Early results of surgery in 123 patients with pseudomyxoma peritonei from a perforated appendiceal neoplasm

Educational Review: Updates on Therapeutic Strategies for Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) commonly presents in advanced stages with metastatic spread to the peritoneal cavity, and outcomes associated with gastric cancer with peritoneal metastasis (GCPM) continue to carry a dismal prognosis. Persistent challenges in the detection of peritoneal metastasis (PM) have resulted in a relative paucity of high-quality data to inform management decisions. Several consensus groups have published recommendations to guide management, including most recently the National Comprehensive Cancer Network guidelines, which now include cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a potential treatment modality in select patients with GCPM. Multiple clinical trials have investigated the use of CRS/HIPEC and other peritoneal-directed therapies, such as intraperitoneal chemotherapy (IPC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC). As high-volume centers work to incorporate such therapies into their practice, ongoing clinical trials are aimed at understanding their efficacy. Recent findings have improved understanding of the mechanisms and pathophysiology underlying GCPM while the discovery of novel targets offers potential for drug development and therapeutic strategies to overcome treatment resistance. This review highlights recent advancements and addresses the persistent challenges in managing GCPM while also offering a comprehensive summary of current guidelines and treatment strategies.

Cytoreductive Surgery (CRS) and HIPEC for Advanced Ovarian Cancer with Peritoneal Metastases: Italian PSM Oncoteam Evidence and Study Purposes

Ovarian cancer is the eighth most common neoplasm in women with a high mortality rate mainly due to a marked propensity for peritoneal spread directly at diagnosis, as well as tumor recurrence after radical surgical treatment. Treatments for peritoneal metastases have to be designed from a patient's perspective and focus on meaningful measures of benefit. Hyperthermic intraperitoneal chemotherapy (HIPEC), a strategy combining maximal cytoreductive surgery with regional chemotherapy, has been proposed to treat advanced ovarian cancer. Preliminary results to date have shown promising results, with improved survival outcomes and tumor regression. As knowledge about the disease process increases, practice guidelines will continue to evolve. In this review, we have reported a broad overview of advanced ovarian cancer management, and an update of the current evidence. The future perspectives of the Italian Society of Surgical Oncology (SICO) are discussed conclusively.

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

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

Mode of Presentation in 1070 Patients With Perforated Epithelial Appendiceal Tumors, Predominantly with Pseudomyxoma Peritonei

BACKGROUND

Perforated epithelial appendiceal tumors are uncommon and can give rise to pseudomyxoma peritonei. Pseudomyxoma peritonei is rare, almost always of appendiceal origin, and presents in various ways relevant to abdominal surgeons.

OBJECTIVE

The aim of this study was to report the mode of presentation of pseudomyxoma peritonei of appendiceal origin in patients treated in a high-volume UK peritoneal malignancy center.

DESIGN

A retrospective observational study was conducted.

SETTINGS

This was a single-center study.

PATIENTS

Retrospective analysis of a prospective database of consecutive patients undergoing surgery between March 1994 and December 2016 was performed.

MAIN OUTCOME MEASURES

Mode of presentation was classified into 7 categories: "histological diagnosis at abdominal surgery for presumed appendicitis," "probable pseudomyxoma peritonei" based on abnormality on cross-sectional imaging (± image-guided biopsy)," "abnormal imaging (other cause suspected) and operative finding of pseudomyxoma peritonei," "diagnostic laparoscopy," "ovarian mass," "new-onset hernia," and "miscellaneous."

RESULTS

Overall, 1070 patients underwent surgery (female 61%, male 39%); median age was 57. The mode of presentation was abnormality on cross-sectional imaging in 324 of 1070 patients (30.3%), histological diagnosis at emergency surgery for presumed appendicitis in 203 of 1070 patients (19%), and abnormal imaging with eventual pseudomyxoma peritonei diagnosis in 180 of 1070 patients (16.8%); 124 of 651 women (19.2%) presented with an ovarian mass. New-onset hernia was the presenting feature in 9.9%; 83 of 1070 patients (7.7%) were diagnosed at diagnostic laparoscopy, and 32 of 1070 patients (3%) were described as "miscellaneous." Overall, 775 of 1070 patients (72.4%) had complete cytoreductive surgery with 10-year survival of 63.5%.

LIMITATIONS

Results are limited by the retrospective nature of the study, radiological improvements over the study period, and the number of patients who had overlapping features at presentation.

CONCLUSION

Perforated appendiceal tumors present in various ways but predominantly at cross-sectional imaging or coincidentally at laparoscopy or laparotomy. All abdominal surgeons will occasionally encounter cases, often unexpectedly, and recognition and referral to a specialized unit results in excellent outcomes in most cases. See Video Abstract at http://links.lww.com/DCR/B256. MODO DE PRESENTACIÓN EN 1070 PACIENTES CON TUMORES EPITELIALES APENDICULARES PERFORADOS, PREDOMINANTEMENTE CON PSEUDOMIXOMA PERITONEAL: Los tumores epiteliales apendiculares perforados son poco frecuentes y pueden dar lugar a Pseudomyxoma peritonei. El pseudomixoma peritoneal es raro, casi siempre de origen apendicular, y se presenta de diversas formas relevantes para los cirujanos abdominales.El objetivo fue informar el modo de presentación del Pseudomixoma peritoneal de origen apendicular en pacientes tratados en un centro de malignidad peritoneal de alto volumen en el Reino Unido.Se realizó un estudio observacional retrospectivo.Este fue un estudio de centro único.Análisis retrospectivo de una base de datos prospectiva de pacientes consecutivos sometidos a cirugía entre marzo de 1994 y diciembre de 2016.El modo de presentación se clasificó en 7 categorías: "diagnóstico histológico en la cirugía abdominal por presunta apendicitis", "probable Pseudomixoma peritoneal" basado en la anormalidad en la imagen de corte transversal (biopsia guiada por imagen +/-), "imagen anormal (se sospecha otra causa) y hallazgo quirúrgico de Pseudomixoma peritoneal", "laparoscopia diagnostica", "masa ovarica", "hernia de reciente aparicion" y "varios".En total, 1070 pacientes fueron operados (mujeres 61%, hombres 39%); edad media 57. El modo de presentación fue anormalidad en la imágen transversal en 324/1070 (30.3%), el diagnóstico histológico en cirugía de emergencia por presunta apendicitis en 203/1070 (19%), la imágen anormal con eventual diagnóstico de Pseudomixoma peritoneal en 180 / 1070 (16.8%), 124/651 (19.2%) las mujeres presentaron una masa ovárica. La hernia de reciente aparición fue la característica de presentación en 9.9%, 83/1070 (7.7%) fueron diagnosticados por laparoscopia diagnóstica y 32/1070 (3%) "misceláneos". En general, 775/1070 (72,4%) se sometió a cirugía citorreductora completa con una supervivencia a 10 años del 63,5%.Una deficiencia es que los resultados están limitados por la naturaleza retrospectiva del estudio, las mejoras radiológicas a lo largo del período de estudio, y varios pacientes tenían características superpuestas en la presentación.Los tumores apendiculares perforados se presentan de varias maneras, pero predominantemente en imágenes transversales o casualmente en laparoscopia o laparotomía. Todos los cirujanos abdominales encontrarán ocasionalmente con casos, a menudo inesperados, y el reconocimiento y la derivación a una unidad especializada da lugar a excelentes resultados en la mayoría de los casos. Consulte Video Resumen en http://links.lww.com/DCR/B256.).

