[Pseudomyxoma Peritonei Caused by Intraductal Papillary Mucinous Neoplasm-A Three Case Series].

Pseudomyxoma peritonei(PMP)is a rare condition caused by intraductal papillary mucinous neoplasm(IPMN). At our institution, 3 cases, along with literature review, of PMP caused by IPMN were treated with cytoreductive surgery. In case 1, a 70-year-old man was pathologically diagnosed with low-grade PMP with intraductal papillary mucinous carcinoma. Recurrence was discovered 68 months after surgery, and the patient died after 78 months. In case 2, a 69-year-old man was pathologically diagnosed with high-grade PMP with signet-ring cell carcinoma caused by intraductal papillary mucinous carcinoma. The patient died 8 months post-surgery. In case 3, a 77-year-old woman was pathologically diagnosed with low- grade(partially high-grade)PMP with intraductal papillary mucinous adenoma. There was a recurrence 14 months post- surgery. The patient is still alive because of systemic chemotherapy 32 months after surgery.

Rationale of Treatment for Peritoneal Metastasis.

In 1998, the Peritoneal Surface Oncology Group International(PSOGI)proposed a novel treatment referred to as comprehensive treatment(COMPT). COMPT involves the complete removal of macroscopic tumors(cytoreductive surgery: CRS) and eradication of micrometastasis(MM)with neoadjuvant chemotherapy(NAC)plus intraoperative hyperthermic intraperitoneal chemotherapy(HIPEC). This article provides a rationale for curative COMPT. Additionally, based on our experience, the selection criteria for treatment will be clarified. RATIONALE: The residual cancer cell burden is lowest immediately following CRS, and intraoperative HIPEC plays a crucial role in the treatment of patients with peritoneal surface malignancy (PSM). COMPT will fail if the number of the MM remaining after CRS exceeds the limit of complete eradication by intraoperative HIPEC(threshold). However, if the residual number of MM is less than the threshold, patients will respond positively to treatment. PATIENTS AND METHODS: To validate the direct effect of HIPEC, laparoscopic HIPEC(LHIPEC)was performed, and changes in the peritoneal cancer index(PCI)were then evaluated. Complete cytoreduction and HIPEC carried out based on the concept of COMPT was performed in 171 gastric cancer(GC)patients with PCI≤12, 183 colorectal cancer(CRC)with PCI≤21 and 460 pseudomyxoma peritonei(PMP)patients with PCI≤28. The postoperative survivals rates were then analyzed. RESULTS: After 1 cycle of LHIPEC, PCIs in GC and PMP were significantly reduced by 1.85 and 2.7 1 month after LHIPEC. However, PCI of CRC increased. Positive cytology at LHIPEC became negative in 57.6%, 42.9% and 60.9% of patients with GC, CRC and PMP, respectively. Median survival time(MST)for GC and CRC was 21.2 and 71.5 months, respectively MST of PMP was not reached. MST of PMP was not reached. Ten-year survival rates were 12.6%, 21.7% and 81.6%, respectively. Grade 5 complications for each disease were 0.8%, 1.0% and 1.1%, respectively. CONCLUSIONS: Complete cytoreductive surgery combined with intraoperative HIPEC may improve the long-term survival of patients with PSM who have PCIs less than the threshold levels, by keeping the mortality rates after CRS plus intraoperative HIPEC within acceptable levels.

Prognostic Factors of Malignant Peritoneal Mesothelioma Experienced in Japanese Peritoneal Metastasis Center.

BACKGROUND AND OBJECTIVES: The current standard of treatment for malignant peritoneal mesothelioma(MPM)is cytoreductive surgery(CRS)plus perioperative intraperitoneal or systemic chemotherapy(comprehensive treatment), The present study was performed to clarify the prognostic factors of PMP after comprehensive treatment. METHODS: Among 63 patients with MPM, male and female patients were 34 and 29. CRSwas performed in 47 patients and complete cytoreduction(CC-0) was performed in 14(22%)patients. Mean numbers of resected peritoneal sectors and organs were 5.2(1-13), and 2.9(0- 9), respectively. Hyperthermic intraperitoneal chemoperfusion(HIPEC)was performed in 27 patients. Grade 1/2, Grade 3, and Grade 4 complications were experienced in 5, 6, and 3 patients, respectively. One patient died of sepsis, and the mortality rate was 2.3%. Independent prognostic factors for favorable prognosis were performance of HIPEC, peritoneal cancer index (PCI)score C12, no distant metastasis and histologic epithelial type. Relative risk of no HIPEC, PCI score B13, presence of distant metastasis and non epithelial type were 7.69, 22.1, 3.6 and 3.9, respectively. CONCLUSIONS: Risk factors for death after comprehensive treatment were no HIPEC, PCI score B13, and non epithelial type. However, only 11(17%)patients showed PCI score C12. Accordingly, PCI score should be reducedC12 before CRSby neoadjuvant chemotherapy.

