectum share similar mutational patterns and unfavourable outcomes at advanced stage, compared with their non-mucinous counterparts, important differences exist with respect to mucin localisation and specific molecular alterations. Technologies--eg, next-generation sequencing--could aid identification of additional driver molecular changes that will help clarify the relation between mucinous carcinomas from different organ sites. Perhaps, then, we can consider moving towards testing and adoption of therapeutic approaches tailored to molecular characteristics of mucinous carcinomas, irrespective of organ site, so patients' survival can be optimised.

Pseudomyxoma peritonei: disseminated peritoneal adenomucinosis variant

Pseudomyxoma peritonei (PMP) is a rare disease and even after advances in its understanding and management it often has a protracted course and multiple recurrences despite aggressive surgery and intraperitoneal chemotherapy. The current preferred treatment of ultraradical surgery and hyperthermic intraperitoneal chemotherapy is associated with considerable morbidity and significant mortality. With better understanding we know that the prognosis of the disease is dependent on the degree of total excision of the disease and type of histology. The authors propose the need to be selective in applying aggressive treatment regimens in all patients with PMP regardless of factors like age, low malignant variants and expected morbidities. Our patient had a good outcome with a conservative approach. However, large studies are needed before reaching a conclusion.

Clinical presentation of pseudomyxoma peritonei

BACKGROUND AND AIMS

We analysed the clinical symptoms and signs of pseudomyxoma peritonei (PMP), a rare syndrome affecting one to two persons per million annually. Presumably, patients with PMP would benefit from early diagnosis. This study was conducted to further characterise the manifestations of PMP.

MATERIAL AND METHODS

We performed a retrospective chart review of a consecutive series of 82 PMP cases at the Helsinki University Central Hospital from June 1984 to September 2009. We then analysed the patients' characteristics, clinical manifestations, indications for surgery and preoperative radiological investigations.

RESULTS

The study involved 53 women (65%) and 29 men (35%). The preponderance of women was statistically significant (p = 0.008). Abdominal pain was the most common chief complaint in the initial evaluation with 23% of the cases. The subsequent more common chief complaints were acute abdomen with 21%, increased abdominal girth with 17%, coincidental diagnosis with 13%, other reasons with 13% and newly onset hernia with 12% of the cases. Suspected ovarian tumour was the most common cause for surgery overall, with 26 of 82 initial operations (32%). Of the 82 initial operations, 23 (28%) were performed with a suspicion or diagnosis of PMP. Computed tomography had a sensitivity of 51% in recognising PMP.

CONCLUSIONS

While only 28% of patients underwent initial surgery for presumed PMP, the accuracy of preoperative diagnostics was modest. Diagnostics of PMP is challenging due to the mimicking nature of the disease. In case of indistinct intra-abdominal tumour, we recommend, careful patient examination prior to the initial surgery, when possible.

Metastatic Neoplasms Involving the Ovary

In this review, ovarian metastatic carcinomas from various sites, as well as other neoplasms secondarily involving the ovary, are discussed. As well as describing the morphology, the value of immunohistochemistry in distinguishing between primary and metastatic neoplasms in the ovary is discussed. While immunohistochemistry has a valuable role to play and is paramount in some cases, the results should be interpreted with caution and with regard to the clinical picture and gross and microscopic pathologic findings.

Nonserous Ovarian Epithelial Tumors

This review covers the group of relatively uncommon nonserous ovarian epithelial tumors. The authors focus on the group's distinctiveness from the much more common serous tumors and show the similarities across entities. Diagnostic criteria that separate the different entities are currently being debated. Particular problems include the reproducible diagnosis of high-grade endometrioid, transitional cell, mixed epithelial and undifferentiated carcinomas. Furthermore, despite recognition that most malignant mucinous tumors involving ovary represent metastases from extraovarian primary sites, many misdiagnoses still occur. The authors discuss their rationale behind their opinions about these problematic topics.

Application of advanced multimodality care to pseudomyxoma peritonei patient: report of first patient treated at a tertiary center

Pseudomyxoma peritonei following dissemination of appendicealmucinous neoplasms is slowly progressive but inevitably a lethal condition. It is locally invasive and does not lead to lymph node or distant metastasis making it amenable for more radical procedures. We present a case of pseudomyxoma peritonei treated by Cytoreductive surgery(CRS)and heated intraperitoneal chemotherapy(HIPEC) with Mitomycin C (12.5mg/m2 ) at 41.50 C. This was followed by five cycles of early postoperative intraperitoneal chemotherapy (EPIC) with 5FU (650 mg/m2) over 5 days. Patient underwent standard Peritonectomy procedure combined with resection of gallbladder, Spleen, subtotal colectomy and resection of part of small bowel. Blood loss during theprocedure was 4000ml. Histopathology revealed Pseudomyxoma peritonei (hybrid type). The patient recuperated well and was discharged and now is living a productive life. Peritonectomy with perioperative intraperitoneal chemotherapy is the current standard of treatment for appendiceal tumors with peritoneal dissemination which offers a hope of disease free long survival in such patients.