Extent of Peritoneal Resection for Peritoneal Metastases: Looking Beyond a Complete Cytoreduction

Completeness of cytoreduction is one of the most important prognostic factors impacting outcomes of cytoreductive surgery (CRS). To what extent the surrounding normal peritoneum needs to be removed is not known. We hypothesized that the extent of peritoneal resection should be different for different tumors and performed this study to find evidence to support this rationale. To determine the extent of resection of surrounding tissue for any tumor, the mechanisms of tumor development and spread, tumor morphology, the possibility of finding disease in the surrounding normal tissue, and the pattern of lymph node metastases should be known. Surgical resections also depend on patterns of recurrence and the impact of varying extent of resection on survival. We performed a review of literature pertaining to pathways and patterns of peritoneal cancer spread to determine the scientific basis for the extent of peritonectomy. We also reviewed studies comparing less and more extensive peritoneal resection. There is no consensus on the extent of lymphadenectomy required for most PM. Based on this review, we provide recommendations for the extent of peritoneal resection and the extent of lymph node dissection that should be performed for some common peritoneal tumors and identify areas that require further research. We propose that a systematic method of synoptic reporting of pathological specimens of CRS should be developed to capture information regarding the disease distribution within the peritoneal cavity and morphology of PM from different tumors. This can in future be used to establish standard guidelines for such resections.

Biphasic learning curve of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy:technical competence and refinement of patient selection

Background

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is routinely used for selected patients with peritoneal metastasis, but can be associated with high complication rates, prolonged hospital stay, and mortality. Our objective was to determine the learning curve of CRS/HIPEC in our institution, representing the largest Asian cohort to date.

Methods

A total of 200 consecutive patients with peritoneal metastasis treated with CRS/HIPEC between 2001 and 2016 were grouped into four cohorts of 50 patients and studied. Primary outcomes were severe morbidity (Clavien-Dindo III-V), procedure-related mortality, and duration of ICU and hospital stays. Secondary outcome was duration of surgery.

Results

Median age was 53 years (10–75). There was no significant age, sex, or histology difference across cohorts. Rates of severe morbidity (23 %), and 60 day inpatient mortality (0.5 %) were comparable to previously reported data. Decreases in rates of serious morbidity, (34 %, 30 %, 12 %, 14 %, p<0.01) and duration of total hospital stay (14, 16, 13, 12 days, p=0.041) were seen across consecutive cohorts. Operation time decreased significantly after the first cohort (10, 7.8, 7.8, 7.2 h, p<0.01), despite increase in average PCI score after the first cohort (8, 14, 12, 13, p=0.063).

Conclusions

Whilst 50 cases were adequate for procedural familiarity and decreased average operation time, significant improvement in rate of serious morbidity was observed after 100 operations. We demonstrate a novel biphasic nature to the learning curve, reflecting initial training in which technical competence is achieved, followed by a subsequent period characterized by increasingly complex cases (higher PCI score) and finally refinement of patient selection.

Does having a gastrectomy delay time to feeding and prolong hospital stay in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy?

AIM

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is routinely used to treat selected patients with peritoneal carcinomatosis, but can be associated with prolonged hospital stay, significant morbidity and mortality. Our objective was to assess whether patients undergoing gastrectomy as part of CRS/HIPEC were at increased risk of delayed feeding time and prolonged hospital stay.

METHODS

Two hundred and fourteen consecutive patients with peritoneal carcinomatosis treated with CRS/HIPEC between 2001 and 2016 were stratified by whether CRS included gastrectomy (n = 19, 9%) and compared. Primary outcomes were time to full feeds and rate of serious morbidity (Clavien-Dindo grades III-V). Secondary outcomes were durations of ICU and hospital stays.

RESULTS

Of 214 patients undergoing CRS/HIPEC, those undergoing gastrectomy (19, 8.9%) had increased time to full feeds (8 vs. 5 days, p < 0.01), and duration of ICU (2 vs. 1 days, p < 0.01) and total hospital stays (16 vs. 14 days, p = 0.013). There was no significant increase in serious complications, although increased risk of pneumonia was noted (21% vs. 4.1%, p = 0.011). Undergoing gastrectomy was not independently prognostic in multivariable analysis including high peritoneal tumour load (PCI >12), multiple CRS procedures (number >2) and operation duration (>480 min) in which operative duration remained independently prognostic (p < 0.01).

