title: Primary colorectal tumour is not an accurate predictor of thymidylate synthase in lymph node metastasis.
abstract: Analysis of tumour markers is helping to predict individual patient response to chemotherapy. However, the difficulties in obtaining metastatic disease samples has led to a reliance on assessment of primary tumour, with little data on its predictive ability. This study assessed thymidylate synthase (TS), a target for the commonly used drug 5FU, in 42 paired primary colorectal tumour and lymph node metastasis. High TS staining was seen in 63% of primary colon tumour cells and 81% of the secondary lymph node. Primary tumour did not have significant predictive power for secondary tumour samples (kappa=0.125; p=0.38). There was no significant relationship between TS staining and expression of G1/S cell cycle proteins p21, p27, p53, cyclin D1, proliferating cell nuclear antigen (PCNA) and retinoblastoma protein (Rb) (p>0.05 in all cases). Discordance in TS protein levels between primary and secondary tumours demonstrates the danger of predicting outcome after chemotherapy in metastatic colorectal cancer from the primary tumour.
authors.affiliation: Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
authors.forename: Sharon
authors.initials: S
authors.lastname: Marsh
authors.forename: Judith A
authors.initials: JA
authors.lastname: McKay
authors.forename: Stephanie
authors.initials: S
authors.lastname: Curran
authors.forename: Graeme I
authors.initials: GI
authors.lastname: Murray
authors.forename: James
authors.initials: J
authors.lastname: Cassidy
authors.forename: Howard L
authors.initials: HL
authors.lastname: McLeod
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D019938:Cyclin D1 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000201:enzymology* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D008875:Middle Aged; D009124:Muscle Proteins; D011237:Predictive Value of Tests; D011379:Prognosis; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D013940:Thymidylate Synthase / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D018809:Proliferating Cell Nuclear Antigen; D016160:Retinoblastoma Protein; C058992:Tagln protein, mouse; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1; D013940:Thymidylate Synthase