Circulating Tumor Cells (CTC) And Circulating Tumor Stem Cells (CTSC) In Colorectal Cancer: Correlation With Clinical Data Variables

Objective To identify CTC(circulating tumor cells) and CTSC(circulating tumor stemcells) from peripheral blood in patients with colorectal cancer, and further analyze thecorrelation of CTC and CTSC number with clinical stages, lymph node metastasis, andtumor distal metastasis of cancer. To verify if CTC and CTSC can be evaluated prognosticand accorded to distant metastasis. Methods Altogether50colorectal cancer patients whohave never received any treatment before were recruited.15ml peripheral blood wasdrawn from each patient at two time points: one week before surgery and one week after.Ficoll were used to separate the blood mononuclear cells from peripheral blood. Cellswere averaged into two portions, and taged respectively with circulating tumor cellssurface markers: CD45, EpCAM and CK, or with circulating tumor stem cells surfacemarkers: CD45, EpCAM, CD44and CD133. Ultra high speed flow cytometrysorter(MOFLO XDP) was used to analyze CTC and CTSC number. Results We identifiedCD45-/EpCAM+/CK+cells as CTC, CD45-/EpCAM+/CD44+cells as CTSC1,45-/EpCAM+/CD133+cells as CTSC2,45-/EpCAM+/CD44+/CD133+cells as CTSC3.We regarded2CTCs and over per7.5ml peripheral blood as positive results, and lessthan2as negative; one CTSC and over per7.5ml peripheral blood as positive results,then CTSC less than1was negative. And the results show as follows:(1)For thosepatients with colorectal cancer before surgery, CTC detected rate is34%, CTSC1detectedrate is44%, CTSC2detected rate is4%; and after the surgery, CTC detected rate is38%,CTSC1detected rate is54%, CTSC2detected rate is6%, are both higher than that ofbefore surgery, but don’t have statistical significance.We didn’t find CTSC3neitherpreoperative nor postoperative, the CTSC3detected rate is0%.(2)Preoperative CTCnumber is related with the tumor’s size and T stages (infiltrating depth)(P<0.05); Whilepostoperative CTC number has significant correlation with T stages, N stages and M stages(distant metastasis)(P<0.05); Both pre-or post-operation CTC number areirrelation to patients’age, sex and TNM stages(P>0.05).(3)Before the operation, CTSC1is associated with the T stages of tumor (P<0.05), whereas postoperative CTSC1numberis not significant correlated with patients’age, sex, tumor size, TNM stages, T stages, Nstages and M stages(P>0.05).(4)Integrated CTC and CTSC1number both before andafter surgery have significant with tumor distant metastasis and TNM stages(P<0.05), andare also correlated with N stages(P=0.063). Conclusions (1)CTC number has significantcorrelation with T stages, N stages and M stages.(2)CTSC1number has significantcorrelation with T stages. CD44as a CTSC surface marker is better than CD133incolorectal cancer patients.(3)The circulating tumor stem cells are useful for circulatingtumor cells detection.