CONCLUSIONS

After surgery, early oral refeeding may be beneficial in the majority of patients undergoing CRS/HIPEC. However, patients found to have high peritoneal tumour load with extended surgery and those who underwent gastrectomy should be considered for early post-operative TPN due to the significant risk of delayed time to full feeds.

Assessment of a novel mucolytic solution for dissolving mucus in pseudomyxoma peritonei: an ex vivo and in vitro study

Background

Pseudomyxoma peritonei (PMP) is difficult to treat. Intraperitoneal delivery of mucolytic solutions might potentially improve therapy, in addition to surgical cytoreduction and hyperthermic intraperitoneal chemotherapy.

Methods

Comparison of mucolytic effect of two formulations (control: bromelain 300 µg/mL+N-Acetylcystein 250 mM; test: bromelain 200 µg/mL+200 mM cysteamine) in vitro on a mucin producing cell lines (HT29) and ex vivo on mucus obtained from 18 PMP patients. Mucin plugs were classified according to their density into three categories: hard, semi hard and soft. Simulation of peritoneal washing ex vivo using a closed heated circulating pump.

Results

Solubilisation was faster with the test vs. the control formulation (90 vs. 180 min) for dissolving the soft mucin plugs (p < 0.05). The test solution was also more effective in dissolving the hard mucus plugs compared to control (82.5±2.74 % vs. 36.33±3.27 %). All mucin types disintegrated in simulated peritoneal washing. Cytotoxicity of the test solution on HT29 cell line was time-dependent.

Conclusions

The test formulation is more effective and faster than the control formulation in dissolving mucus plugs of various densities. Mucus plugs were all solubilised after 40 min in simulated peritoneal washing. This novel mucolytic formulation might pave the way for an effective and less invasive therapy of PMP in the future.

Physical and chemical characteristics of mucin secreted by pseudomyxoma peritonei (PMP)

Background: Pseudomyxoma peritonei (PMP) is a rare disease with excess intraperitoneal mucin secretion. Treatment involves laparotomy, cytoreduction and chemotherapy that is very invasive with patients often acquiring numerous compromises. Hence a mucolytic comprising of bromelain and N-acetyl cystein has been developed to solubilise mucin in situ for removal by catherization. Owing to differences in mucin appearance and hardness, dissolution varies. Therefore the current study investigates the inter-mucin physical and chemical characteristics, in order to reformulate an effective mucolytic for all mucin. Method: PMP mucin, from the three categories (soft, semi hard and hard mucin) was solubilised and then various physical characteristics such as turbidity, density, kinematic viscosity were measured. The water content and the density of solid mucin were also determined. This was followed by the determination of sialic acid, glucose, lipid, Thiol (S-S and S-H) content of the samples. Lastly, the distribution of MUC2, MUC5B and MUC5AC was determined using western blot technique. Results: Both turbidity and kinematic viscosity and sialic acid content increased linearly as the hardness of mucin increased. However, density, hydration, protein, glucose, lipid and sulfhydryl and disulphide content decreased linearly as hardness of mucin increased. The distribution ratio of mucins (MUC2:MUC5B:MUC5AC) in soft mucin is 2.25:1.5:1.0, semi hard mucin is 1:1:1 and hard mucin is 3:2:1. Conclusion: The difference in texture and hardness of mucin may be due to cellular content, hydration, glucose, protein, lipids, thiol and MUC distribution. Soft mucin is solely made of glycoprotein whilst the others contained cellular materials.

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.

Organ dysfunction in critically ill cancer patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

The aim of the present study was to observe the incidence of organ dysfunction and the intensive care unit (ICU) outcomes of critically ill cancer patients during the cytoreductive surgery with hyperthermic intraperitoneal chemotherapy post-operative period. The present study included 25 critically ill cancer patients admitted to the ICU of the National Cancer Institute (Mexico City, Mexico) between January 2007 and February 2013. The incidence of organ dysfunction was 68% and patients exhibiting ≤1 organ system dysfunction during ICU admittance remained in hospital for a significantly shorter period compared with patients who exhibited ≥2 organ system dysfunctions (12.4±10.7 vs. 24.1±12.8 days; P=0.025). Therefore, the present study demonstrated that a high incidence of organ dysfunction was associated with a longer ICU hospital stay.

Secreted mucins in pseudomyxoma peritonei: pathophysiological significance and potential therapeutic prospects

Pseudomyxoma peritonei (PMP, ORPHA26790) is a clinical syndrome characterized by progressive dissemination of mucinous tumors and mucinous ascites in the abdomen and pelvis. PMP is a rare disease with an estimated incidence of 1-2 out of a million. Clinically, PMP usually presents with a variety of unspecific signs and symptoms, including abdominal pain and distention, ascites or even bowel obstruction. It is also diagnosed incidentally at surgical or non-surgical investigations of the abdominopelvic viscera. PMP is a neoplastic disease originating from a primary mucinous tumor of the appendix with a distinctive pattern of the peritoneal spread. Computed tomography and histopathology are the most reliable diagnostic modalities. The differential diagnosis of the disease includes secondary peritoneal carcinomatoses and some rare peritoneal conditions. Optimal elimination of mucin and the mucin-secreting tumor comprises the current standard of care for PMP offered in specialized centers as visceral resections and peritonectomy combined with intraperitoneal chemotherapy. This multidisciplinary approach has reportedly provided a median survival rate of 16.3 years, a median progression-free survival rate of 8.2 years and 10- and 15-year survival rates of 63% and 59%, respectively. Despite its indolent, bland nature as a neoplasm, PMP is a debilitating condition that severely impacts quality of life. It tends to be diagnosed at advanced stages and frequently recurs after treatment. Being ignored in research, however, PMP remains a challenging, enigmatic entity. Clinicopathological features of the PMP syndrome and its morbid complications closely correspond with the multifocal distribution of the secreted mucin collections and mucin-secreting implants. Novel strategies are thus required to facilitate macroscopic, as well as microscopic, elimination of mucin and its source as the key components of the disease. In this regard, MUC2, MUC5AC and MUC5B have been found as the secreted mucins of relevance in PMP. Development of mucin-targeted therapies could be a promising avenue for future research which is addressed in this article.

