Objective To determine the role of multimodal preoperative evaluation (MPE) system of transrectal ultrasound (TRUS), 64 multi-slice spiral computer tomography (MSCT) and serum amyloid A protein (SAA) in assessment of preoperative staging and selection of operative procedures of the lower and middle rectal cancer in multi-disciplinary team. Methods Prospectively enrolled 150 patients, who were diagnosed definitely as lower and middle rectal cancer (distance of tumor to the dentate line ≤10 cm) at West China Hospital of Sichuan University from November 2008 to March 2009, randomly assigned into two groups. In one group named MPE group, MPE consisting of TRUS, MSCT and SAA were made for the preoperative evaluation. In another group named MSCT+SAA group, both MSCT and SAA were made preoperatively. Then, the preoperative staging and predicted operative procedures were compared with postoperative pathologic staging and practical operative procedures, respectively. Furthermore, the pooled data were analyzed for the correlative relationship between the choice of surgery strategy and clinicopathological factors. Results According to the criteria, 146 patients with lower and middle rectal cancer were randomly assigned into MPE group (n=74) and MSCT+SAA group (n=72). The baselines characteristics of two groups were statistically identical. For MPE group the accuracy of preoperative staging T, N, M and TNM were 94.6% (70/74), 85.1% (63/74), 100% （74/74） and 82.4% (61/74), respectively; For MSCT+SAA group the corresponding rates were 77.8% (56/72), 84.7% (61/72), 100% （72/72） and 81.9% (59/72), respectively. The analysis showed a statistically difference in the accuracy of preoperative T staging between two groups (P=0.003) while there was no statistically significant difference of the accuracies of preoperative N, M and TNM staging between two groups (Pgt;0.05). There wasn’t a statistically significant increasing of the accuracy of prediction to operative procedures in MPE group compared with MSCT+SAA group 〔95.9% (71/74) vs.88.9% (64/72), P=0.106〕. When analyzing the relationship between multiple clinicopathologic factors and the operative procedures of lower and middle rectal cancer, there were statistical correlations between the pathological T staging (r=0.216， P=0.009), N staging (r=0.264， P=0.001), TNM staging (r=0.281， P=0.001), serum level of SAA before operation (r=0.252， P=0.002) or the distance of tumor to the dentate line (r=－0.261， P=0.001) and the operative procedures. Conclusion MPE system could display the accurate preoperative staging for lower and middle rectal cancer, on which the prediction of operative procedures can rest convincingly.
Objective To establish the optimal morphological criteria combined with fibrinogen level for evaluation of lymph node metastasis in colorectal cancer. Methods A consecutive series of 690 patients who underwent curative surgery for colorectal cancer, were examined by abdominopelvic enhanced multi-slice spiral computed tomography (MSCT) scan. If regional lymph nodes appeared, the maximal long-axis diameter (MLAD), maximal short-axis diameter (MSAD), and axial ratio (MSAD/MLAD) were recorded. At each lymph node size cut-off value, the following were calculated: accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Moreover, preoperative plasma level of fibrinogen was retrospectively examined to identify metastatic or inflammatory lymph node combined with MSCT image. Both modalities, MSCT plus fibrinogen and MSCT alone, were compared based on the pathologic findings. Results The study population consisted of 100 patients with regional lymph nodes show. No significant difference was found between metastatic and inflammatory lymph nodes in imaging characteristics (Pgt;0.05). The best cut-off value of MSAD was 6 mm for lymph node metastasis with the sensitivity of 46.8%, specificity of 68.4%, accuracy of 55.0%, PPV of 70.7% and NPV of 44.1%. The best cut-off value of MLAD was 8 mm with the sensitivity of 43.5%, specificity of 63.2%, accuracy of 51.0%, PPV of 65.9% and NPV of 40.7%. Using hyperfibrinogenemia (FIB ≥3.5 g/L) to identify small metastatic lymph node, of which MSAD lt;6 mm or MLAD lt;8 mm, showed statistical diagnostic value (Kappa=0.256, P=0.047). Compared with MSAD (6 mm) alone, MSAD (6 mm) combined with hyperfibrinogenemia had a higher sensitivity (79.0% vs. 46.8%, Plt;0.001), but a similar accuracy (66.0% vs. 55.0%, Pgt;0.05) and a lower specificity (44.7% vs. 68.4%, P=0.037). MLAD (8 mm) combined with hyperfibrinogenemia led to a greater diagnostic value in sensitivity (80.6% vs. 43.5%, Plt;0.001) and accuracy (66.0% vs. 51.0%, P=0.031) than MLAD (8 mm) alone, with a no-significantly decreasing specificity (42.1% vs. 63.2%, Pgt;0.05). Conclusions This present study recommend MSAD ≥6 mm or MLAD ≥8 mm as the optimal criteria for preoperative N staging in colorectal cancer. Moreover, the sensitivity and even accuracy could be improved by combining hyperfibrinogenemia for lymph node metastasis identification.
Objective To summarize recent advances on preoperative staging strategies in rectal cancer. Methods Relevant references about preoperative staging strategies were collected and reviewed. The multimodal preoperative evaluation (MPE) system recently documented was focused on. Results The comparably accurate T and M stage could be achieved preoperatively by following an appropriate available method; however, the N stage’s accuracy was still not satisfying. The MPE system， incorporating with the advantages of transrectal ultrasound， computerized tomography and serum amyloid A protein in a multi-disciplinary mode could display the most accurate preoperative staging for rectal cancer currently. Conclusion The MPE has potential prospects in preoperative staging of rectal cancer， and can provide the most accurate preoperative staging for rectal cancer at present.