Epidemiology: Extent of the Problem

Peritoneal carcinomatosis (PC) most commonly represents local or regional evolution of an abdominal carcinoma. Sometimes it can be synchronous with the primary tumor (primary carcinomatosis) but more often is present as recurrent disease (metachronous or secondary) after first-line treatment of the originating tumor. Patients with tumors from colon, ovary, and stomach cancer are more likely to present with PC during their clinical course. Less frequently, other abdominal malignancies, such as uterus, pancreas, small bowel, biliary, or urinary tract, can involve the peritoneum. Tumors originating from the peritoneum itself are definitely rarer: mesothelioma, pseudomyxoma peritonei (PMP), primitive peritoneal carcinoma, and desmoplastic small-round-cell tumor. PC from extra-abdominal tumors, such as lung, breast, melanoma, or peritoneal sarcomatosis, is exceptional, and few epidemiological data are available on them. Statistical analysis of worldwide cancer incidence, prevalence, and mortality rate is available on GLOBOCAN 2012 [1]. In Italy, most epidemiological data are available in the reports from the Italian Association of Tumor Registries (AIRTUM) [2], which collects data regarding incidence, prevalence, and mortality rates from all local and regional tumor registries, covering at least 34% of total population. This data is considered a high-quality regional coverage by and international ranking system (GLOBOCAN 2012 rate B).