Unilateral or Bilateral Retroperitoneal Lymph Node Dissection in Nonseminoma Patients with Postchemotherapy Residual Tumour? Results from RETROP, a Population-based Mapping Study by the Swedish Norwegian Testicular Cancer Group.

The distribution of retroperitoneal lymph node metastases for patients with nonseminoma and a residual tumour of 10-49 mm in a population-based setting is unknown. This information is needed to justify selection of patients for a unilateral template resection.

To describe the location of retroperitoneal metastases and recurrences in patients with nonseminoma germ cell tumour (NSGCT) with a residual tumour of 10-49 mm.

RETROP is a population-based prospective observational mapping study of 213 patients in Sweden and Norway with a retroperitoneal residual tumour of 10-49 mm who underwent postchemotherapy retroperitoneal lymph node dissection for metastatic NSGCT during 2007-2014 with median follow-up of 100 mo. Patients were classified according to the testis primary tumour and the distribution of unilateral or bilateral lymph node metastases (with reference to the aorta) present on pre- and/or postchemotherapy computed tomography (CT) scans.

The distribution and rate of teratoma or cancer in unilateral or bilateral retroperitoneal fields and the location and rate of retroperitoneal recurrence were measured.

In total, 65% of the patients had unilateral retroperitoneal lymph node metastases (RLNMs) on CT scans. Patients with unilateral RLNMs had a low risk of contralateral teratoma or cancer (1.6% for right- and 2.6% for left-sided NSGCT) or retroperitoneal recurrence (0% for right- and 4% for left-sided NSGCT). A weakness of the study is that the pathology specimen could not be fully designated to one specific area for some of the patients.

Men with postchemotherapy residual disease of 10-49 mm and unilateral metastases on pre- and postchemotherapy CT scans have a low risk of contralateral disease and should be considered for a unilateral template resection.

The surgeon can use computed tomography (CT) scans in deciding on the extent of lymph node dissection in patients with testicular cancer.

European urology oncology. 2021 Mar 06 [Epub ahead of print]

Axel Gerdtsson, Anna Thor, Anna Grenabo Bergdahl, Bjarte Almås, Ulf Håkansson, Magnus Törnblom, Helene F S Negaard, Ingrid Glimelius, Dag Halvorsen, Ása Karlsdóttir, Hege Sagstuen Haugnes, Kristine Engen Andreassen, Signe Melsen Larsen, Göran Holmberg, Rolf Wahlqvist, Torgrim Tandstad, Gabriella Cohn-Cedermark, Olof Ståhl, Anders Kjellman

Department of Clinical Science, Intervention and Technology, Division of Urology, Karolinska Institutet, Stockholm, Sweden; Department of Urology, Skåne University Hospital, Malmö, Sweden. Electronic address: ., Department of Clinical Science, Intervention and Technology, Division of Urology, Karolinska Institutet, Stockholm, Sweden; Department of Urology, Pelvic Cancer, Karolinska University Hospital, Stockholm, Sweden., Department of Urology, Gothenburg University, Gothenburg, Sweden; Department of Urology, Sahlgrenska University Hospital, Gothenburg, Sweden., Department of Urology, Haukeland University Hospital, Bergen, Norway., Gastrocenter, Lund, Sweden., Department of Clinical Science and Education, Section of Urology, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden; Department of Surgery, Visby County Hospital, Visby, Sweden., Department of Oncology, Oslo University Hospital, Oslo, Norway., Department of Immunology, Genetics and Pathology, Unit of Clinical and Experimental Oncology, Uppsala University, Uppsala, Sweden., Department of Urology, St. Olavs University Hospital, Trondheim, Norway., Department of Oncology, Haukeland University Hospital, Bergen, Norway., Department of Oncology, University Hospital of North Norway, Tromsø, Norway; Department of Clinical Medicine, UIT-The Arctic University of Norway, Tromsø, Norway., Department of Urology, Oslo University Hospital, Oslo, Norway., Department of Urology, Sahlgrenska University Hospital, Gothenburg, Sweden., The Cancer Clinic, St. Olavs University Hospital, Trondheim, Norway; Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway., Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden; Department of Pelvic Cancer, Genitourinary Oncology Unit, Karolinska University Hospital, Stockholm, Sweden., Department of Oncology, Skåne University Hospital, Lund, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.