Effects of Cytoreductive Surgery Combined with Perioperative Chemotherapy on Long-Term Survivals of Colorectal Cancer Patients with Peritoneal Metastasis, with Special Reference to the Involved Peritoneal Sectors and Organs.

Peritoneal Surface Oncology Group International(PSOGI)proposed a novel treatment, named comprehensive treatment for peritoneal metastasis(PM)from colorectal cancer(CRC). The present study demonstrated the efficacies of the treatment regarding the peritoneal sectors and organs involved with PM from CRC. MATERIALS AND METHODS: Among 365 patients received laparotomy, 278 CRC patients with PM underwent complete cytoreductive surgery(CC-0). RESULTS: After CC-0 resection Grade 3, Grade 4, and Grade 5 postoperative complication were found in 20(7.2%), 26(9.3%), and 6(2.2%). Five- and 10-year survival rate(YSR)of CC-0 resection were 24.5%, and 11.6% with median survival time(MST)of 42.0 months. Regarding the peritoneal cancer index(PCI)of small bowel(SB-PCI), all patients of PCI B3 died of the disease. In contrast, 10-YSR of patients with SB-PCI of 0, 1, and 2 were 26.1%, 19.5%, and 6.2%, respectively. Ten-YSR of patients with the number of involved peritoneal sectors C9 ranged from 6.9% to 29.8%. MST of patients with PM in each peritoneal sector(sector 0 to sector 8)ranged from 26.4 months to 49.2 months, and 10-YSR ranged from 4.2%to 17.2%. Ten-YSR of patients with involvement of rectum, stomach, liver capsule, seminal vesicle, ureter, uterus, or ovary ranged from 0% to 16.9%. CONCLUSIONS: From the present data, PM should be removed aggressively to achieve complete cytoreduction, when the patients with PCIC26, involved peritoneal sectorsC9 and SB-PCIC2 are supposed to receive complete cytoreduction of PM.

Analysis of Treatment Failure after Complete Cytoreductive Surgery for Peritoneal Metastasis from Appendiceal Mucinous Neoplasm at a Japanese High Volume Center for Peritoneal Surface Malignancy.

BACKGROUND AND OBJECTIVES: Treatment failure after complete cytoreduction for appendiceal mucinous carcinoma peritonei (AMCP)has not been fully investigated. The present study was performed to clarify the risk factor for recurrence after complete cytoreduction for AMCP. METHODS: A total of 400 patients with AMCP who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated. RESULTS: Documented recurrence was developed in 135 (33.8%)patients. The 5- and 10-year progression-free survival was 51% and 49%, respectively. By multivariate analysis, histological subtype of peritoneal disease(high-grade AMCP[AMCP-H]and AMCP-H with signet ring cells), serum CA19- 9 level, and PCIB20 were significantly associated with reduced progression-free survival. In contrast, histologic subtype of mucin without epithelial cells(MWEC)showed the lowest risk for recurrence. Eighty-six patients had localized intra-abdominal recurrence, and 42 patients had diffuse peritoneal recurrence. Recurrence was found in the various peritoneal sectors. Eighty-one patients underwent complete cytoreduction for the recurrence, and the overall survival 5-year survival rate after secondary cytoreduction was 49%. CONCLUSIONS: Risk factors for recurrence were histologic subtype, PCI cutoff level, and serum CA19-9 levels. Aggressive second attempt of cytoreduction in patients with localized recurrence improved the survival.

Effects of Neoadjuvant Laparoscopic Hyperthermic Intraperitoneal Chemotherapy and Neoadjuvant Intraperitoneal/Systemic Chemotherapy on Peritoneal Metastases from Gastric Cancer.

