Detection of micrometastases by flow cytometry in sentinel lymph nodes from patients with renal tumours.
Stage is an important prognostic factor in renal tumours and dissemination to regional lymph nodes is associated with poor outcomes. Lymph nodes are routinely assessed by immunohistochemistry and microscopic evaluation, a time-consuming process where micrometastases might go undiagnosed. We evaluate an alternative method for detecting metastatic cells in sentinel nodes (SNs) by flow cytometry.



A total of 15 nodes from 5 patients diagnosed with renal tumours were analysed by flow cytometry. Staining for the intracellular marker cytokeratin 18 (CK18) with the surface markers carbonic anhydrase IX (CA9) and Cadherin 6 were used in flow cytometry analysis. Peripheral blood mononuclear cells (PBMCs) with the addition of known concentrations of cancer cell lines were analysed to investigate the sensitivity of micrometastasis detection.



Stability of the assay was marked by low intra-assay variability (coefficient of variance ⩽16%) and low inter-assay variability (R2=0.9996-1). Eight nodes in four patients were positive for metastasis; six of them were considered being micrometastatic. These metastases were undetected by routine pathology and the patients were restaged from pN0 to pN1.



Flow cytometry is able to detect micrometastases in lymph nodes of renal tumour patients that were undetected under H&E examination.
Karolinska Institutet, Department of Medicine Solna, Unit of Immunology and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.
Ciputra Adijaya
CA
Hartana
Karolinska Institutet, Department of Medicine Solna, Unit of Immunology and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.
Johan
J
Kinn
Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, 901 85 Umeå, Sweden.
Robert
R
Rosenblatt
Department of Urology, Stockholm South General Hospital, Karolinska Institutet, Stockholm, Sweden.
Stefan
S
Anania
Department of Urology, Västmanland Hospital, Västerås, Sweden.
Farhood
F
Alamdari
Karolinska Institutet, Department of Medicine Solna, Unit of Immunology and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.
Hans
H
Glise
Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, 901 85 Umeå, Sweden.
Amir
A
Sherif
Karolinska Institutet, Department of Medicine Solna, Unit of Immunology and Allergy, Karolinska University Hospital, 171 76 Stockholm, Sweden.
Ola
O
Winqvist
D018249:Adenoma, Oxyphilic / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology / Q000556:secondary; D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor; D015820:Cadherins / Q000032:analysis; D000071231:Carbonic Anhydrase IX / Q000032:analysis; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D045744:Cell Line, Tumor; D004801:Eosine Yellowish-(YS); D005188:False Negative Reactions; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006416:Hematoxylin; D006801:Humans; D053538:Keratin-18 / Q000032:analysis; D007680:Kidney Neoplasms / Q000737:chemistry / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D061206:Neoplasm Micrometastasis / Q000175:diagnosis; D009363:Neoplasm Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D000071036:Sentinel Lymph Node / Q000473:pathology*; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013194:Staining and Labeling
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015820:Cadherins; D053538:Keratin-18; D009363:Neoplasm Proteins; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D004801:Eosine Yellowish-(YS); C087310:K cadherin; D006416:Hematoxylin