Preoperative Tumor Staging of Gastric Cancer: Comparison of Double Contrast-Enhanced Ultrasound and Multidetector Computed Tomography.

OBJECTIVES: The purpose of this study was to compare the sensitivity and specificity of double contrast-enhanced ultrasound (CEUS) and multidetector computed tomography (MDCT) in the preoperative tumor staging of gastric cancer (GC) to stratify patients for suitable treatment. METHODS: Fifty-four patients with GC proved by histologic findings were included. The sensitivity and specificity of double CEUS and MDCT for tumor staging were calculated and compared. The differences between these methods were evaluated by using the area under the curve (AUC) from a receiver operating characteristic curve analysis. RESULTS: There were no significant differences in AUC values for T1 and T2 stages between double CEUS and MDCT (P = .190 and .256, respectively). However, the sensitivity of double CEUS in the detection of the T1 stage was higher than that of MDCT (88% versus 75%). The AUC values of MDCT for T3 and T4 stages were 0.833 and 0.905, which were both significantly higher than those of double CEUS (0.759 and 0.696; P < .05). The sensitivities of double CEUS and MDCT for the T3 stage were both 89%, but the accuracy and specificity of double CEUS were lower than those of MDCT (76% versus 83% and 63% versus 78%). The specificities of double CEUS and MDCT for the T4 stage were both 98%, but the accuracy and sensitivity of double CEUS were lower than those of MDCT (85% versus 94% and 42% versus 83%). CONCLUSIONS: Multidetector CT is superior to double CEUS for T3 and T4 GC, and double CEUS may be regarded as an important complementary method to MDCT.

KRAS and BRAF gene mutations and DNA mismatch repair status in Chinese colorectal carcinoma patients.

AIM: To investigate gene mutations and DNA mismatch repair (MMR) protein abnormality in Chinese colorectal carcinoma (CRC) patients and their correlations with clinicopathologic features. METHODS: Clinical and pathological information for 535 patients including 538 tumors was reviewed and recorded. Mutation analyses for exon 2 of KRAS gene and exon 15 of BRAF gene were performed by Sanger sequencing except that in 9 tumors amplification refractory mutation system PCR was used. Expression of MMR proteins including MHL1, MSH2, MSH6 and PMS2 was evaluated by immunohistochemistry. Correlations of KRAS and BRAF mutation status and the expression status of MMR proteins with age, gender, cancer stage, location, and histology were analyzed. Correlations between KRAS or BRAF mutations and MMR protein expression were also explored. RESULTS: The overall frequencies of KRAS and BRAF mutations were 37.9% and 4.4%, respectively. KRAS mutations were more common in patients ≥ 50 years old (39.8% vs 22% in patients < 50 years old, P < 0.05). The frequencies of BRAF mutants were higher in tumors from females (6.6% vs males 2.8%, P < 0.05), located in the right colon (9.6% vs 2.1% in the left colon, 1.8% in the rectum, P < 0.01), with mucinous differentiation (9.8% vs 2.8% without mucinous differentiation, P < 0.01), or being poorly differentiated (9.5% vs 3.4% well/moderately differentiated, P < 0.05). MMR deficiency was strongly associated with proximal location (20.5% in the right colon vs 9.2% in the left colon and 5.1% in the rectum, P < 0.001), early cancer stage (15.0% in stages I-II vs 7.7% in stages III-IV, P < 0.05), and mucinous differentiation (20.2% vs 9.2% without mucin, P < 0.01). A higher frequency of MLH1/PMS2 loss was found in females (9.2% vs 4.4% in males, P < 0.05), and MSH2/MSH6 loss tended to be seen in younger (<50 years old) patients (12.0% vs 4.0% ≥ 50 years old, P < 0.05). MMR deficient tumors were less likely to have KRAS mutations (18.8% vs 41.7% in MMR proficient tumors, P < 0.05) and tumors with abnormal MLH1/PMS2 tended to harbor BRAF mutations (15.4% vs 4.2% in MMR proficient tumors, P < 0.05). CONCLUSION: The frequency of sporadic CRCs having BRAF mutation, MLH1 deficiency and MSI in Chinese population may be lower than that in the Western population.

Mast cells or not? - CD117 positive cells in esophageal leiomyoma.

The presence of CD117 positive cells in esophageal leiomyoma may lead to a misdiagnosis of GIST. We reviewed 46 esophageal tumors which were smooth muscle tumors or GIST. Based on morphology, immunohistochemistry and mutation analysis, there were 44 (95.6%) leiomyomas, 1 (2.2%) leiomyosarcoma, and 1 (2.2%) GIST. Variable numbers of CD117 positive cells were seen in all leiomyomas. Tryptase immunostaining identified mast cells in 93.2% (41/44) of leiomyomas, and the number of mast cells per tumor decreased significantly from tumors of the upper esophagus to the esophageal-gastric junction (p<0.01). Immunofluorescence study further confirmed the presence of two types of CD117 positive spindle cells which included spindle-shaped mast cells and DOG-1-positive interstitial cells of Cajal. This is the first study to systemically review mast cells in esophageal leiomyomas and tumors which may be included in the differential diagnosis. We demonstrate that both spindled mast cells and hyperplastic interstitial cells of Cajal are present within esophageal leiomyomas. The immunoreactivity of these cells with CD117 may suggest a diagnosis of GIST, but the presence of mast cells itself supports a diagnosis of esophageal leiomyoma.

A modified GEWF solution is cost-saving and effective for lymph node retrieval in resected colorectal carcinoma specimens.

Lymph node (LN) retrieval is important for proper staging of colorectal carcinoma. Although various assistant techniques were recommended to facilitate LN identification, most of them were unavoidably time-consuming, resource intensive and costly. We prepared a modified GEWF solution (RE-GEWF) by use of recycled alcohol and a familiar dye, eosin and investigated its efficacy on 55 colorectal carcinoma specimens. Of the 55 studied cases, 33 of them with <12 LNs (Group A) and 22 with ≥12 LNs were detected (Group B) before RE-GEWF treatment. All were subsequently treated with RE-GEWF for 14-16h and were inspected again for LNs. The number of LNs revealed before and after RE-GEWF treatment was 539 and 476 respectively. The mean number of LNs per cases increased from 9.80±6.27 to 18.43±8.77. Twelve accessory LN metastases were found in 9 cases. Upgrade of pN stage was only present in 7 of the Group A cases. The results show that RE-GEWF is as effective as other reported LN revealing solutions. Use of RE-GEWF not only can assure the quality of LN detection, but also minimize the cost and reduce the release of waste.