BACKGROUND: The Peritoneal Cancer Index (PCI) is the most important prognostic factor following comprehensive treatment for peritoneal metastasis (PM) from gastric cancer (GCPM); however, 70 % of patients with GCPM showed a PCI score above the cut-off level at the time of diagnosis. Furthermore, neoadjuvant chemotherapy may reduce the PCI score to lower than the cut-off levels. In this study, the effects of neoadjuvant laparoscopic hyperthermic intraperitoneal chemoperfusion (NLHIPEC) and neoadjuvant intraperitoneal/systemic chemotherapy (NIPS) were investigated. MATERIALS AND METHODS: In group A, NLHIPEC was performed twice in 53 patients with GCPM, separated by a 1-month rest interval. Changes in the PCI were studied at the time of first and second laparoscopy. In group B, after NLHIPEC, a series of 3-week cycles of NIPS were performed over three courses in 52 patients. A laparotomy for cytoreductive surgery (CRS) was then carried out and the PCI changes were studied. RESULTS: In group A, the PCI score at the time of the second session (11.8 ± 11.0) was significantly lower than at the time of the first session (14.2 ± 10.7), while in group B, the PCI at the time of laparotomy (9.9 ± 11.3) was significantly lower than at the time of NLHIPEC (14.8 ± 11.4). After NLHIPEC plus NIPS, complete cytoreduction was achieved in 30 (57.6 %) patients. CONCLUSIONS: NLHIPEC and NIPS are effective methods of reducing PCI levels before CRS.

Comprehensive Treatment Using Cytoreductive Surgery Combined with Perioperative Chemotherapy Improved Outcome of Colorectal Cancer Patients with Metachronous Peritoneal Metastasis.

To analyze the role of cytoreductive surgery(CRS)plus perioperative chemotherapy on the survival of colorectal cancer(CRC)patients with metachronous peritoneal metastasis(PM). A comprehensive treatment consisting of neoadjuvant chemotherapy plus CRS was performed in 291 CRC patients. Among the 291, 142 and 149 patients had synchronous and metachronous PM, respectively. The results showed no survival difference between the 2 groups. Median survival time(MST)of patients with metachronous PM with complete cytoreduction(CCR-0), small bowel(SB)-PCIC2, PCIC14 and differentiated histologic type ranged from 3.1 to 4.1 years. Five-year survival rates of metachronous group of the CCR-0, SB-PCIC2, PCI C14 and differentiated histologic type ranged from 25.8 to 38.9%. However, the 5-year survival rates of the incomplete cytoreduction(CCR-1), SB-PCIB3, PCIB15 and poorly differentiated type were significantly lower than those of the CCR-0, SB-PCIC2, PCIC14 and differentiated histologic type. Postoperative Grade 3, and Grade 4 morbidity were experienced in 11(5.8%)and 16(10.7%)in metachronous group. Mortalities of metachronous group were 1.3%(2/149). The comprehensive treatment can be performed safely and improves the survival of CRC patients with metachronous PM. After NAC, patients with SB-PCIC2, PCIC14 and differentiated type of histology are candidates for CRS, and CCR-0 resection combined with HIPEC is recommended.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Dissemination from Small Bowel Malignancy: Results from a Single Specialized Center.

BACKGROUND: Peritoneal dissemination is a frequent pattern of recurrence and metastasis of small bowel malignancy (SBM). However, the survival of patients with peritoneal dissemination from SBM is not clear, and there is no consensus on the treatment for it. PATIENTS AND METHODS: A total of 31 selected patients with peritoneal dissemination from SBM were treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) between January 2006 and January 2014. The major focus of this study was overall survival, as well as morbidity and mortality. RESULTS: Twenty-five patients had small bowel adenocarcinoma (SBA), and six patients had non-adenocarcinoma SBM. HIPEC was performed on 21 patients, and 21 patients received complete cytoreduction. There was no treatment-related mortality, and eight (25.8 %) patients had grade 3-4 complications. Until the latest follow-up, the median survival of 31 patients after CRS and HIPEC was 36 months (range 5-95 months), and the median survival after diagnosis was 51 months (range 18-101 months). For 25 patients with peritoneal carcinomatosis from SBA, the median survival after CRS and HIPEC was 36 months (range 6-95 months), and the median survival after diagnosis was 50 months (range 18-101 months). Multivariate analysis revealed that peritoneal cancer index <15 (p = 0.009) and HIPEC (p < 0.001) were independent predictors of better survival in patients with peritoneal dissemination from SBM treated by CRS and HIPEC. CONCLUSIONS: Until more data become available, a reasonable strategy for the treatment of SBM is CRS and HIPEC. It can be applied with acceptable safety in selected patients with peritoneal dissemination from SBM.

