Chondromodulin-1 and vascular endothelial growth factor-A expression in esophageal squamous cell carcinoma: accelerator and brake theory for angiogenesis at the early stage of cancer progression.

BACKGROUND: Magnifying endoscopy has demonstrated dramatic morphologic changes in the surface microvasculature of superficial esophageal squamous cell carcinoma (ESCC) according to the depth of invasion. We investigated the mechanism of angiogenesis in early-stage ESCC by examining the expression of vascular endothelial growth factor (VEGF)-A and chondromodulin (ChM)-1. METHODS: Using 41 samples of superficial esophageal cancer (EP and LPM 19 cases, MM or deeper 22 cases) and 7 samples of regenerative squamous epithelium, the expression of VEGF-A and ChM-1 was examined in relation to the histological grade or morphology of the surface microvasculature demonstrated by magnifying endoscopy (types A, B, and C correspond to types A, B1, and B2 and B3 of the magnifying endoscopic classification of the Japan Esophageal Society, respectively). We also investigated the correlation between CD31-positive microvessel density (MVD) and VEGF-A or ChM-1 expression. RESULTS: In normal squamous epithelium, regenerative squamous epithelium, EP and LPM cancer, and MM or deeper cancer, the positivity rates for VEGF-A and ChM-1 were 0%, 85.7%, 52.6% and 90.9%, respectively, and 48.5%, 71.4%, 73.7% and 23.8%, respectively. The VEGF-A and ChM-1 positivity rates in type B or type C vasculature were 70.0% and 76.2%, respectively, and 75.0% and 19.0%, respectively. The expression of neither VEGF-A nor ChM-1 in cancer cells was correlated with MVD (P = 0.19 and 0.68, respectively), whereas that of VEGF-A in stromal mononuclear cells (SMCs) was significantly correlated with MVD (P = 0.04). CONCLUSION: Angiogenesis at the early stage of ESCC progression is configured by the balance between accelerator (angiogenic factors from both cancer cells and SMCs) and brake (angiogenic inhibitor) factors.

Thymidine phosphorylase and angiogenesis in early stage esophageal squamous cell carcinoma.

BACKGROUND: The relationship between thymidine phosphorylase (TP) and angiogenesis at the early stage of esophageal squamous cell carcinoma has been unclear. METHODS: Using 14 samples of normal squamous epithelium, 11 samples of low-grade intraepithelial neoplasia, and 64 samples of superficial esophageal cancer, microvessel density (MVD) was estimated using immunostaining for CD34 and CD105. TP expression was also evaluated in both cancer cells and stromal monocytic cells (SMCs). We then investigated the correlation between MVD and TP expression in both cancer cells and SMCs. RESULTS: On the basis of the above parameters, MVD was significantly higher in cancerous lesions than in normal squamous epithelium. In terms of CD34 and CD105 expression, MVD showed a gradual increase from normal squamous epithelium, to low-grade intraepithelial neoplasia, and then to M1 and M2 cancer, and M3 or deeper cancer. M1 and M2 cancer showed overexpression of TP in both cancer cells and SMCs. There was no significant correlation between TP expression in cancer cells and MVD estimated from CD34 (rS = 0.16, P = 0.21) or CD105 (rS = 0.05, P = 0.68) expression. Significant correlations were found between TP expression in SMCs and CD34-related (rS = 0.46, P < 0.001) and CD105-related (rS = 0.34, P < 0.01) MVD. In M3 or deeper cancers, there were no significant correlations between TP expression in cancer cells or SMCs and venous invasion, lymphatic invasion, and lymph node metastasis. CONCLUSION: TP expression is activated in both cancer cells and stromal monocytic cells at the very early stage of ESCC progression. TP expression in SMCs, rather than in cancer cells, is significantly correlated with angiogenesis.

A newly developed continuous zoom-focus endocytoscope.