Cytoreductive surgery plus perioperative intraperitoneal chemotherapy in pseudomyxoma peritonei: aspects of the learning curve

BACKGROUND

Cytoreductive surgery (CRS) plus perioperative intraperitoneal chemotherapy is a highly invasive treatment of peritoneal metastasis and requires many surgical procedures before mastering. The aim of this study was to estimate how many procedures are needed before stabilization can be seen in surgical outcome (R1 surgery, adverse events and bleeding) in patients with pseudomyxoma peritonei (PMP).

PATIENTS AND METHODS

All 128 patients with PMP who were treated with CRS alone or CRS plus perioperative intraperitoneal chemotherapy between 2003 and 2008 at the Uppsala University Hospital, Uppsala, Sweden, were included. The learning curve was calculated using the partial least square (PLS) and cumulative sum control chart (CUSUM) graph. Two groups were formed based on the results of the learning curve. The learning curve plateau was considered the same as the stabilization in the CUSUM graph. Group I consisted of patients included during the learning period (n = 73) and Group II of patients treated after the learning period ended (n = 55). Comparisons between the groups were made on surgical outcome, survival and adverse events.

RESULTS

Stabilization was seen after 220 ± 10 procedures. A higher occurrence of R1 surgery was seen in Group II (80%) compared to Group I (48%; P = 0.0002). Overall survival increased at four years after surgery in Group II compared to Group I (80% vs. 63%; P = 0.02).

CONCLUSION

CRS plus perioperative intraperitoneal chemotherapy is a highly demanding procedure that requires more than 200 procedures before optimisation in surgical outcome is seen.

Perioperative management of patients undergoing cytoreductive surgery combined with heated intraperitoneal chemotherapy for peritoneal surface malignancy: a multi-institutional experience

BACKGROUND

Cytoreductive surgery (CRS) combined with heated intraperitoneal chemotherapy (HIPEC) is an established treatment for patients with pseudomyxoma peritonei. There is now increasing evidence for the use of CRS and HIPEC in the treatment of other peritoneal surface malignancies. There is currently no consensus on the perioperative management of this patient group.

METHODS

An international survey of practice was conducted using an online survey tool. Centers were identified from the list of delegates attending the Seventh International Workshop on Peritoneal Surface malignancy held in Uppsala, Sweden, in September 2010.

RESULTS

Fully completed surveys were received from 29 of 41 identified centers (71 %). The survey covers the combined experience amassed by anesthesiologists caring for 8,467 patients undergoing cytoreductive surgery. Intraoperative fluid management, management of coagulopathy, management of the HIPEC phase of the operation, and postoperative analgesia caused the greatest difficulties for the anesthesia team with variation in management identified between different institutions. The incidence of epidural abscess in this patient group was found to be 1:2,139.

CONCLUSIONS

Optimal preoperative, intraoperative, and postoperative care is crucial to diminish the complications in this complex treatment strategy. Multicenter collaboration is suggested to gain evidence on the best strategies for perioperative management. Further data collection needs to be undertaken to assess the safety of epidural anesthesia in this patient group.

Outcome differences between debulking surgery and cytoreductive surgery in patients with Pseudomyxoma peritonei

BACKGROUND

The aim of this study was to compare debulking surgery and cytoreductive surgery (CRS) in patients with Pseudomyxoma peritonei (PMP) regarding efficacy and safety.

PATIENTS AND METHODS

Data were extracted from medical records and treatment outcomes were analyzed for all 152 patients with PMP who were scheduled for debulking surgery and intraperitoneal chemotherapy (IPC) or CRS and IPC at Uppsala University Hospital, Uppsala, Sweden, between September 1993 and December 2008.

RESULTS

One hundred and ten patients (73%) were treated with CRS and IPC and 40 (27%) with debulking surgery and IPC. In two patients (1%), surgery was defined as open and close. Patients with CRS and IPC had a 74% 5-year overall survival (OS) rate compared with 40% for those treated with debulking surgery (P < 0.001). Patients with no residual macroscopic tumour (R1 resection) had a better 5-year OS rate of 94% compared with 28% for patients with macroscopic residual tumour (R2) (P < 0.001). Grades II-IV adverse events were seen in 29% of debulked patients and in 47% of CRS/IPC patients (P = 0.053).

CONCLUSIONS

CRS and IPC seems more efficient than debulking surgery and IPC but with numerically higher morbidity. Therefore, if surgically possible, CRS should be the treatment of choice for PMP patients. However, debulking surgery may still be of benefit to selected patients for palliative purposes.

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion: The University of Arizona early experience

AIM: To evaluate the safety and effectiveness of our new cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) program.

METHODS: Retrospective review of patients with gastrointestinal malignancies who were suitable candidates for CRS and HIPEC between 12/1/2009 and 10/1/2010. All clinicopathologic data were reviewed with a special focus on the surgical outcome and the postoperative morbidity and mortality.

RESULTS: Fourteen patients were identified. Median age was 64 years; seven were female. The primary tumors were: colonic (29%), appendiceal (36%), peritoneal mesothelioma (14%), gastric (7%), adenocarcinoma of unknown primary (7%), and gastrointestinal stromal tumor (7%). Eleven patients (79%) received CRS/HIPEC, three for palliation. Three patients that did not undergo CRS/HIPEC had an average peritoneal cancer index (PCI) of 25. The eight patients that underwent curative CRS/HIPEC had an average PCI of 10 and a completeness of cytoreduction score of 0 (87.5%) or 1 (12.5%). Postoperative morbidity was 36%; the worst adverse event was Grade 3 ileus. Mortality rate was 0%.

CONCLUSION: CRS with HIPEC is safe and feasible at tertiary institutions with fledgling programs. PCI is an accurate predictor of surgical outcomes.