Neoadjuvant FOLFOX chemotherapy in 34 consecutive patients with mucinous peritoneal carcinomatosis of appendiceal origin

BACKGROUND

A treatment option for patients with peritoneal mucinous carcinomatosis (PMCA) from an appendiceal neoplasm is cytoreductive surgery and perioperative intraperitoneal chemotherapy. Also, these patients are recommended for systemic chemotherapy using an oxaliplatin and 5-fluorouracil (FOLFOX) regimen. A major question concerns the proper timing (neoadjuvant vs. adjuvant) of the systemic chemotherapy.

METHODS

In January of 2005 a prospective study was initiated to routinely treat patients with peritoneal dissemination of a mucinous adenocarcinoma of the appendix with neoadjuvant chemotherapy using FOLFOX. All patients had a clinical, CT, intraoperative, and histopathological assessment of chemotherapy effects. The study was closed in July of 2009.

RESULTS

Thirty-four consecutive patients were available for evaluation. In the clinical evaluation and CT evaluation, 24 (71%) and 22 (65%), respectively, had stable disease on chemotherapy. By intraoperative examination 17 (50%) patients were observed to have progressed. By histopathology seven had a partial response and three patients a complete response (29%).

CONCLUSIONS

In these carcinomatosis patients clinical and CT assessment of response to neoadjuvant chemotherapy seldom provided useful data over this short time period. Intraoperative findings indicated progression in 50% of patients. By histopathology, 29% of patients had a response.

Use of FDG-PET Imaging for Patients with Disseminated Cancer of the Appendix

The goal of this study is to evaluate the use of positron emission tomography (PET) in evaluation of patients with peritoneal dissemination of carcinoma of appendiceal origin (PDA). Thirty-three patients with PDA, who had preoperative PET or PET/CT imaging, were analyzed. Using operative, pathology, and PET ± CT data, presence or absence of disease in each abdominal quadrant was noted and the use of 18fluoro-deoxy-glucose (FDG) PET for each quadrant was evaluated. The mean age was 52, and there were 17 males; 58 per cent had low-grade lesions. PET was positive in only 35 per cent of cases overall (30 and 41% sensitivity for low-grade and high-grade, respectively). PET without CT sensitivity for low-grade and high-grade lesions was 21 and 8 per cent, respectively. PET imaging has limited use for patients with PDA. We do not recommend the use of FDG-PET for patients with PDA from cancer of the appendix.

Epithelial neoplasms of the appendix

CONTEXT

The appendix gives rise to an array of epithelial neoplasms showing glandular or neuroendocrine differentiation, and some tumors with elements of both cell types. Although some appendiceal neoplasms resemble their counterparts in the small and large intestines (conventional adenocarcinoma and carcinoid tumor), the appendix also gives rise to relatively unique entities including mucinous neoplasms and goblet cell carcinoid tumors, which present a challenge in pathologic classification and clinical management.

OBJECTIVE

To review clinical and diagnostic issues for 3 pathologic types of epithelial neoplasms of the appendix: (1) adenocarcinoma, with specific focus on mucinous neoplasm; (2) goblet cell carcinoid tumor and associated adenocarcinoma; and (3) typical carcinoid tumor.

DATA SOURCES

Case-derived material and literature review.

CONCLUSIONS

The most important issue in pathologic assessment of epithelial tumors of the appendix is to understand the clinical implications inherent in the diagnosis.

Secondary cytoreduction and perioperative intraperitoneal chemotherapy after initial debulking of pseudomyxoma peritonei: a study of timing and the impact of malignant dedifferentiation

BACKGROUND

Cytoreductive surgery and perioperative intraperitoneal chemotherapy (PIC) is recognized as an effective treatment modality for patients with pseudomyxoma peritonei. This study investigates its role as a secondary definitive treatment procedure after earlier primary treatments.

STUDY DESIGN

Patients with pseudomyxoma peritonei undergoing secondary cytoreduction combined with PIC were identified from a prospective database. Retrospective analysis investigated the outcomes, prognostic factors, critical time points, and impact of malignant dedifferentiation. Survival analysis was performed via the Kaplan-Meier method and compared via the log-rank test.

