Thymidylate synthase expression as a predictor of the prognosis of curatively resected colon carcinoma in patients registered in an adjuvant immunochemotherapy clinical trial

The expression levels of thymidylate synthase (TS) affect the sensitivity of tumor cells to fluorinated pyrimidine cytotoxic agents and determine the response of patients with colorectal cancer to fluorinated-pyrimidine-based chemotherapy. The correlation between the expression of TS and the prognosis of patients with colorectal cancer was examined in a prospective study. Evaluation of biomarkers including TS expression was performed using tumor specimens from 229 colorectal cancer patients. Immunohistochemical analysis of TS expression was performed using an antibody raised against a C-terminal epitope (D186-V313) of the human TS. The intensity of TS staining and the expression of other biomarkers were blindly scored. The five-year survival rates were 63.4% and 85.6% among patients with high and low intratumoral TS expressions, respectively (p=0.0007). Similarly, the disease-free survival (DFS) rate was 51.2% and 80.3% in the high and low TS expression groups, respectively (p=0.0004). In a subset analysis of Dukes' stage C patients, the survival and DFS rates were 44.0% and 40.0% in the high TS expression group, and 73.5% and 67.4% in the low TS expression group, respectively. Significant differences were observed in both survival (p=0.0048) and DFS (p=0.0054) rates. No significant correlation was observed between the expression of other biomarkers and prognosis. Significantly poorer prognosis of curatively resected colon cancer in patients with high TS expression levels in tumor tissue was confirmed by a double-blind prospective study conducted on samples obtained from patients enrolled in an adjuvant immunochemotherapy randomized clinical trial.     

Thymidylate synthase expression in colorectal cancer: a prognostic and predictive marker of benefit from adjuvant fluorouracil-based chemotherapy.

PURPOSE: We studied the prognostic value of thymidylate synthase (TS) expression in primary colorectal cancer (CRC) and the role of TS expression as a predictor of chemotherapeutic benefit in patients treated with adjuvant chemotherapy. PATIENTS AND METHODS: TS expression was immunohistochemically assessed on tumor sections from 862 patients with CRC Dukes' stages B and C enrolled onto randomized trials evaluating fluorouracil (5-FU)-based adjuvant chemotherapy. RESULTS: TS expression was an independent prognostic factor for disease-free (P =.05) and overall survival (P =.05). In the subgroup treated with surgery alone, TS was an independent prognostic factor for disease-free (P <.001) and overall survival (P =.001), whereas this was not the case in the subgroup of adjuvantly treated patients. Patients whose tumors expressed high TS levels had a tendency to improved outcome after adjuvant therapy (not significant). The group whose tumors expressed the highest TS grade, grade 3 (34% of the patients), had a significantly longer disease-free survival if they were treated with adjuvant therapy compared with surgery alone (multivariate analyses, P =.02), whereas patients whose tumors expressed low TS levels (28% of the patients) had an impaired outcome after adjuvant therapy (multivariate analyses: disease-free survival, P =.01; overall survival, P =.01). CONCLUSION: TS expression predicts for survival independent of Dukes' stage in patients with CRC treated with surgery alone. The study indicates that patients with high TS levels may benefit from adjuvant 5-FU-based chemotherapy. However, patients with low TS levels seem to have a worse outcome when treated with adjuvant chemotherapy.     

Predictive role of thymidylate synthase, dihydropyrimidine dehydrogenase and thymidine phosphorylase expression in colorectal cancer patients receiving adjuvant 5-fluorouracil

