title: Expression of c-myc proteins in breast cancer as related to established prognostic factors and survival.
abstract: The expression of c-myc proteins was analysed immunohistochemically in a series of 206 breast carcinomas with special focus on established prognostic factors and patient survival. Nuclear expression of c-myc proteins was detected in 12% of carcinomas, and it was related to the lack of estrogen receptors (p = 0.05). Cytoplasmic expression of c-myc was present in 95% of the tumours. Expression of cytoplasmic c-myc at the invasive margin was related to tumour grade (p = 0.0013), low mitotic index (p = 0.0002) and low S phase fraction (p = 0.026), and weakly associated with distant metastasis at diagnosis (p = 0.06) and to a high proportion of intraductal growth (p = 0.08). Long recurrence-free survival of the patients was related to strong cytoplasmic expression of c-myc at the invasive margin in the entire series (p = 0.0049) and in axillary lymph node-negative (ANN) (p = 0.0028) tumours. Cytoplasmic c-myc expression in the central areas of the tumour predicted metastasis at diagnosis (p = 0.002), non-ductal type of growth (p = 0.018) and low mitotic index (p = 0.005). Expression of c-myc in the stroma was related to the lack of estrogen receptors (p = 0.02) and to high S phase fraction (p = 0.01). The results show that overexpression of c-myc is involved in a highly complex manner with the early stages of breast cancer development, but it shows hardly any independent prognostic value over standard prognostic factors in clinical disease.
authors.affiliation: Department of Pathology, University of Kuopio, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Pietiläinen
authors.forename: P
authors.initials: P
authors.lastname: Lipponen
authors.forename: S
authors.initials: S
authors.lastname: Aaltomaa
authors.forename: M
authors.initials: M
authors.lastname: Eskelinen
authors.forename: V M
authors.initials: VM
authors.lastname: Kosma
authors.forename: K
authors.initials: K
authors.lastname: Syrjänen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D016259:Genes, myc; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000032:analysis; D017154:Stromal Cells / Q000473:pathology; D015996:Survival Rate; D013997:Time Factors
chemical_list: D004273:DNA, Neoplasm; D016271:Proto-Oncogene Proteins c-myc; D011960:Receptors, Estrogen