Cytoreduction

Cytoreduction refers to strategies aimed at reducing the number of cancer cells or the size of tumors, with the goal of improving symptoms, slowing progression, or increasing the effectiveness of subsequent therapies. It may involve surgery, chemotherapy, radiotherapy, or combinations of modalities, and is used across several solid and hematologic cancers.

In surgical oncology, cytoreduction, or cytoreductive surgery (CRS), involves extensive debulking to remove as much visible tumor as possible. It is standard in selected peritoneal surface malignancies and gynecologic cancers, notably advanced ovarian cancer, where no residual disease is the goal when feasible. Similar approaches are used for colorectal or appendiceal cancers with peritoneal metastases.

When paired with intraperitoneal chemotherapy, often hyperthermic intraperitoneal chemotherapy (HIPEC), CRS aims to eradicate microscopic residual disease. HIPEC delivers heated chemotherapy directly into the peritoneal cavity during surgery to enhance penetration and kill remaining cancer cells.

Assessment and outcomes depend on disease extent and patient factors. Tools such as the peritoneal cancer index (PCI) and the completeness of cytoreduction (CCR) score help predict results. Achieving complete cytoreduction is associated with longer survival in several settings, though benefits vary with tumor biology.

Risks and limitations include substantial morbidity and mortality, infection, organ dysfunction, and prolonged recovery. CRS/HIPEC is not suitable for all patients. In hematologic malignancies, cytoreduction may refer to reducing tumor burden with induction chemotherapy or other systemic therapies, often followed by consolidation or transplantation.