Preoperative local staging of colorectal carcinoma in Mongolian patients using computed tomography / Шинэ санаа Шинэ нээлт

ABSTRACT

In Europe, colorectal cancer (CRC) is the second most frequent malignancy and the second commonest cause of death from cancer. -The prognosis of CRC patients is dependent on the stage of disease at the time of diagnosis. Contrast-enhanced computed tomography (CT) examinations allows simultaneous assessment of tumor’s local staging, estimation of its possible invasion into neighboring organs, and detection of nodal and distant metastases; which is essential for appropriate treatment planning and estimation of its outcomes. The lack of reports on CT findings in CRC in Mongolia, increase in CRCmorbidity, and significant potential benefits of early detection served as background for this study.We investigated subjects with histologically proven adenocarcinoma who underwent CRC-related operative treatment either at National Cancer Center, First State Central Hospital, or Ulaanbaatar Songdo Hospital (UBSH) in 2009-2012. We retrospectively reviewed and analyzed from the UBSH’ database their preoperative CT, colonoscopy, surgical and pathohistologic reports using PACSPLUS,OCS operation systems. CECT examinations were performed at Siemens Somatom 64 multidetector scanner.Countrywide, 111 patients underwent surgery for colorectal cancer in 2009-2012. Totally, we involved86 subjects, whose age ranged from 25 to 87 years (mean 61.3years ±13.7SD). The F M= 48 (55.8%)38 (44.2%).The CECT determined T2 staging in 10/86 (11.6%),T3 in 61/86 (70.9%); T4 in 15/86 (17.4%);a significant difference in T-staging between CECT and histopathological examination (х2=41.28, p=0.00 (p<0.05)) was found. The CECT detected no peritumoral lymphadenopathy (N0) in 39/86 (45.3%), N1 in 18/86 (20.9%) and N2 in 29/86 (33.7%) patients; there was a significant difference in N-staging between CT and histopathological evaluation (х2=17.74, p=0.007(p<0.05)). For T-staging, CECT evaluation yielded sensitivity of 50% in T2 , 83.6% in T3, 71.4% in T4 staging; Diagnostic accuracy of CT for T2 staging was 89.7%, for T3- 78.2%, for T4- 88.7%. For N-staging, CECT had sensitivity of 88.2%, specificity of 64% and accuracy of 73.8%.Preoperative colorectal cancer patients in Mongolia receive initial MDCT in late stage. The similarsensitivity in staging of T-parameter to that of the international comparable studies. Nodal heterogeneity on CECT was more sensitive for nodal metastases than the size.