Abstract: PD53-11
Sources of Funding: None

Introduction

To evaluate progression-free survival of stage II A/B seminoma patients (pts) undergoing primary retroperitoneal lymph node dissection (RPLND) without adjuvant treatment. To date there are only few publications reporting primary RPLND in Stage II seminoma. Aim is to present initial data of a feasibility study and a prospective phase II trial._x000D_

Methods

Before starting the phase II trial, 9 pts have been treated within a pilot feasibility study including one CS IIC patient and one patient with atypical inguinal recurrence. Since 3.2016 additional 2 pts were treated within the prospective phase II design (NCT 2015053664) with a primary retroperitoneal lymph node dissection (open or daVinci robot assisted) in Stage II A/B seminoma in a single center. All patients including those within the feasibility study were evaluated for peri- and postoperative outcome and oncologic data including recurrence free survival. The trial is designed to exclude a > 30% recurrence to standard treatment and will have to accrue 30 pts._x000D_

Results

Eleven patients with seminomatous germ cell tumors have been included in both cohorts since 5.2014. Two patients received RPLND after inguinal orchiectomy as a primary treatment, 5 patients (46%) after early relapse and 4 patients (36%) after late relapse. 6/9 (67%) patients were under active surveillance, 3/9 (22%) patients received one cycle of carboplatin. Mean tumor size was 2.6 cm at a mean patient age of 43 years. 7 conventional, 1 inguinal and 3 DaVinci robot assisted RPLNDs were performed, mean OR time was 144 min with a mean blood loss of 109 cc. One patient after DaVinci RPLND developed ureteral stricture requiring an ileal ureter substitute. The mean follow-up of all pts is 18 month (4 – 28 month). 7/11 (64%) patients are recurrence free. So far, four patients (including the CS IIC patient and the patient with atypical inguinal lymph nodes) developed recurrences 3, 3, 3 and 9 month after surgery (3x outside field and 1x inside field relapse). 1 patient received radiotherapy (36Gy) and 3 patients received CTX with 4xPE, 3xBEP and 3xBEP, 3/4 (75%) patients are currently recurrence free._x000D_

Conclusions

Primary retroperitoneal lymph node dissection (RPLND) in stage II A/B seminoma is an experimental treatment alternative with promising short term results. RPLND should be performed only within clinical trials and in specialised high volume referral centers. _x000D_

Funding

None