OBJECTIVE: The combined assessment of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and thymidine phosphorylase (TP) gene expressions in metastatic colorectal cancer has been reported to be able to predict the efficacy of fluoropyrimidine-based chemotherapy. In order to evaluate the prognostic role in the adjuvant setting, we investigated the TS, DPD and TP expression in primary tumors of colorectal cancer patients treated with 5-fluorouracil (5-FU). METHODS: TS, DPD and TP expression levels were determined by immunohistochemistry in paraffin-embedded primary tumor tissues from 62 patients with Dukes' stage B and C colorectal cancers who underwent surgery and received adjuvant systemic chemotherapy with 5-FU. The median follow-up was 90 months (range 17-127). RESULTS: Dukes' stage C cancer and high TS expression were independent markers of poor prognosis for disease-free survival (DFS; p = 0.0009 and p = 0.007, respectively) and overall survival (OS; p = 0.0005 and p = 0.011, respectively). By multivariate analysis, patients with high DPD expression had significantly shorter DFS (p = 0.007) and OS (p = 0.005) compared to patients with low DPD expression. In the combined analysis of 2 markers, patients with low TS and low DPD had the best outcome in terms of DFS (p = 0.007) and OS (p = 0.03). The analysis of all 3 proteins showed that the patients with low expression of all 3 markers had significantly longer DFS (p = 0.04) and OS (p = 0.01) than patients with a high value of any one of the protein expressions. However, the joint analysis of 3 markers (group with TS-/DPD-/TP-) could not identify a subgroup of patients with a better prognosis compared to the analysis of 2 markers (group with TS-/DPD-). The analysis of Dukes' stage C cancer patients confirmed a significant benefit in terms of DFS and OS (p = 0.001 and p = 0.006, respectively) when all 3 markers had low expression. We also found a positive significant correlation between TS and TP protein expression (p = 0.033). CONCLUSIONS: This retrospective investigation suggests that the combined assessment of TS and DPD may be useful to evaluate the prognosis of patients with Dukes' B and C colon carcinoma receiving 5-FU adjuvant chemotherapy. The role of TP as a predictor for 5-FU-based therapy needs further investigations.     

Detection of thymidylate synthase expression in lymph node metastases of colorectal cancer can improve the prognostic information.

PURPOSE: The level of thymidylate synthase (TS) in primary colorectal cancer (CRC) has been reported as a prognostic marker. The purpose of this study was to determine whether TS expression in lymph node metastases of Dukes' C CRC is a prognostic marker. PATIENTS AND METHODS: TS expression in the primary tumor and lymph node metastases from 348 patients with Dukes' C CRC was retrospectively assessed using immunohistochemistry and the monoclonal antibody TS 106. The patients had all been enrolled onto our previous study of 862 CRC patients who were included in Nordic trials that randomly assigned the patients to either surgery alone or surgery plus adjuvant chemotherapy. RESULTS: TS expression in lymph node metastases was a distinct prognostic marker in the entire study group for overall survival (OS; P = .02) and disease-free survival (DFS; P = .04). A low TS expression in the lymph node metastases correlated with a better clinical outcome. In the subgroup of patients treated with surgery alone, the expression of TS in lymph node metastases also had a prognostic value for OS (P = .04) and DFS (P = .03), but this was not the case for the other subgroup who received adjuvant fluorouracil-based chemotherapy (OS, P = .5; DFS, P = .2). The expression of TS in the primary tumor only had a significant prognostic value among patients who were treated with surgery alone (OS, P = .03; DFS, P = .03) and not among the entire patient population. CONCLUSION: These data show that TS expression in lymph node metastases is a prognostic marker for patients with Dukes' C CRC.     

Thymidylate synthase expression pattern is a prognostic factor in patients of colorectal cancer treated with 5-fluorouracil

High intratumoral expression of thymidylate synthase (TS) has been reported as a factor of poor prognosis in patients with advanced colorectal cancer (CRC), but such association is unclear in some studies. Also, TS has been stated as a typical cytosolic enzyme, but nuclear location has been occasionally reported, and data on the clinical meaning of TS intracellular location are scarce. A retrospective study was performed in paraffin-embedded sections of primary tumor from 77 CRC patients treated with surgical resection and adjuvant 5-FU-based chemotherapy. TS levels and expression patterns were determined by immunohistochemistry (IHQ) using TS-106 antibody. Qualitative and quantitative variables were compared respectively by chi2 and Kruskal-Wallis tests; overall survival (OS) and disease-free survival (DFS) were analyzed with the Kaplan-Meier method and compared using the log-rank and Wilcoxon tests. TS was cytoplasmic in 27.1% of positive tumors and both, nuclear and cytoplasmic in 72.9%; specimens from seven patients (9.1%) lacked TS expression. TS levels were high in 21.6% of tumors with nuclear expression and low in 5.6%, whereas 68.4% of cytoplasmic ones showed low immunostaining intensity (p=0.02); cytoplasmic pattern was also associated to longer OS (p<0.009) and DFS (p=0.003). In patients with nuclear expression, low TS expression was associated to shorter OS (p<0.003) and DFS (p<0.04). These results indicate that, in our study, TS immunostaining patterns were related with OS and DFS, the best prognostic corresponding to cytoplasmic one, and, within the subset of patients with nuclear expression, low TS levels were associated to worse clinical outcome.     

