Prognostic value of metastatic lymph node ratio in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVES</b>To evaluate the value of the metastatic to examined lymph nodes (rN) ratio in gastric cancer patients who underwent radical resection.</p><p><b>METHODS</b>In this retrospective study, data were collected from the medical records of 710 patients who underwent radical gastrectomy (R0) for gastric cancer from 1980 to 2006 in the Department of Surgical Oncology at the First Affiliated Hospital of China Medical University. The patients were divided into 2 groups according to the number of examined lymph nodes: Group 1 consisted of 327 patients with <15 examined lymph nodes and Group 2 consisted of 383 patients with ≥15 lymph nodes. rN categories staging and pN categories were divided separately according to the metastatic lymph node ratio and the examined lymph nodes. The prognostic factors were analyzed by univariate (Log-rank) and multivariate (Cox model) analysis methods.</p><p><b>RESULTS</b>The median survival time was 74 months (95% CI:55.6-92.4 months) in Group 1 and 96 months (95% CI:77.8-119.2 months) in Group 2, and the difference was not statistically significant (P>0.05). On multivariate analysis, the N ratio remained as an independent prognostic factor in both Group 1 (P<0.01, RR=1.225, 95% CI:1.102-1.362) and Group 2 (P<0.01, RR=1.421, 95% CI:1.269-1.592). However, pN stage was an independent prognostic factor only in Group 1. When the rN ratio classification was applied, there were no significant differences between each categories (P>0.05). However, the overall survival of patients with pN1 disease in Group 1 was significantly shorter than that in Group 2 according to the pN stage classification (P<0.01).</p><p><b>CONCLUSIONS</b>The metastatic lymph node ratio is an independent prognostic factor of the prognosis of gastric cancer. The staging system based on metastatic lymph node ratio (rN) is more reliable than the system based on the number of metastatic lymph nodes in the prediction of the prognosis of gastric cancer.</p>

Lymphadenectomy adjacent to inferior mesenteric artery root during radical operation and prognosis in rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of lymphadenectomy adjacent to inferior mesenteric artery root on the prognosis of rectal cancer.</p><p><b>METHODS</b>Clinicopathological data of 260 cases with rectal cancer undergone radical operation were analyzed retrospectively. The patients were divided into two groups. Group D(2): the lymph nodes adjacent to mesenteric artery root were not excised (n=188). Group D(3): the lymph nodes adjacent to mesenteric artery root were excised (n=72). Prognosis of two groups was compared during the follow-up period.</p><p><b>RESULTS</b>In group D(2), the 1-, 3-, 5-year total survival rates (TS) were 97.3%, 87.2% and 77.1%, and tumor-free survival rates (TFS) were 93.1%, 83.0% and 76.8% respectively. In group D(3 ), the 1-, 3-, 5-year total survival rates (TS) were 94.4%, 79.2% and 73.6%, and tumor-free survival rates (TFS) were 86.1%, 76.4% and 71.0% respectively. The differences of TS and TFS between two groups were not significant according to Kaplan-Meier analysis (P>0.05). Multivariate analysis revealed that the excision of lymph nodes adjacent to mesenteric artery root was not statistically correlated with the recurrence, metastasis and survival time after radical operation of rectal cancer.</p><p><b>CONCLUSION</b>Excision of lymph nodes adjacent to inferior mesenteric artery root has no significant impact on prognosis and it is unnecessary in the radical operation of rectal cancer.</p>

Rational approach to the management of IV stage gastric carcinoma with hepatic metastasis / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the benefit of surgical resection on the prognosis of patients with advanced gastric carcinoma and liver metastasis.</p><p><b>METHODS</b>Data of 102 cases of advanced gastric carcinoma with liver metastases from 1993 to 2004 were studied retrospectively.</p><p><b>RESULTS</b>The half-, one- and two-year postoperative survival rates of gastric carcinoma patients with H(1) metastasis undergone palliative resections were 69%, 44% and 6% respectively, which were significantly better than those of patients not undergone resection(accepted by-pass procedure or exploratory laparotomy) (P=0.009). The half-, one- and two-year postoperative survival rates of gastric carcinoma patients with H(2) metastasis undergone palliative resections were 56%,13% and 6% respectively, which were not significantly different compared with those of patients not undergone resection(P=0.068). The half-, one- and two-year postoperative survival rates of gastric carcinoma patients with H(3) metastasis undergone palliative resections were 25%, 13% and 0, which were not significantly different compared with those of cases not undergone resection (P=0.157). Regardless of peritoneal metastases, there were no significant differences between the survival rate of resection group and that of non-resection group.</p><p><b>CONCLUSIONS</b>Gastric carcinoma patients with H(1) metastasis would benefit from palliative resection regardless of peritoneal metastasis. Gastric carcinoma patients with H(2) or H(3) metastasis are not benefit from surgical resection.</p>