Treatment Failure Following Complete Cytoreductive Surgery for Peritoneal Metastasis from Colorectal Cancer.

Treatment failure after complete cytoreduction for peritoneal metastasis(PM)from colorectal cancer(CRC)has not been fully investigated. The present study was performed to clarify the risk factors for recurrence after complete cytoreduction for CRC with PM and the role of repeat surgery for recurrence. MATERIALS AND METHODS: A total of 205 patients with CRC who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated. RESULTS: Recurrence occurred in 149(73%)patients. The 5-year overall and progression-free survival rates were 26%and 7%, respectively. By multivariate analysis, positive cytology, serum CEA level higher than normal range, and small bowel peritoneal cancer index B3 were significantly associated with reduced progression-free survival. Blood-borne recurrence was found in 62 (44%)of 149 patients. Repeat surgery was performed in 44(30%), and complete removal was performed in 28(64%) patients. Long-term survival after repeat surgery was experienced in patients with localized peritoneal recurrence and/or liver recurrence. CONCLUSIONS: This study showed that a second attempt at cytoreduction in patients with localized intra-abdominal and liver recurrence is of benefit. Blood-borne recurrence was found in 44% of recurrent patients. The prophylaxis of recurrence should therefore be performed using systemic chemotherapy after CRS plus HIPEC.

Outcome data of patients with peritoneal carcinomatosis from gastric origin treated by a strategy of bidirectional chemotherapy prior to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in a single specialized center in Japan.

BACKGROUND: Management of peritoneal disseminated gastric cancer (GC) remains a challenging problem. The purpose of our study was to evaluate the outcome of bidirectional induction chemotherapy [bidirectional intraperitoneal and systemic induction chemotherapy (BIPSC)] in patients with peritoneal carcinomatosis (PC) arising from GC who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). PATIENTS AND METHODS: Overall, 194 patients with PC arising from GC were treated with BIPSC comprising intraperitoneal docetaxel at a dose of 20 mg/m(2) and cisplatin at a dose of 30 mg/m(2) followed by four cycles of oral S-1 at a dose of 60 mg/m(2). CRS and HIPEC were performed in responders to BIPSC. RESULTS: Of these 194 patients, 152 (78.3 %) underwent CRS and HIPEC between January 2005 and December 2012. Treatment-related mortality was 3.9 %, and major complications occurred in 23.6 % of patients. The median survival rate was 15.8 months, with 1-, 2-, and 5-year survival rates of 66, 32 and 10.7 %, respectively, in the patients treated with combined treatment. Multivariate analysis identified pathologic response to BIPSC (p = 0.001), low tumor burden [peritoneal cancer index (PCI) ≤ 6] (p = 0.001), and completeness of CRS (CC-0, CC-1) (p = 0.001) as independent predictors for a better prognosis. CONCLUSION: As a viable option, BIPSC with CRS and HIPEC for patients with PC arising from GC may be performed safely, with acceptable morbidity and mortality, in a specialized unit. Response to BIPSC, optimal CRS and limited peritoneal dissemination seem to be essential to achieve the best outcomes in these patients.

[A case of gastric adenosquamous carcinoma with peritoneal dissemination in which treatment with S-1 plus paclitaxel therapy resulted in improved long-term survival].

Gastric adenosquamous carcinoma is a rare malignancy with a poor prognosis. We recently performed palliative gastrectomy for a gastric adenosquamous carcinoma with peritoneal dissemination and provided a course of systemic chemotherapy with S-1 plus paclitaxel(PTX)after the surgery. No serious adverse events were observed, and treatment with S-1 plus PTX was continued for 1 year before being switched to adjuvant chemotherapy with S-1 alone for another year. The tumor maker levels normalized within 2 months of the initial treatment, and the peritoneal dissemination could no longer be detected by abdominal computed tomography(CT). The patient remained in clinical remission and maintained long-term survival of over 8 years.

Pharmacokinetics of docetaxel during hyperthermic intraperitoneal chemotherapy for peritoneal metastasis.

