Stage I Seminoma

Radical inguinal orchiectomy with no retroperitoneal node radiation therapy followed by chest x-rays and computed tomography (CT) scans of the abdomen and pelvis (surveillance). These studies are typically performed every 4 months for the first 3 years, then every 6 months for 3 years, and then annually for an additional 4 years.[1]Results of multiple clinical series, including more than 1,200 patients with stage I seminoma managed by postorchiectomy surveillance, have been reported.[2-9] The overall 10-year tumor recurrence rate is 15% to 20%, and nearly all patients whose disease recurred were cured by radiation therapy or chemotherapy. Thus, the overall cure rate is indistinguishable from that achieved with adjuvant radiation therapy or carboplatin chemotherapy. Relapses after 5 years are unusual but can occur in as many as 4% of patients.[6] Independent risk factors for relapse include tumor size greater than 4 cm and invasion of the rete testis.[2] The 5-year risk of relapse is about 10% without either risk factor, 16% with one risk factor, and 32% with both risk factors.

Removal of the testicle via radical inguinal orchiectomy followed by radiation therapy is an approach that is associated with a 5-year relapse-free survival (RFS) rate of 95% to 96% and a 5-year disease-specific survival rate over 99% in multiple large series and randomized controlled trials.[11-17]One of the following two treatment fields is typically used: a para-aortic strip covering the retroperitoneal nodes or a dog-leg field that includes the ipsilateral iliac lymph nodes as well as the retroperitoneum. The dose ranges from 20 Gy to 26 Gy. Relapse rates and toxic effects were studied in a randomized comparison (MRC-TE10) of para-aortic radiation therapy alone versus para-aortic radiation therapy with an added ipsilateral iliac lymph node field.[13,18] The 5-year RFS rates were virtually identical (96.1% for patients who were treated with the para-aortic strip vs. 96.2% for patients who were treated by a dog-leg field) as were overall survival (OS) rates (one death from seminoma occurred in the para-aortic radiation therapy arm). Pelvic RFS rates were 98.2% versus 100%; the 95% confidence interval (CI) for the difference in pelvic RFS rates was 0% to 3.7%. A statistically significant increase was observed in leukopenia and diarrhea associated with the ipsilateral iliac radiation therapy. In a randomized trial (MRC-TE18), a radiation dose of 20 Gy over 10 daily fractions was clinically equivalent to 30 Gy over 15 fractions after a median follow-up of 7 years in both RFS and OS. Patients reported that lethargy and their ability to perform normal work were better in the lower-dose regimen.[14,18][Level of evidence A1]Radiation therapy for clinical stage I testicular seminoma is no longer favored because of evidence that this treatment is associated with an increased risk of secondary malignancies and an increased risk of death from secondary malignancies. An analysis of data from the population-based Surveillance, Epidemiology, and End Results (SEER) Program registries in the United States between the years 1973 and 2001 indicated that among 7,179 men receiving radiation therapy for stage I seminoma, 246 had an increased risk of death from secondary cancers compared with the general population (standardized mortality ratio, 1.89; 95% CI, 1.67–2.14).[19] An international study of more than 40,000 testicular cancer survivors reported that among the 7,885 survivors who had been followed for 20 to 29 years, radiation therapy was associated with a doubling of the risk of secondary cancers (relative risk, 2.0; 95% CI, 1.8–2.3).[20]

Radical inguinal orchiectomy followed by either one or two doses of carboplatin adjuvant therapy. In a large, randomized, controlled, noninferiority trial (MRC-TE19 [NCT00003014]), 1,477 men with stage I seminomas were assigned to undergo para-aortic (or dog-leg field, if clinically indicated) radiation therapy or to receive a single dose of carboplatin (concentration-versus-time or area-under-the-curve [AUC] × 7) after radical inguinal orchiectomy study participants were followed up for a median of 6.5 years.[18,21] The RFS rate at 5 years was 94.7% in the carboplatin arm and 96.0% in the radiation therapy arm (1.3% difference; 90% CI, 0.7%–3.5%; hazard ratio [HR], 1.25 [nonsignificant trend in favor of radiation therapy]; 90% CI, 0.83–1.89). The one death from seminoma occurred in the radiation therapy arm. There was a reduced number of contralateral testicular germ cell tumors in the carboplatin arm: 2 versus 15 (HR, 0.22; 95% CI, 0.05–0.95; P = .03).[21][Level of evidence A1] In this trial, AUC dosing was based on radioisotope measurement of glomerular filtration rate; dosing based on calculations of creatinine clearance is not equivalent, has not been validated in this setting, and is discouraged. Phase II studies, including several with more than 4 years median follow-up, have consistently reported lower relapse rates (0%–3.3%) when two doses of carboplatin were administered either 3 or 4 weeks apart and dosed either at 400 mg/m2 or at an AUC of 7.[3,4,22-26] Administration of two doses of carboplatin has never been compared with a single dose nor with radiation therapy in a randomized trial.