Sang Yong Song

Preoperative staging of rectal cancer: accuracy of 3-Tesla magnetic resonance imaging

The purpose of this study was to evaluate the accuracy of 3-Tesla magnetic resonance imaging (MRI) for the preoperative staging of rectal cancer. Thirty-five patients with a primary rectal cancer who underwent preoperative 3-T MRI using a phased-array coil and had a surgical resection were enrolled in the study group. Preoperatively, three experienced radiologists independently assessed the T and N staging. A confidence level scoring system was used to determine if there was any perirectal invasion, and receiver operating characteristic (ROC) curves were generated. The interobserver agreement was estimated using κ statistics. The overall accuracy rate of T staging for rectal cancer was 92%. The diagnostic accuracy was 97% for T1, 89% for T2 and 91% for T3, respectively. The predictive accuracy for perirectal invasion by the three observers was high (Az>0.92). The interobserver agreement for T staging was moderate to substantial. The overall sensitivity, specificity, and accuracy for the detection of mesorectal nodal metastases were 80%, 98%, and 95%, respectively. In conclusion, preoperative 3-T MRI using a phase-array coil accurately indicates the depth of tumor invasion for rectal cancer with a low variability.

Recurrence of Retroperitoneal Liposarcoma: Imaging Findings and Growth Rates at Follow-Up CT

OBJECTIVE The purpose of this study was to evaluate the CT features and growth rates of recurrent retroperitoneal liposarcoma on follow-up CT scans. CONCLUSION Retroperitoneal liposarcoma frequently recurs asymptomatically within 2 years, usually within 6 months-2 years, of the initial surgical resection. The CT features of recurrent liposarcoma are similar to those of the initial manifestation; recurrent liposarcoma shows rapid growth, with a mean tumor volume doubling time of 98 days (range, 46-151 days; median, 104 days).

Characteristics of intramucosal gastric carcinoma with lymph node metastatic disease

Aim:  Recent trends in treatment strategy for early gastric cancer (EGC) are towards minimal surgical procedures, such as endoscopic mucosal resection and laparoscopic partial resection. There is a possibility of incomplete removal of regional lymph nodes in minimal procedures, which may subsequently decrease the chance of a cure. Therefore, it is essential to be able to predict lymph node status and to make careful selection of candidates for mucosal resection.

Bronchogenic cyst of the stomach masquerading as benign stromal tumor

Gastric bronchogenic cyst is an extremely rare lesion. A 62‐year‐old Korean woman presented with an incidentally found perigastric nodule. An abdominal ultrasonogram and computed tomography showed a 1.5 cm solid, homogeneous, low‐density nodule in the hepatogastric ligament near the gastric lesser curvature. At the time of surgery, a soft 1.7 cm nodule was found in the lesser curvature side just below the gastroesophageal junction, and a gelatinous mass was protruded from the nodule during the resection. Microscopically, the gastric subserosa showed cystic structures lined by pseudostratified ciliated columnar epithelium, seromucinous gland, connective tissue and complete layers of smooth muscle bundles. Neither cartilage nor gastrointestinal epithelium was identified. A mucocele was found near the cyst and foamy cells and faintly bluish mucinous substances were found near the cystic structures. All the mucinous substances were stained by alcian blue at pH 2.5 with varying degrees of staining intensity. The present case is the smallest reported cyst among the gastric bronchogenic cysts, and these lesions are unusually located at the lesser curvature side of the stomach. Although these lesions are very rare, gastric bronchogenic cyst should be included in the differential diagnosis of gastric wall mass.

