Malignant Peritoneal Tumors - Introduction.

This article provides an introduction to peritoneal tumors, which are the subject of a series of review papers published in Issue 5 (2019) of Klinicka onkologie. Many malignant peritoneal tumors are characterized by production of mucinous and gelatinous masses, multiple peritoneal disability, so-called peritoneal carcinomatosis, and various grades of malignancy depending on their origin, staging, and histological type. Malignant peritoneal tumors are rare and their clinical symptomatology is nonspecific and varies according to the extent of disability. Diagnosis, particularly in the initial asymptomatic stages, is very complicated and often impossible, and tumors are often diagnosed by chance during other operations. Malignant peritoneal tumors were regarded as incurable and lethal for a long time; however, this view has changed over the past three decades. The Sugarbaker method, a combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, was introduced in the 1990s. Postoperative cytostatic lavage is usually performed in specific cases. Classifications for the extent of disease and completeness of cytoreduction were established. Studies repeatedly confirmed the efficacy of this treatment for peritoneal malignancy. The combination of an aggressive surgical approach and intraperitoneal chemotherapy not only enhances quality of life, but also prolongs progression-free survival and overall survival in selected patients. Specialized centers for treatment of peritoneal malignancy were established based on results from the Czech Republic and around the world. These centers provide complex care, including specific surgical interventions and follow-up, for selected patients with primary and secondary peritoneal malignancy.

Treatment of Malignant Peritoneal Mesothelioma.

Malignant mesothelioma is a highly malignant disease that most often occurs in the pleura of the thoracic cavity, followed by the peritoneum, pericardium, or tinea vaginalis testis. Malignant peritoneal mesothelioma (MPM) accounts for 10-15% of all mesotheliomas. The most significant risk factor for MPM is exposure to asbestos. There is no specific symptomatology, and imaging (computed tomography) and histopathology are crucial for diagnosis. There are no generally accepted guidelines for radical treatment of MPM. Previously, the prognosis of MPM patients was poor, with survival of up to 1 year. However, median survival of patients who are suitable candidates for radical therapy is currently 3-5 years. A combination of cytoreductive surgery (CRS) and hyperthermic perioperative chemotherapy (HIPEC) is recommended in selected patients, while chemotherapy alone has insufficient efficacy. Systemic chemotherapy remains the only treatment option for patients who are unsuitable for CRS and HIPEC. In selected patients scheduled for or currently undergoing CRS and HIPEC, surgery may be performed in combination with systemic chemotherapy in the neoadjuvant or adjuvant setting; however, the benefit is unclear. There are no recommendations for follow-up of MPM patients after radical surgery. Existing guidelines for the pleural form (e.g., those issued by the European Society for Medical Oncology) do not specify the frequency or method of investigation. In the absence of specific serum markers, only CA 125 and mesothelin are generally available. Imaging methods include ultrasonography, computed tomography, and magnetic resonance imaging.

Short article: Influence of regulatory NLRC5 variants on colorectal cancer survival and 5-fluorouracil-based chemotherapy.

BACKGROUND: NLRC5 is an interferon γ-inducible protein, which plays a role in immune surveillance with a potential influence on cancer survival. OBJECTIVE: We aimed to evaluate the effect of potential regulatory variants in NLRC5 on overall survival and survival after 5-fluorouracil (5-FU)-based therapy of colorectal cancer (CRC) patients. PATIENTS AND METHODS: We carried out a case-only study in a Czech population of 589 cases; 232 received 5-FU-based therapy. Eleven variants within NLRC5 were selected using in-silico tools. Associations between polymorphisms and survival were assessed by Cox regression analysis adjusting for age at diagnosis, sex, and TNM stage. Survival curves were derived using the Kaplan-Meier method. RESULTS: Two variants showed a significant association with survival. All patients and metastasis-free patients at the time of diagnosis (pM0) who were homozygous carriers of the minor allele of rs27194 had a decreased overall survival (OSall and OSpM0) and event-free survival (EFSpM0) under a recessive model (OSall P=0.003, OSpM0 P=0.005, EFSpM0 P=0.01, respectively). OS was also decreased for all patients and for pM0 patients who carried at least one minor allele of rs289747 (OSall P=0.03 and OSpM0 P=0.003, respectively). Among CRC patients, who underwent a 5-FU-based adjuvant regimen, rs12445252 was associated with OSall, OSpM0 and EFSpM0, according to the dosage of the minor allele T (OSall P=0.0004, OSpM0 P=0.0001, EFSpM0 P=0.008, respectively). CONCLUSION: Our results showed that polymorphisms in NLRC5 may be used as prognostic markers of survival of CRC patients, as well as for survival in response to 5-FU treatment.