Oncologic significance of para-aortic lymph node and inferior mesenteric lymph node metastasis in sigmoid and rectal adenocarcinoma.

BACKGROUND: Recurrence patterns or survival in colorectal cancer patients might differ according to inferior mesenteric lymph node (IMLN) metastasis. However, few studies have compared para-aortic lymph node (PALN) metastasis and IMLN metastasis. The aim of the current study is to identify survival and recurrence patterns in patients with sigmoid colon and rectal adenocarcinoma with either PALN or IMLN metastasis and to evaluate the prognostic significance of PALN and IMLN metastasis. METHODS: A retrospective study involving 3076 patients with stage III and IV sigmoid and rectal cancer, who underwent curative surgery between January 2000 and December 2009, was performed. Clinicopathologic features, recurrence patterns, and survival outcomes of 27 patients with PALN metastasis were compared with those of 47 patients with IMLN metastasis. Patients with both IMLN and PALN metastasis were included in the PALN+ group. RESULTS: After curative resection, there was no significant difference in the 5-year disease-free and overall survival rates between the PALN+ and IMLN+ groups (27.5% vs. 29.8%, p = 0.24, and 37% vs. 39.2%, p = 0.19, respectively). Furthermore, there were no significant differences in recurrence rate (PALN+ group, 70.4%; and IMLN+ group, 63.8%; p = 0.69) or recurrence patterns. CONCLUSIONS: The results suggest that IMLN metastasis, similar to PALN metastasis, is associated with adverse oncologic outcomes and has prognostic significance. Therefore, it is preferable that IMLN metastasis should be considered under the category of systemic metastasis (M1).

Transient adverse neurologic effects of spinal pain blocks.

OBJECTIVE: Chronic neck or back pain can be managed with various procedures. Although these procedures are usually well-tolerated, a variety of side effects have been reported. In this study we reviewed cases of unexpected temporary adverse events after blocks and suggest possible causes. METHODS: We reviewed the records of patients treated with spinal pain blocks between December 2009 and January 2011. The types of blocks performed were medial branch blocks, interlaminar epidural blocks and transforaminal epidural blocks. During the first eight months of the study period (Group A), 2% mepivacaine HCL and triamcinolone was used, and during the last six months of the study period (Group B), mepivacaine was diluted to 1% with normal saline. RESULTS: There were 704 procedures in 613 patients. Ten patients had 12 transient neurologic events. Nine patients were in Group A and one was in Group B. Transient complications occurred in four patients after cervical block and in eight patients after lumbar block. Side effects of lumbar spine blocks were associated with the concentration of mepivacaine (p<0.05). The likely causes were a high concentration of mepivacaine in five patients, inadvertent vascular injection in three patients, intrathecal leak of local anesthetics in one, and underlying conversion disorder in one. CONCLUSION: Spinal pain blocks are a good option for relieving pain, but clinicians should always keep in mind the potential for development of inevitable complications. Careful history-taking, appropriate selection of the anesthetics, and using real-time fluoroscopy could help reduce the occurrence of adverse events.

Clinico-pathologic Parameters for Prediction of Microsatellite Instability in Colorectal Cancer.