Background and study aims We report the features of a newly developed endocytoscopy system (ECS), the GIF-Y0074. Patients and methods The GIF-Y0074 offers high-definition resolution with a consecutive increase of magnification to × 500. Using ECS, we observed 32 cases of esophageal squamous cell carcinoma (ESCC), 11 cases of gastric cancer, and five cases of duodenal adenoma. Results The images of cells obtained using the GIF-Y0074 at maximum magnification were brighter and clearer than those obtained with previous ECS systems. For diagnosis of ESCC, clearer visualization of the nucleus made nuclear abnormality easier to recognize. Cancer cells were visualized in 10/11 cases of gastric cancer, but removal of mucus still remained a problem. Duodenal adenomas were found to have atypical cells with villi and tubules at the mucosal surface, thus assisting their histological diagnosis in vivo. Conclusion The GIF-Y0074 is an excellent ECS in terms of ease of use, satisfactory resolution, and magnification power, and therefore achieves a level of utility that makes its commercial release justifiable. This ECS heralds a new era of endoscopic and histological diagnosis.

[Minilaparotomy in Pancreas-Preserving Total Duodenectomy for Familial Adenomatous Polyposis Associated with Spigelman Stage â £ Duodenal Polyposis].

INTRODUCTION: Reports on pancreas-preserving total duodenectomy (PPTD) for duodenal polyposis (DP) in familial adenomatous polyposis (FAP) patients are rare. We herein report a case of PPTD performed by minilaparotomy for DP in an FAP patient. CASE: A 27-year-old female FAP patient was diagnosed with Spigelman classification (SC) stage Ⅳ DP on gastroduodenoscopy. She underwent PPTD through a 7 cm upper abdominal incision. All polyps were confirmed as adenomas histopathologically. After 6 months of follow-up, complications related to total duodenectomy, such as weight loss, diabetes mellitus, and fatty liver have not been observed. DISCUSSION: SC stage Ⅳ refers to non-advanced cancers, and PPTD is basically prophylactic surgery. Therefore, pancreatoduodenectomy seems too aggressive for SC stage Ⅳ patients. PPTD by minilaparotomy is suitable for young female patients for its curability, esthetic outcome, and safety.

[Efficacy of Postoperative Chemotherapy in Stage â £ Colorectal Cancer with Perforation].

The clinical outcome and efficacy of postoperative chemotherapy in patients with Stage Ⅳ colorectal cancer with perforation were investigated. We compared the clinical outcomes between 11 patients with Stage Ⅳ colorectal cancer (perforation group), who underwent emergency surgery for colonic perforation between September 2005 and March 2012, and 22 matched patients (matching group) who underwent elective colorectal surgery during the same period. The colostomy rate in the perforation group was significantly higher than that of the matching group: patients with perforation received stoma construction surgery more frequently (p<0.01). Seven patients (64%) in the perforation group received postoperative chemotherapy, while 20 patients (91%) in the matching group received chemotherapy (p=0.15). Oxaliplatin-based chemotherapy was administered to all patients in both groups. There was no difference in the median relative dose intensity of oxaliplatin between these groups (p=0.37). No significant difference was observed between the cumulative 3-year overall survival rate in the perforation group and that of the matching group (35% and 54%, respectively; p=0.35). Moreover, the 3-year overall survival rates of patients who received oxaliplatin-based chemotherapy were 51%in the perforation group and 57% in the matching group (p=0.74). Our results suggest that postoperative oxaliplatin-based chemotherapy may improve the prognosis of patients with Stage Ⅳ colorectal cancer with perforation.

[Problems in the Treatment of Stage â ¢ Colorectal Cancer with Perforation].

We retrospectively investigated clinical outcome and treatment strategies in Stage Ⅲcolorectal cancer patients who underwent emergency surgery because of tumor-related perforation. We compared the clinical outcome of 6 patients (perforation group) who underwent emergency surgery for colonic perforation due to Stage Ⅲ colorectal cancer with 12 matched patients (matching group) who underwent elective colorectal surgery, between April 1998 and March 2012. Patients in the perforation group underwent colostomy procedures more frequently (p=0.02), had longer operative times (p=0.02), and more bleeding (p=0.04) than those in the matching group. There was no significant difference between the groups in terms of the introduction rate of chemotherapy, recurrence rate, or recurrence pattern. The 3-year disease-free survival rate was 44% in the perforation group and 81% in the matching group, resulting in no significant differences between these groups (p=0.28). The 3-year disease-free survival rates in the perforation and the matching groups were 44% and 81%, respectively (p=0.07). The 3-year overall survival rates in the perforation and the matching groups were 17% and 81%, respectively (p<0.01). The 3-year overall survival rate of patients who received adjuvant chemotherapy was 50% in the perforation group and 88%in the matching group (p=0.03). We concluded that patients with perforated Stage Ⅲ colorectal cancer had a significantly poorer prognosis compared with patients with non-perforated Stage Ⅲ colorectal cancer.