Prognostic and predictive value of the thymidylate synthase expression in patients with non-metastatic colorectal cancer.

AIMS: To assess the value of thymidylate synthase (TS) expression as a predictive factor in the efficacy of adjuvant chemotherapy in colorectal cancer, as well as its independent prognostic value for survival. METHODS: We studied 114 high risk colorectal carcinoma patients (high risk stage II and stage III), distributed in two treatment groups: surgery alone (61 patients) or surgery followed by 5-FU-based chemotherapy (53 patients). TS protein expression in the tumour tissue was assessed by immunohistochemistry. RESULTS: In the surgery alone subgroup, overall survival (OS) at 5 years were 77.5% for the patients with low TS expression, against 57.7% for the patients with high TS expression (p=0.006). Among patients with low TS, there was no difference in OS as a result of whether adjuvant chemotherapy was carried out or not (65.8 vs 77.5%, p=0.29). Among the patients with high TS, there was a significant gain in OS in favor of chemotherapy (87.8 vs 57.7%, p=0.04). Analyzing the complete sample, TS expression was not shown as an independent prognostic factor for survival in the multivariate analysis. CONCLUSIONS: The immunohistochemical TS expression may be used for selecting patients for better adjuvant chemotherapy protocols. In this sample, TS expression was not an independent prognostic factor for survival.     

A Combined Analysis of Mismatch Repair Status and Thymidylate Synthase Expression in Stage II and III Colon Cancer

BackgroundColon cancer with mismatch repair deficiency and low TS expression has been associated with an improved prognosis. Data also indicate that MMR proficient colon cancer with high TS expression has a better response to adjuvant 5-FU-based chemotherapy. This study evaluates if a combined analysis of MMR status and TS expression in colon cancer can add prognostic value and better predict response to adjuvant 5-FU-based chemotherapy. The potential relationship between MMR status and TS expression is also investigated.Patients and MethodsThis study includes a subgroup of 716 patients with colon cancer out of 2224 stage II and stage III colorectal cancer patients enrolled in Nordic trials randomized to surgery alone or surgery plus adjuvant 5-FU-based chemotherapy. After immunohistochemical analysis of tumor MMR status and TS expression the patients were divided into 4 groups.ResultsThere was a nonsignificant difference in overall survival between group 1 (patients with deficient MMR tumors with low TS) and group 4 (patients with proficient MMR tumors expressing high TS). When comparing group 1 and group 4 patients treated with surgery alone a trend to better overall survival was found in group 1, P = .06. In group 4, stage III patients had a significantly improved survival when receiving adjuvant 5-FU-based chemotherapy compared with surgery alone, P = .01. No relationship was found between MMR status and TS expression.ConclusionsA combined instead of a single marker analysis of MMR status and TS expression can improve the prediction of response to 5-FU-based chemotherapy in stage III colon cancer.     

Investigation of the prognostic and predictive value of thymidylate synthase, p53, and Ki-67 in patients with locally advanced colon cancer.

PURPOSE: To evaluate the value of thymidylate synthase (TS), Ki-67, and p53 as prognostic markers in patients with Dukes' B2 and C colon carcinoma. METHODS: We conducted a retrospective analysis to evaluate the prognostic value of TS, Ki-67, and p53 in 465 patients with Dukes' B2 (220 patients) or Dukes' C (245 patients) colon carcinoma. Patients represent a nonrandom subset obtained from five randomized phase III trials and were treated with either surgery alone (151 patients) or surgery plus fluorouracil-based chemotherapy (314 patients). All three markers were assayed using immunohistochemical techniques. RESULTS: With a minimum follow-up of 5 years, our retrospective analysis failed to demonstrate a consistent and significant association between TS, Ki-67, or p53 and either disease-free survival or overall survival. Exploratory analyses did not reveal a convincing explanation for these results that are in conflict with the published literature. Notable interactions were observed. In particular, high Ki-67 levels were associated with increased (decreased) survival in patients with low (high) TS intensity. Patients whose tumors stained positively for p53 seemed to benefit substantially from the use of adjuvant chemotherapy compared with those who were not treated (P =.05). CONCLUSION: This retrospective investigation failed to demonstrate a significant association between TS, Ki-67, or p53 staining and clinical outcome.     

