TY - JOUR
T1 - The clinical value of HER-2 overexpression and PIK3CA mutations in the older breast cancer population
T2 - A FOCUS study analysis
AU - Engels, Charla C.
AU - Kiderlen, Mandy
AU - Bastiaannet, Esther
AU - van Eijk, Ronald
AU - Mooyaart, Antien
AU - Smit, Vincent T.H.B.M.
AU - de Craen, Anton J.M.
AU - Kuppen, Peter J.K.
AU - Kroep, Judith R.
AU - van de Velde, Cornelis J.H.
AU - Liefers, Gerrit Jan
N1 - Publisher Copyright:
© The Author(s) 2016.
PY - 2016/4
Y1 - 2016/4
N2 - Studies to confirm the effect of acknowledged prognostic markers in older breast cancer patients are scarce. The aim of this study was to evaluate the prognostic value of HER-2 overexpression and PIK3CA mutations in older breast cancer patients. Female breast cancer patients aged 65 years or older, diagnosed between 1997 and 2004 in a geographical region in The Netherlands, with an invasive, non-metastatic tumour and tumour material available, were included in the study. The primary endpoint was relapse-free period and secondary endpoint was relative survival. Determinants were immunochemical HER-2 scores (0/1+, 2+ or 3+) and PIK3CA as a binary measure. Overall, 1698 patients were included, and 103 had a HER-2 score of 3+. HER-2 overexpression was associated with a higher recurrence risk (5 years recurrence risk 34% vs. 12%, adjusted p = 0.005), and a worse relative survival (10 years relative survival 48% vs. 84% for HER-2 negative; p = 0.004). PIK3CA mutations had no significant prognostic effect. We showed, in older breast cancer patients, that HER-2 overexpression was significantly associated with a worse outcome, but PIK3CA mutations had no prognostic effect. These results imply that older patients with HER-2 overexpressing breast cancer might benefit from additional targeted anti-HER-2 therapy.
AB - Studies to confirm the effect of acknowledged prognostic markers in older breast cancer patients are scarce. The aim of this study was to evaluate the prognostic value of HER-2 overexpression and PIK3CA mutations in older breast cancer patients. Female breast cancer patients aged 65 years or older, diagnosed between 1997 and 2004 in a geographical region in The Netherlands, with an invasive, non-metastatic tumour and tumour material available, were included in the study. The primary endpoint was relapse-free period and secondary endpoint was relative survival. Determinants were immunochemical HER-2 scores (0/1+, 2+ or 3+) and PIK3CA as a binary measure. Overall, 1698 patients were included, and 103 had a HER-2 score of 3+. HER-2 overexpression was associated with a higher recurrence risk (5 years recurrence risk 34% vs. 12%, adjusted p = 0.005), and a worse relative survival (10 years relative survival 48% vs. 84% for HER-2 negative; p = 0.004). PIK3CA mutations had no significant prognostic effect. We showed, in older breast cancer patients, that HER-2 overexpression was significantly associated with a worse outcome, but PIK3CA mutations had no prognostic effect. These results imply that older patients with HER-2 overexpressing breast cancer might benefit from additional targeted anti-HER-2 therapy.
KW - Anti-HER2 therapy
KW - Breast cancer
KW - Competing risk
KW - Epidemiology
KW - Geriatric oncology
KW - HER-2
KW - PIK3CA
KW - Prognostic markers
UR - http://www.scopus.com/inward/record.url?scp=85007009175&partnerID=8YFLogxK
U2 - 10.1007/s10549-016-3734-y
DO - 10.1007/s10549-016-3734-y
M3 - Article
C2 - 26968397
AN - SCOPUS:85007009175
SN - 0167-6806
VL - 156
SP - 361
EP - 370
JO - Breast Cancer Research and Treatment
JF - Breast Cancer Research and Treatment
IS - 2
ER -