Primary peritoneal carcinoma is an acquired malignancy arising from the mesothelial lining of the peritoneum. No hereditary causative gene is identified in this packet, and the condition does not follow a defined Mendelian inheritance pattern. The specific molecular drivers of malignant transformation in peritoneal mesothelium are under ongoing investigation. The histologic and molecular overlap with ovarian surface epithelial-stromal tumors suggests shared pathogenic mechanisms, though the peritoneal origin distinguishes this condition as a separate entity.

Diagnosis requires histologic confirmation of a peritoneal serous malignancy combined with careful exclusion of a primary ovarian or fallopian-tube origin. Specifically, the ovaries must be uninvolved or show surface-only involvement without stromal invasion, and peritoneal tumor burden must exceed ovarian surface involvement. Because the condition shares histologic features with ovarian and related tumors, thorough pathologic evaluation is necessary for accurate classification. A multidisciplinary review process that incorporates clinical, radiologic, and pathologic data typically supports the final diagnostic determination.

Two FDA-approved therapies are available for primary peritoneal carcinoma. Olaparib (LYNPARZA), a small molecule therapy approved through the NDA pathway by the FDA's Center for Drug Evaluation and Research (CDER), received approval in 2017. Bevacizumab (AVASTIN), a biologic therapy also approved through the CDER pathway, received approval in 2004. Treatment planning is individualized based on disease extent, tumor characteristics, and individual circumstances and is not governed by a single standard sequence. Care typically involves a multidisciplinary oncology team. Treatment goals vary by clinical context and may include disease control, symptom management, or curative intent depending on the specific situation. Several additional investigational therapies are in active clinical development for this condition.

Prognosis in primary peritoneal carcinoma depends on disease extent at the time of diagnosis, tumor characteristics, and individual response to available therapies. Outcomes vary substantially among affected individuals. Advances in the available treatment options have expanded the therapeutic landscape over time. Access to specialized oncology expertise and clinical trial participation may offer additional options in the management of this condition.

Primary peritoneal carcinoma is an active area of clinical investigation. Numerous certified active trial records are present, spanning drug-based, biologic, procedural, and other investigational approaches. Published literature includes a substantial proportion of clinical trial publications as well as biomarker research. Several additional investigational therapies are under development and are the subject of ongoing trials.