Specific metabolic biomarkers as risk and prognostic factors in colorectal cancer

Table 1 Features of the insulin-like growth factors genes[117]

Gene	Molecular weight(kDa)	Mature protein(number of amino acids)	Chromosomallocalization	Gene size (kb)	Exons (n)
IGF1	7.7	70	12q22-12q24	100	6
IGF2	7.5	67	11p15	30	9
IGF1R	225	α 706	15q25-15q26	100	21
		β 626
IGF2R	270	2450	6q25-6q27	140	48
IGFBP1	25.3	234	7p12-7p14	5.2	4
IGFBP2	31.4	289	2q31-2q34	32	4
IGFBP3	28.7	264	7p12-7p14	8.9	5
IGFBP4	26	237	17q12-17q21	12	4
IGFBP5	28.6	252	2q31-2q24	33	4
IGFBP6	22.8	216	12q13	4.7	4
IGFBP7	29.130	282	4q12

IGF: Insulin-like growth factor; IGFBP: Insulin-like growth factor binding proteins.

Table 2 Insulin-like growth factor system/prognostic factors in colorectal cancer

IGF system	Researches
Insulin	There were no statistical significance relative to insulin serum level in groups independently of clinical stage of CRC and tumor localization, Nowakowska-Zajdel et al[127], Kaczka et al[147], Nowakowska-Zajdel[148]
	Hyperinsulinemia and hyperglycaemia has been associated with higher mortality from CRC, Yang et al[131], Deng et al[149]
IGF1	High IGF1 levels is associated with increased risk of CRC, Ma et al[156]
	IGF1 serum levels are increased in patients with locally advanced CRC (pT3, pT4) in comparison to less advanced cancer. Higher serum level of IGF1 is observed in patients with G3 (histopathological malignancy), in male patients older than 60 yr and in mucinogenous cancer, Kukliński et al[157]
	EPIC cohort and meta-analysis of prospective studies pointed a relatively modest association of CRC risk with IGF1 levels, Rinaldi et al[160]
IGF2	The serum levels is significantly elevated in patient with CRC vs control group and without difference between metastatic and local CRC, Matuschek et al[158]
	Higher IGF2 levels were associated with better overall survival in CRC patients, Liou et al[166]
	IGF2 serum levels were higher in patients with more advancer CRC, Zhao et al[164]
	The IGF2 overexpression in tumor cells was associated with more advanced CRC and poor survival, Wang et al[162], Kuklinski et al[163]
IGF1R	IGF1R is overexpressed in CRC cells, Pollak et al[168]
IGF2R	IGF2R imprinting is observed in CRC, Ouyang et al[170], Kuhlmann et al[171]
IGF1/IGFBP3 ratio	Higher IGF1/IGFBP-3 ratio is associated with CRC risk, Rowlands et al[179]
IGFBPs	Total IGFBP-3 levels is significantly related with risk of CRC, Rinaldi et al[160]
	Lower IGFBP-3 levels correlate with the CRC risk, Wolpin et al[128]
	High levels of IGFBP-3 has been associated with reduced risk of CRC, Ma et al[181]
	No correlation between circulating IGFBP-3 and mortality, Kaplan et al[178]
	IGFBP-7 is overexpressed in CRC cells, Ruan et al[177]

IGF: Insulin-like growth factor; IGFBP: Insulin-like growth factor binding proteins; CRC: Colorectal cancer.