BMC Cancer 2009, 9:11 http://www.biomedcentral.com/1471-2407/9/11 Table 1: Clinicopathological characteristics of the patients in the study and validation groups Parameter Study (Array) All samples TN paired NUMBER % Validation RT-PCR 37 20 49 57 (36–97) 62 (35–97) 59 (35–97) Total Age (yrs) Median (Range) Gender Male Female Therapy prior to surgery None Yes Smoking history Yes No Alcohol history Yes No Unknown Histological grading Well-differentiated Mod-differentiated Poorly-differentiated Unknown Lymph node involvement (Pathologic) Negative Positive Unknown TNM Stage (Pathologic) 22 (59.5) 15 (40.5) 22 (59.5) 15 (40.5) 19 (51.4) 18 (48.6) 14 (37.9) 23 (62.1) 0 6 (16.2) 24 (64.9) 7 (18.9) 0 26 (70.2) 11 (29.8) 0 12 (60) 8 (40) 12 (60.0) 8 (40.0) 11 (55.0) 9 (45.0) 8 (40.0) 12 (60.0) 0 3 (15) 13 (65) 4 (20) 0 13 (65) 7 (35) 0 26 (53) 23 (47) 34 (69.4) 15 (30.6) 30 (61.2) 19 (38.8) 20 (40.8) 26 (59.2) 3 9 (18) 32 (65) 8 (16) 0 25 (51) 24 (49) 0 Page 3 of 13 (page number not for citation purposes)