The Sword of Damocles and the Treatment of Stage I Seminoma

Randomized trial of carboplatin versus radiotherapy for stage I seminoma: mature results on relapse and contralateral testis cancer rates in MRC TE19/EORTC 30982 study (ISRCTN27163214)

PURPOSE

Initial results of a randomized trial comparing carboplatin with radiotherapy (RT) as adjuvant treatment for stage I seminoma found carboplatin had a noninferior relapse-free rate (RFR) and had reduced contralateral germ cell tumors (GCTs) in the short-term. Updated results with a median follow-up of 6.5 years are now reported.

PATIENTS AND METHODS

Random assignment was between RT and one infusion of carboplatin dosed at 7 × (glomerular filtration rate + 25) on the basis of EDTA (n = 357) and 90% of this dose if determined on the basis of creatinine clearance (n = 202). The trial was powered to exclude a doubling in RFRs assuming a 96-97% 2-year RFR after radiotherapy (hazard ratio [HR], approximately 2.0).

RESULTS

Overall, 1,447 patients were randomly assigned in a 3-to-5 ratio (carboplatin, n = 573; RT, n = 904). RFRs at 5 years were 94.7% for carboplatin and 96.0% for RT (RT-C 90% CI, 0.7% to 3.5%; HR, 1.25; 90% CI, 0.83 to 1.89). One death as a result of seminoma (in RT arm) occurred. Patients receiving at least 99% of the 7 × AUC dose had a 5-year RFR of 96.1% (95% CI, 93.4% to 97.7%) compared with 92.6% (95% CI, 88.0% to 95.5%) in those who received lower doses (HR, 0.51; 95% CI, 0.24 to 1.07; P = .08). There was a clear reduction in the rate of contralateral GCTs (carboplatin, n = 2; RT, n = 15; HR, 0.22; 95% CI, 0.05 to 0.95; P = .03), and elevated pretreatment follicle-stimulating hormone (FSH) levels (> 12 IU/L) was a strong predictor (HR, 8.57; 95% CI, 1.82 to 40.38).

CONCLUSION

These updated results confirm the noninferiority of single dose carboplatin (at 7 × AUC dose) versus RT in terms of RFR and establish a statistically significant reduction in the medium term of risk of second GCT produced by this treatment.

Management options for stage I seminoma

Stage I seminoma is the most common clinical scenario among patients with testicular cancer. Following orchiectomy, various treatment alternatives (adjuvant radiotherapy, surveillance, chemotherapy) can be offered that yield similar efficacy results and definitive cure is the rule. However, there is no consensus on the optimal management choice and considerable debate has been raised in recent years. The pros and the cons associated with each therapy, as well as their long-term outcomes are discussed in this review. Overall burden of treatment needed, therapy-related morbidity, economic costs, quality of life issues and patient preferences should all be considered. Refinement in the knowledge of predictive factors for relapse and mounting experience with both surveillance and adjuvant chemotherapy have led to consideration of risk-adapted treatment strategies as an alternative to standard radiotherapy. Although this model needs to be improved and validated, active close surveillance for low-risk patients and adjuvant therapy for those uncompliant or at higher risk of relapse seem to be acceptable options for patients with stage I seminoma.

Adjuvant treatment in the management of testis-confined germ cell tumours after orchidectomy

Germ cell tumours are highly curable, especially when still at the localized stage, which is the case for most testicular tumours. Various options are available for organ-confined disease; depending on the histological review, patients with clinical stage I seminomas can be offered radiotherapy, surveillance or chemotherapy, whereas those with clinical stage I nonseminomas can be offered retroperitoneal lymph node dissection, surveillance or chemotherapy. As it is unlikely that any of these approaches will have a clear survival advantage, the most appropriate variables to be considered are acute and late side-effects, acceptability and quality of life. In recent years adjuvant chemotherapy has been extensively evaluated in patients with seminoma or nonseminoma. In this review we discuss the advantages and disadvantages of the different strategies for treating seminomas and nonseminomas, and their associated prognostic factors, and then consider future developments.