title: Tumour-derived mutated K-ras codon 12 expression in regional lymph nodes of stage II colorectal cancer patients is not associated with increased risk of cancer-related death.
abstract: This study examined the frequency of lymph node micrometastases detected by expression of mutant K-ras oncogene present in the respective primary tumour. The study population consisted of consecutive patients with stage II colorectal cancer (CRC) undergoing curative resection and with disease-free survival of 60 months or longer or CRC-related death. Of 27 patients found to have K-ras mutations at codon 12, 17 had genomic DNA suitable for PCR recovered from corresponding regional lymph node tissue. The same K-ras mutation was identified in the lymph nodes of 13 patients (76%), four of whom (30%) died of CRC recurrence within 5 years. A single patient in the negative group (25%) also died. Lymph node micrometastases detected by this technique thus show no relationship to mortality in stage II CRC. Further study of this technique is necessary before it can be used in the selection of patients for adjuvant chemotherapy.
authors.affiliation: Division of Gastroenterology, Mater Misericordiae Hospital, University College Dublin, Eccles Street, Dublin 7, Ireland. gclarke@rics.bwh.harvard.edu
authors.forename: G A
authors.initials: GA
authors.lastname: Clarke
authors.forename: E
authors.initials: E
authors.lastname: Ryan
authors.forename: J P
authors.initials: JP
authors.lastname: Crowe
authors.forename: J C
authors.initials: JC
authors.lastname: O'Keane
authors.forename: P
authors.initials: P
authors.lastname: MacMathúna
mesh_terms: D001483:Base Sequence; D002881:Chromosomes, Human, Pair 12; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D018572:Disease-Free Survival; D005260:Female; D015870:Gene Expression; D011905:Genes, ras / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D007494:Ireland; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000235:genetics* / Q000473:pathology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015996:Survival Rate
chemical_list: D004273:DNA, Neoplasm; D005819:Genetic Markers