Management of peritoneal carcinomatosis secondary to metastatic cancer of unknown primary in men.

Peritoneal seeding of cancer cells leading to peritoneal carcinomatosis (PC) is an ominous finding that has primarily been described in women with underlying ovarian malignancy. It is also a common development in patients with gastrointestinal malignancy and may sometimes occur in the absence of a known, identified primary malignancy. Peritoneal carcinomatosis resulting from a cancer of unknown primary (CUP) is a rare and ill-defined entity, and as a result, there is no clear guidance on the most effective management strategy for this group of patients. The indiscriminate use of numerous investigations in an attempt to identify a primary malignant focus is discouraged. A subjective approach to the patient, with the aim of identifying patients who would benefit from therapeutic management and those who should be managed with palliative intent, should be employed. Aggressive therapeutic measures such as cytoreduction, peritonectomy and hyperthermic intraoperative intraperitoneal chemotherapy may offer some long-term survival, but selection of appropriate patients is essential. Large randomized studies are needed in patients with PC secondary to CUP to determine the efficacy of such treatment options. Studies into the pathogenesis and molecular pathways of this condition are required to improve understanding and guide development of novel therapeutic strategies.