Does timing of adjuvant chemotherapy for early breast cancer influence survival?

PURPOSE: Theoretically, patients with early breast cancer might benefit from starting adjuvant chemotherapy soon after surgery, and this would have important clinical implications. We have addressed this question from a large, single-center database in which the majority of patients received anthracyclines. PATIENTS AND METHODS: A total of 1161 patients from a prospectively maintained database treated with adjuvant chemotherapy for early breast cancer at the Royal Marsden Hospital (London, United Kingdom), including 686 (59%) receiving anthracyclines, were retrospectively analyzed. The disease-free survival (DFS) and overall survival (OS) of the 368 patients starting chemotherapy within 21 days of surgery (group A) were compared with those of the 793 patients commencing chemotherapy >or= 21 days after surgery (group B). Median follow-up time was 39 months (range, 12 to 147 months). RESULTS: No significant difference in 5-year DFS was found between the two groups overall (70% for group A v 72% for group B; P =.4) or in any subgroup. Likewise, there was no difference in 5-year OS (82% for group A v 84% for group B; P =.2) or when the interval to the start of chemotherapy was considered as a continuous variable (P =.4). CONCLUSION: We have been unable to identify any significant survival benefit from starting adjuvant chemotherapy early after surgery, either overall or in any subset of patients.     

TS和MMR联合检测在结直肠癌预后判断中的作用

目的:对133例结直肠癌患者临床病例资料进行回顾性分析,分析胸苷酸合成酶(thymidylate synthase,TS)蛋白与错配修复(mismatch repair,MMR)状态联合检测与结直肠癌患者临床病理特征及预后之间的关系.方法:免疫组化测定TS和MMR(MLH-1/MSH-2)蛋白表达.根据TS蛋白和MMR状态差异进行相应的配对组合,将纳入患者分为四组:TS蛋白高表达/MMR蛋白高表达(HtHm)组、TS蛋白低表达/MMR蛋白高表达(LtHm)组、TS蛋白低表达/MMR蛋白低表达(LtLm)组、TS蛋白高表达/MMR蛋白低表达(HtLm)组.分析TS和MMR联合检测与患者临床病理因素及预后的关系.结果:TS和MMR联合检测生存分析显示,LtHm组患者(39例)的3年生存率为69.2%,HtLm(20例)组患者的3年生存率为40.0%,两组总体生存率具有统计学差异(P=0.012),该差异在术后辅助化疗患者中仍存在(P=0.011).结论:辅助化疗组患者中LtHm组总体生存率显著高于HtLm组,LtLm组患者较HtHm组患者更易从氟尿嘧啶类药物辅助化疗中获益.     

Prognostic of DNA-synthesizing enzyme activities (thymidine kinase and thymidylate synthase) in 908 T1-T2, N0-N1, M0 breast cancers: a retrospective multicenter study

