. Author manuscript; available in PMC: 2013 Jan 1.

Published in final edited form as: J Neuropathol Exp Neurol. 2012 Jan;71(1):73–82. doi: 10.1097/NEN.0b013e318240fa65

Table 2.

Comparison Between 2 Different Fluorescence In Situ Hybridization Interpretation Criteria and Loss of Heterozygosity Methods of 1p/19q Testing

1p/19q FISH criteria	1p/19q FISH relative to 1p/19q LOH
1p/19q FISH criteria	% Sensitivity (95% CI)	% Specificity (95% CI)	% PPV (95% CI)	% NPV (95% CI)
Original FISH criteria	98.5 (91.7—100.0)	56.5 (41.1—71.0)	76.2 (65.6—84.8)	96.3 (81.0—99.9)
Modified FISH criteria	93.9 (85.0—98.3)	67.4 (51.9—80.5)	80.3 (69.6—88.5)	88.6 (73.3—96.8)

One hundred eleven grade II and III oligodendrogliomas were analyzed for 1p/19q codeletion by both FISH and LOH assays. Relative to 1p/19q LOH testing, increasing the stringency of FISH ratio cutoff criteria from < 0.87 (Original) to < 0.75 (Modified) improved the specificity and positive predictive value (PPV) of FISH, at the cost of reduced sensitivity and negative predictive value (NPV). CI = confidence interval; FISH = fluorescence in situ hybridization; LOH = loss of heterozygosity.