Novel strategy for optimal sequential application of clinical criteria, immunohistochemistry and microsatellite analysis in the diagnosis of hereditary nonpolyposis colorectal cancer.
Clinical criteria, microsatellite analysis (MSA) and immunohistochemistry (IHC) are important diagnostic tools for identification of hereditary nonpolyposis colorectal cancer (HNPCC) patients who are likely to carry pathogenic germline mutations in mismatch repair genes. Based on MSA and IHC results and subsequent mutation analyses of 1,119 unrelated index patients meeting the Amsterdam II criteria or the classical Bethesda guidelines, we analyzed the value of these tools to predict MLH1 and MSH2 mutations with the aim of establishing optimal strategies for their most efficient sequential use. The overall prevalence of pathogenic germline mutations in our cohort was 20.6% (95% CI = 18.3-23.0%) and 61.8% (95% CI = 56.8-66.6%), respectively, after MSA/IHC-based preselection. IHC was highly predictive (99.1%) and specific (99.6%) with regard to MSA. However, 14 out of 230 mutations (6%) escaped detection by IHC. Thus, IHC cannot be recommended to substitute MSA fully. Nonetheless, IHC is important to indicate the gene that is likely to be affected. To combine both methods efficiently, we propose a novel screening strategy that provides 2 alternative ways of sequential IHC and MSA application, either using IHC or MSA in the first place. A logistic regression model based on the age of the index patient at first tumor diagnosis and the number of fulfilled HNPCC criteria is used to allocate individual patients to that alternative pathway that is expected to be least expensive. A cost analysis reveals that about 25% of the costs can be saved using this strategy.
Engel
Christoph
C
Institute of Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany. engel@imise.uni-leipzig.de
Forberg
Jochen
J
Holinski-Feder
Elke
E
Pagenstecher
Constanze
C
Plaschke
Jens
J
Kloor
Matthias
M
Poremba
Christopher
C
Pox
Christian P
CP
Rüschoff
Josef
J
Keller
Gisela
G
Dietmaier
Wolfgang
W
Rümmele
Petra
P
Friedrichs
Nicolaus
N
Mangold
Elisabeth
E
Buettner
Reinhard
R
Schackert
Hans K
HK
Kienle
Peter
P
Stemmler
Susanne
S
Moeslein
Gabriela
G
Loeffler
Markus
M
D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D020137:Base Pair Mismatch; D002352:Carrier Proteins / Q000235:genetics; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics*; D004249:DNA Damage; D004260:DNA Repair; D003937:Diagnosis, Differential; D005260:Female; D005820:Genetic Testing; D018095:Germ-Line Mutation; D017408:Guidelines as Topic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein