A significant proportion of elderly patients develop hormone-dependant "luminal-B" tumours associated with aggressive characteristics.
BACKGROUND
To investigate the influence of ageing on the incidence of breast cancer (BC) molecular subtypes, patient age at diagnosis was correlated with bio-pathological data collected retrospectively from 2723 consecutive patients diagnosed/treated at our Institute between 2000 and 2003.


METHODS
According to their bio-characteristics, 61% of the samples could be assigned to a molecular subtype: the "HER-2+", the "ER & HER2 negative" or one of the two "luminal-like" subtypes divided according to their histological grade ("A" [HER-2-/ER+/grade 1-2] and "B" [HER-2-/ER+/grade 3]).


CONCLUSIONS
Age is highly influencing the incidence of BC molecular subtypes. Patients younger than 40 develop a statistically higher rate of high grade proliferating "HER-2" (27%) and "ER & HER2 negative" (31%) BC whereas patients older than 50 develop mostly less aggressive hormone-dependant "luminal-A" BC (>67%). Nevertheless, a significant proportion of patients older than 70 develop "luminal-B" (19%) tumours associated with high proliferation, high grade, large size and nodal invasion.
Durbecq
V
V
Translational Research Unit, Jules Bordet Institute, Université Libre de Bruxelles, Brussels, Belgium.
Ameye
L
L
Veys
I
I
Paesmans
M
M
Desmedt
C
C
Sirtaine
N
N
Sotiriou
C
C
Bernard-Marty
C
C
Nogaret
J M
JM
Piccart
M
M
Larsimont
D
D
D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism* / Q000473:pathology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis; D012189:Retrospective Studies
D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone