Eur Urol: How effective is retroperitoneal lymph node dissection in patients with clinical stage IIA/B testicular germ cell tumors?

Retroperitoneal lymph node dissection (RPLND) for clinically staged (CS) stage IIA/B seminoma is an experimental treatment with no adjuvant therapy to avoid radiotherapy or chemotherapy-related toxicity
with standard treatments.

Recently, researchers from Germany published an article in Eur Urol that they conducted the PRIMETEST trial, which aims to prospectively evaluate the oncological efficacy and surgical safety
of RPLND.

PRIMETEST is a single-arm, single-center, prospective Phase 2 trial
.
Patients
with seminoma, unilateral retroperitoneal lymph node metastasis < 5 cm, and human chorionic gonadotropin <5 mU/ml were included.
Patients with CS IIA/B seminoma at initial diagnosis, and patients who relapse under active surveillance or after adjuvant carboplatin therapy with CS type I disease were eligible for inclusion
.
Patients undergo unilateral open or robotic-assisted RPLND
.
The primary endpoint of the study was progression-free survival (PFS)
after 36 months.
If < 30% of patients experience relapse, the effect of the trial is considered positive
.

Between 2016 and 2021, a total of 33 patients were recruited (9 with primary CS IIA/B, 19 with relapse during active surveillance, and 5 with adjuvant post-carboplatin).

Of these, 13 and 20 patients were CS IIA and IIB
, respectively.
Fourteen (42%) and 19 (58%) patients underwent either open or robotic-assisted RPLND surgery
, respectively.
After 32 months of median follow-up (interquartile range 23-46), 10 relapses were identified (30%, 95% confidence interval, CI: 16-49%); Therefore, the primary endpoint was not reached
.
Three of the 10 patients developed on-site relapses
.
In addition, current analysis of risk factors cannot determine predictors
of recurrence.
3 of 33 patients (9%) developed pN0
.

Oncology findings and recurrence investigated at follow-up

In summary, the PRIMETEST trial did not meet its primary endpoint
.
However, after a median follow-up of 32 months, 70% of PFS indicated that this treatment was meaningful
for carefully selected patients.
However, selection criteria also need to be defined and validated
in a larger prospective patient population.
Until then, single surgery for patients with CS IIA/B seminoma cannot be recommended outside of a clinical trial setting
.

Original source:

Andreas Hiester， Yue Che， Achim Lusch et al.
T Phase 2 Single-arm Trial of Primary Retroperitoneal Lymph Node Dissection in Patients with Seminomatous Testicular Germ Cell Tumors with Clinical Stage IIA/B (PRIMETEST).
Eur Urol.
Nov 2022