D Gareth Evans, Central Manchester Foundation Trust
17 April 2009
Panchal et al have published an interesting paper using risk models to calculate the likelihood of carrying a BRCA1 or BRCA2 mutation in 200 non-BRCA carriers and 100 BRCA carriers, consecutively tested between August 1995 and March 2006. We believe they may not have correctly used the Manchester combined score as the sensitivity for the BRCA1 and BRCA2 independant scores is good but the combined score is not. Correct use of the Manchester combined score should add ALL of the points from both the BRCA1 and BRCA2 score without taking into account prior testing. In other words an ovarian cancer should score 5 points for BRCA2 and a male breast cancer 5 points for BRCA1 regardless of the outcome of testing as published in our update paper [1]. We urge Panchal et al to recalculate the combined score to determine if the Manchester score is as accurate as the other models utilised.
1. Evans DG, Lalloo F, Wallace A, Rahman N. Update on the Manchester Scoring System for BRCA1 and BRCA2 testing. J Med Genet. 2005 Jul;42(7):e39
Competing interests
I am the first author of the orginal and update paper on the Manchester scoring system
Reply to : Correct use of the Manchester scoring system
Louise Bordeleau, Juravinski Cancer Centre
5 May 2009
We greatly appreciate the feedback provided by Dr. Evans on the correct use of the Manchester scoring system. We have since recalculated the combined scores of the Manchester Model using the correct scoring system. The AUC of the Manchester Model using the updated calculation is 0.73 (0.64-0.79); low risk subset 0.67 (0.50-0.80) and high risk subset 0.75 (0.65-0.83) [Table 4]. At the conventional testing threshold of 15, both the sensitivity and specificity of the Manchester Model are 0.66 [Table 5]. The performance of the Manchester Model is therefore similar to the performances observed with other models used in our analyses including the BRCAPRO, PennII, Myriad II, FHAT and BOADICEA. The clarification in the use of the model deserves to be noted as it can affect the performance of the model based on the results observed in our study.
Correct use of the Manchester scoring system
17 April 2009
Panchal et al have published an interesting paper using risk models to calculate the likelihood of carrying a BRCA1 or BRCA2 mutation in 200 non-BRCA carriers and 100 BRCA carriers, consecutively tested between August 1995 and March 2006. We believe they may not have correctly used the Manchester combined score as the sensitivity for the BRCA1 and BRCA2 independant scores is good but the combined score is not. Correct use of the Manchester combined score should add ALL of the points from both the BRCA1 and BRCA2 score without taking into account prior testing. In other words an ovarian cancer should score 5 points for BRCA2 and a male breast cancer 5 points for BRCA1 regardless of the outcome of testing as published in our update paper [1]. We urge Panchal et al to recalculate the combined score to determine if the Manchester score is as accurate as the other models utilised.
1. Evans DG, Lalloo F, Wallace A, Rahman N. Update on the Manchester Scoring System for BRCA1 and BRCA2 testing. J Med Genet. 2005 Jul;42(7):e39
Competing interests
I am the first author of the orginal and update paper on the Manchester scoring system
Reply to : Correct use of the Manchester scoring system
5 May 2009
We greatly appreciate the feedback provided by Dr. Evans on the correct use of the Manchester scoring system. We have since recalculated the combined scores of the Manchester Model using the correct scoring system. The AUC of the Manchester Model using the updated calculation is 0.73 (0.64-0.79); low risk subset 0.67 (0.50-0.80) and high risk subset 0.75 (0.65-0.83) [Table 4]. At the conventional testing threshold of 15, both the sensitivity and specificity of the Manchester Model are 0.66 [Table 5]. The performance of the Manchester Model is therefore similar to the performances observed with other models used in our analyses including the BRCAPRO, PennII, Myriad II, FHAT and BOADICEA.
The clarification in the use of the model deserves to be noted as it can affect the performance of the model based on the results observed in our study.
Competing interests
None