RESULTS

The median time to progression after secondary cytoreduction was 28 months (95% CI 14 to 41 months), median survival was 97 months (95% CI 82 to 113 months), and 10-year survival was 25%. Median overall survival from initial diagnosis was 17 years and 10-year survival rate was 75%. Forty-five patients remained disease free (63%). Requiring an urgent treatment (waiting time < 60 days) after disease progression (p = 0.045) and having moderate or severe symptoms (p = 0.033) were associated with a shorter time to progression. Improved survival was associated with patients who had low-grade tumors (p = 0.029), and those who required less urgent treatment (wait > 30 days) after disease progression (waiting up to 15 days, p = 0.010; waiting up to 30 days, p = 0.005). Malignant dedifferentiation appeared to affect survival from initial diagnosis (p = 0.062) and after secondary cytoreduction (p = 0.006).

CONCLUSIONS

Secondary cytoreduction with PIC achieves long-term survival. Tumors that undergo malignant dedifferentiation appear to adversely affect survival, and this may support the rationale for early definitive treatment with cytoreduction and PIC.

Survival of patients with pseudomyxoma peritonei treated by serial debulking

AIM

We evaluated the outcome of patients with pseudomyxoma peritonei (PMP) after traditional debulking. PMP is a clinical condition characterized by disseminated intraperitoneal mucinous tumours often accompanied by mucinous ascites derived usually from an appendiceal neoplasm. Patients with PMP have traditionally been treated by serial debulking, but aggressive cytoreduction followed by hyperthermic intraperitoneal chemotherapy is now advocated as standard treatment in PMP.

METHOD

The analysis included 33 consecutive patients with PMP who underwent traditional debulking surgery between June 1984 and August 2008. The patient characteristics and details of the treatment were analysed retrospectively. The primary end-point was survival.

RESULTS

The overall 5- and 10-year survival rates were 67% and 31% respectively. The patients underwent an average of 3.2 +/- 0.4 operations (range 1-10). Of 33 patients, 23 (70%) underwent only 1-3 operations. The 30-day operative mortality rate was 2.7%. However, four patients (12%) seemed to have achieved long-term disease-free survival of more than 5 years.

CONCLUSIONS

The 5-year survival is comparable with results achieved in patients receiving a combination of cytoreductive surgery and intraperitoneal chemotherapy, but in the long term, the latter seems superior.

Mucinous adenocarcinomas with intra-abdominal dissemination: a review of current therapy

Peritoneal carcinomatosis has been considered a terminal disease with a median survival time of 5.2-12.6 months. Systemic chemotherapy and cytoreductive surgery (CRS) have long been used to treat macroscopic disease, with limited success. However, a comprehensive treatment approach involving cytroreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) has evolved into a novel approach for peritoneal carcinomatosis. Surgery removes the primary cancer and any dissemination within the peritoneal cavity and adjuvant HIPEC eradicates macroscopic or microscopic tumor residue, thus reducing the risk for recurrence. This approach offers a new potential treatment option for patients with metastatic disease confined to the peritoneum. The present review provides an update of the most recent data on the current therapy for pseudomyxoma peritonei (PMP) and mucinous colorectal adenocarcinoma (MCA) with metastatic disease confined to the peritoneum.

Appendiceal mucinous neoplasms: controversial issues

Low grade appendiceal mucinous neoplasms can spread to the peritoneum as pseudomyxoma peritonei even though they are not obviously invasive in the appendix. During the past several decades, several problematic issues surrounding this enigmatic tumor have been debated in the literature, including appropriate nomenclature for the appendiceal tumors and their peritoneal metastases. In this article, the most contentious issues in the area of appendiceal mucinous tumors are examined. First, the classification systems that have been proposed for these tumors are compared in the context of whether the appendiceal mucinous tumors are ruptured adenomas or invasive carcinomas. The controversy about the nature of pseudomyxoma peritonei and its classification systems is discussed in the following section. A brief discussion follows that examines the issue of localized pseudomyxoma peritonei and its clinical significance. Next reviewed is the largely resolved controversy about whether ovarian mucinous tumors in this setting are separate primaries or are metastases from the appendiceal tumor. Finally, the controversy about the most effective treatment of patients with pseudomyxoma peritonei is discussed.

Metastasectomy for stage IV colorectal cancer

Metastatic colorectal cancer traditionally has been considered incurable. Over the past 3 decades, however, resection of low-volume hepatic disease has been recognized as beneficial in some cases. More recently, resection of isolated pulmonary metastases has been shown to offer long-term survival in carefully selected patients. Resection of metastases to more unusual sites (ovary, brain, peritoneal cavity) is more controversial; nevertheless, retrospective data suggest that a few patients may be cured with resection of these tumors. In this article, we review the history and current status of metastasectomy in stage IV colorectal cancer.

Establishment and characterization of a murine xenograft model of appendiceal mucinous adenocarcinoma

We describe the clinical, pathologic and molecular characteristics of a xenograft model of metastatic mucinous appendiceal adenocarcinoma. Tumours from patients with mucinous appendiceal neoplasms were implanted in nude mice and observed for evidence of intraperitoneal tumour growth. Morphologic and immunohistochemical features, temporal growth characteristics relative to controls, and loss of heterozygosity (LOH) at multiple chromosomal alleles were assessed in a successfully engrafted tumour. Two of seventeen implanted tumours successfully engrafted and only one mucinous adenocarcinoma propagated throughout the course of the study. The successful xenograft is morphologically similar to the original tumour, produces abundant extracellular mucin and exhibits non-invasive growth on peritoneal surfaces. The temporal growth characteristics of the xenograft tumour relative to controls reveal that tumour burden can be followed indirectly by measuring the weight or abdominal girth of engrafted animals. The cytokeratin, mucin core protein, CDX2, Ki-67 and p53 expression patterns are identical in the xenograft and resected tumour and are consistent with the expected pattern of protein expression for mucinous adenocarcinoma of the appendix. LOH was found in 1 of 10 informative chromosomal loci (chromosome 10p23) in xenograft tumour cells. Although we were unable to engraft a low-grade appendiceal mucinous neoplasm, the engrafted adenocarcinoma will be useful for future evaluation of novel therapeutic strategies directed at mucinous appendiceal adenocarcinoma and evaluation of strategies for treating widespread, bulky, mucinous peritoneal surface neoplasms. Xenograft tumour enrichment can facilitate molecular studies of appendiceal epithelial neoplasia.

Surgical responsibilities in the management of peritoneal carcinomatosis

In the past, cancer surgery for gastrointestinal malignancy focused on clearance (an R-0 resection) and containment (no surgically induced spillage of cancer cells). A new responsibility that cancer surgeons must accept is the knowledgeable prevention or treatment of cancer that disseminates to peritoneal surfaces. Carcinomatosis can be prevented and can be successfully treated using cytoreductive surgery and perioperative chemotherapy.

Mucinous Neoplasms of the Vermiform Appendix

Most epithelial neoplasms of the vermiform appendix are of mucinous type and can be stratified into 3 main diagnostic categories: (1) adenoma, (2) mucinous neoplasms of uncertain malignant potential or low-grade mucinous neoplasm, and (3) adenocarcinoma. Clinically, appendiceal mucinous adenomas and adenocarcinomas may present as right lower abdominal pain mimicking acute appendicitis, a mass, or pseudomyxoma peritonei. Nomenclature currently in use to describe and diagnose mucinous tumors of the appendix, particularly those of low morphologic grade, varies among surgical pathologists and centers, resulting in different histologic and clinical features being attributed to these entities in the literature. It may be of help, as already attempted by some investigators, to simply apply algorithmic parameters for such lesions (grade of the primary lesion, extensiveness and composite of extra-appendiceal involvement, and so forth), instead of adopting rigid classification categories. This approach allows for more objective data to be collected in hopes that it will provide a more nuanced understanding of the clinical behavior of the spectrum of mucinous appendiceal tumors. Remaining focused on histopathologic parameters of the primary and secondary sites of involvement may help in avoiding circular reasoning.

Serrated lesions of the appendix: a morphologic and immunohistochemical appraisal

We performed a histologic and immunohistochemical assessment of 53 noninvasive appendiceal epithelial proliferations, appropriating terminology and using markers shown useful in differentiating serrated colorectal polyps. These were classified as hyperplastic polyp (HP), sessile serrated adenoma (SSA), mixed serrated and adenomatous lesion (MSAL), mucinous cystadenoma (MCA), or conventional adenoma (CAD). Immunohistochemical analysis for cytokeratin (CK) 20, Ki-67, MUC6, and beta-catenin was performed. Diagnoses were as follows: HP, 6; SSA, 12; HP vs SSA, 3; MSAL, 16; MCA, 14; and CAD, 2. All HPs showed expanded (beyond surface) CK20 and expanded or normal (base) Ki-67; 1 was MUC6+. Most SSAs and MSALs were CK20-expanded or expanded with random expression in deep crypts (Ex/I) and Ki-67-expanded, Ex/I (expanded with asymmetry), or normal. All SSAs and 8 of 16 MSALs were MUC6+. CADs were CK20-Ex/I, Ki-67-Ex, and MUC6-; 1 showed nuclear beta-catenin expression. Serrated appendiceal lesions can be categorized using colorectal terminology. MUC6 is associated with SSA morphologic features. Similar immunohistochemical patterns in SSA and MSAL suggest a link between these lesions.

