Peritoneal mesothelioma: current status and future directions

Prolonged survival with systemic chemotherapy in an advanced malignant mesothelioma: A case report

Peritoneal mesotheliomas are very rare tumors. Their prognosis is poor, average survival does not exceed 1 year after peritoneal cytoreduction. Systemic chemotherapy is considered to have no proven value in the management of peritoneal mesotheliomas. Objective responses with systemic chemotherapy are very rare. We report here a case of an advanced peritoneal mesothelioma which achieved an unexpected partial response with chemotherapy, allowing the patient to have a right colectomy. The patient was referred to a specialized center on HIPEC, but taking in account the long awaiting interval, the HIPEC was judged to be inefficient and then the poursuit of 6 cycles of systemic chemotherapy was decided. The patient is still alive without any symptom and with a good performance status at 59 months after diagnosis. Throughout our case, we provide an encouraging evidence of the role of initial systemic chemotherapy in the downstaging of initially unresectable primary malignant mesothelioma and in the improvement of overall survival.

Intraperitoneal chemotherapy for gastric cancer with peritoneal metastasis

Peritoneal metastasis is the most frequent pattern of gastric cancer recurrence or metastasis and is a definitive determinant of prognosis. However, an effective means of treating peritoneal disease has not yet been established. Systemic chemotherapy has only a limited effect on peritoneal metastasis, although some progress has been shown in terms of median survival time, especially among patients with a minimal or moderate disease burden. Clinical research related to intraperitoneal administration of anticancer drugs is currently underway. An advantage of intraperitoneal chemotherapy is the ability to achieve high concentrations of anticancer drugs in the peritoneal cavity and the direct exposure of peritoneal deposits and free cancer cells to those drugs. In addition, pharmacokinetic studies with taxanes have shown that these high intraperitoneal drug concentrations are sustained for a considerable length of time, allowing prolonged exposure. As taxanes are the most appropriate drugs for intraperitoneal administration, the development of repeated intraperitoneal chemotherapy using taxanes for gastric cancer peritoneal metastasis-either alone or in combination with systemic chemotherapy-has taken place over the past decade, mostly in Japan. Several phase II trials and a phase III trial have recently demonstrated the efficacy of this therapy, including median survival times of 14.4-24.6 months and one-year overall survival rates of 67-91%. These results may lead to the approval of intraperitoneal taxanes, especially paclitaxel, for official insurance coverage in the near future.

Metachronous Uterine Endometrioid Adenocarcinoma and Peritoneal Mesothelioma in Lynch Syndrome: A Case Report

Lynch syndrome is a hereditary disease with germline mutation in a DNA mismatch repair gene, most often presenting with colorectal and/or endometrial carcinomas; however, the spectrum of Lynch syndrome-associated tumors is expanding. In this article, we report a case of a primary peritoneal epithelioid mesothelioma that developed in a Lynch syndrome patient 10 months after diagnosis of uterine endometrioid adenocarcinoma. To our knowledge, this is the first reported case of a Lynch syndrome patient with metachronous uterine endometrioid adenocarcinoma and primary peritoneal mesothelioma.

Peritoneal Mesothelioma: An Unusual Cause of High-Protein Ascites

We present a case illustrating the workup and diagnosis of peritoneal sarcomatous mesothelioma as an unusual etiology of intestinal obstruction and high-protein ascites in an otherwise healthy man. This rare disorder is diagnosed based on immunohistochemistry, which is necessary to differentiate it from other rare sarcomatous carcinomas. In many cases, localized disease can be treated to cure with surgery and intraperitoneal chemotherapy. Advanced disease is often treated for palliation of symptoms.

