Management of the post chemotherapy subcentimeter residual mass: the case for observation

Abstract

With the introduction of cisplatin-based chemotherapy, testis cancer has now become a highly curable disease. For patients presenting with good risk disease, the primary goal for physicians is to decrease the treatment-related morbidity without compromising cure. For low-volume ( 5 cm) stages II and III disease, initial treatment is typically systemic chemotherapy. Following the systemic chemotherapy, patients achieving a partial radiographic response (PR) generally undergo post chemotherapy (PC) surgery as 50–60% harbor either teratoma or active cancer. Thus, patients achieving a PR require dual therapy: chemotherapy plus surgery. The controversy arises as to the optimal treatment for patients achieving a complete radiographic response (CR) to systemic chemotherapy: observation or surgery. The argument for either approach relates to the interpretation of data on the ability of chemotherapy as monotherapy to cure patients with metastatic disease. As teratoma is chemorefractory, and residual microscopic teratoma may be present PC in complete responders, some institutions have adopted the policy for PC surgery in all patients including CRs. The rationale is twofold: (1) all patients with metastatic disease require dual therapy: chemotherapy to eradicate active germ cell tumor and surgery to eradicate microscopic teratoma as (2) unresected microscopic teratoma has an unpredictable biologic behavior and may ultimately have a deleterious eVect on outcome. Proponents of observation in those achieving a CR to chemotherapy argue that (1) PC microscopic teratoma may be by and large biologically benign, (2) the small relapse rates of those observed does not justify surgery in all patients achieving a CR and (3) patients that do relapse remain curable. This paper will address the incidence of microscopic teratoma in complete responders to chemotherapy, and attempt to deWne the biologic behavior of PC microscopic teratoma.