Comparison of linear discriminant analysis methods for the classification of cancer based on gene expression data

Table 1 Characteristics of the six microarray datasets used

Dataset	No. of samples	Classes (No. of samples)	No. of genes	Original ref.	Website
Two-class lung cancer	181	MPM(31), adenocarcinoma(150)	12533	[8]	http://www.chestsurg.org
Colon	62	normal(22), tumor(40)	2000	[9]	http://microarray.princeton.edu/oncology/affydata/index.html
Prostate	102	normal(50), tumor(52)	6033	[10]	http://microarray.princeton.edu/oncology/affydata/index.html
Multi-class lung cancer	68(66) ^a	adenocarcinoma(37), combined(1), normal(5), small cell(4), squamous cell(10), fetal(1), large cell(4), lymph node(6)	3171	[11, 12]	http://www-genome.wi.mit.edu/mpr/lung/
SRBCT	88(83) ^b	Burkitt lymphoma (29), Ewing sarcoma (11), neuroblastoma (18), rhabdomyosarcoma (25), non-SRBCTs(5)	2308	[13]	http://research.nhgri.nih.gov/microarray/Supplement/
Brain	42(38) ^c	medulloblastomas(10), CNS AT/RTs(5), rhabdoid renal and extrarenal rhabdoid tumours(5), supratentorial PNETs(8), non-embryonal brain tumours (malignant glioma) (10), normal human cerebella(4)	5597	[14]	http://research.nhgri.nih.gov/microarray/Supplement/

Note: Some samples were removed for keeping adequate number of each type.
a. One combined and one fetal cancer samples were removed, and real sample size is 66;
b. Five non-SRBCT samples were removed, and real sample size is 83;
c. Four normal tissue samples were removed, and real sample size is 38.

ISSN: 1756-9966