UNLABELLED: The purpose of this manuscript is to report the pharmacokinetics of docetaxel during hyperthermic intraperitoneal chemotherapy (HIPEC) after peritonectomy. MATERIALS AND METHODS: Eleven patients with peritoneal metastasis (PM) underwent peritonectomies combined with 40 min of HIPEC with 40 mg/body of docetaxel. The pharmacokinetics of docetaxel were studied by using high-performance liquid chromatography. RESULTS: The docetaxel concentration at the start of HIPEC (0 min) was 9.084 ± 0.972 mg/L. The concentration gradually decreased to 5.599 ± 0.458 mg/L 40 min after HIPEC. In contrast, serum docetaxel levels increased during HIPEC, reaching a maximum level of 0.1334 ± 0.0726 mg/L at 40 min. The clearance (CLp) was 3.164 ± 1.383 L/hr, and the area under the curve (AUC) ratio was 95.12 ± 87.32. The AUC ratio of less-extensive peritonectomies was significantly higher than that of extended peritonectomies. The docetaxel concentration in the tumor tissue increased at 40 min (4.45 mg/gr). The apparent permeability (Papp, 40 min) was 1.47 ± 0.67 mm/40 min. No severe adverse effects were observed after HIPEC. CONCLUSION: From these results, 40 mg is a safe dose for docetaxel combined with HIPEC, and the locoregional intensity of docetaxel is enough to control PM less than 1.47 mm in diameter.

Cytoreductive surgery for synchronous and metachronous colorectal peritoneal dissemination: Japanese P classification and peritoneal cancer index.

Aim: The outcomes of cytoreductive surgery (CRS) for synchronous and metachronous colorectal peritoneal dissemination were investigated using the Japanese P classification and peritoneal cancer index (PCI). Methods: CRS was performed in 111 cases of synchronous peritoneal dissemination and 115 cases of metachronous peritoneal dissemination. The P classification and PCI were determined at the time of laparotomy. Results: In the synchronous dissemination group, the 5-year overall survival rates after CRS in P1/P2 and P3 cases were 51% and 13%, respectively. Even for P3, 51% of the patients achieved macroscopic cytoreductive complete resection (CC-0), with a 5-year survival rate of 40%. When P3 cases were classified into PCI 0-9, 10-19, 20-29, and 30-39, CC-0 was achieved in 93%, 70%, 6%, and 0% of the cases, respectively, and the 5-year survival rate of PCI 0-9 was 41%. In the metachronous dissemination group, the 5-year survival rates were 62% for PCI 0-9 and 22% for PCI 10-19; 5-year survival was not observed in patients with a PCI ≥ 20. CC-0 was significantly associated with the postoperative prognosis in both synchronous and metachronous peritoneal dissemination. Conclusion: In cases of synchronous dissemination, CRS must be performed for P1 and P2 cases or those with a PCI < 10, while detailed examination using PCI is required for P3 cases. In cases of metachronous dissemination, CRS should be considered when the PCI score is <20.

Preoperative carcinoembryonic antigen level predicts prognosis in patients with pseudomyxoma peritonei treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Even though management of pseudomyxoma peritonei (PMP) was improved with cytoreductive surgery (CRS) and hyperthermic chemotherapy (HIPEC), several aspects of PMP still need to be optimized, including patient selection for surgery and prognostic factors. We assessed the role of preoperative carcinoembryonic antigen (CEA) levels in PMP patients treated with CRS and HIPEC. METHODS: A total of 449 PMP patients with documented preoperative CEA levels referred to our center between 2005 and 2011 underwent CRS and HIPEC. The association between CEA levels and characteristics of patients with PMP was assessed with χ (2) test, linear correlation, and logistic regression analyses. Survival analysis was performed with Cox proportional hazard model. RESULTS: Median age was 55 (range 19-84) years. There were 245 (54.5 %) females and 204 (45.5 %) males. Preoperative CEA levels were elevated in 328 (73 %, sensitivity) patients with PMP. Preoperative CEA levels were also related to peritoneal cancer index (P < 0.0001), cytoreductive surgery scores (P < 0.0001), progress free survival (P < 0.001) and overall survival (P < 0.001) in patients with PMP. CONCLUSIONS: Our results indicated that preoperative CEA levels are useful in predicting the extent of disease and surgical success as well as progress-free and overall survival in patients with PMP treated with cytoreductive surgery and HIPEC.