Double-mutant dihydrofolate reductase gene transfection into bone marrow cells protects mice from chemotherapy / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the feasibility of transfecting DHFR (human double-mutant dihydrofolate reductase) gene into mouse bone marrow cells and the effect of resistance to high dose MTX chemotherapy.</p><p><b>METHODS</b>After DHFR gene was transfected into mouse bone marrow cells with retroviral vector, the cells were treated with methotrexate (MTX) and then CFU-GM (granulocyte-macrophage colony-forming unit) assay was performed. Peripheral blood leucocytes and platelets, body weight and survival rate were observed. After treatment with high dose MTX, the expression of drug resistance gene was checked by RT-PCR in the transfected bone marrow cells.</p><p><b>RESULTS</b>SFG-F/S-NeoR gene-transfected mice bone marrow cells yielded drug-resistance colonies to MTX (donor mice: 15.8%, recipient mice: 18.0%, control: 0) The peripheral blood leucocytes and platelets, body weight recovered gradually and the survival rate was 83.3% at the 40th day, while 0 in controls in gene transfected mice after large dose MTX treatment. RT-PCR of transgenic mouse marrow cells showed the band of F/S gene (400 bp).</p><p><b>CONCLUSION</b>DHFR gene can not only be integrated and expressed in bone marrow cells but also improve their drug-resistence to MTX.</p>

Mice transduced with double-mutant dihydrofolate reductase-cytidine deaminase fusion gene attained protection from high dose chemotherapy / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of transferring fusion gene of dihydrofolate reductase (DHFR) gene and cytidine deaminase (CD) gene into mouse bone marrow cells in order to observe the drug resistance of high dose methotrexate (MTX) and cytosine arabinoside (Ara-C) in the bone marrow cells and to improve the tolerance of myelosuppression following combination chemotherapy.</p><p><b>METHODS</b>Human double-mutant dihydrofolate reductase-cytidine deaminase fusion gene was transferred into two mice bone marrow cells by retroviral vector. Resistant colony-forming unit granulocyte-macrophage (CFU-GM) assays were performed in mouse bone marrow cells by retroviral infection and after treatment by drugs (Ara-C, MTX, and Ara-C + MTX). DNA was extracted from mouse bone marrow cells. The expression of drug resistant genes in mouse bone marrow cells after transferring by retroviral vector was checked by polymerase chain reaction (PCR).</p><p><b>RESULTS</b>Bone marrow cells after coculture with the retroviral producer cells transduced with the genes (SFG-F/S-CD) showed the drug resistance colonies yield (Colony formation after exposure to Ara-C, MTX and Ara-C + MTX were 56%, 22% and 14%, respectively) and the increase in drug resistant to both MTX and Ara-C (P < 0.005). Expression of DHFR and CD gene in extracted DNA of transfected mice were demonstrated by PCR.</p><p><b>CONCLUSIONS</b>Double drug resistant gene can not only integrate and co-express in mice bone marrow cells but also increase the drug resistance to MTX and Ara-C.</p>

The study of the minimum number of examined lymph nodes for the TNM classification of gastric cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the minimum number of lymph nodes that should be examined for the UICC/AJCC TNM classification of gastric cancer.</p><p><b>METHODS</b>The clinical and pathological data of four hundred and thirty-six patients underwent curative resection for gastric cancer were analyzed by Chi-square and Student-Newman-Keuls test.</p><p><b>RESULTS</b>The pN0 patients with 1 to 4, 5 to 9 examined nodes showed significantly lower survival rate than those with 10 to 14, 15 or more examined nodes (P < 0.05), and the patients with 10 to 14 examined nodes had as good a prognosis as those with 15 or more examined nodes. In the pN1, pN2 categories, the patients with 1 to 4, 5 to 9 and 10 to 14 examined nodes tended toward significantly lower survival rates than those with 15 or more examined nodes (P < 0.05). Among the patients who were classified as stage II, the survival rate of those with 10 to 19 examined nodes was significantly lower than that with 20 or more examined nodes. Among the patients classified as stage III, those with 5 to 9, 10 to 19 and 20 to 29 examined nodes had significantly lower survival rates than those with 30 or more examined nodes (P < 0.05).</p><p><b>CONCLUSIONS</b>The number of lymph nodes examined has significant prognostic impact within each pN category of gastric carcinoma. The minimum number of lymph nodes to examine in order to determine pN0 classification can be reduced from 15 to 10. For tumor with lymph node metastasis, the minimum number should be 15. In stage II, 20 or more nodes should be examined, and in stage III and IV 30 or more.</p>