Tumor Budding Versus Mismatch Repair Status in Colorectal Cancer - An Exploratory Analysis.

BACKGROUND: Tumor budding and a proficient mismatch repair (pMMR) status are considered adverse prognostic factors in colorectal cancer (CRC). The aim of this pilot study was to assess tumor budding in primary CRC with pMMR versus that with deficient mismatch repair (dMMR). MATERIALS AND METHODS: Tumor budding was retrospectively examined in the tumor from 134 patients with stage II and stage III CRC with known MMR status. The 29 available dMMR cases who developed recurrence or distant metastases (met+) were matched with a dMMR group with no recurrence or metastases (met-), and the pMMR/met+ group with pMMR/met- cases. RESULTS: Using tumor budding cut-offs of 5 and 10, a significantly higher percentage of high-grade tumor budding (≥5 and ≥10) was only found in the dMMR/met+ compared to pMMR/met+ subgroup (p=0.01 and p=0.02, respectively). CONCLUSION: A significantly higher grade of tumor budding was observed in the dMMR/met+ group, suggesting that tumor budding can provide prognostic information for patients with a dMMR status.

HER3 expression is correlated to distally located and low-grade colon cancer.

UNLABELLED: Background HER3 is a member of the human epidermal growth factor receptor complex (EGFR, HER2, HER3 and HER4). It has been investigated as a prognostic biomarker in colorectal cancer but is sparingly studied in colon cancer. HER3 can affect cellular proliferation, differentiation and migration in oncogenesis through ligand binding and activation of intracellular signal pathways. Recently, we found that expression of cell surface HER3 can be detected at a high extent in primary colorectal tumors, lymph node and liver metastases and that it correlated with poor prognosis. This large, explorative, retrospective study evaluates the prognostic value of HER3 in colon cancer and the association of HER3 to tumor location. MATERIAL AND METHODS: Immunohistochemical detection with a monoclonal HER3 antibody in primary colon tumors of stage II and III, from 521 patients, was performed. Results HER3 was expressed at high levels in 67% of the colon tumors. High HER3 expression was associated with distal tumor location (p < 0.0001) and low-grade tumor (p < 0.0001). In the group of patients with distal colon cancer (230/521), HER3 expression correlated to shorter disease-free survival (DFS) (p = 0.03) in the univariate analysis and in the multivariate analysis, a hazard ratio of 0.56 (95% CI 0.31-0.99) (p = 0.047) was observed. Conclusion In this explorative, retrospective study, high HER3 expression in colon cancer was associated to distal colon location and low-grade tumor. High HER3 expression was of prognostic value according to DFS in distal colon cancer in univariate and multivariate analysis. We could not find a significant value of HER3 expression with respect to overall survival (OS).

HER3 expression in primary colorectal cancer including corresponding metastases in lymph node and liver.

BACKGROUND: The human epidermal growth factor receptor complex (EGFR-1, HER2, HER3 and HER4) plays an important role in pathogenesis of solid tumours. We have previously reported high expression of HER3 in 70% of primary colorectal cancer (CRC) and that high expression were linked to a worse clinical outcome. The purpose of this study is to evaluate the HER3 expression in primary CRC and metastases. MATERIAL AND METHODS: Tissue samples from primary CRC, corresponding lymph node metastases and liver metastases from 107 patients were analysed by immunohistochemistry. RESULTS: Of 107 patients, 80% showed high HER3 expression in primary CRC tumours and 81% of the stage III patients presented high expression in the lymph node metastases. All patients had liver metastases and 82% presented high HER3 expression. HER3 expression in primary tumour correlated with expression in the corresponding lymph node metastases (r = 0.65, p < 0.001) and in the liver metastases (r = 0.45, p < 0.001). A correlation between HER3 expression in corresponding lymph node and liver metastases (r = 0.65, p < 0.001) was seen. CONCLUSION: High HER3 expression is seen in about 80% of primary CRC, corresponding lymph node metastases and liver metastases. There is a correlation between HER3 expression in primary tumour and metastases in CRC.

AmotL2 disrupts apical-basal cell polarity and promotes tumour invasion.