MR staging accuracy for endometrial cancer based on the new FIGO stage

Background Magnetic resonance imaging (MRI) has been frequently used to determine a preoperative treatment plan for gynecologic cancers. However, the MR accuracy for staging an endometrial cancer is not satisfactory based on the old FIGO staging system. Purpose To evaluate MR accuracy for staging endometrial cancer using the new FIGO staging system. Material and Methods Between January 2005 and May 2009, 199 women underwent surgery due to endometrial cancer. In each patient, an endometrial cancer was staged using MR findings based on the old FIGO staging system and then repeated according to the new FIGO staging system for comparison. Histopathologic findings were used as a standard of reference. Results The accuracy of MRI in the staging of endometrial carcinoma stage I, II, III, and IV using the old FIGO staging system were 80% (159/199), 89% (178/199), 90% (179/199), and 99% (198/199), respectively, compared to 87% (174/199), 97% (193/199), 90% (179/199), and 99% (198/199), respectively, when using the new FIGO staging criteria. The overall MR accuracy of the old and new staging systems were 51% (101/199) and 81% (161/199), respectively. Conclusion MRI has become a more useful tool in the preoperative staging of endometrial cancers using the new FIGO staging system compared to the old one with increased accuracy.

In vitro chemosensitivity based on depth of invasion in advanced colorectal cancer using ATP-based chemotherapy response assay (ATP-CRA).

BACKGROUND Tumors are composed of subpopulations of cells with heterogeneous characteristics that allow for tumor progression and development of treatment resistance. The purpose of this study was to determine if there is heterogeneity in the in vitro chemosensitivity in different invasive sections of a single tumor. MATERIALS AND METHODS Chemosensitivity in advanced colorectal cancer specimens was examined using an ATP-based chemotherapy response assay. Four chemotherapeutic agents (5-fluorouracil (5-FU), oxaliplatin, irinotecan, and mitomycin) were used for chemosensitivity studies. Tumor tissues were obtained from the superficial (mucosa/submucosa) and deep parts (muscle/subserosa/serosa), respectively. Twenty patients who had results for both the superficial and deep parts were evaluated. RESULTS The chemosensitivity study showed variable cell death rates in both parts of the tumor. Regression analysis showed some correlations with 5-FU and irinotecan, but not with oxaliplatin or mitomycin. With the exception of three patients in whom no drug was recommended, at least one chemotherapeutic drug showed some consistency between the superficial and deep parts of the tumor. Mitomycin was the most frequently active agent for the superficial part. In the deep part, oxaliplatin and mitomycin were the most active agents. CONCLUSIONS There may be heterogeneity in the responses to anti-chemotherapeutic agents in advanced colorectal cancer, according to the depth of invasion. Therefore, in clinical situations, chemosensitivity test specimens should be mixed with various parts of the whole tumor in order to obtain representative chemosensitivity and chemoresistance profiles.

Prognostic indicators of gastric carcinoma confined to the muscularis propria

Aims:  Gastric carcinoma confined to the muscularis propria (MPGC) is considered an intermediate‐stage carcinoma. A method of discriminating between more favourable and less favourable prognostic groups of this entity is critically needed in dealing with this heterogeneous disease. The aim of this study was to examine the correlation between survival of patients with MPGC and its various clinicopathological parameters.

Genetic profiling to predict recurrence of early cervical cancer

OBJECTIVE Recurrence is the major cause of death in early cervical cancer. We compared the prediction powers for disease recurrence between the gene set prognostic model and the clinical prognostic model. MATERIALS AND METHODS A gene set model to predict disease free survival was developed using the cDNA-mediated annealing, selection, extension, and ligation (DASL) assay data set from a cohort of early cervical cancer patients who had been treated with radical surgery with or without adjuvant therapy. A clinical prediction model was also developed using the same cohort, and the ability of predicting recurrence from each model was compared. RESULTS Adequate DASL assay profiles were obtained from 300 patients, and we selected 12 genes for the gene set model. When patients were categorized as having a low or high risk by the prognostic score, the Kaplan-Meier curve showed significantly different recurrence rates between the two groups. The clinical model was developed using FIGO stage and post-surgical pathological findings. In multivariate Cox regression analysis of prognostic models, the gene set prognostic model showed a higher hazard ratio than that of the clinical prognostic model. CONCLUSIONS The genetic quantitative approach may be better in predicting recurrence in early cervical cancer patients.