title: Detection of circulating tumour cells and nodal metastasis by reverse transcriptase-polymerase chain reaction technique.
abstract: BACKGROUND
  In the search for occult metastases in lymph nodes or circulating tumour cells, a reverse transcriptase-polymerase chain reaction (RT-PCR) assay was developed to detect tumour-specific splice variants of the transcript of the CD44 gene. The assay was highly sensitive and could detect ten tumour cell per 10(5) leucocytes.
  
  
  METHODS
  RNA was purified from peripheral blood (n = 24) and regional lymph nodes (n = 14) from patients with colorectal cancer. Complementary DNA was made and amplified using primers specific for the CD44 gene. Southern blotting with exon-specific probes was used to enhance the sensitivity.
  
  
  RESULTS
  Tumour cells were detected in peripheral blood samples in four patients and lymph nodes in nine, in one of whom conventional histology had not detected tumour cells.
  
  
  CONCLUSIONS
  This technique may be useful in the early diagnosis of primary or metastatic tumours, in assessing prognosis and in detecting residual disease after treatment.
authors.affiliation: Department of Surgery, Walsgrave Hospital NHS Trust, UK.
authors.forename: L S
authors.initials: LS
authors.lastname: Wong
authors.forename: J E
authors.initials: JE
authors.lastname: Cantrill
authors.forename: S
authors.initials: S
authors.lastname: Odogwu
authors.forename: A G
authors.initials: AG
authors.lastname: Morris
authors.forename: I A
authors.initials: IA
authors.lastname: Fraser
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D015139:Blotting, Southern; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D004586:Electrophoresis; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D016133:Polymerase Chain Reaction; D012334:RNA, Neoplasm / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D018960:Hyaluronan Receptors; D012334:RNA, Neoplasm