The establishment and maintenance of apical-basal cell polarity is essential for the functionality of glandular epithelia. Cell polarity is often lost in advanced tumours correlating with acquisition of invasive and malignant properties. Despite extensive knowledge regarding the formation and maintenance of polarity, the mechanisms that deregulate polarity in metastasizing cells remain to be fully characterized. Here we show that AmotL2 expression correlates with loss of tissue architecture in tumours from human breast and colon cancer patients. We further show that hypoxic stress results in activation of c-Fos-dependent expression of AmotL2 leading to loss of polarity. c-Fos/hypoxia-induced p60 AmotL2 interacts with the Crb3 and Par3 polarity complexes retaining them in large vesicles and preventing them from reaching the apical membrane. The resulting loss of polarity potentiates the response to invasive cues in vitro and in vivo in mice. These data provide a molecular mechanism how hypoxic stress deregulates cell polarity during tumour progression.

The expression of CYP2W1 in colorectal primary tumors, corresponding lymph node metastases and liver metastases.

INTRODUCTION: Metastatic disease is a major cause of death in patients with colorectal cancer (CRC). We have previously investigated expression of an orphan cytochrome P450 (CYP) enzyme, CYP2W1, and found high expression in about one third of colorectal tumors. CYP2W1 has proven to metabolize duocarmycin analogs into cytotoxic substances, compounds that in xenografts of CRC cells expressing CYP2W1 completely inhibit tumor growth. This study was designed to evaluate whether the enzyme is expressed in primary CRC and corresponding metastases. MATERIAL AND METHODS: Samples from primary tumors, corresponding lymph node metastases and liver metastases from 96 patients were collected and analyzed by immunohistochemistry. Data regarding patient's demographics, tumor characteristics and survival were also collected. RESULTS: Out of 96 patients, 25 (26%) had high CYP2W1 expression in the primary tumor and 46 (48%) showed high levels in the liver metastasis. In total 59 patients had lymph node metastases, and 31% of them had high CYP2W1 expression. When comparing the expression in primary tumor with that of the first liver metastasis, the increase in expression was statistically significant (p = 0.005). CONCLUSION: High CYP2W1 expression is seen in 26% of primary CRC and in 48% of corresponding liver metastases. This opens possibilities for new targeted therapies to metastatic CRC in the future.

A combined analysis of mismatch repair status and thymidylate synthase expression in stage II and III colon cancer.

UNLABELLED: This study in 716 colon cancer patients evaluates if a combined instead of a single marker analysis of mismatch repair (MMR) status and thymidylate synthase (TS) expression could individualize the treatment decision. The results indicate that a combined analysis of MMR status and TS expression can improve prediction of response to adjuvant 5-fluorouracil (5-FU)-based chemotherapy in stage III colon cancer. BACKGROUND: Colon 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 METHODS: This 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. RESULTS: There 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. CONCLUSIONS: A 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.

Mismatch repair protein expression is an independent prognostic factor in sporadic colorectal cancer.

Abstract Background. Mismatch repair (MMR) status has been reported as a prognostic and predictive factor in sporadic colorectal cancer (CRC). The purpose of this study was to determine the prognostic and predictive value of MMR protein expression in the adjuvant setting. Patients and methods. The MMR status in the primary tumor was retrospectively assessed on paraffin-embedded formalin-fixed samples from 1 006 patients with sporadic CRC (488 stage II and 518 stage III) using immunohistochemical analysis (IHC) of MLH1 and MSH2 expression. The patients were included in adjuvant Nordic trials between 1991 and 1996 randomly assigned to surgery alone or surgery plus adjuvant 5-fluorouracil (5-FU)-based chemotherapy. Data was censored at 120 months after surgery. Results. One hundred fifty-seven patients (15.6%) showed a loss of MMR protein expression (139 MLH1 negative, 15 MSH2 negative and 3 MLH1 and MSH2 negative) and were classified as MMR protein negative. A normal MMR protein expression was found in 849 patients who were defined as MMR protein positive. MMR protein expression was a significant prognostic marker in the entire study group with a better overall survival (OS) among patients with MMR protein negative tumors compared to patients with MMR protein positive tumors (p=0.01). In a multivariate analysis the MMR protein expression was significantly associated with OS, (HR 0.70 [95% CI, 0.40 to 0.99]; p=0.01). The MMR status did not predict survival benefit from adjuvant 5-FU-based chemotherapy. Conclusion. This study reveals that IHC of MLH1 and MSH2 expression can yield important prognostic information but is not a predictive factor for adjuvant 5-FU-based chemotherapy in sporadic CRC.

The expression of the novel CYP2W1 enzyme is an independent prognostic factor in colorectal cancer - a pilot study.

