Tumour characteristics and prognosis of breast cancer patients carrying the germline CHEK2*1100delC variant.
BACKGROUND
The germline CHEK2*1100delC variant has been associated with breast cancer in multiple case families where involvement of BRCA1 and BRCA2 has been excluded.


METHODS
We have investigated the tumour characteristics and prognosis of carriers of this germline variant by means of a prospective cohort study in an unselected cohort of 1084 consecutive patients with primary breast cancer. Data were collected for 34 patients with a germline CHEK2*1100delC mutation and for 102 patients without this mutation, stratified by age and date of diagnosis of the first primary breast cancer (within 1 year).


RESULTS
Carriers developed steroid receptor positive tumours (oestrogen receptor (ER): 91%; progesterone receptor (PR): 81%) more frequently than non-carriers (ER: 69%; PR: 53%; p = 0.04). Mutation carriers more frequently had a female first or second degree relative with breast cancer (p = 0.03), or had any first or second degree relative with breast or ovarian cancer (p = 0.04). Patients with the CHEK2 variant had a more unfavourable prognosis regarding the occurrence of contralateral breast cancer (relative risk (RR) = 5.74; 95% confidence interval (CI) 1.67 to 19.65), distant metastasis-free survival (RR = 2.81; 95% CI 1.20 to 6.58), and disease-free survival (RR = 3.86; 95% CI 1.91 to 7.78). As yet, no difference with respect to overall survival has been found at a median follow up of 3.8 years.


CONCLUSIONS
We conclude that carrying the CHEK2*1100delC mutation is an adverse prognostic indicator for breast cancer. If independently confirmed by others, intensive surveillance, and possibly preventive measures, should be considered for newly diagnosed breast cancer cases carrying the CHEK2*1100delC variant.
de Bock
G H
GH
Department of Medical Decision Making, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands. g.h.de_bock@lumc.nl.
Schutte
M
M
Krol-Warmerdam
E M M
EM
Seynaeve
C
C
Blom
J
J
Brekelmans
C T M
CT
Meijers-Heijboer
H
H
van Asperen
C J
CJ
Cornelisse
C J
CJ
Devilee
P
P
Tollenaar
R A E M
RA
Klijn
J G M
JG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D064447:Checkpoint Kinase 2; D015331:Cohort Studies; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D018095:Germ-Line Mutation / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D016019:Survival Analysis
D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases