Application of fat clearance technique in pathologic staging for colon cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate whether the use of fat clearance technique improves the accuracy of staging for colon cancer.</p><p><b>METHODS</b>Between June 2007 and December 2008, surgical specimens of 91 patients with colon cancer were procured. Between June 2007 and January 2008, routine technique for lymph node harvest including visualization and tactile sensation was used in 45 patients (conventional group), while lymph nodes of 46 patients between February 2008 and December 2008 were examined using fat clearance technique(fat clearance group).</p><p><b>RESULTS</b>The mean of lymph nodes harvested was 32.7 using fat clearance technique, significantly higher than that(15.3) of the conventional group(P<0.01). The mean positive lymph nodes was 2.7 and 1.8 in the two groups, respectively, with a statistically significant difference(P<0.05). There were more stage III( colon cancer in the postoperative staging than that in the preoperative staging using fat clearance technique (31 vs.19, P<0.05), while there was no difference in stage III( colon cancer between postoperative staging and preoperative staging using conventional method (21 vs.19, P>0.05).</p><p><b>CONCLUSIONS</b>Fat clearance technique significantly increases number of lymph node retrieval and positive nodes, therefore the accuracy of postoperative staging is improved.</p>

Comparison of fat clearance and fat lucidification in examining rectal cancer specimen / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare fat clearance and fat lucidification in the examination of rectal cancer specimen, and to study the distribution pattern of lymph nodes in rectal cancer specimen.</p><p><b>METHOD</b>Between January 2007 and December 2007, sixty-four cases undergone total mesorectal excision were divided into two groups. The fat clearance technique was used to examine the specimens in one group, while fat lucidification was used in the other. The total number and the number of metastatic lymph nodes between two groups were compared, as well as the time for processing specimens and that for dissecting the lymph nodes.</p><p><b>RESULTS</b>An average of 37.4 lymph nodes were detected with fat clearance, in which 3.3 lymph nodes were metastatic; while an average of 36.2 nodes were detected with fat lucidification, in which 3.2 were metastatic. There were no significant differences in either the total number or the number of metastatic lymph nodes. The time for processing specimens in the fat lucidification group was 28 hours, while in the fat clearance group was 72 hours. The time for specimen processing was significantly shorter in the fat lucidification group (P<0.05). The mean time for dissecting lymph nodes in the fat clearance group was 2.1 hours, while in the fat lucidification group was 2.0 hours, the difference was not statistically significant.</p><p><b>CONCLUSION</b>When processing rectal cancer specimens with the fat lucidification technique can result in the similar number of lymph nodes compared to the fat clearance technique, with significantly shorter specimen processing time. The spatial position of the lymph nodes is better preserved using the fat lucidification technique, which may help study the distribution pattern of the normal and metastatic lymph nodes.</p>

The influence of lymph nodes detection on pathological staging in rectal cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the influence of lymph nodes detection on the pathological staging in rectal cancer specimens.</p><p><b>METHODS</b>From January 2007 to June 2008, 75 patients with rectal cancer who underwent total mesorectal excision were randomly divided into two groups: conventional group (n = 39), in which lymph nodes were detected by sight and palpation; fat clearance group (n = 36), in which lymph nodes were harvested after the specimens immersed in a fat clearance solution for 24 hours. The lymph node number harvested was compared between the two groups, and metastasis of the lymph nodes and its impact on the pathologic staging was analyzed in the two groups.</p><p><b>RESULTS</b>A total of 75 patients (42 male and 33 female, the average age was 53.2 years) were enrolled in this study. In the conventional group, a mean of 14.4 lymph nodes (range, 8 - 27) was detected, and was significantly less than that in fat clearance group (mean 36.2, range, 18 - 62) (t = 5.800, P < 0.05). The tumor invasion was classified as T1 in 4 cases and 5 cases, T2 in 9 cases and 6 cases, T3 in 24 cases and 22 cases and T4 in 2 cases and 3 cases in conventional group and fat clearance group, respectively. No significant difference was found in T classification between the two groups (Z = 0.160, P = 0.850). The mean number of metastatic lymph nodes harvested in conventional group was 1.5, and it was 3.2 in the fat clearance group (Z = 3.500, P < 0.05). According to the regional lymph nodes, patients classified as N0, N1 and N2 were 20, 12, 7 cases in conventional group, and were 9, 14, 13 cases in the fat clearance group, respectively; and there was significant difference between the two groups (Z = 2.410, P = 0.016).</p><p><b>CONCLUSIONS</b>The variation of the number of harvested lymph nodes in surgical specimens from rectal cancer after total mesorectal excision is great. The metastasis of mesorectal lymph nodes is not only associated with the tumor staging, but also related to the number of harvested lymph nodes. It is questionable that 12 lymph nodes is currently seen as enough to evaluate the pathologic staging for rectal cancer.</p>