Among the methodological approaches of tumor proliferation, thymidine kinase (TK) and thymidylate synthase (TS) assays take into account the specific pathways of pyrimidine synthesis. Studies pointing to a prognostic value of TK and TS in breast cancer involved small numbers of patients. We investigated the prognostic value of these enzymes and their combination in a large retrospective multicenter study. Nine hundred eight T1T2, N0N1, M0 primary breast cancer samples (median follow-up 68 months) were tested. TK and TS were measured in cytosols by using standardized radioenzymatic methods. Although a positive correlation was obtained between TK and TS (p<10(-5)), major discrepancies were observed in some tumors. High levels of both enzymes were associated with large tumor size, histological grade III and steroid receptor-negative tumors. Univariate analysis showed that TK, TS and their combination were predictive of poor metastasis-free (MFS) (p < 10(-4); p=0.004; p < 10(-4)) and disease-free survival (DFS) (p < 10(-4); p=0.007; p=0.0001). TK was selected as an independent factor for MFS in Cox analysis. It was the only variable selected in node-negative patients. Subgroups with specific outcomes, with possible therapeutic implications, were identified: a) in node-negative patients not receiving adjuvant treatment, TK values in the 4th quartile were associated with poor MFS (p=0.0002) and DFS (p=0.0005) as compared to the other quartiles; b) in node-positive patients receiving adjuvant chemotherapy, low levels of both TK and TS were associated with the highest survival rates (MFS: p=0.04; DFS: p=0. 03).     

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.     

Patterns of failure in a randomized trial of adjuvant chemotherapy in postmenopausal patients with early breast cancer treated with tamoxifen.

BACKGROUND: We studied the effect of adjuvant anthracycline-based chemotherapy in postmenopausal patients with resected early breast cancer treated with adjuvant tamoxifen. PATIENTS AND METHODS: The trial included 835 patients with either axillary lymph node involvement, or tumors with histological grade II or III. They were randomized after local surgery to receive either tamoxifen (TAM group) or tamoxifen plus chemotherapy (TAM-CT group) consisting of six courses of 5-fluorouracil, doxorubicin and cyclophosphamide (FAC), or 5-fluorouracil, epidoxorubicin and cyclophosphamide (FEC). Radiotherapy was given after completion of adjuvant chemotherapy in the TAM-CT group and after surgery in the TAM group. RESULTS: The 5-year disease-free survival (DFS) rates were 73% in the TAM group and 79% in the TAM-CT group (log-rank test, P = 0.06). The 5-year overall survival rates were 82% and 87%, respectively (P = 0.06). The 5-year distant metastasis rates were 22% and 16% (P = 0.02), and the 5-year local recurrence rates were 6% and 4%, respectively (P = 0.23). There were no significant differences for contralateral breast cancer or other new primary malignancies. Chemotherapy tended to be more effective for patients who had tumors without estrogen receptors (trend test, P = 0.05). CONCLUSIONS: Anthracycline-based chemotherapy administered to postmenopausal patients receiving adjuvant tamoxifen gave a borderline significant benefit on overall and DFS, mainly by a reduction in distant metastases. Delaying radiotherapy after six courses of chemotherapy did not affect local control after up to 10 years of follow-up.     

Prognosis and efficacy of postoperative adjuvant chemotherapy in colorectal cancer correlates with nucleic acid metabolizing enzymes

We assessed the correlation among immunohistologically-stained nucleic acid metabolizing enzymes, such as thymidine phosphorylase (TP), thymidilate synthase (TS) and dehydropyrimidine dehydrogenase (DPD) detected in colorectal cancer patients, and the clinicopathologic factors, prognosis and efficacy of postoperative adjuvant chemotherapy. Results showed that TP staining positive cases had a higher incidence of vascular invasion and progression, and those with TS staining accounted for 30%. These cases also had lower 5-year survival rates. TS staining of 40% and DPD positive cases did not correlate with results shown in the TP positive and 30% TS staining group. Prognosis was better in patients who had undergone postoperative adjuvant chemotherapy and had negative DPD, TP and TS staining. These findings suggest that TP and TS are prognostic factors of colorectal cancer and that staining results of DPD combined with either TS or TP indicate the efficacy of postoperative adjuvant chemotherapy.     

Prognostic value of thymidylate synthase, Ki-67, and p53 in patients with Dukes' B and C colon cancer: a National Cancer Institute-National Surgical Adjuvant Breast and Bowel Project collaborative study.