Post-operative critical care management of patients undergoing cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC)

Background

Cytoreductive surgery (CRS) and Heated Intraperitoneal Chemotherapy (HIPEC) results in a number of physiological changes with effects on the cardiovascular system, oxygen consumption and coagulation. The Critical Care interventions required by this cohort of patients have not yet been quantified.

Methods

This retrospective audit examines the experience of a Specialist Tertiary Centre in England over an 18 month period (January 2009-June 2010) during which 69 patients underwent CRS and HIPEC. All patients were extubated in the operating theatre and transferred to the Critical Care Unit (CCU) for initial post-operative management.

Results

Patients needed to remain on the CCU for 2.4 days (0.8-7.8). There were no 30 day mortalities. The majority of patients (70.1%) did not require post-operative organ support. 2 patients who developed pneumonia post-operatively required respiratory support. 18 (26.1%) patients required vasopressor support with norepinephrine with a mean duration of 13.94 hours (5-51 hours) and mean dose of 0.04 mcg/kg/min. Post-operative coagulopathy peaked at 24 hours. A significant drop in serum albumin was observed.

Conclusion

The degree of organ support required post-operatively is minimal. Early extubation is efficacious with the aid of epidural analgesia. Critical Care monitoring for 48 hours is desirable in view of the post-operative challenges.

Management of peritoneal carcinomatosis from colorectal cancer

The management of peritoneal carcinomatosis from colorectal cancer is evolving. The introduction of new chemotherapeutic and biologic agents has certainly improved the outlook for many patients with metastatic colorectal cancer. Traditionally, patients with limited hepatic or pulmonary metastases were the only candidates for metastasectomy. However, patients with metastasis localized to the peritoneum have been shown to be candidates for metastasectomy with improved clinical outcomes. Cytoreductive surgery with the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) in this cohort of patients offers the only chance for long-term survival. Complete cytoreduction in combination with HIPEC for peritoneal surface disease has been demonstrated to produce survival outcomes similar to liver resection for hepatic metastases. This review will examine recent evidence pertaining to the evolving surgical oncology paradigm for management of colorectal peritoneal carcinomatosis.

Cyto-reductive Surgery combined with Hyperthermic Intra-peritoneal Chemotherapy for Peritoneal Surface Malignancies: current treatment and results

Cyto-reductive Surgery (CS) combined with Hyperthermic Intra-peritoneal Chemotherapy (HIPEC) as loco-regional treatment of Peritoneal Surface Malignancies (PSM) has increasingly gained acceptance in clinical practice. This review summarizes the more relevant studies on this topic. Indications, pre-operative work-up, technical aspects, outcome and future directions of this combined approach in the treatment of Peritoneal Surface Malignancies are discussed here and proposed in an informative and didactic manner.

A new standard of care for the management of peritoneal surface malignancy

Cancer dissemination to peritoneal surfaces was, in the past, a lethal condition with a limited survival. Clinical and pharmacologic research have shown that options for both treatment and prevention are now reality. The diseases most commonly treated include peritoneal dissemination from appendiceal malignancy, colorectal malignancy, and peritoneal mesothelioma. Selection factors are important to minimize the number of treated patients who will experience short-term benefit. Treatments involve cytoreductive surgery and perioperative chemotherapy. The intraperitoneal chemotherapy in the operating room is used with heat. Although this combined approach has been criticized, the informed oncologist will seek to identify those patients that may benefit from this more optimistic concept of peritoneal dissemination of cancer.

Operative findings, early complications, and long-term survival in 456 patients with pseudomyxoma peritonei syndrome of appendiceal origin

BACKGROUND

Pseudomyxoma peritonei syndrome is a clinical entity characterized by mucinous ascites usually originating from a perforated mucinous appendiceal tumor. Currently optimal therapy is considered complete macroscopic tumor removal (complete cytoreduction) combined with heated intraperitoneal chemotherapy. When complete cytoreduction is not achievable, major tumor debulking is undertaken. The long-term follow-up of patients undergoing surgery for perforated appendiceal tumors in a national pseudomyxoma center is reported.

METHODS

Between March 1994 and July 2009, 456 patients with pseudomyxoma peritonei syndrome from perforated appendiceal tumors underwent surgery. The treatment strategy involved a combination of cytoreductve surgery aiming for macroscopic tumor removal, combined with hyperthermic intraperitoneal chemotherapy with mitomycin C. Where complete tumor removal was not possible, maximal tumor debulking was performed. Perioperative outcomes and predicted 5- and 10-year survival are reported.

RESULTS

Overall 15 of 456 (3%) tumors were not resectable at laparotomy. Of the 441 patients who had resection, 289 (66%) had complete cytoreduction and 152 (34%) had major tumor debulking. Postoperative in-hospital mortality was 1.6% and grade 3/4 morbidity was 7%. The Kaplan-Meier method predicted 5- and 10-year overall survival of 69% and 57%, respectively. Five- and 10-year predicted survival was 87% and 74% for the 289 patients who had complete cytoreduction compared with 34% and 23% for the 152 who had major tumor debulking.

CONCLUSION

Complete tumor removal was achieved in 289 of 441 (66%) patients with peritoneal dissemination from perforated appendiceal tumors with good long-term survival and probable cure in more than two-thirds.

Changes induced by surgical and clinical factors in the pharmacology of intraperitoneal mitomycin C in 145 patients with peritoneal carcinomatosis

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are a combined treatment modality considered for selected patients with peritoneal carcinomatosis from colorectal and appendiceal cancer. Mitomycin C is a drug often used in this clinical setting. The surgical and clinical factors that may influence the pharmacokinetics of hyperthermic intraperitoneal chemotherapy should be further elucidated.

MATERIALS AND METHODS

The patients included were 145 who had colorectal or appendiceal carcinomatosis resected using cytoreductive surgery prior to treatment with hyperthermic intraperitoneal chemotherapy with mitomycin C as part of a multidrug regimen. The effect of clinical and surgical factors on drug distribution after single intraperitoneal bolus administration with mitomycin C was determined.