Angiogenesis in superficial esophageal squamous cell carcinoma: assessment of microvessel density based on immunostaining for CD34 and CD105.

OBJECTIVE: The esophagus is the only organ where changes in the superficial microvasculature from normal squamous epithelium to invasive cancer are evident by magnifying endoscopy. We investigated in detail the features of angiogenesis in early-stage esophageal cancer using CD34 and CD105 immunostaining, and also the correlation between angiogenesis and mononuclear cell infiltration. MATERIALS AND METHODS: Using 10 samples of normal squamous epithelium, 7 samples of low-grade intraepithelial neoplasia, and 45 samples of superficial esophageal cancer, we determined the microvessel density at hot spots showing positive staining for CD34 and CD105. We observed the histological features of CD34- and CD105-positive microvessels that corresponded to observations made by magnifying endoscopy. We then investigated the correlation between microvessel density and each histological situation or the grade of mononuclear cell infiltration. RESULTS: The histological features of CD34- and CD105-positive microvessels were able to explain the morphological changes in the microvasculature during cancer progression observed by magnifying endoscopy. The microvessel density for CD34 or CD105 was significantly correlated with each of the histological types (P < 0.001, rS = 0.51 and 0.76, respectively). Mononuclear cell infiltration at CD105 hot spots was most frequent in M1 and M2 cancer (94.7%). The correlation between the degree of mononuclear cell infiltration and microvessel density for CD105 staining was also significant (P < 0.001, rS = 0.49). CONCLUSIONS: The microvessel density based on CD34 and CD105 immunostaining can be used to corroborate observations of superficial esophageal squamous cell carcinoma made by magnifying endoscopy. Mononuclear cell infiltration may play an important role in angiogenesis at the early stage of cancer progression.

[Evaluation of immunity in elderly patients with unresectable gastric cancer receiving S-1/Lentinan combination chemotherapy].

PURPOSE: This retrospective study evaluated immunity in elderly patients with unresectable gastric cancer receiving S-1/ Lentinan combination chemotherapy. PATIENTS AND METHODS: This study included 10 patients aged≥70 years with unresectable gastric cancer who received S-1/Lentinan combination chemotherapy between October 2008 and December 2012. All patients gave written informed consent. Immune parameters for regulatory T cell(Treg)ratio, prostaglandin E2(PGE2), C3, CH50, and granulocyte/lymphocyte ratio were measured before chemotherapy initiation and at 7 weeks after it. Clinicopathological or immune parameters affecting overall survival(OS)were consequently evaluated. RESULTS: A high Treg ratio(p=0.02) and low PGE2(p=0.05)levels at 7 weeks after chemotherapy and a decrease in the Treg ratio(p=0.02)were found to be significant favorable factors affecting OS. CONCLUSION: The outcome of elderly patients with unresectable gastric cancer receiving S-1/Lentinan combination chemotherapy seemed to be correlated with the change in immunity.

[Significance of the granulocyte-to-lymphocyte ratio as a prognostic predictor in patients with stage IV colorectal cancer undergoing chemotherapy].

The aim of this study was to evaluate the clinical significance of the granulocyte-to-lymphocyte(G/L)ratio as a prognostic predictor in patients with Stage IV colorectal cancer. A total of 83 patients who underwent oxaliplatin-based chemotherapy for Stage IV colorectal cancer were enrolled in the study. Univariate analysis indicated that the G/L ratio; number of involved organs(more than one organ); performance status ≥1; noncurability; and levels of hemoglobin, C-reactive protein, albumin, alkaline phosphatase, carbohydrate antigen 19-9, and lactate dehydrogenase before chemotherapy were significant prognostic factors. Noncurability was identified to be an independent, unfavorable factor for survival on multivariate analysis. When patients were divided into 2 groups according to the G/L ratio(the median was considered the cut-off value), the median survival time of patients with a high G/L ratio(≥3.0)was significantly worse than that of patients with a low G/L ratio(<3.0; 16.1 months vs 25.4 months, p=0.03). Further studies with more patients are required to examine whether the G/L ratio is a convenient biomarker affecting survival in patients with Stage IV colorectal cancer.