PURPOSE: To define the value of thymidylate synthase (TS), Ki-67, and p53 as prognostic markers in patients with stage II and III colon carcinoma. PATIENTS AND METHODS: We retrospectively analyzed the prognostic value of TS, Ki-67, and p53 in 706 patients with Dukes' B (291 patients) or Dukes' C (415 patients) colon carcinoma who were treated with either surgery alone (275 patients) or surgery plus fluorouracil (FU)-leucovorin chemotherapy (431 patients) in National Surgical Adjuvant Breast and Bowel Project (NSABP) protocols C01-C04. All three markers were assayed using immunohistochemical techniques. RESULTS: Using 5 years of follow-up data, our retrospective analysis demonstrated an association between TS intensity (relapse-free survival [RFS]: risk ratio [RR] = 1.46, P =.01; overall survival [OS]: RR = 1.54, P =.002), Ki-67 (RFS: RR = 0.76, P =.05; OS: RR = 0.62, P =.001), and p53 (RFS: RR = 1.49, P =.01; OS: RR = 1.21, P =.18) for RFS and OS. High TS intensity levels and positive p53 staining were associated with a worse outcome. Tumors containing a high percentage of Ki-67-positive cells enjoyed an improved outcome compared with those patients whose tumors contained relatively few positive cells. An interaction with treatment was not identified for any of the markers. CONCLUSION: This retrospective investigation demonstrated that TS, Ki-67, and p53 staining each had significant prognostic value for patients with Dukes' B and C colon carcinoma. However, none of the markers could be used to clearly discern groups of individuals who would be predicted to derive greater or lesser benefit from the use of adjuvant chemotherapy.     

The Influence of Adjuvant Chemotherapy Dose Intensity on Five-Year Outcomes in Resected Colon Cancer: A Single Centre Retrospective Analysis

There is evidence that achieving a dose intensity > 80% in adjuvant colon cancer treatment improves survival. In total, 192 consecutive patients with resected stage III and high-risk stage II colon cancer that received adjuvant chemotherapy were retrospectively analyzed. Patients who received at least 6 weeks of adjuvant therapy were included. The primary objective was to assess the influence of dose index (DI) and relative dose intensity (RDI) on DFS and OS at 3 and 5 years in patients receiving fluorouracil-based doublet therapy with oxaliplatin (FOLFOX) (5-FU and oxaliplatin assessed separately), or capecitabine monotherapy. In the capecitabine group, DFS rates for 3 and 5 years were 66.7% and 57.6%, respectively, while OS rates were 80.3% and 66.7%, respectively. Those who received FOLFOX had DFS rates of 76.9% and 71.2% at 3 and 5 years, respectively. OS rates were 86.4% and 76.7% at 3 and 5 years, respectively. Median RDI was 73.8% for capecitabine and 76.3% and 85.6% for the oxaliplatin and 5-FU components respectively. Based on a multivariate analysis in patients receiving FOLFOX, those with an oxaliplatin DI > 80% had improvements in DFS and OS compared to those with an oxaliplatin DI of ≤80%. Otherwise, there was no significant difference in DFS or OS when comparing patients who achieved an RDI or a DI of above versus below 80% in the patients receiving adjuvant chemotherapy for resected colon cancer.     

Prognostic impact of multidrug resistance gene expression on the management of breast cancer in the context of adjuvant therapy based on a series of 171 patients

Study of the prognostic impact of multidrug resistance gene expression in the management of breast cancer in the context of adjuvant therapy. This study involved 171 patients treated by surgery, adjuvant chemotherapy+/-radiotherapy+/-hormonal therapy (mean follow-up: 55 months). We studied the expression of multidrug resistance gene 1 (MDR1), multidrug resistance-associated protein (MRP1), and glutathione-S-transferase P1 (GSTP1) using a standardised, semiquantitative rt-PCR method performed on frozen samples of breast cancer tissue. Patients were classified as presenting low or high levels of expression of these three genes. rt-PCR values were correlated with T stage, N stage, Scarff-Bloom-Richardson (SBR) grade, age and hormonal status. The impact of gene expression levels on 5-year disease-free survival (DFS) and overall survival (OS) was studied by univariate and multivariate Cox analysis. No statistically significant correlation was demonstrated between MDR1, MRP1 and GSTP1 expressions. On univariate analysis, DFS was significantly decreased in a context of low GSTP1 expression (P = 0.0005) and high SBR grade (P = 0.003), size > or = 5 cm (P = 0.038), high T stage (P = 0.013), presence of intravascular embolus (P = 0.034), and >3 N+ (P = 0.05). On multivariate analysis, GSTP1 expression and the presence of ER remained independent prognostic factors for DFS. GSTP1 expression did not affect OS. The levels of MDR1 and MRP1 expression had no significant influence on DFS or OS. GSTP1 expression can be considered to be an independent prognostic factor for DFS in patients receiving adjuvant chemotherapy for breast cancer.     

