Impact of Previous Gynecologic Surgical Procedures on Outcomes of Non-Gynecologic Peritoneal Malignancies Mimicking Ovarian Cancer: Less Is More?

Critical reappraisal of prognostic indicators for 949 mucinous appendiceal neoplasm patients

BACKGROUND AND OBJECTIVES

The standard of care for treatment of an appendiceal mucinous neoplasm with peritoneal dissemination is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). These two treatments are combined in the operating room. A crucial requirement for benefit long-term is proper patient selection. Clinical and histopathologic prognostic indicators are used, along with the patient's fitness for surgery, to select patients to receive CRS and HIPEC.

METHODS

This study seeks to identify the reliable prognostic indicators for four different groups of patients. They are (1) the low-grade appendiceal mucinous neoplasms (LAMN) with a complete CRS, (2) the mucinous appendiceal adenocarcinomas (MACA) with complete CRS, (3) MACA with lymph node metastases (MACA-LN) with complete CRS, and (4) all histologic subtypes with incomplete cytoreduction. The prognostic indicators were evaluated for their impact on overall survival in these four groups of patients.

RESULTS

The completeness of cytoreduction (CC) score statistically significantly showed survival differences in all three histologic subtypes. The peritoneal cancer index (PCI) showed significance with LAMN and MACA-LN but not with MACA and not with incomplete CRS. The prior surgical score (PSS) was a prognostic indicator that predicted the outcome with LAMN, MACA-LN, and incomplete CRS patients but not with the MACA group. Patients who were symptomatic or who had extensive systemic chemotherapy before CRS had a significantly reduced survival.

CONCLUSION

The utility of prognostic indicators varied greatly within our four different groups of appendiceal mucinous neoplasms. CC score was always a reliable prognosticator. Surprisingly, PCI was not.

Colorectal carcinoma peritoneal metastases-derived organoids: results and perspective of a model for tailoring hyperthermic intraperitoneal chemotherapy from bench-to-bedside

BACKGROUND

Peritoneal metastases from colorectal cancer (CRCPM) are related to poor prognosis. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been reported to improve survival, but peritoneal recurrence rates are still high and there is no consensus on the drug of choice for HIPEC. The aim of this study was to use patient derived organoids (PDO) to build a relevant CRCPM model to improve HIPEC efficacy in a comprehensive bench-to-bedside strategy.

METHODS

Oxaliplatin (L-OHP), cisplatin (CDDP), mitomycin-c (MMC) and doxorubicin (DOX) were used to mimic HIPEC on twelve PDO lines derived from twelve CRCPM patients, using clinically relevant concentrations. After chemotherapeutic interventions, cell viability was assessed with a luminescent assay, and the obtained dose-response curves were used to determine the half-maximal inhibitory concentrations. Also, induction of apoptosis by different HIPEC interventions on PDOs was studied by evaluating CASPASE3 cleavage.

RESULTS

Response to drug treatments varied considerably among PDOs. The two schemes with better response at clinically relevant concentrations included MMC alone or combined with CDDP. L-OHP showed relative efficacy only when administered at low concentrations over a long perfusion period. PDOs showed that the short course/high dose L-OHP scheme did not appear to be an effective choice for HIPEC in CRCPM. HIPEC administered under hyperthermia conditions enhanced the effect of chemotherapy drugs against cancer cells, affecting PDO viability and apoptosis. Finally, PDO co-cultured with cancer-associated fibroblast impacted HIPEC treatments by increasing PDO viability and reducing CASPASES activity.

CONCLUSIONS

Our study suggests that PDOs could be a reliable in vitro model to evaluate HIPEC schemes at individual-patient level and to develop more effective treatment strategies for CRCPM.

Selection Factors for Treatment and Stratification of Rare Abdominal or Pelvic Tumors with Peritoneal Metastases

To maximize the results of treatments for peritoneal metastases for rare abdominal or pelvic tumors, selection of patients with a possibility for long-term success is necessary. Because these malignancies are rare, data from which these selection factors can be extracted do not exist. In order to facilitate knowledgeable patient selection for treatment, the well established clinical and histopathologic features of the common malignancies treated for peritoneal metastases were reviewed. The potential application of selection factors for common diagnoses was explored in an attempt to provide selection factors for rare tumors. The histopathologic grade, the lymph node status, the Ki-67 proliferation index, prior surgical score (PSS), preoperative radiologic imaging, preoperative laparoscopic assessment, response to neoadjuvant chemotherapy, peritoneal cancer index (PCI), and completeness of cytoreduction score were all included in this search for relevant selection factors for a rare disease. To facilitate the use of selection factors from common peritoneal metastases diagnoses, these diseases were divided into four groups. Placement of the rare cause of peritoneal metastases into one of these four groups will allow knowledgeable selection for treatment. Rare diseases with a natural history resembling low-grade appendiceal neoplasms are in group 1, diseases resembling lymph node negative colorectal cancer are in group 2, diseases resembling lymph node positive colorectal peritoneal metastases in group 3, and diseases resembling gastric cancer in group 4.

Progression of perforated cystadenoma of the appendix to pseudomyxoma peritonei over 18 years. A case report

INTRODUCTION AND IMPORTANCE

In the past, mucinous appendiceal neoplasms (MAN) greater than 2 cm in diameter were treated by a right colon resection. New data shows that treatment options are to be determined by the histopathologic grade of the appendiceal tumor and the condition of the wall of the appendix (intact vs. breached).

CASE PRESENTATION

A 39-year-old woman had an incidental diagnosis of a low-grade appendiceal mucinous neoplasm (LAMN) at the time of a hysterectomy. The appendiceal tumor had small quantities of mucus surrounding an enlarged appendix. No tumor cells were seen in the mucus by histologic study. The patient was placed in follow-up. Eighteen years later she required treatment for advanced pseudomyxoma peritonei.

CLINICAL DISCUSSION

When 5 different histopathologic types of MAN are considered with an intact vs. perforated wall of the appendix, four different treatment options develop. With LAMN and well or moderately differentiated mucinous appendiceal adenocarcinoma (MACA), the patient does not require operative intervention if the wall of the appendix is intact. If mucus or mucus plus tumor cells are identified outside the appendix an intervention is indicated. In patients, as the one presented, in whom only small amounts of mucus are outside the appendix, surveillance may be recommended.

CONCLUSIONS

In patients with a diagnosed low-grade MAN, dissemination to regional lymph nodes is rare. Dissemination to the peritoneal space places the patient at risk to develop pseudomyxoma peritonei. As this case report illustrates, if surveillance is recommended, long-term follow-up is required.