Abstract:

Objective To investigate the clinical roles of serum amyloid A（SAA） and C-reactive protein（CRP） in gastrointestinal cancer staging. Methods Totally,400 patients with gastrointestinal cancer（157 gastric cancer cases and 243 colorectal cancer cases）,97 polyp patients and 104 healthy subjects were recruited. The levels of SAA,CRP,carcinoembryonic antigen（CEA）,carbohydrate antigen（CA） 242,CA19-9 and CA50 were determined,and the patients' pathological stage data were collected postoperatively. The role of tumor stage was judged by each index using receiver operating characteristic（ROC） curve. Results The levels of SAA,CRP,CA242,CA19-9,CEA and CA50 were higher in gastrointestinal cancer group than those in healthy control and polyp groups（P<0.01）. There was no statistical significance for all the indicators in polyp group and healthy control group（P>0.05）. SAA levels had statistical significance among different clinical stages,different T stages and different N stages in gastrointestinal cancer patients（P<0.05）,and there was no statistical significance between different M stages（P>0.05）. CRP levels had no statistical significance among different pathological stages in patients with gastrointestinal cancer（P>0.05）. The areas under curves（AUC） of SAA,CRP,CA242,CA19-9,CEA and CA50 single determinations for the evaluation of lymph node metastasis in gastrointestinal cancer were 0.732,0.505,0.626,0.631,0.604 and 0.625,respectively. The highest efficacy of the SAA+CRP+CA242 combined determination was observed. The combined determination model was Logit（P）=-0.988+0.013×SAA+0.003×CRP+0.010×CA242,and the AUC for judging lymph node metastasis of gastrointestinal cancer was 0.769. Conclusions SAA and CRP can be considered clinically useful in pathological staging and lymph node metastasis judging of gastrointestinal cancer.

Key words: Serum amyloid A, C-reactive protein, Tumor marker, Pathological staging, Gastric cancer, Colorectal cancer