Is orchiectomy always necessary in retroperitoneal extragonadal germ cell tumours? commentary

Punjani and colleagues review their 35-year, single-centre experience of 14 patients treated with chemotherapy for retroperitoneal extragonadal germ cell tumours (GCT) with no ultrasonographic or palpable abnormality in the testicles. Eight underwent orchiectomy at the time of retroperitoneal lymph node dissection (RPLND), two (14%) had viable disease, and one had intratubular germ cell neoplasia (ITGCN). This paper raises some important points. The authors, while not formally recommending postchemotherapy orchiectomy in all patients, hint that retroperitoneal GCTs may, in fact, all be testicular GCTs and we should carefully evaluate the need for orchiectomy in these patients. I feel we should be cautious advocating for orchiectomy for all based on the limited series that have examined this. At Princess Margaret, we agree with orchiectomy when suspicion of a lesion is present in the testicle after chemotherapy. In the few case series that have examined this, pathology in the testicle post-chemotherapy harbours the same risk of viable GCT or teratoma as residual masses elsewhere in the body and, thus, orchiectomy appears warranted. 1 However, when there is no clinical or radiographic abnormality in the testicle preand post-chemotherapy, such as the scenario described in this study, we typically survey the testicle and avoid orchiectomy. The risk of this practice is subsequent appearance of an ipsilateral metachronous testicular GCT — whether from growth of a chemo-resistant GCT or progression of ITGCN to GCT. Metachronous tumour development in this setting has been estimated at 10% over 10 years. 2 The risk is higher when the retroperitoneum contains nonseminoma (14%) as compared to seminoma (1.4%). However, the majority (70%) of metachronous testicular tumours are seminomas and the stage distribution and clinical behaviour mirrors new testicular cancers as opposed to an aggressive metastatic counterpart; thus, most can be managed with orchiectomy alone followed by surveillance. This pattern is homologous to the risk of subsequent development of a contralateral testicular GCT in a patient with a prior testicular GCT. This risk is as high as 5%, 3 and the tumours are typically low-stage seminomas that can be managed with orchiectomy alone. 3 The similarity between metachronous ipsilateral tumour in extragonadal GCT and contralateral second testicular primary is because both are believed due to the presence of ITGCN. Testicular biop sies at the time of diagnosis of retroperitoneal GCT sug gest ITGCN in 20‒40%, 4 and it is believed that one-third of ITGCN present will persist in a testicle after chemotherapy, with half of ITGCN subsequently developing into a GCT. The consequence of performing orchiectomy in all patients with retroperitoneal GCT and no testicular abnormality is the risk of removing a normal testicle in up to 90%.