title: Lymph node count and prognosis in colorectal cancer: the influence of examination quality.
abstract: Colorectal cancer guidelines recommend adjuvant chemotherapy in stage II disease when less than 12 lymph nodes are assessed. The recommendation bases on previous studies showing an association of a low lymph node count and adverse outcome. Compared to current standards, however, the quality of lymph node examination in the studies was low. We, therefore, investigated the prognostic role of <12 lymph nodes in cancers diagnosed adherent to current quality measures. Stage I-IV colorectal cancers from 1,899 patients enrolled into a population-based cohort study were investigated for the prognostic impact of a lymph node count <12. The stage specific share of patients diagnosed with ≥12 nodes (stage I-IV: 62, 85, 85, 78%, respectively) was used to compare lymph node examination quality to other studies. We found no impact of a lymph node count <12 on overall, cancer-specific or recurrence-free survival for any tumour stage. Compared to studies reporting an adverse prognostic impact of a low lymph node count in stages II and III the stage-specific shares of patients with ≥12 nodes were markedly higher in this study (85% vs. 24-58% in previous analyses) and this correlated with increased rates of stage III compared to stage II cancers. In conclusion our data indicate, that the previously reported effect of a low lymph node count on the patients' outcomes is eliminated by improved lymph node examination quality and thus question the general applicability of a 12 lymph node cut off for adjuvant chemotherapy decision making in stage II disease.
authors.affiliation: Department of General Pathology, Institute of Pathology, Charite University Medicine Hospital, Charitéplatz 1, Berlin, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bläker
authors.forename: Bert
authors.initials: B
authors.lastname: Hildebrandt
authors.forename: Hanno
authors.initials: H
authors.lastname: Riess
authors.forename: Moritz
authors.initials: M
authors.lastname: von Winterfeld
authors.forename: Barbara
authors.initials: B
authors.lastname: Ingold-Heppner
authors.forename: Wilfried
authors.initials: W
authors.lastname: Roth
authors.forename: Matthias
authors.initials: M
authors.lastname: Kloor
authors.forename: Peter
authors.initials: P
authors.lastname: Schirmacher
authors.forename: Manfred
authors.initials: M
authors.lastname: Dietel
authors.forename: Sha
authors.initials: S
authors.lastname: Tao
authors.forename: Lina
authors.initials: L
authors.lastname: Jansen
authors.forename: Jenny
authors.initials: J
authors.lastname: Chang-Claude
authors.forename: Alexis
authors.initials: A
authors.lastname: Ulrich
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmeister
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies
keywords: colorectal cancer; lymph nodes; prognosis