[Significant prognostic factors in stage IV gastric cancer].

The aim of this study was to evaluate clinicopathological variables, including the granulocyte-to-lymphocyte ratio(G/L ratio), as prognostic factors for Stage IV gastric cancer patients. A total of 70 patients treated for Stage IV gastric cancer were enrolled in this study. Univariate analysis indicated that age ≥70 years, performance status >2, resection not being performed, chemotherapy not being administered, high C-reactive protein(CRP)levels, and carbohydrate antigen 19-9 levels were significantly associated with poor survival. Multivariate analysis of these factors identified resection not being performed, chemotherapy not being administered, and high CRP levels as independent unfavorable factors of survival. Although the G/L ratio was not a prognostic factor for Stage IV gastric cancer patients in this study, further studies with greater number of patients are required to determine whether the G/L ratio is a significant biomarker associated with survival.

[Efficacy of oxaliplatin-based adjuvant chemotherapy in stage II and III colorectal cancer with perforation].

This retrospective study evaluated the efficiency of oxaliplatin-based (Oxa-based) adjuvant chemotherapy for colorectal cancer with perforation. The study included 38 patients who underwent surgery for perforation associated with StageII and III colorectal cancer between April 1998 and March 2013. Patients with operative mortality were excluded from the study. The numbers of patients with StageII and III disease were 26 and 12, respectively. Adjuvant chemotherapy was received by 16 patients (62%) in the Stage II group. Seven patients (54%) in the Stage III group received adjuvant chemotherapy, of which 6 received Oxa-based adjuvant chemotherapy. The median relative dose intensity(range)of oxaliplatin was 83.3 (28.8- 100)%. Grade 3 adverse events were reported in 2 cases. The 3-year overall survival rates in the StageII and III groups were 60% and 79%, respectively. There was no significant difference in overall survival between the groups (p=0.28). Patients who received adjuvant chemotherapy had a 2.3-fold greater 3-year overall survival rate than those who did not receive adjuvant chemotherapy (80% vs 35%, p=0.01). The 3-year overall survival rates were 100% in patients who received Oxabased adjuvant chemotherapy (n=6), and 76%in patients who received adjuvant chemotherapy without oxaliplatin (n=17), with no significant difference between the groups (p=0.24). The Oxa-based adjuvant chemotherapy was tolerated equally well in Stage II and III colorectal cancer patients with or without perforation. Further studies are needed to compare the effect of oxaliplatin with other adjuvant chemotherapies.

[Theoretical background of our original single-incision laparoscopic-assisted surgery technique for colon cancer via a periumbilical approach].

We assessed the theoretical background of our original single-incision laparoscopic-assisted surgery( SILS) technique involving a periumbilical approach. The subjects included 10 cases who underwent periumbilical SILS colectomy and had their surgical wounds photographed before and after skin incision between September 2009 and October 2010. Using an image analyzer, we estimated the theoretical oval area after a 3/4-circumferential periumbilical skin incision, the actual oval area after placement of the wound retractor, and the length of the skin incision. The mean oval area after the placement of the wound retractor was 2.9 times (range: 1.6-5.0 times) larger than that of the theoretical area. The square of the length of the skin incision positively correlated with the actual oval area created by placing the wound retractor( p=0.04, r=0.67). There were 5 patients, whose actual oval area was ≤700 mm2, and thus required additional radial skin incision( s)( 1 in 3 cases, 2 in 1 case and 3 in 1 case). When performing our original SILS via the periumbilical approach, the area of the actual surgical window can be predicted by measuring the distance from the center of the umbilicus to its edge.

[Effect of chemotherapy in primary tumor of MSI-H colon cancer aged 50 years or younger].

Microsatellite instability( MSI) in colorectal carcinoma is reportedly associated with resistance to 5-fluorouracil-based chemotherapy. Moreover, colorectal cancer patients aged ≤ 50 years could potentially have Lynch syndrome. In the present study, we examined 11 colorectal cancer patients with unresectable Stage IV disease who underwent resection of the primary tumor between January 2006 and December 2012. The relationship between the MSI status and the efficacy of first- line oxaliplatin-based chemotherapy was retrospectively examined. The MSI status included MSI-H in 1 patient, MSS-L in 2 patients, and MSS in 8 patients. The MSI-H in 1 patient was associated with familial adenomatous polyposis. Following chemotherapy, among 8 MSS patients, 3 showed stable disease (SD) and 1 showed partial response (PR). Moreover 2 MSH-L patients and 1 MSI-H patient showed progressive disease (PD) after chemotherapy. However, additional data collection is required to determine the effect of oxaliplatin-based chemotherapy for MSS-H or MSS-L colorectal patients aged ≤ 59 years.