AIM: Cytochrome P450 (CYP) enzymes are important for drug metabolism. A novel cytochrome P450 enzyme, CYP2W1, has recently been identified. This enzyme is mainly found in foetal colon tissue and in tumour tissue. In this pilot study, we have investigated the expression of CYP2W1 in 162 tumours from patients with stages II and III colorectal cancer. METHODS: The expression of CYP2W1 enzyme was immunohistochemically detected using a polyclonal antibody. Staining intensity was defined using a visual grading scale from 0 to 3. Grades 0-2 were classified as low, and grade 3 was classified as high expression of CYP2W1. RESULTS: About 64% of the tumours expressed a low level of CYP2W1-expression, and 36% expressed a high level. CYP2W1-expression was an independent prognostic factor for overall survival (p=0.007), where a high expression was associated with a worse clinical outcome. CONCLUSIONS: Immunohistochemically assessed expression of CYP2W1 is an independent prognostic factor in patients with stages II and III colorectal cancer.

Expression of thymidylate synthase in liver and lung metastases of colorectal cancer and their matched primary tumours.

BACKGROUND: In advanced colorectal cancer (CRC) a low expression of thymidylate synthase (TS) in metastases predicts a higher response to 5-fluorouracil (5-FU). The purpose of this study was to investigate the expression of TS in liver and lung metastases of CRC and their matched primary tumours. PATIENTS AND METHODS: Immunohistochemical analysis of TS expression was performed on tissue samples of 48 CRC metastases (liver n=38, lung n=10) and their matched primary tumours (n=45). RESULTS: There was no significant correlation between TS expression in 33/48 (69%), matched samples of metastases and primary tumours (r=0.02, p=1.0). CONCLUSION: This study indicates that TS expression in liver and lung metastases of CRC does not always reflect the level of TS in their corresponding primary tumours. Therefore, it might not be accurate to solely rely on analyses of TS in the primary tumours to predict the effect of 5-FU-based chemotherapy in metastatic CRC.

The number of analyzed lymph nodes - a prognostic factor in colorectal cancer.

The prognostic significance of the number of lymph nodes examined in surgical specimen of colorectal cancer was determined. One thousand and twenty five patients with colorectal cancer stage II and III were included in the study. These patients underwent surgery from 1991 to 1997 and were enrolled in clinical trials to evaluate the efficacy of adjuvant 5-fluorouracil (5FU) based chemotherapy. The median number of examined lymph nodes was five. Only 13% of the patients had > or = 12 lymph nodes analyzed. The number of examined lymph nodes was an independent prognostic factor for overall survival in the entire group of patients with stage II and III colorectal cancer (p=0.009). Patients with a higher number of lymph nodes examined had a longer overall survival. In stage III colorectal cancer the ratio of the number of metastatic lymph nodes to the number of examined lymph nodes (lymph node ratio, LNR) was an independent prognostic factor for overall survival. A decreasing LNR was correlated with a longer overall survival (p<0.0001). Increasing age was associated with a reduction of lymph node harvest (p=0.04). Patients with rectal cancer treated with preoperative radiotherapy had a lower number of lymph nodes analyzed compared with non-radiated (p<0.001). The number of examined lymph nodes in the surgical specimen is an independent prognostic factor for overall survival in colorectal cancer. The LNR is an independent prognostic factor in stage III colorectal cancer.

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 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.

Thymidylate synthase expression in rectal cancer and proliferation, assessed by cyclin A and Ki-67 expression.

BACKGROUND: Levels of the enzyme thymidylate synthase (TS) are of prognostic significance in colorectal cancer. It may be argued that the levels of TS merely reflect the proliferative activity and could be replaced by markers of proliferation. MATERIALS AND METHODS: We used immunohistochemical approaches to examine the expression of TS, Cyclin A and Ki-67 in morphologically well-defined tumor areas in consecutive slices of rectal cancer, using the antibodies TS 106, NCL-Cyclin A and Mib-1. RESULTS: There was a linear relationship between Cyclin A- and Ki-67-positive cells (p < 0.0001). There did not seem to be any significant relationship between TS-expression and the frequency of Cyclin A-positive cells (p = 0.1) but a significant correlation was observed between TS-expression and the frequency of Ki-67-positive cells (p = 0.02). CONCLUSION: TS, immunohistochemically-detected in rectal cancer cells, is not associated with an accurate assessment of the proliferative stage. The prognostic value of TS determination can only partly be explained by the proliferative activity.