RESULTS

The pharmacokinetics of 145 patients treated with intraperitoneal mitomycin C showed a 27 times greater exposure to peritoneal surfaces when compared to plasma. At 90 min, 29% of the drug remained in the chemotherapy solution, 62% was retained in the body, and 9% was excreted in the urine. The extent of peritonectomy increased the clearance of mitomycin C from the peritoneal space (p = 0.051). A major resection of visceral peritoneal surface and a contracted peritoneal space reduced drug clearance. A contracted peritoneal space significantly reduced (p = 0.0001) drug concentrations in the plasma.

CONCLUSIONS

Surgical and clinical factors may require modifications of drug dose or timing of chemotherapy administration. A large visceral resection and a contracted peritoneal space caused a reduced mitomycin C clearance. Total diffusion surface is an important determinant of mitomycin C pharmacokinetics.

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.

Pathophysiology and biology of peritoneal carcinomatosis

Peritoneal carcinomatosis represents a devastating form of cancer progression with a very poor prognosis. Its complex pathogenesis is represented by a dynamic process comprising several steps. To the best of our knowledge pathogenesis can be partly explained by 3 major molecular pathways: (1) dissemination from the primary tumor; (2) primary tumor of peritoneum; and (3) independent origins of the primary tumor and peritoneal implants. These are not mutually exclusive and combinations of different mechanisms could occur inside a single case. There are still several aspects which need explanation by future studies. A comprehensive understanding of molecular events involved in peritoneal carcinomatosis is of paramount importance and should be systematically pursued not only to identify novel strategies for the prevention of the condition, but also to obtain therapeutic advances, through the identification of surrogate markers of prognosis and development of future molecular targeted therapies.

Pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is an uncommon “borderline malignancy” generally arising from a perforated appendiceal epithelial tumour. Optimal treatment involves a combination of cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC). Controversy persists regarding the pathological classification and its prognostic value. Computed tomography scanning is the optimal preoperative staging technique. Tumour marker elevations correlate with worse prognosis and increased recurrence rates. Following CRS with HIPEC, 5-year survival ranges from 62.5% to 100% for low grade, and 0%-65% for high grade disease. Treatment related morbidity and mortality ranges from 12 to 67.6%, and 0 to 9%, respectively. Surgery and HIPEC are the optimal treatment for PMP which is at best a “borderline” peritoneal malignancy.

Treatments and outcomes of peritoneal surface tumors through a centralized national service (United kingdom)

PURPOSE

Treatment of peritoneal surface malignancies with combined cytoreductive surgery and heated intraperitoneal chemotherapy may improve oncologic outcome. To better define treatment pathways, five-year results in patients referred to one of two centralized national treatment centers in the United Kingdom were analyzed.

METHODS

A prospective database of patients referred to the Manchester Peritoneal Tumor Service, established in 2002, was analyzed. Outcomes were evaluated using Kaplan-Meier life tables and Cox models.

RESULTS

Two hundred seventy-eight patients (median age, 56.9 (range, 16-86) years) were considered by a dedicated multidisciplinary team and tracked on seven clinical pathways. Among the 118 surgically treated, the most common diagnosis was pseudomyxoma peritonei (101 patients, 86%). Major complications occurred in 11 patients (9%); there was no 30-day mortality. Where complete cytoreduction was achieved, three-year and five-year tumor-related survival rates were 94% and 86%, respectively. In the Cox model, incompleteness of cytoreduction (P = 0.001) and high-grade tumor (P < 0.0001) were independent prognosticators of poor outcome.

CONCLUSION

The establishment of a national treatment center has allowed refinement of techniques to achieve internationally recognized results. Having achieved low levels of morbidity and mortality in the treatment of mainly pseudomyxoma peritonei of appendiceal origin, the technique of cytoreductive surgery and heated intraperitoneal chemotherapy may be considered for peritoneal carcinomatosis of colorectal origin.

Morbidity and mortality with cytoreductive surgery and intraperitoneal chemotherapy: the importance of a learning curve

Evidence for the efficacy of cytoreductive surgery, combined with hyperthermic intraperitoneal chemotherapy (HIPEC), in the treatment of peritoneal carcinomatosis is accumulating. Many centers around the world now have considerable experience of the complex techniques required to achieve complete cytoreduction with the administration of HIPEC. Procedure-related morbidity ranges from 12% to 67.6% and mortality from 0% to 9% in recent studies of cytoreductive surgery and HIPEC for pseudomyxoma peritonei. A number of specialized centers have studied the factors that influence perioperative complications and mortality and have demonstrated impressive reductions in morbidity and mortality over time. However, for this treatment to be accepted as standard of care, teams undertaking this treatment strategy must aim to minimize morbidity and mortality by learning from the experience of established centers and using the "global learning curve."

Consensus statement on the loco-regional treatment of appendiceal mucinous neoplasms with peritoneal dissemination (pseudomyxoma peritonei)

Pseudomyxoma peritonei (PMP) is a rare condition mostly originating from low malignant potential mucinous tumours of the appendix. Although this disease process is minimally invasive and rarely causes haematogenous or lymphatic metastases, expectation of long-term survival are limited with no prospect of cure. Recently, the combined approach of cytoreductive surgery (CRS) and perioperative loco-regional chemotherapy (PLC) has been proposed as the standard of treatment for the disease. The present paper summarizes the available literature data and the main features of the comprehensive loco-regional treatment of PMP. The controversial issues concerning the indications and technical methodology in PMP management were discussed through a web-based voting system by internationally known experts. Results were presented for further evaluation during a dedicated session of "The Fifth International Workshop on Peritoneal Surface Malignancy (Milan, Italy, December 4-6, 2006)". The experts agreed that multiple prospective trials support a benefit of the procedure in terms of improved survival, as compared with historical controls. Concerning the main controversial methodological questions, there was an high grade of consistency among the experts and agreement with the findings of the literature.

Peritoneal pseudomyxoma: results of a systematic policy of complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND

Pseudomyxoma peritonei (PMP) is characterized by progressive intraperitoneal accumulation of mucous and mucinous implants, usually derived from a ruptured, possibly malignant mucinous neoplasm of the appendix. Treatment based on complete cytoreductive surgery (CCRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is gaining support. The aim of this study was to identify pre- and perioperative factors of prognostic value.

