Analysis of the characteristics and outcomes of patients with pseudomyxoma peritonei of appendiceal origin treated with curative-intent surgery.

BACKGROUND: There are no previous studies on pseudomyxoma peritonei regarding the details of surgical procedures included in cytoreductive surgery and quantitative evaluation for peritoneal metastases by region in the abdominal cavity. This study aimed to describe the characteristics and procedural details involved in cytoreductive surgery, and survival outcomes of patients with pseudomyxoma peritonei originating from appendiceal mucinous neoplasm, and identify differences in the difficulty of cytoreductive surgery based on tumor location. METHODS: Patient characteristics and survival outcomes were studied through a retrospective review. The complete cytoreduction rate (i), the 5-year survival rate for patients with complete cytoreduction (ii), and an index as a complement (i × ii × 100) were described for patients who had tumors larger than 50 mm in one of the 13 regions of the abdominal cavity. RESULTS: A total of 989 patients were treated with curative-intent cytoreductive surgery. The median peritoneal cancer index was 18 (interquartile range, 6-29), with complete cytoreduction achieved in 702 patients (71%); the major complication rate was 17%. The median overall survival was 92.9 months, compared to 53.8 months for patients who underwent total gastrectomy and 30.4 months for those who underwent total colectomy. In the 13 abdominal regions, the index scores indicating cytoreduction difficulty were categorized into three risk groups: upper and mid-abdominal (>20), lateral abdominal (10-20), and small bowel (<10). CONCLUSIONS: Cytoreductive surgery offered favorable survival outcomes, even in cases involving total gastrectomy. The difficulty of achieving complete cytoreduction varied across abdominal regions and was classified into three levels.

[Pancreatic Acinar Cell Carcinoma with Peritoneal Recurrence Treated with Peritonectomy and Intraoperative Hyperthermic Intraperitoneal Chemotherapy-A Case Report].

A 31-year-old man with a big epigastric mass from pancreas body was completely removed by distal pancreatectomy and segmental gastrectomy. Two years after oral administration of S-1 for 4 courses, peritoneal dissemination on the right subdiaphragmatic space was detected. Laparotomy revealed white colored round nodules were found scattered on the peritoneal surface, and the peritoneal cancer index(PCI)was 18. To achieve complete resection of peritoneal nodules, peritonectomy was performed. After complete removal of macroscopic peritoneal metastasis(PM), intraoperative hyperthermic intraoperative peritoneal chemotherapy using 1 gr of gemcitabine and 60 mg of docetaxel was performed for 40 min with thermal dose of 41.5 min. Postoperative course was uneventful. Drug sensitivity test(HDRA method)showed that gemcitabine that gemcitabine showed the highest inhibition rate. The patient was treated with systemic gemcitabine chemotherapy. He is still alive without recurrence 18 months after peritonectomy plus intraoperative HIPEC. Pathological examination showed pancreatic acinar cell carcinoma(PACC)demonstrating positive for chymotrypsin. In conclusion, we present a PACC-case with PM successfully treated by a comprehensive treatment. Intraoperative HIPEC using gemcitabine may be effective for PACC patients with PM in treating residual micrometastasis after peritonectomy.

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.

Thirty-three long-term survivors after cytoreductive surgery in patients with peritoneal metastases from colorectal cancer: a retrospective descriptive study.

BACKGROUND: Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) improves survival in selected patients with peritoneal metastasis (PM) from colorectal cancer (CRC). However, little has been reported on characteristics and clinical course of long-term survivors with CRC-PM beyond 5 years. The objective of this study was to identify the clinical and oncological features affecting long-term survival of CRC-PM after comprehensive treatment. METHODS: Between January 1990 and April 2015, CRC-PM patients who underwent CRS with or without HIPEC in two Japanese tertiary hospitals were analyzed. Clinicopathological parameters and therapeutic details for long-term survivors (patients surviving ≥ 5 years after CRS) were described and compared with those for non-survivors (patients surviving < 5 years). RESULTS: The study identified 236 patients with CRC-PM who underwent CRS, with a median follow-up period of 2.5 years. Thirty-three patients (14.0%) were considered as long-term survivors. Compared with non-survivors, long-term survivors had a lower median peritoneal cancer index (PCI) [4 (1-27) vs 9 (0-39), p < 0.001]. Complete cytoreduction (CCR-0) was achieved in all long-term survivors, with a significantly higher rate [33/33 (100%) vs 141/203 (69.8%), p < 0.001]. Metachronous onsets of PM were more frequently observed in the long-term survivor group [26/33 (78.8%) vs 103/203 (50.3%), p = 0.018]. Regarding histopathology, long-term survivors more frequently had mucinous adenocarcinoma than non-survivors [8/33 (24.2%) vs 27/203 (13.3%)] and less likely exhibited poorly differentiated or signet ring cell carcinoma [2/33 (6.1%) vs 48/203 (23.7%)] (p < 0.001). CONCLUSIONS: One in seven patients with CRC-PM achieved the long-term milestone after CRS. A long-term survival was associated with the presence of low PCI, CCR-0, metachronous onset, and mucinous histology.

Advances with pharmacotherapy for peritoneal metastasis.

INTRODUCTION: A new treatment strategy involving cytoreductive surgery (CRS) combined with perioperative intraperitoneal (IP) chemotherapy was proposed in 1999 by the Peritoneal Surface Oncology Group International, and the strategy is now justified as a state-of-the-art treatment to improve the long-term survival of patients with peritoneal metastasis (PM). To achieve cure in the patients with PM, complete removal of macroscopic tumors and eradication of micrometastasis on the peritoneum, left after CRS are essential. Systemic chemotherapy is not indicated for the treatment of PM. In contrast, intraperitoneal (IP) chemotherapy brings about significantly higher locoregional dose intensity in the peritoneal cavity and subperitoneal tissues. In combination with anticancer drugs, hyperthermia enhances cytotoxicity against cancer cells. AREA COVERED: This article provides a systematic overview of PM from various cancers including gastric, colorectal, small bowel, appendiceal cancer, and mesothelioma. It also includes all the essential aspects of therapy. EXPERT OPINION: CRS plus perioperative intraperitoneal chemotherapy is safe with acceptable morbidity and mortality. It is justified as a standard treatment to improve the long-term survival of patients with PM and is now performed with curative intent for PM from various malignancies.