A clinicopathologic analysis of peritoneal metastases of colorectal and appendiceal origin

OBJECTIVE

To predict clinical outcome by classification of peritoneal metastases (PM) of colorectal or appendiceal origin.

BACKGROUND

This study investigates whether standardized histological classification can predict outcome for PM of colorectal or appendiceal origin treated with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

Histology of PM (n = 269) was evaluated by analysis of mitotic activity, atypia, cellularity, and mucinous component. For overall survival (OS) and disease-free survival (DFS) Cox proportional-hazard models were constructed. Covariates included tumor, patient, and treatment characteristics.

RESULTS

PM could be categorized into four groups: low-grade, well-differentiated mucinous tumor (DPAM); intermediated-grade mucinous carcinoma (PMCA-i); high-grade mucinous carcinoma (PMCA); and high-grade nonmucinous carcinoma (PCA). Multivariate analysis showed that histological classification, gender, number of segments affected, completeness of cytoreduction, and HIPEC as primary treatment were significant related to OS and DFS. The 5-year OS was 64% in the DPAM group, 36% in the PMCA group, and 24% in the PCA group. Of PM originating from an appendix tumor, 29% were of non-DPAM type. Of primary colorectal tumors, 37% resulted in mucinous PM, and another 26% of PM of colorectal origin had partly mucinous histology.

CONCLUSION

Histology is a significant predictive factor of OS and DFS in PM treated with surgical cytoreduction and HIPEC. Low-grade PM (DPAM) should be regarded as a separate entity because of its clearly different clinical course. High-grade mucinous PM has significant better prognosis than nonmucinous PM and should thus be distinguished.

Pseudomyxoma peritonei: a French multicentric study of 301 patients treated with cytoreductive surgery and intraperitoneal chemotherapy

OBJECTIVE

To analyze a large series of patients with pseudomyxoma peritonei (PMP) treated with cytoreductive surgery associated with perioperative intraperitoneal chemotherapy (PIC) in 18 French-speaking centers.

PATIENTS AND METHODS

From March 1993 to December 2007, 301 patients with diffuse PMP were treated by cytoreductive surgery with PIC. Complete cytoreductive surgery was achieved in 219 patients (73%), and hyperthermic intraperitoneal chemotherapy (HIPEC) was performed in 255 (85%), mainly during the latter period of the study.

RESULTS

Postoperative mortality and morbidity were 4.4% and 40%, respectively. The mean follow-up was 88 months. The 5-year overall and disease-free survival rates were 73% and 56%, respectively. The multivariate analysis identified 5 prognostic factors: the extent of peritoneal seeding (p=0.004), the center (p=0.0004), the pathologic grade (p=0.03), gender (p=0.02), and the use of HIPEC (p=0.04). When only the 206 patients with complete cytoreductive surgery were considered, the extent of peritoneal seeding was the only significant prognostic factor (p=0.004).

CONCLUSION

This large multicentric retrospective study confirms that cytoreductive surgery combined with PIC (with the use of hyperthermia) should be considered as the gold standard treatment of PMP and should be performed in specialized centers. It underlines the prognostic impact of the extent of peritoneal seeding, especially in patients treated by complete cytoreductive surgery. This prognostic impact appears to be greater than that of the pathologic grade.

Peritoneal carcinomatosis of gastrointestinal origin: natural history and treatment options

BACKGROUND

Peritoneal carcinomatosis (PC) is a challenging consequence of certain malignancies, associated with a poor prognosis and limited treatment options. Generally, PC has been treated similarly to metastatic cancers of the primary tumor, but associated with worse outcomes when compared to other sites of metastatic disease from the same primary tumor site. With supportive care alone, the median survival with PC is 3-6 months. More recently, a limited number of centers have reported success with cytoreductive surgery (CS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in a subset of patients with PC, resulting in improved survival compared with historical controls.

OBJECTIVES

This paper outlines the natural history of PC, and surgical, chemotherapeutic, and combined modality treatment options, with a focus on PC of colorectal (CRC) and appendiceal origin.

RESULTS

At this time, the 'standard' treatment for PC remains incompletely defined. As such, the optimal management strategies for both 'localized' and unresectable disease is unclear. CS + HIPEC is a promising treatment with a significant survival benefit of 10 months over systemic therapy alone demonstrated in a clinical trial of patients with CRC.

CONCLUSION

Well-designed clinical trials need to continue to be offered to improve care and determine the optimal treatment strategies for PC.