[Outcomes of patients with small bowel carcinoma treated with appropriate chemotherapy selected on the basis of genetic analysis findings].

Small bowel carcinoma is a rare tumor, for which a standardized chemotherapy regimen has not yet been established. Further, this tumor may belong to the group of Lynch syndrome-associated tumors, which are resistant to 5-fluorouracil (5-FU) -based chemotherapy. We investigated mismatch repair protein expression and K-ras gene mutation status in 8 patients with aggressive small bowel carcinoma and determined the chemotherapy regimen used in these patients. Immunohistochemical staining indicated normal mismatch repair protein expression in all surgical specimens. Of 8 patients, 4( 50%) had K-ras codon 12 mutations. Because small bowel carcinoma is not significantly associated with Lynch syndrome, 5-FU-based chemotherapy would be appropriate for the treatment of these patients. The prevalence of K-ras codon 12 mutations was relatively similar to that in patients with sporadic colorectal carcinoma, and the usefulness of anti- epidermal growth factor receptor (EGFR) antibody for the treatment of small bowel carcinoma should be evaluated in the future.

[Clinicopathological characteristics and treatment outcome of retroperitoneal liposarcoma].

Six patients with retroperitoneal liposarcoma were referred to our institution and retrospectively analyzed. Clinicopathological factors, initial treatment, postoperative recurrence, treatment, disease-free survival, and overall survival were investigated. Median age was 67 years and the male to female ratio was 0.5. Every patient underwent a surgical procedure as an initial treatment. Maximum tumor diameter was 190 mm (range, 100-250 mm). Three patients had local excisions, whereas the remaining 3 had extended surgery. Histological classification included well-differentiated type in 3, dedifferentiated type in 2, and mucinous type in 1. Three patients developed recurrence (local, n=3; hematogeneous, n=2). Local recurrence was excised but the disease relapsed in 2 patients. Median disease-free survival period was 21 months and 3-year survival rate was 62.5%. Since surgical resection remains the only promising treatment for liposarcoma, total removal of the tumor with negative surgical margins is mandatory. Wide resection, including the neighboring organs, should be performed without hesitation in selected cases.

[Predictive value of Köhne's index on the efficacy of FOLFIRI regimen in the treatment of unresectable liver metastatsis of colorectal cancer].

The aim of this retrospective study was to analyze the predictive value of Köhne's index on the efficacy of FOLFIRI regimen in the treatment of unresectable liver metastasis of colorectal cancer. The subjects were 44 patients with unresectable liver metastasis from colorectal cancer treated with FOLFIRI regimen as second-line, for all of whom oxaliplatin-based regimen had previously failed. Bevacizumab was concomitantly used in 23 patients. Classification of the Köhne's index revealed high risk in 22 patients, intermediate risk in 7 patients, and low risk in 15 patients. The response rate was 13.6% in the patients with high risk(H group) and 27.3% in the patients with intermediate or low risk(non-H group)(p=0.45). The disease control rate was 50% in the H group and 68.2% in the non-H group (p=0.36). In the H group, the median progression -free survival time was 4.1 months and in the non-H group it was 7.1 months (p=0.33). Compared with the H group, the non-H group showed significantly better overall survival (10.8 months vs 23.9 months, p=0.03). None of the patients has received hepatectomy (conversion therapy). These results suggest that the predictive value of Köhne's index is limited in terms of the effect of shrinkage of liver metastases, including conversion therapy.

[Clinical outcomes in refractory colorectal cancer patients with wild-type K-ras treated with bevacizumab and oxaliplatin-based chemotherapy as a first-line treatment].

