Prognostic Analysis Of Tumor Infiltration In Mesorectum Of Spiral CT Scan For Patients With Rectal Cancer

Objective To investigate the relationship between tumor infiltration in mesorectum of spiral CT and prognosis of patients with rectal cancer and the relationship between circumferential margin status of spiral CT and prognosis of patients with rectal cancer.Methods One hundred and six patients with rectal cancer diagnosed by colonoscopy and biopsy from the Affiliated Hospital of Qingdao University Medical College ranging from January2007to May2008underwent preoperative spiral computed tomography scanning. Degrees of tumor infiltration in mesorectum and circumferential margin status of spiral CT were determined. After total mesorectal excision (TME), the local recurrence rate, metastasis rate and five-year survival rate were investigated respectively.Results Follow-up data showed a total local recurrence rate of17.9%(19/106), a total metastasis rate of32.1%(34/106) and a total five-year survival rate of64.2%(68/106). There were45patients diagnosed as spiral CT infiltration in mesorectum of Degree â… ,whose local recurrence rate was4.4%(2/45), metastasis rate13.3%(6/45) and five-year survival rate86.7%(39/45). There were28patients diagnosed as spiral CT infiltration in mesorectum of Degree â…¡, whose local recurrence rate was7.1%(2/28), metastasis rate28.6%(8/28) and five-year survival rate64.3%(18/28). There were33patients diagnosed as spiral CT infiltration in mesorectum of Degree III, whose local recurrence rate was45.5%(15/33), metastasis rate60.6%(20/33) and five-year survival rate33.3%(11/33). Kaplan-Meier survival analysis showed a close correlation between infiltration degree in mesorectum of spiral CT (log-rank, P=0.011). Infiltration degrees in mesorectum of spiral CT correlated with T staging(x2=15.832, P=0.015), N staging(x2=9.642, P=0.047) and diameter of tumor (x2=5.048, P=0.025). Circumferential margin(CRM) positive rate of spiral CT was17.0%(18/106). Compared with patients with negative CRM, patients with positive CRM had a higher local recurrence rate [38.9%(7/18) to13.6%(12/88), x2=6.477, P=0.018], a higher metastasis rate[66.7%(12/18) to25.0%(22/88), x2=11.908, P=0.001] and a lower five-year survival rate[22.2%(4/18) to72.7%(64/88),x2=16.574, P=0.000]. Kaplan-Meier survival analysis showed a close correlation between CRM ststus of spiral CT and survival time (log-rank, P=0.006). CRM status of spiral CT correlated with T staging(x2=15.499, P=0.001), N staging(x2=13.390, P=0.001), diameter of tumor(x2=5.048, P=0.025) and location of tumor (x2=28.459, P=0.000)Conclusion Degree of infiltration in mesorectum of spiral CT and CRM status of spiral CT have a close correlation with survival time. They can be used as indicators of prognosis of patients with rectal cancer.