Peritoneal cancer is a malignancy affecting the peritoneum, the thin lining of the abdominal cavity that covers the organs and inner wall. When cancer develops in this tissue, it often spreads widely across the abdominal space. Because it is frequently diagnosed at a late stage, patients often seek clarity regarding the potential for a cure. Addressing this requires understanding the disease’s nature, the factors influencing its progression, and the aggressive, specialized treatments available through a multidisciplinary approach.
Understanding Peritoneal Cancer
Peritoneal cancer is categorized into two types based on origin. Primary peritoneal cancer (PPC) is rare, arising directly from the peritoneum. PPC is histologically similar to advanced ovarian cancer and is often treated using protocols developed for gynecological malignancies.
The far more common form is secondary peritoneal cancer, or peritoneal carcinomatosis. This occurs when cancer cells detach from a primary tumor elsewhere in the body and seed the abdominal lining. Common primary sites include the colon, stomach, appendix, and ovaries. The origin site is a fundamental determinant in the diagnostic and treatment approach. Secondary peritoneal cancer is typically considered Stage IV disease, indicating significant spread from the initial site. Both primary and secondary types are often diagnosed at this advanced stage due to a lack of distinct early symptoms.
Defining Curability and Prognosis
Achieving a traditional, permanent “cure” for advanced peritoneal cancer is uncommon due to the disease’s advanced nature at diagnosis. Modern oncology focuses instead on achieving durable, long-term survival, sustained remission, and effective disease control.
The disease is often managed as a chronic, recurring condition, with the goal of extending life and maintaining quality of life. Recent advancements have significantly improved the outlook, with median survival rates extending beyond historical norms. For patients with primary peritoneal, ovarian, or fallopian tube cancer, the five-year survival rate can approach 50% with aggressive therapy.
For patients with secondary peritoneal cancer receiving specialized multimodal treatment, median overall survival has increased from a few months to five years or more. This substantial improvement hinges on specialized cancer centers delivering complex, intensive treatment protocols.
Key Factors Determining Treatment Strategy
Physicians rely on specific clinical and pathological variables to determine a patient’s candidacy for aggressive, potentially life-extending treatments.
Key Determinants
The cancer’s origin, as the primary tumor site influences the cancer’s biological behavior and sensitivity to chemotherapy.
The aggressiveness of the cancer cells, indicated by their grade and histology; lower-grade tumors generally offer a more favorable outlook.
The Peritoneal Carcinomatosis Index (PCI) quantifies the total amount of disease spread and is a specific factor guiding treatment. The PCI score is calculated by dividing the abdomen into 13 regions and assigning a score (zero to three) based on the size of tumor nodules. The total score ranges from zero to 39; a lower score indicates less extensive disease and a better likelihood of successful intervention.
The patient’s overall physical condition, or performance status, is another consideration. Treatment involves major surgery and intensive chemotherapy, requiring the patient to be healthy enough to tolerate the physical stress. Factors like age, fitness level, and other medical conditions are weighed against the predicted benefit. Treatment is generally feasible only if there is a high probability of achieving a complete removal of all visible tumor.
Comprehensive Treatment Approaches
The modern approach relies on a specialized, two-part operation combined with systemic drug therapy. Cytoreductive Surgery (CRS) is an extensive procedure aimed at removing every visible tumor nodule and all affected peritoneal tissue. This may involve removing portions of affected organs, such as the spleen, gallbladder, or parts of the colon, to achieve no visible residual disease.
Immediately following CRS, the patient undergoes Hyperthermic Intraperitoneal Chemotherapy (HIPEC). This technique involves circulating a highly concentrated, heated chemotherapy solution (41 to 42 degrees Celsius) directly throughout the abdominal cavity for 60 to 120 minutes. The heat enhances the chemotherapy’s effect, and the direct application allows a high dose to kill remaining microscopic cancer cells.
Systemic chemotherapy is often administered before surgery (neoadjuvant therapy) to shrink tumors and assess responsiveness. It may also be used after surgery (adjuvant therapy) to target cancer cells that may have spread outside the peritoneal cavity. Targeted therapies and immunotherapies are emerging options for selected patients, offering new ways to block cancer growth pathways or harness the body’s immune system to fight the malignancy.