Long-term disease control and patterns of failure in early stage testicular seminoma treated with limited or extended-field radiotherapy portals

Abstract

To report tumor control outcomes and patterns of failure in patients who received radiotherapy limited to the para-aortic region (PA) or PA plus ipsilateral iliac lymph node (dogleg, DL) radiation therapy for early stage testicular seminoma, and to analyze outcomes among stage I patients with known negative histopathologic characteristics. From 1990–2002, 198 patients were treated with radiation therapy (RT) for stages I and II seminoma. One hundred forty-five patients (73%) were stage I and 53 (27%) patients had stage II disease. Of the patients with stage I disease, 52 (36%) were treated with PA RT and 93 (64%) were treated with DL RT. A retrospective review of pathology reports was conducted to identify prognostic factors that have been associated with relapse in patients who are observed after orchiectomy (primary tumor size > 4cm and rete testis involvement). Sufficient pathologic data were available for 126 stage I patients (47/52 PA patients and 77/93 DL patients). Of these, 63% of patients treated with PA RT and 61% stage I patients treated with DL RT had one or both prognostic factors. With a median follow-up time of 37 months (range: 1–161 months) after completion of RT, the 5-year actuarial local control (LC), distant metastasis-free survival (DMFS), and overall survival (OS) for stage I patients were 98%, 99% and 98% respectively and for stage II patients were 98%, 82%, and 97% respectively (p = NS for LC; p = .002 for DMFS; p = NS for OS). Four of 198 patients (2%) experienced local failure. Two of these patients underwent PA RT and relapsed in the external iliac lymph nodes. The other two failures underwent DL RT; one was stage I and one was stage II. One patient failed in his mid-abdomen within the radiation portal and one recurred at the margin of the radiation portal at the level of L2-L3. The one recurrent stage II patient subsequently developed distant metastasis. All four patients were treated with 4 cycles of etoposide and cisplatin chemotherapy. At the time of last follow-up, all four patients were without evidence of disease. The 5-year actuarial LC, DMFS, and OS for stage I patients treated with PA RT were 96%, 98%, and 100% respectively and for DL RT were 99%, 100%, and 98% respectively (p = NS). The presence of poor prognostic factors did not negatively impact LC, DMFS or OS. Excellent outcomes are observed for stage I and II seminoma treated with adjuvant RT. Omission of the pelvic field in stage I patients did not significantly impact upon LC, DMFS, or OS outcomes. Only 2% of patients treated with PA RT failed in the pelvic lymph nodes consistent with the results of the previously reported randomized trial. Stage I patients with negative histopathologic characteristics who are treated with RT have similar outcomes as those without these poor prognostic factors