METHODS

A total of 105 patients (with no residual tumours exceeding 2 mm) were treated with CCRS plus HIPEC based on oxaliplatin. Clinical, radiological, pathological factors and blood markers were analysed to determine their prognostic value for survival.

RESULTS

Mortality (7.6 per cent) and morbidity (67.6 per cent) were significantly correlated with peritoneal index, pathological grade and blood CA19.9 level. The median follow-up was 48 months. Seven patients died after hospital discharge. Overall and disease-free 5-year survival rates were 80.0 and 68.5 per cent respectively. The Cox model identified only two significant factors impacting on disease-free survival: CA19.9 level and pathological grade.

CONCLUSION

CCRS is the most effective treatment for PMP, and adding HIPEC prolongs long-term survival. Further strategies should focus on improving postoperative outcome in extended PMP.

The porta hepatis as a site of recurrence of mucinous appendiceal neoplasms treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy

BACKGROUND

A successful new treatment for a particular disease may change the natural history of that disease as patients go on to longer survival. The goal of this study was to investigate the porta hepatis as a site of recurrence of appendiceal mucinous neoplasms.

METHODS

A prospective database on patients with peritoneal dissemination of mucinous appendiceal neoplasms has been maintained for 21 years. In patients with complete cytoreduction, disease progression/recurrence in and around the porta hepatis has been noted as a new manifestation of this disease.

RESULTS

In 710 patients treated for mucinous appendiceal cancer with a complete cytoreduction, 140 developed recurrent disease. Seven patients (5%) had disease recurrence in and around the porta hepatis. Four of the seven had biliary obstruction and three had masses within the liver hilum not causing bile duct obstruction. Four of the seven patients were successfully palliated by surgical procedures within the liver and biliary tree. Two patients were successfully palliated using a biliary stent and one patient was not treated.

CONCLUSIONS

Progression of mucinous neoplasms within the porta hepatis may be related to imperfect cytoreduction technique. Reoperative surgical treatment and biliary stents were beneficial in some of these patients.

A phase II study evaluating the use of concurrent mitomycin C and capecitabine in patients with advanced unresectable pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is a rare neoplastic process characterised by progressive intra-abdominal dissemination of mucinous tumour, and generally considered resistant to systemic chemotherapy. A phase II study in patients with advanced unresectable PMP was undertaken to evaluate the combination of systemic concurrent mitomycin C (7 mg m(-2) i.v. on day 1) and capecitabine (1250 mg m(-2) b.d. on days 1-14) in a 3-weekly cycle (MCap). Response was determined by semiquantitative assessment of disease volume on serial computed tomographic (CT) scans and serum tumour marker (CEA, CA125, CA19-9) changes at 12 weeks. Between 2003 and 2006, 40 patients were recruited through a national centre for the treatment of peritoneal surface tumours. At baseline, 23 patients had progressive disease and 17 had stable disease. Of 39 assessable patients, 15 (38%, 95% confidence intervals (CIs): 25, 54%) benefited from chemotherapy in the form of either reductions in mucinous deposition or stabilisation of progressive pretreatment disease determined on CT scan. Notably, two patients, originally considered unresectable, following MCap and re-staging underwent potentially curative cytoreductive surgery. Grade 3/4 toxicity rates were low (6%, 95% CIs: 4, 9%). Twenty out of 29 assessed patients (69%, 95% CIs: 51, 83%) felt that their Global Health Status improved during chemotherapy. This is the first trial to demonstrate an apparent benefit of systemic chemotherapy in patients with advanced unresectable PMP.

Postoperative adverse events and long-term survival after cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND

Peritoneal carcinomatosis (PC) is fatal without special combined cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC). This study was designed to identify factors that may increase the risk of postoperative morbidity and mortality from combined CRS and IPC interventions for PC. Survival based on primary tumour type and extent of surgery is reported.

METHODS

Between May 1991 and November 2004, 123 patients were treated with CRS and IPC for PC. Based on the National Cancer Institute Common Toxicity Criteria for grade 3 and 4, data on 30 days postoperative morbidity and 90 days mortality were analysed.

RESULTS

Grade 3-4 adverse events were observed in 51 patients (41%) and were associated with stoma formation, duration of surgery, peroperative blood loss and peritoneal cancer index (PCI). Excision, or electrocautery evaporation, of tumour from small bowel surface was correlated to bowel morbidity. Five patients had treatment-related mortality (4%) within 90 days. Survival was associated with macroscopic radical surgery, prior surgical score, PCI and primary tumour type.

CONCLUSIONS

CRS and IPC for PC are associated with high morbidity and mortality. However, in light of the potential benefit indicated by long-term survival, the adverse event from this treatment is considered acceptable.

Pseudomyxoma peritonei secondary to epithelial appendicular neoplasms. Experience in a non-specialised centre

INTRODUCTION

Pseudomyxoma peritonei is an infrequent entity, defined by collections of gelatinous material in the abdomen and pelvis and mucinous implants on peritoneum, secondary to the rupture of a mucinous lesion, usually of ovarian or appendiceal origin.

MATERIALS AND METHODS

We present our experience of 11 cases (6 males and 5 females) diagnosed with pseudomyxoma peritonei secondary to epithelial appendicular neoplasms over 27 years. The mean age of the patients was 68 years. Clinical manifestations were abdominal distension (55%), right lower quadrant pain (45%) suggesting acute appendicitis and constitutional syndrome (36%). An abdominal mass was detected at physical examination in 4 patients. CT scan revealed a tumour in right iliac fossa in 4 patients, peritoneal enlargement in 1 and a liquid collection in 1. Preoperative diagnosis was acute abdomen in 5 patients, peritoneal carcinomatosis in 3 and undetermined abdominal mass in 3.