PURPOSE: Although the incidence of microsatellite instability (MSI) accounts for 10-15% of cases of colorectal cancer, its clinical application for all colorectal cancers has widened. We attempted to identify clinical and pathological parameters that may be helpful in selection of patients with MSI-high (MSI-H). MATERIALS AND METHODS: A total of 120 resected colorectal cancers were enrolled retrospectively for this MSI study. Polymerase chain reaction (PCR) and denaturing high performance liquid chromatography and/or real time PCR methods with five markers and immunohistochemistry (IHC) for MLH1 and MSH2 were performed for analysis of cancer and blood specimens. Clinico-pathologic parameters, including IHC, were investigated in order to determine their usefulness as predictive factors of MSI. RESULTS: Among 120 cases of colorectal cancer, MSI was observed in 15 cases (12.5%), including 11 cases of MSI-H and four cases of MSI-low. Patients with MSI were younger, less than 50 years old, had a family history of cancer, Rt. sided colon cancer and/or synchronous multiple colorectal cancer, mucinous histologic type, and serum carcinoembryonic antigen group in the normal range. Results of multivariate analysis showed Bethesda guidelines, Rt. sided and/or synchronous multiple colorectal cancer, and negative expression of IHC for MLH1, which was consistently associated with MSI-H. MSI-H colorectal tumors have met at least one of these three parameters and their sensitivity and specificity were 100% and 72.5%, respectively. CONCLUSION: Bethesda guidelines, tumor location, and negative expression of MLH1 protein are important parameters for selection of patients with colorectal cancers for MSI testing. MSI testing is recommended for patients showing any of these three parameters.

Melanoma-associated antigen (MAGE) expression in the normal mucosa around colorectal cancer after curative resection: presence of undetectable free cancer cells.

PURPOSE: Curative surgical resection is of great importance and some trials have been performed to identify free undetectable cancer cells using molecular markers. The aim of this study is to investigate melanoma-associated antigen (MAGE) expression in normal mucosa around colorectal cancer and its clinical significance.? MATERIAL AND METHOD: From October 2003 to June 2004, we collected 46 colorectal cancer and matched normal mucosal tissues within 20 mm, 20 to 50 mm and more than 50 mm from tumors after the curative operation. Twenty-two mucosal tissues were harvested from patients with benign colorectal diseases as controls. MAGE expression was assayed using nested RT-PCR of MAGE A1-6 mRNA.? RESULTS: The MAGE expression rates in cancer tissue and adjacent normal mucosa were 65.2%, 6.5% (<20 mm), 2.2% (20-50 mm) and 0.0% (>50 mm), respectively, while MAGE was not expressed in the mucosa of benign diseases. The MAGE-positive cases in the normal mucosa around tumors were located in the left colon or rectum, and one patient showed anastomotic mucosal site recurrence.? CONCLUSIONS: MAGE expression in normal-appearing mucosa around colorectal cancer showed some clinical findings suggesting the presence of undetectable free cancer cells after curative resection.

Genetic alterations of APC, K-ras, p53, MSI, and MAGE in Korean colorectal cancer patients.

BACKGROUND AND AIM: Colorectal cancer (CRC) is one of the most rapidly increasing cancers in Korea, but no comprehensive analysis has been performed to speculate the genetic basis of CRC development. We investigated the presence of adenomatous polyposis coli gene (APC), Kirsten-ras (K-ras), p53, microsatellite instability (MSI), and melanoma antigen gene (MAGE) alterations in CRC and correlated the results obtained with clinical data. MATERIALS AND METHODS: We collected 78 cancer tissues from CRC patients. Genetic analyses were performed on APC, K-ras, p53, and MSI (BAT 25 and BAT 26), and in addition, MAGE expression was tested by reverse transcription polymerase chain reaction. Correlations between genetic markers and clinical factors were analyzed after reviewing medical records. RESULT: The positive rates for alterations of APC, K-ras, p53, MSI, and MAGE in 78 tissue samples were 33.3, 29.5, 34.6, 9.0, and 68.4%, respectively. Mutations were frequently detected in codons 1291 and 1450 of APC, in codon 12 of K-ras and in codons 248, 282, and 176 of p53. APC mutations were frequently noted in early-stage cancer, whereas MSI was observed in right-sided and multiple cancers. No associations were found between the presence of alterations in APC, K-ras, p53, MSI, and MAGE. INTERPRETATION: In Koreans, positive rates of alterations in APC and p53 were slightly lower than those of APC and p53 in Caucasians, and the genetic alterations including MAGE expression are involved in 92.1% of CRCs. The lack of multiple mutations and of a relation between mutation rates and clinical stage suggest that genetic alterations might have independent influences on CRC development in Koreans.