Advances in the management of peritoneal mesothelioma

Malignant peritoneal mesothelioma (PM) is an infrequent disease which has historically been associated with a poor prognosis. Given its long latency period and non-specific symptomatology, a diagnosis of PM can be suggested by occupational exposure history, but ultimately relies heavily on imaging and diagnostic biopsy. Early treatment options including palliative operative debulking, intraperitoneal chemotherapy, and systemic chemotherapy have marginally improved the natural course of the disease with median survival being approximately one year. The advent of cytoreduction (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has dramatically improved survival outcomes with wide median survival estimates between 2.5 to 9 years; these studies however remain largely heterogeneous, with differing study populations, tumor biology, and specific treatment regimens. More recent investigations have explored extent of cytoreduction, repeated operative intervention, and choice of chemotherapy but have been unable to offer definitive conclusions. CRS and HIPEC remain morbid procedures with complication rates ranging between 30% to 46% in larger series. Accordingly, an increasing interest in identifying molecular targets and developing targeted therapies is emerging. Among such novel targets is sphingosine kinase 1 (SphK1) which regulates the production of sphingosine-1-phosphate, a biologically active lipid implicated in various cancers including malignant mesothelioma. The known action of specific SphK inhibitors may warrant further exploration in peritoneal disease.

Intraperitoneal chemotherapy against peritoneal carcinomatosis: current status and future perspective

Peritoneal carcinomatosis (PC), caused by advanced abdominal malignancies, such as those of the ovarian and gastrointestinal tracts, has an extremely poor prognosis. Intraperitoneal (IP) chemotherapy has been clinically applied for several decades, but its clinical efficacy has not been fully determined. An accumulating body of evidence suggests that cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the optimal treatment for selected patients with ovarian and colorectal cancers with PC. Recent studies suggest that IP administration of taxane with systemic chemotherapy in a neoadjuvant setting improves patient survival in gastric cancer with PC. The pharmacokinetics of IP-administered drugs should be primarily considered in order to optimize IP chemotherapy. Therefore, the development of specific IP drugs using newly emerging molecular targeted reagents or new drug delivery systems, such as nanomedicine or controlled absorption/release methods, is essential to improve the efficacy of IP chemotherapy.

Drug development for intraperitoneal chemotherapy against peritoneal carcinomatosis from gastrointestinal cancer

Intraperitoneal (IP) chemotherapy for peritoneal carcinomatosis (PC) from gastrointestinal cancer has been investigated and applied clinically for several decades. Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy have been considered to be the optimal treatment options for selected patients with colorectal and gastric cancers with PC. Accumulating evidence suggests that the administration of IP paclitaxel for patients with PC from gastric cancer may improve the patient survival. The pharmacokinetics of such treatment should be considered to optimize IP chemotherapy. In addition, newly emerging molecular-targeted therapies and research into new drug delivery systems, such as nanomedicine or controlled absorption/release methods, are essential to improve the effects of IP chemotherapy. This review summarizes the current status and future prospects of IP chemotherapy for the treatment of gastrointestinal cancer.

Intraperitoneal paclitaxel induces regression of peritoneal metastasis partly by destruction of peripheral microvessels

PURPOSE

Intraperitoneal (IP) administration of paclitaxel (PTX) can enable direct infiltrate of high amount of PTX into peritoneal nodules and elicit remarkable clinical responses against peritoneal metastases. In this study, we examined the mechanisms leading to tumor shrinkage after IP PTX.

METHODS

We compared the microscopic features of peritoneal metastases before and after IP PTX in surgically removed human samples, as well as in a murine xenograft model using immunohistochemistry.

RESULTS

We found that many microvessels exist in the peripheral areas of metastatic nodules in human samples before treatment. However, peripheral vessels were greatly reduced in number, and luminal obstructions were observed in lesions showing complete response after chemotherapy including IP PTX. Similar changes were observed in peripheral vessels of peritoneal tumors in MKN45-inoculated nude mice treated with IP-PTX. Moreover, pimonidazole staining revealed that highly hypoxic regions were produced by IP PTX at the tumor periphery.

CONCLUSIONS

These findings strongly suggest that the remarkable efficacy of IP PTX in the treatment of peritoneal metastases is, at least in part, dependent on the destruction of peripheral microvessels by exposure to infiltrated PTX.