RESULTS

Surgical findings suggested pseudomyxoma peritonei in 8 patients and peritoneal carcinomatosis in 3. Appendicectomy was performed in 9 patients, and in 3 of them bilateral anexectomy was also performed. One patient underwent ileocaecal resection and another a right hemicolectomy. In all the cases, mucinous material was eliminated as much as possible. Pathology revealed mucinous cystoadenoma in 6 cases, mucinous cystoadenocarcinoma in 3 and epithelial hyperplasia in 2 patients. Median survival was 54 months, with a 5- year survival rate of 40%. The last case we treated was sent to a reference centre for the treatment of pseudomyxoma peritonei.

CONCLUSIONS

There is no consensus on the best treatment for pseudomyxoma peritonei. We recommend avoiding incomplete surgical resections in non-reference centres and submitting patients to a reference centre to undergo adequate treatment.

Swedish experience with peritonectomy and HIPEC. HIPEC in peritoneal carcinomatosis

BACKGROUND

Peritonectomy with heated intraperitoneal chemotherapy (HIPEC) has shown a survival benefit in selected patients with peritoneal carcinomatosis. This prospective non-randomized study was designed to identify factors associated with postoperative morbidity and survival after peritonectomy HIPEC in patients with this condition.

METHOD

Data were prospectively collected from all patients with peritoneal carcinomatosis treated by means of peritonectomy and HIPEC at Uppsala University Hospital between October 2003 and September 2006. Depending on the primary tumor, mitomycin C or a platinum compound was used as a chemotherapeutic agent for perfusion.

RESULTS

A total of 103 patients were treated. Primary tumors were pseudomyxoma peritonei (47 patients), colorectal cancer (38 patients), gastric cancer (6 patients), ovarian cancer (6 patients) and mesothelioma (5 patients). Postoperative morbidity was 56.3% and was significantly lower in patients treated with mitomycin C for pseudomyxoma peritonei (42%) than in those with another diagnosis treated with platinum compound (71%, P < 0.05). Postoperative mortality was less than 1%. At 2 years, overall survival was estimated to be 72.3%, and disease-free survival was 33.5%. Factors influencing overall and disease-free survival were tumor type and optimal cytoreduction.

CONCLUSION

Postoperative morbidity is dependent mainly on a tumor type; however, the chemotherapeutic agent used might also influence morbidity. Survival is determined by optimal cytoreduction and tumor type. Irrespective of age, patients with good performance status benefit from this treatment.

Pseudomyxoma peritonei: clinical pathological and biological prognostic factors in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC)

BACKGROUND

Surgical cytoreduction combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has been recently advocated as the standard of care for pseudomyxoma peritonei (PMP). We reviewed our 10-year monoinstitutional case series to identify selection factors predicting postoperative outcome.

METHODS

One hundred and four patients with PMP were operated on with the aim of performing adequate cytoreduction (residual tumor nodules < or =2.5 mm) and closed-abdomen HIPEC with mytomicin-C and cisplatin. Previously, 26 patients had systemic chemotherapy. PMP was histologically classified into disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), and intermediate/discordant group (ID). Immunohistochemical stains were performed for cytokeratin (CK)-7, CK-20, CDX-2, MUC-2, MUC-5AC, CD-44s. The significance of 22 potential clinical, pathological, and biological prognostic variables was assessed by multivariate analysis.

RESULTS

Adequate cytoreduction was performed in 89 patients, suboptimal cytoreduction in six, palliative surgery in nine. Operative mortality was 1%. Seventy-eight patients were diagnosed with DPAM, 26 with PMCA, and none with ID. Median follow-up was 37 months (range, 1-110) for the overall series. Five-year overall survival (OS) and progression-free survival (PFS) were 78.3% and 31.1%, respectively. At multivariate analysis, adequate cytoreduction, no previous systemic chemotherapy, and DPAM correlated to better OS and PFS, elevated serum CA19.9 correlated only to better PFS. In most cases, CK20, CDX-2, and MUC-2 were diffusely positive, while CK-7, MUC-5AC, and CD44s were variably expressed. CK20 expression correlated to prognosis at univariate analysis.

CONCLUSIONS

Favorable outcome after comprehensive treatment can be expected in patients with DPAM, not treated with preoperative systemic chemotherapy and amenable to adequate cytoreduction. MUC-2, CK-20, and CD44s expression may be related to PMP unique biologic behavior.

Appendiceal neoplasms and pseudomyxoma peritonei: a population based study

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare disease with an estimated incidence of 1 per million per year, and is thought to originate usually from an appendiceal mucinous epithelial neoplasm. However it is not known exactly how often these neoplasms lead to PMP. The aim of this study is to investigate the incidence of both lesions and their relation.

METHODS

The nationwide pathology database of the Netherlands (PALGA) was searched for the incidence of all appendectomies, the incidence of primary epithelial appendiceal lesions and the incidence and pathology history of patients with PMP. All regarded the 10-year period of 1995-2005.

RESULTS

In the 10-year period 167,744 appendectomies were performed in the Netherlands. An appendiceal lesion was found in 1482 appendiceal specimens (0.9%). Nine percent of these patients developed PMP. Coincidentally, an additional epithelial colonic neoplasm was found in 13% of patients with an appendiceal epithelial lesion. A mucinous epithelial neoplasm was identified in 0.3% (73% benign, 27% malignant) of appendiceal specimens and 20% of these patients developed PMP. For mucocele and non-mucinous neoplasm the association with PMP was only 2% and 3%, respectively. From the nationwide database 267 patients (62 men and 205 women) with PMP were identified, which demonstrates an incidence of PMP in the Netherlands approaching 2 per million per year. The primary site was identified in 68% and dominated by the appendix (82%).

CONCLUSIONS

Primary epithelial lesions of the appendix are rare. One third of these lesions are mucinous epithelial neoplasms and especially these tumours may progress into PMP. The incidence of PMP seems to be higher than thought before. Furthermore there is a considerable risk of an additional colonic epithelial neoplasm in patients with an epithelial neoplasm at appendectomy.