CLINICOPATHOLOGICAL CHARACTERISTICS OF ADVANCED COLORECTAL CANCER 30mm OR SMALLER IN DIAMETER

Objective To investigate the clinicopathological characteristics of advanced colorectal cancer which was 30 mm or smaller in diameter. Methods Retrospective analysis documented 80 patients with small advanced colorectal cancer from May 1985 to May 2002. According to the diameter of tumors, all patients were divided into three groups: Group A (10 mm or less), Group B (11-20 mm), Group C (21-30 mm). Considering the number of patients in Group A was smaller, we combined Group A with Group B as Group D. Then various clinicopathological characteristics were compared between Group C and Group D. Results The most common site of small advanced colorectal cancer was sigmoid colon and rectum that accounted for 36.2% and 35.0% of all cases. The average diameter of total tumors was 23.3 mm. Type 2 was the most common macroscopic type (63.7%) and the moderate differentiation was seen in 77.5% of cases. Thirty-eight (47.5%) cases had lymph node metastasis. Three (3.8%) cases had liver metastasis and three (3.8%) cases had peritoneal metastasis. The frequency of lymph node metastasis was found significantly different between Group C and Group D (54.2% vs. 28.6%, P<0.05), as well as between the groups with different depth of invasion (P<0.05). Curability A resection was performed in 69 (86.2%) cases. Conclusions Tumor size and depth of invasion are related to lymph node metastasis in small advanced colorectal cancer. However, the small size of tumor may not always be a.reliable parameter for estimating the risk of lymph node metastasis. Small colorectal cancers also do not always mean the early stage. Surgeons should be aware of the features of small advanced colorectal cancers to select ideal management and perform perfect resection.

Analysis of Structure Transition and Compatibility of PTT/PC Blend without Transesterification

Poly（trimethylene terephthalate）/polycarbonate （PTT/PC） blends were prepared by solvent mixing to avoid transesterification during high temperature blending. The influences of compositions on the thermal behavior, crystallization morphology and structure of the blends were studied. FTIR results indicated that there was no CO0 linking to two phenyl groups on each side chain and DSC results supported no transesterification reaction. DSC curves showed that Tc and Tmc increased to maximum range when PC contents were between 7 wt%-15 wt%, however, Tm decreased constantly with the increase of PC contents. It was observed from POM that PTT spherulitic morphology and crystallization kinetics were obviously influenced by the change of PC contents. Structural evolutions during cooling were investigated by SAXS which showed Lc of PTT remained a constant with different PC contents and also fixed during crystallization, nevertheless, it revealed a maximum value of Lnc for sample PTT93. It was concluded that PC chains could be permeated into not only amorphous crystallite structure but also amorphous lamellae structure and 7 wt% PC content was supposed to be the ＂proper＂ penetration amount into PTT lamellae structure which led to a maximum capacity of amorphous lamellar layer. Fringedmicelle crystal model was adopted to illustrate semi-crystalline physical structures of the blend in two kinds of component aggregation states.