Researchers have reported follow-up data on the randomized trial of carboplatin versus radiation therapy (MRC TE19, EORTC 30982) for treatment of Stage I seminoma; these data show non-inferiority of single-dose carboplatin versus radiation therapy for prevention of relapses. The details of this study were presented at the 2008 meeting of the American Society of Clinical Oncology in Chicago, May 30-June 2.¹

Following surgical orchiectomy, approximately 15% of patients with a Stage I seminoma will experience a recurrence if they are not treated with additional therapy. By administering relatively low doses of chemotherapy and/or radiation therapy to the retroperitoneal and inguinal lymph nodes after surgery, the chance of cancer recurrence can be almost completely eliminated.

In one study, 125 patients with Stage I seminoma received either one or two courses of carboplatin after orchiectomy.² Cancer recurred in 8.6% of patients who received one course of carboplatin; all were cured with further chemotherapy. None of the patients who received two courses of carboplatin experienced a cancer recurrence. In another study, 107 patients with Stage I seminoma received two courses of carboplatin after orchiectomy; during an average of six years of follow-up, none of the patients experienced a cancer recurrence.³ These studies suggest that adjuvant treatment with two doses of Paraplatin is as effective as radiation therapy and may be better tolerated.

Between 1996 and 2001, 1,447 patients with Stage I seminoma were randomly allocated to receive a single dose of carboplatin or radiation therapy. The median follow-up of this study is now 6.5 years. (Previous findings from this study are reported related news).

• Relapse-free survival was 95% for chemotherapy and 96% for radiation therapy.
• Only one death has been reported in the entire cohort.
• There were two germ cell tumors of the opposite testicle in patients receiving chemotherapy versus 15 in patients receiving radiation therapy.
• Higher doses of carboplatin were associated with fewer recurrences.
• Larger tumors were associated with a higher relapse rate.

These authors concluded that a single dose of carboplatin was as effective as radiation therapy for prevention of recurrences in patients with Stage I seminoma. They suggested that adequate dosing was a necessary caveat and that studying higher doses would be a good idea.

Comments: These data confirm earlier observations of this study. However, it would appear reasonable to increase the dose of carboplatin as has been shown in other Phase II studies. It will also be of interest to determine what the comparative long-term effects of the two treatments are. One could expect more complications from patients receiving radiation therapy.

Related News:

Single Dose Adjuvant Paraplatin® as Effective as Radiation Therapy for Stage I Seminoma (07/25/2005)

Reference:

¹ Oliver RT, Mead GM, Fogarty PJ, et al. Radiotherapy versus carboplatin for stage I seminoma: Updated analysis of the MRC/EORTC randomized trial (ISRCTN27163214). Journal of Clinical Oncology. 2008;26:abstract number 1.

² Dieckmann KP, Brüggeboes B, Pichlmeier U, Küster J, Müllerleile U, Bartels H. Adjuvant treatment of clinical stage I seminoma: is a single course of carboplatin sufficient? Urology. 2001;55:102-6.

³ Reiter WJ, Brodowicz T, Alavi S et al. Twelve-year experience with two courses of adjuvant single-agent carboplatin therapy for clinical stage I seminoma. Journal of Clinical Oncology. 2001;19:101-4.