The clinical outcomes, including adverse events, in 34 unresectable advanced colorectal cancer patients with wild-type K-ras, who were treated with bevacizumab and oxaliplatin-based chemotherapy as a first-line treatment, were analyzed for confirmation of the effectiveness and safety of this treatment. The response rate of the patients was 44% (complete remission, 2 patients; and partial remission, 13 patients). The median progression-free survival and overall survival in these patients was 11.1 and 25.1 months, respectively. Adverse events of greater than grade 3 were observed in 18 patients. Of these patients, 10 exhibited grade 3/4 neutropenia, and 6 had peripheral neuropathy. Our results were similar to those of randomized phase III trials from abroad, including those using anti-epidermal growth factor receptor antibody, with respect to effectiveness and safety. Furthermore, patients with liver metastasis had poor prognosis compared to those with metastasis to organs other than the liver. Further analysis will be required to better understand these results.

[Adjuvant chemotherapy comprising modified FOLFOX6 after curative resection of synchronous or metachronous metastasis from colorectal cancer].

PURPOSE: This retrospective study evaluated the outcome of adjuvant chemotherapy comprising modified FOLFOX6 (mFOLFOX6) after potentially curative metastasectomy from colorectal cancer. PATIENTS AND METHODS: The subjects were 40 patients with colorectal cancer who underwent potentially curative metastatectomy without any prior chemotherapy between December 2003 and November 2011. Patient background, type of adjuvant chemotherapy, and prognosis were examined. RESULTS: Adjuvant chemotherapy was given in 30 patients (mFOLFOX6, n=26; oral fluoropyrimidines, n=4). The median relapse-free survival tended to be longer in patients treated with mFOLFOX6 compared to those treated with fluoropyrimidines (28.5 months vs 14.8 months; p=0.11). The median overall survival did not differ significantly between the 2 groups (37.9 months vs 31.3 months, p=0.56). When the analysis was restricted to patients treated with mFOLFOX6, no significant differences were found in relapse-free survival (p=0.46), overall survival (p=0.29), and frequency of adverse events during chemotherapy(Grade 3, p=0.32) between patients with synchronous metastasis(n=11) and those with metachronous metastasis (n=15). CONCLUSION: These results suggest that mFOLFOX6 might contribute to prolonging the time to relapse and that the timing of developing metastasis(synchronously or metachronously) may not have any effect on the outcome of adjuvant mFOLFOX6.

[Prediction of the efficacy of first-line oxaliplatin-based chemotherapy for unresectable liver metastases of colorectal cancer by Köhne's index].

PURPOSE: This retrospective study was undertaken to examine the usefulness of Köhne's index(KI) for predicting the efficacy of first-line oxaliplatin-based chemotherapy for unresectable liver metastases of colorectal cancer. PATIENTS AND METHODS: The subjects were 84 patients with unresectable liver metastases of colorectal cancer in whom first-line oxaliplatin- based chemotherapy was administered. The outcome of treatment was analyzed in relation to the KI. RESULTS: The patients were classified into 3 groups: high risk group (n=12), intermediate risk group (n=20), and low risk group (n=52). There were no significant differences between the groups with regard to response rate, disease control rate, disease-free survival, overall survival, and the rate of conversion to hepatic metastatectomy. CONCLUSION: Our results suggest that KI might not be useful for predicting the efficacy of first-line oxaliplatin-based chemotherapy for unresectable liver metastases of colorectal cancer.

[Clinical differences between palliative gastrectomy and reduction surgery for gastrectomy in curatively unresectable gastric cancer].

Surgical treatments for curatively unresectable gastric cancer include reduction surgery and palliative surgery(palliative gastrectomy and bypass operation). Both palliative gastrectomy and reduction surgery reduce the tumor volume. In this study, the clinical significance of these treatment methods was investigated. The subjects were 58 patients with unresectable gastric cancer for which surgery was performed as the primary treatment. Of these patients, 38 patients underwent reduction surgery and 20 patients underwent palliative surgery. On univariate analysis, age and gender were not significant. Pre-operative performance status(PS) in patients treated with reduction surgery was favorable compared to that in patients receiving palliative surgery(PS 0: 65.8 vs 40.0%, p=0.06). The administration rate of post-operative chemotherapy in patients treated with reduction surgery was higher than that in patients with palliative surgery (92.1 vs 65.0%, p<0.01). The median survival time in patients treated with reduction surgery was 18.2 months, while that in patients with palliative surgery was 11.0 months (p<0.01). These results indicated that reduction surgery was clinically different compared to palliative surgery in terms of the administration rate of post-operative chemotherapy and prognosis.