A rare case of pseudomyxoma peritonei with Morgagni hernia.

Both pseudomyxoma peritonei and Morgagni hernias in adults are rare clinical conditions. A 70-year-old woman who was diagnosed with pseudomyxoma peritonei with Morgagni hernia underwent cytoreductive surgery and primary repair. Pseudomyxoma peritonei causes increased intra-abdominal pressure that may lead to acquired congenital diaphragmatic hernia when there is a local fragility in the diaphragmatic musculature. Parietal peritonectomy of the right diaphragmatic peritoneum can safely remove the hernia sac. The high rate of infections associated with cytoreductive surgery causes hesitation for concurrent mesh repair for Morgagni hernia. This is the first report of pseudomyxoma peritonei with Morgagni hernia. Cytoreductive surgery including parietal peritonectomy of the right diaphragmatic peritoneum plus primary repair of hernial defect was performed safely and successfully, which achieved positive short-term results for patients with pseudomyxoma peritonei-associated Morgagni hernia.

Treatment results of diffuse malignant peritoneal mesothelioma.

During the last 7 years, 21 patients with DMPM were treated. Histologic types were epitheloid type in 18 patients, biphasic type in 2 patients and sarcomatoid type in 1 patient. Preoperative systemic chemotherapy, hyperthermic intraperitoneal chemotherapy(HIPEC) by laparoscopy(LHIPEC), and intraperitoneal(IP) chemotherapy were done in 14, 3 and 1 patients, respectively. Cytoreductive surgery(CRS) was done in 13 patients. Ten patients received HIPEC after CRS. Partial responses were experienced in 4 of 13 patients treated with preoperative systemic chemotherapy. One of three patients treated by LHIPEC showed complete response. Among 13 patients received laparotomy, complete removal of PC was done in 4(31%) patients. The other 9 patients who received incomplete cytoreduction had diffuse involvement on the small bowel and its mesentery. All over 5-year survival was 17%. Patients treated with HIPEC survived significantly longer than non-HIPEC group. Neoadjuvant laparoscopic HIPEC may have a great role in the preoperative control of small PC on the surface of small bowel.

The Development of Peritoneal Metastasis from Gastric Cancer and Rationale of Treatment According to the Mechanism.

In the present article, we describe the normal structure of the peritoneum and review the mechanisms of peritoneal metastasis (PM) from gastric cancer (GC). The structure of the peritoneum was studied by a double-enzyme staining method using alkaline-phosphatase and 5'-nucreotidase, scanning electron microscopy, and immunohistological methods. The fundamental structure consists of three layers, mesothelial cells and a basement membrane (layer 1), macula cribriformis (MC) (layer 2), and submesothelial connective tissue containing blood vessels and initial lymphatic vessels, attached to holes in the MC (layer 3). Macro molecules and macrophages migrate from mesothelial stomata to the initial lymphatic vessels through holes in the MC. These structures are characteristically found in the diaphragm, omentum, paracolic gutter, pelvic peritoneum, and falciform ligament. The first step of PM is spillage of cancer cells (peritoneal free cancer cells; PFCCs) into the peritoneal cavity from the serosal surface of the primary tumor or cancer cell contamination from lymphatic and blood vessels torn during surgical procedures. After PFCCs adhere to the peritoneal surface, PMs form by three processes, i.e., (1) trans-mesothelial metastasis, (2) trans-lymphatic metastasis, and (3) superficial growing metastasis. Because the intraperitoneal (IP) dose intensity is significantly higher when generated by IP chemotherapy than by systemic chemotherapy, IP chemotherapy has a great role in the treatment of PFCCs, superficial growing metastasis, trans-lymphatic metastasis and in the early stages of trans-mesothelial metastasis. However, an established trans-mesothelial metastasis has its own interstitial tissue and vasculature which generate high interstitial pressure. Accordingly, it is reasonable to treat established trans-mesothelial metastasis by bidirectional chemotherapy from both IP and systemic chemotherapy.

Treatment results of peritonectomy combined with perioperative chemotherapy for colorectal cancer-patients with peritoneal carcinomatosis.

