title: MUC1 expression in primary breast cancer: the effect of tamoxifen treatment.
abstract: This was a non-randomised single institution retrospective study. Forty-six banked frozen tumour specimens were obtained from a group of patients who had undergone 3 weeks of neoadjuvant treatment with tamoxifen between biopsy and surgery. Fifty-one comparison specimens were randomly selected from a group of concomitantly treated primary breast cancer patients who did not receive neoadjuvant tamoxifen. Specimen selection was not based on prognostic factors: hormone receptor status, patient age, or menopausal status. MUC1 expression and cell cycle distribution were assessed by flow cytometry. S-phase fraction of MUC1 positive and MUC1 negative cells were compared. A lower percentage of cells expressed MUC1 following 3-week tamoxifen treatment 18.2% versus 28.5% (p = 0.03, Mann-Whitney) and lower levels of MUC1 expression were seen following tamoxifen treatment 31,519 molecules/cell versus 39,387 (p = 0.04, Mann-Whitney). MUC1 positive cells, irrespective of treatment group, had a greater proportion of cells in S-phase of the cell cycle 27.9% versus 16.8% (p = 0.0004, Mann-Whitney) and demonstrated more cases of aneuploidy 80.65% versus 42.6% (p < 0.0001). MUC1 levels in primary tumours treated neoadjunctively with 3 weeks of tamoxifen were lower than a comparison group which did not receive tamoxifen. MUC1 should be explored further as an intermediate biomarker for assessment of treatment and prognosis.
authors.affiliation: Department of Surgery, University of Newcastle upon Tyne, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Hanson
authors.forename: D A
authors.initials: DA
authors.lastname: BroweIl
authors.forename: W J
authors.initials: WJ
authors.lastname: Cunliffe
authors.forename: J
authors.initials: J
authors.lastname: Varma
authors.forename: A
authors.initials: A
authors.lastname: Allen
authors.forename: D
authors.initials: D
authors.lastname: Hemming
authors.forename: B K
authors.initials: BK
authors.lastname: Shenton
authors.forename: J R
authors.initials: JR
authors.lastname: Young
authors.forename: M J
authors.initials: MJ
authors.lastname: Higgs
authors.forename: I
authors.initials: I
authors.lastname: Brotherick
authors.forename: J P
authors.initials: JP
authors.lastname: Pearson
mesh_terms: D000368:Aged; D000782:Aneuploidy; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D002453:Cell Cycle; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D018396:Mucin-1 / Q000096:biosynthesis* / Q000235:genetics; D020360:Neoadjuvant Therapy; D011379:Prognosis; D012189:Retrospective Studies; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D018396:Mucin-1; D013629:Tamoxifen