ASCO 2021: Surveillance After Complete Response in Patients with Metastatic Nonseminomatous Germ Cell Tumors

(UroToday.com) The optimal management of patients with complete response after first-line chemotherapy remains unsettled with guidelines recommending either surveillance or retroperitoneal lymph node dissection (RPLND). At the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, Dr. Jennifer King and colleagues presented results of their study assessing long-term outcomes from a large dataset of patients managed with surveillance after achieving complete response to first-line chemotherapy.


The prospectively maintained Indiana University testicular cancer database was queried for patients with metastatic nonseminomatous germ cell tumors (NSGCT) treated between 1990-2017 who achieved a complete response after first-line chemotherapy. Complete response was defined as normalization of tumor markers (AFP + hCG) and no residual mass > 1cm. Kaplan-Meier methods were used to analyze progression-free survival (PFS) and overall survival (OS).

There were 388 patients that met eligibility and were included in this analysis. The median age at diagnosis was 28.4 (range: 13-61.5) years and the primary site was testis in 385 patients (99%). Primary tumor predominant histology was embryonal carcinoma (n = 241), mixed (n = 61), seminoma (n = 31), yolk sac tumor (n = 20), choriocarcinoma (n = 10), and teratoma (n = 14); 126 patients (32.5%) had teratoma in the primary tumor. Metastasis sites included the retroperitoneum (n = 295), mediastinal lymph nodes (n = 15), pulmonary (n = 149), liver (n = 15), bone (n = 7), and brain (n = 6). IGCCCG risk was good in 325 patients, intermediate in 25, and poor in 32 patients. Pre-chemotherapy retroperitoneal lymph node size was available in 232 patients, including < 3cm in 170 patients and ≥ 3cm in 62 patients. Median pre-chemo AFP was 10.7 (range 1-31,000) and hCG was 16.5 (range0-595,930). First-line chemotherapy was BEP x 3 in 274 patients, BEP x 4 in 30 patients, other regimens in 82 patients. With a median follow-up of 3.9 years, 34 patients (8.8%) had disease progression. At most recent follow-up, 363 (93.6%) patients were alive with no evidence of disease and 10 patients (2.6%) died of their disease. The estimated 2-yr PFS was 90.1% (95% CI 86.2-93%) and 2-yr OS was 97.8% (95% CI 95.2-99%). The estimated 2-yr PFS by IGCCCG risk category was 90.4% for good versus 90.4% for intermediate versus 86.5% for poor risk (p = 0.23):

ASCO_RPLND.png

The estimated 2-yr OS was 98.6% for good versus 95.5% for intermediate versus 92.9% for poor risk disease respectively (p = 0.002):

ASCO_2-yr_OS.png

For the 34 patients who progressed on surveillance, 16 (4%) progressed in the retroperitoneum only. There were 3 patients that had malignant transformation of teratoma to PNET, adenocarcinoma, or other elements. Furthermore, 11 of progressed patients were treated with surgery, 12 were treated with salvage chemo, and 11 were treated with surgery + chemotherapy. At most recent follow-up, 21 of progressed patients showed no evidence of disease, 10 had died of disease, and 3 were lost to follow up.

Dr. Jennifer King concluded this presentation with the following take-home messages:

  • Patients with metastatic NSGCT who achieve complete response after first-line chemotherapy can be safely observed with surveillance
  • Most patients who relapse can be salvaged with surgery and/or chemotherapy

Presented by: Jennifer King, MD, Indiana University School of Medicine, Indianapolis, IN

Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia Twitter: @zklaassen_md at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, Virtual Annual Meeting #ASCO21, June, 4-8, 2021
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