CT pelvimetry and clinicopathological parameters in evaluation of the technical difficulties in performing open rectal surgery for mid-low rectal cancer.

The present study aimed to evaluate the predictive value of pelvic anatomical and clinicopathological parameters for use in the estimation of the likely technical difficulties that may be encountered when performing open rectal surgery for mid-low rectal cancer. Sixty consecutive patients, undergoing open rectal surgery for mid-low rectal cancer were recruited between June 2009 and April 2014. All of the surgical procedures conducted, were low anterior resection (LAR) or abdominoperineal resection (APR). The operations were performed by the same surgeon and surgical team. Pelvic dimensions and angles were measured using three-dimensional reconstruction of spiral computerized tomography (CT) images. Operative time and intraoperative blood loss were used as indicators of operative difficulty. The independent variables were pelvic anatomical and clinicopathological parameters, and the dependent variables were operative time and intraoperative blood loss. Univariate and multivariate analyses were performed in order to determine the predictive significance of these variables. The pelvis width was significantly wider in females than in males (P<0.05), while the sacrococcygeal bending degree was significantly greater in males than in females (P<0.05). No significant difference were detected between the pelvis depth of females and males (P>0.05). Multivariate analyses showed that body mass index (BMI), tumor height, lymph node metastasis, anteroposterior diameter of the pelvic inlet, anteroposterior diameter of the pelvic outlet, height of the pubic symphysis, the sacrococcygeal distance, sacrococcygeal-pubic angle and diameter of the upper pubis to the coccyx were the main factors affecting the operative time (all P<0.05), while the maximum diameter of the tumor was the primary factor affecting intraoperative blood loss (P<0.05). Between the two procedures, the clinicopathological parameters appeared to be more valuable for predicting difficulty in LAR, in which operative time was associated with tumor height and tumor staging (RC2=0.312; P<0.001). By contrast, the pelvic anatomical parameters appeared to be more valuable predictors of variation in APR, in which intraoperative blood loss was associated with the anteroposterior diameter of the mid-pelvis, the anteroposterior diameter of the pelvic outlet, the interspinous diameter, the depth of the sacral curvature and the sacropubic distance (RC2=0.608; P=0.002). BMI, tumor height and the maximum diameter of the tumor may be used to predict the operative difficulty in performing open rectal surgery for mid-low rectal cancer. In addition to the associated clinicopathological parameters, wider, shallower and less curved pelvises may make the greatest contribution to reducing operative time and intraoperative blood loss. Operative difficulty is likely to be increased in deeper and narrower pelvises, or in those with greater sacrococcygeal curvature.

Clinicopathological and molecular genetic analysis of HNPCC in China.

AIM: To explore the clinicopathological and molecular genetic features of hereditary nonpolyposis colorectal cancer (HNPCC) in Chinese population. METHODS: We collected 16 Chinese HNPCC families from Wenzhou, Zhejiang Province, China. Tumor tissues and peripheral white blood cells were studied using microdissection, microsatellite analysis, immunostaining of hMSH2 and hMLH1 proteins and direct DNA sequencing of hMSH2 and hMLH1 genes. RESULTS: (1) A total of 50 patients had CRC. Average age at diagnosis of the first CRC was 45.7 years; 40.9% and 28.7% of the CRCs were located proximal to the splenic flexure and in the rectum, respectively. Thirty-eight percent of the colorectal cancer patients had synchronous and metachronous CRC. 34.4% and 25% of the CRCs were poor differentiation cancer and mucinous adenocarcinoma, respectively. Fourteen extracoloni tumors were found, and the hepatic cancer was the most common tumor type. Twenty-one patients whose median survival time was 5.7 years died during 1-23 years. Twenty-nine patients have survived for 1-28 years, 58.6%, 41.4% and 24.1% patients have survived for more than 5, 10 and 15 years, respectively; (2) All nine tumor-tissues showed microsatellite instability (MSI) at more than two loci. Four tumor-tissues lost hMSH2 protein expression and one lost hMLH1 protein expression. Three pathological germline mutations were identified from five genetically analyzed families; two of three mutations had not been reported previously as they were a transition from C to A in exon 14 (codon 743) of hMSH2 and a TTC deletion in exon 14 (codon 530) of hMLH1. CONCLUSION: Chinese HNPCC have specific clinicopathological features, such as early onset, propensity to involve the proximal colon, and high frequency of multiple CRCs, liver cancer more frequent than endometrial cancer. Chinese HNPCC showed relatively frequent germline mutation of mismatch repair (MMR) genes that correlated closely with high-level MSI and loss of expression of MMR genes protein.

[Clinical analysis and molecular genetic study of hereditary nonpolyposis colorectal cancer kindreds].

OBJECTIVE: To study the clinicopathological and molecular genetic characteristics of hereditary nonpolyposis colorectal cancer (HNPCC), to enable the early diagnosis and to evaluate the treatment. METHODS: We analyzed 12 families of HNPCC from Wenzhou, Zhejiang province, China. Mismatch repair genes hMSH2 and hMLH1 expression and microsatellite instability of tumor tissue were studied using microdissection, microsatellite analysis, immunohistochemical staining and Gene Scan analysis. Direct DNA sequencing of hMSH2 and hMLH1 were performed subsequently. RESULTS: Altogether 32 patients with colorectal cancer were recognized in 12 HNPCC families, with the median age of 45.2 years (75.0% before the age of 50 years). The proximal tumors accounted for 51.1%, while multiple colorectal cancers accounted for 34.4%. Poor differentiation cancers occupied half of the patients (53.1%). And 68.8% of the patients had the tumor of Dukes A and B. Among 12 HNPCC families, 7 cases in 6 HNPCC families developed extracolonic cancer. 13 cases died during follow up of 1 - 23 years. The median survival time was 6.4 years. 19 alive cases followed up from 1 to 28 years. All tumors (9/9) displayed microsatellite instability, with the half losing hMSH2 or hMLH1 expression. In the 5 genetic analyzed kindreds 3 possessed germline mutation. Two of three mutations have not been reported in the worldwide database previously. CONCLUSION: HNPCC showed distinct clinicopathological characteristics. Microsatellite instability analysis and immunohistochemical staining might be the effective screening methods before direct DNA sequencing for the detection of mutation in mismatch repair genes. It is important to analyze the members of affected families.