Predictive value of thymidylate synthase expression in resected metastases of colorectal cancer

Recent investigations have focused on the prognostic value of thymidylate synthase (TS) assessment in metastases of colorectal carcinoma (CRC). In order to evaluate the prognostic impact of TS expression after resection of metastases of colorectal cancer followed by systemic adjuvant chemotherapy, we performed an immunohistochemical characterisation of TS in the primary tumours and in the corresponding radically resected hepatic and pulmonary metastases. An additional objective was to compare the levels of TS in primary and metastatic disease. TS expression was assessed by immunohistochemistry using the monoclonal antibody TS 106. The study population consisted of 60 patients: 48 underwent liver and 12 lung resection. All of them received adjuvant chemotherapy after metastasectomy according to the Mayo Clinic schedule. In the 49 evaluable primary tumours, TS score was high in 53% and low in 47% of patients, while in the 60 metastatic samples TS immunostaining was high in 33% and low in 67%. There was a significantly smaller number of high TS expressors in metastatic than in primary tumours (P<0.04). No correlation was observed between TS expression and the site of the metastasis. TS status did not significantly correlate with the median disease-free interval (DFI) after metastasectomy, although this parameter was longer for patients with low TS immunoreactivity in the resected metastases than for those with high TS lesions (19.6 versus 13.8 months). Patients with high TS levels, however, had a significantly shorter median overall survival (OS) (27.6 months) than those with low TS expression (36.3 months) (P<0.008). TS status in the resected metastases confirmed its independent prognostic value in the multivariate analysis and was the only prognostic marker of OS in the subgroup of patients with resected liver metastases. These results suggest that high TS levels in resected metastases of colorectal cancer are associated with a poor outcome after surgery and 5-FU adjuvant therapy; therefore, a prospective assessment of TS levels in resected colorectal metastases could be useful to define which patients will most likely benefit from 5-FU adjuvant therapy after metastasectomy. Chemotherapeutic agents that target TS may not be the appropriate adjuvant treatment after metastasectomy for patients with a high TS expression in the resected metastases of colorectal cancer.     

The prognostic value of Stathmin-1, S100A2, and SYK proteins in ER-positive primary breast cancer patients treated with adjuvant tamoxifen monotherapy: an immunohistochemical study

INTRODUCTION : We recently found that DNA methylation of S100A2, spleen tyrosine kinase (SYK), and Stathmin-1 (STMN1) correlates with response to tamoxifen therapy in metastatic breast cancer. In this retrospective study, we investigated immunohistochemically whether these three markers are predictors of relapse in early breast cancer (EBC) patients treated with adjuvant tamoxifen alone. METHODS : Immunohistochemical staining was performed for S100A2, SYK and STMN1 on a tissue microarray containing ER-positive invasive breast carcinomas from a study cohort of 215 operable breast cancer patients, who underwent radical local therapy and who were treated with adjuvant tamoxifen monotherapy. Cox regression was used to correlate staining intensity of the three markers with main endpoints in our study; disease-free survival (DFS), and disease-specific survival (DSS). RESULTS : In univariate analysis, only STMN1 staining intensity strongly correlated with DFS (P = 0.014) and DSS (P = 0.002). In the groups of low and high STMN1 intensity, DFS was 84% and 63%, and DSS was 89% and 70%. STMN1 retained its prognostic value for DFS (P = 0.002) and DSS (<0.001) in the multivariate model together with lymph node status. We found also a trend to better DFS in patients with low STMN1 intensity in both lymph node-positive (P = 0.001) and -negative patients (P = 0.065). As the tumour cells did not express S100A2 (except in one case) the potential prognostic value of this marker was not evaluated. CONCLUSIONS : Staining intensity of STMN1, but not SYK, predicted outcome in our collective of ER- positive tamoxifen treated EBC patients.