Detection of micrometastases by flow cytometry in sentinel lymph nodes from patients with renal tumours

• BACKGROUND: 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.METHODS: 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.RESULTS: Stability of the assay was marked by low intra-assay variability (coefficient of variance ⩽16%) and low inter-assay variability (R(2)=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.CONCLUSIONS: Flow cytometry is able to detect micrometastases in lymph nodes of renal tumour patients that were undetected under H&E examination.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Urologi och njurmedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Urology and Nephrology (hsv//eng)

Keyword

kidney neoplasms

sentinel lymph node biopsy

lymphatic metastasis

flow cytometry

Publication and Content Type

ref (subject category)

art (subject category)