Primitive neuroectodermal tumor of the kidney at the advanced stage: A case series of eight Chinese patients

Primitive neuroectodermal tumor (PNET) rarely occurs as a primary renal neoplasm. Renal (r)PNET is a rare but aggressive neoplasm with poor prognosis; the majority of patients are diagnosed as advanced stage at presentation and face a worse prognosis than patients with localized disease. The present study describes the diagnosis and management of eight cases of rPNET at an advanced stage, who were treated at two institutions [Lingnan Hospital (branch of The Third Affiliated Hospital) and the Cancer Center of Sun Yat-sen University, Guangzhou], from December 2004 to January 2013. The clinical and pathological results of all patients were retrospectively obtained. Kaplan-Meier analysis was performed to estimate patient survival. The study cohort comprised five males and three females. Radical nephrectomy was performed in seven cases, while the remaining case only received needle biopsy of the tumor. Five cases received adjuvant chemotherapy, while three received no further treatment after surgery. Of note, one case received cytokine-induced killer (CIK) cell immunotherapy combined with surgery and chemotherapy. The overall median survival was 20 months with a 3-year survival rate of 25%. The overall survival of the four patients who received adjuvant chemotherapy following surgery was 36 months, compared with 10 months in the three patients without further treatment. The patient who received CIK cell immunotherapy survived for 20 months. Based on the observations of the present and previous studies, surgical excision and chemotherapy are recommended for treating rPNET at advanced stage. Furthermore, the present study was the first to report on CIK cell immunotherapy for a patient with rPNET, indicating that it may be a promising optional treatment. However, further studies are required to validate the benefit of CIK cells and to establish an appropriate immunotherapy protocol.