title: Breast screening: axillary lymph node status of interval cancers by interval year.
abstract: The aim of this study was to determine whether the excess risk of axillary lymph node metastases (N+) differs between interval breast cancers arising shortly after a negative mammography and those presenting later. In a registry-based series of pT1a-pT3 breast carcinoma patients aged 50-74 years from the Italian screening programmes, the odds ratio (OR) for interval cancers (n=791) versus the screen-detected (SD) cancers (n=1211) having N+ was modelled using forward stepwise logistic regression analysis. The interscreening interval was divided into 1-12, 13-18, and 19-24 months. The prevalence of N+ was 28% among SD cancers. With a prevalence of 38%, 42%, and 44%, the adjusted (demographics and N staging technique) OR of N+ for cancers diagnosed between 1-12, 13-18, and 19-24 months of interval was 1.41 (95% confidence interval 1.06-1.87), 1.74 (1.31-2.31), and 1.91 (1.43-2.54), respectively. Histologic type, tumour grade, and tumour size were entered in turn into the model. Histologic type had modest effects. With adjustment for tumour grade, the ORs decreased to 1.23 (0.92-1.65), 1.58 (1.18-2.12), and 1.73 (1.29-2.32). Adjusting for tumour size decreased the ORs to 0.95 (0.70-1.29), 1.34 (0.99-1.81), and 1.37 (1.01-1.85). The strength of confounding by tumour size suggested that the excess risk of N+ for first-year interval cancers reflected only their higher chronological age, whereas the increased aggressiveness of second-year interval cancers was partly accounted for by intrinsic biological attributes.
authors.affiliation: Romagna Cancer Registry, IRST, Forlì, Italy. l.bucchi@ausl.fo.it
authors.forename: Lauro
authors.initials: L
authors.lastname: Bucchi
authors.forename: Donella
authors.initials: D
authors.lastname: Puliti
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ravaioli
authors.forename: Laura
authors.initials: L
authors.lastname: Cortesi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Lisi
authors.forename: Fabio
authors.initials: F
authors.lastname: Falcini
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferretti
authors.forename: Alfonso
authors.initials: A
authors.lastname: Frigerio
authors.forename: Lucia
authors.initials: L
authors.lastname: Mangone
authors.forename: Marco
authors.initials: M
authors.lastname: Petrella
authors.forename: Chiara
authors.initials: C
authors.lastname: Petrucci
authors.forename: Priscilla
authors.initials: P
authors.lastname: Sassoli de Bianchi
authors.forename: Adele
authors.initials: A
authors.lastname: Traina
authors.forename: Rosario
authors.initials: R
authors.lastname: Tumino
authors.forename: Roberto
authors.initials: R
authors.lastname: Zanetti
authors.forename: Manuel
authors.initials: M
authors.lastname: Zorzi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Paci
mesh_terms: D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D012042:Registries; D012306:Risk; D013997:Time Factors