Operation results of 81 colorecatal cancer-patients with peritoneal carcinomatosis (PC) treated with peritonectomy plus perioperative chemotherapy are reported. The patients who had the following evidences are considered to be eligible for peritonectomy: 1) No evidence of N3 lymph node involvement, 2) No evidence of hematogenous metastasis, 3) No progressive disease after preoperative chemotherapy, 4) No severe co-morbidities or no poor general condition. Complete cytoreduction resection is aimed for removing all macroscopic tumors by peritonectomy using electrosurgical techniques. The completeness of cytoreduction (CC scores) after peritonectomy is classified into the following 4 criteria: CC-0-no peritoneal seeding was exposed during the complete exploration, CC-1-residual tumor nodules are less than 2.5 mm in diameter, CC-2-nodules are between 2 .5 mm and 25 mm in diameter, CC-3-nodules are greater than 25 mm in diameter, CC-2 and CC-3 are regarded as incomplete cytoreduction. Operation time and blood loss were 237 ± 124 min. (799-90 min) and 1,598 ± 1,411 mL (6,500-20 mL), respectively. Postoperative complications developed in 37( 46%) patients. The patients received CC-0/ -1 resection survived significantly longer than those of CC-2/ -3 group. The patients with PCI ≤ 10 survived significantly longer than those with PCI≥ 11. CC and PCI scores are the independent prognostic factors. The relative risk for death of CC-2/-3 group was 4.6-fold higher than that of CC-0/ -1 group. Accordingly, peritonectomy is indicated for patients with PCI score≤ 10.

Indication of peritonectomy for peritoneal dissemination.

A total of 521 patients with peritoneal carcinomatosis (PC) were treated by peritonectomy and perioperative chemotherapy. Each of the 95, 58, 316, 31, 10 and 11 patients were from gastric, colorectal, appendiceal, ovarian, small bowel cancer and mesothelioma, respectively. The distribution and volume of PC are recorded by the Sugarbaker peritoneal carcinomatosis index (PCI). Peritonectomy was performed with a radical resection of the primary tumor and all gross PC with involved organs, peritoneum, or tissue that was deemed technically feasible and safe for the patient. The postoperative major complication of grade 3 was found in 14%, and total 30-day mortality was 2.7%. The survival of gastric cancer patients with a PCI score ≤ 6 was significantly better than those with a PCI score ≥ 7. In appendiceal neoplasm, patients with PCI score less than 28 showed significantly better survival than those with PCI score greater than 29. The survival of colorectal cancer patients with a PCI score ≥ 11 was significantly poorer than those with a PCI score ≤ 10. Among the various prognostic factors in appendiceal neoplasm and gastric cancer patients, CC-0 complete cytoreduction was the most important independent prognostic factor. Peritonectomy is done to remove macroscopic disease and perioperative intraperitoneal chemotherapy to eradicate microscopic residual disease aiming to remove disease completely with a single procedure. Peritonectomy combined with perioperative chemotherapy may achieve long-term survival in a selected group of patients with PC. The higher mortality rate underlines this necessarily strict selection that should be reserved to experienced institutions.

Retrospective Analysis of Patients with Signet Ring Subtype of Colorectal Cancer with Peritoneal Metastasis Treated with CRS & HIPEC.

Signet ring cell subtype (SRC) of colorectal cancer (CRC) is a rare subtype and occurs in approximately 1% of all patients with CRC. Patients with peritoneal metastasis (PM) of SRC have a poor prognosis, and this subtype is frequently considered as a contra-indication for extensive surgical treatment. This retrospective study from two dedicated peritoneal surface malignancy centers in Japan included all patients treated with CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between July 1994 and December 2017 from a prospectively maintained database. Preoperative, operative, and postoperative parameters were recorded, including complication rates and follow-up. Sixty of the 320 patients treated with CRS due to CRC were diagnosed with SRC subtype. The mean age of the patients was 51.4 years, and the mean peritoneal carcinomatosis index (PCI) was 13.1. Complete cytoreduction was achieved in 61.7% of cases. The postoperative morbidity rate was 25% and the mortality rate was 1.7%. The median overall survival (OS) was 14.4 months. Cox regression analysis revealed small bowel PCI > 2 (hazard ratio (HR) 6.5; p = 0.008) as the most important factor for OS. With accurate patient selection (e.g., PCI ≤ 12 or small bowel PCI ≤ 2), even patients with PM of CRC with SRC subtype may benefit from CRS and HIPEC, with median OS from 17.8 to 20.8 months and 5-year OS of 11.6%.