title: A molecular signature of the Nottingham prognostic index in breast cancer.
abstract: The Nottingham prognostic index (NPI) is a widely used clinicopathological staging system for breast cancer prognostication. Using a step-wise classification approach where breast tumor expression profiles were first divided into general "molecular subtypes" [estrogen receptor (ER)+, ER-, ERBB2+], followed by an independent analysis of each subtype, we identified a 62-gene expression signature (NPI-ES) highly correlated to the NPI in ER+ tumors. The NPI-ES classified the majority of ER+ tumors into two distinct groups with high confidence and was significantly correlated to NPI status in two independent sets of ER+ tumors derived from different centers. The NPI-ES is comparable to the classical NPI in identifying patients likely to exhibit a poor clinical prognosis, as well as to a recently described "prognosis signature" for breast cancer. Our findings demonstrate how expression profiling can complement classical staging systems employing histopathological parameters scored over a continuous range of values.
authors.affiliation: National Cancer Center, Singapore, Republic of Singapore.
authors.forename: Kun
authors.initials: K
authors.lastname: Yu
authors.forename: Chee How
authors.initials: CH
authors.lastname: Lee
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
authors.forename: Ga Sze
authors.initials: GS
authors.lastname: Hong
authors.forename: Siew Bok
authors.initials: SB
authors.lastname: Wee
authors.forename: Chow Yin
authors.initials: CY
authors.lastname: Wong
authors.forename: Patrick
authors.initials: P
authors.lastname: Tan
mesh_terms: D001943:Breast Neoplasms / Q000145:classification* / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D006801:Humans; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis / Q000235:genetics; D015996:Survival Rate
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen