Table 2.

Results of volcano plot analysis for HILIC dataset. Important metabolic features (marker candidates) occurring in all types of comparisons between lung cancer (LC) patients and chronic obstructive pulmonary disease (COPD) patients were bolded. Directions of comparison in fold change analysis: LC/COPD when grouping variable was cancer status; current smokers/former smokers when grouping variable was smoking status.

The grouping variable—cancer status
A. LC vs COPD all patients			B. LC vs COPD current smokers			C. LC vs COPD former smokers
Metabolite	Fold change	FDR-adjusted P value	Metabolite	Fold change	FDR-adjusted P value	Metabolite	Fold change	FDR-adjusted P value
Glutamic acid	0.70	< 0.0001	Allantoin	0.64	< 0.0001	Aspartic acid	0.69	< 0.0001
Allantoin	0.60	< 0.0001	Glutamic acid	0.70	< 0.0001	Glutamic acid	0.70	< 0.0001
Succinic acid	0.71	< 0.0001	Succinic acid	0.70	0.0007	Inosine	2.50	< 0.0001
Aspartic acid	0.75	< 0.0001	Catechol	0.54	0.0069	Allantoin	0.57	< 0.0001
Inosine	2.65	< 0.0001	Malic acid	0.74	0.0091	Succinic acid	0.71	< 0.0001
Hypotaurine	0.66	< 0.0001	Inosine	2.83	0.0213	Hypotaurine	0.57	0.0001
Malic acid	0.73	< 0.0001				Guanosine	2.28	0.0015
Guanosine	2.23	< 0.0001				Malic acid	0.72	0.0027
Fucose	0.54	0.0070				Tyrosine	0.75	0.0066

The grouping variable—smoking status
D. current smokers vs former smokers			E. LC current smokers vs LC former smokers			F. COPD smokers vs COPD former smokers
Metabolite	Fold change	FDR-adjusted P value	Metabolite	Fold change	FDR-adjusted P value	Metabolite	Fold change	FDR-adjusted P value
Malic acid	0.76	0.0040	Aconitic acid	0.77	0.0136	Catechol	1.76	0.0201
						Malic acid	0.75	0.0201