Stroma-normalised vessel density predicts benefit from adjuvant fluorouracil-based chemotherapy in patients with stage II/III colon cancer.

BACKGROUND: Identification of biomarkers associated with benefit of adjuvant chemotherapy in stage II/III colon cancer is an important task. METHODS: Vessel density (VD) and tumour stroma were analysed in a randomised-trial-derived discovery cohort (n = 312) and in a stage II/III group of a population-based validation cohort (n = 85). VD was scored separately in the tumour centre, invasive margin and peritumoral stroma compartments and quantitated as VD/total analysed tissue area or VD/stroma area. RESULTS: High stroma-normalised VD in the invasive margin was associated with significantly longer time to recurrence and overall survival (OS) (p = 0.002 and p = 0.006, respectively) in adjuvant-treated patients of the discovery cohort, but not in surgery-only patients. Stroma-normalised VD in the invasive margin and treatment effect were significantly associated according to a formal interaction test (p = 0.009). Similarly, in the validation cohort, high stroma-normalised VD was associated with OS in adjuvant-treated patients, although statistical significance was not reached (p = 0.051). CONCLUSION: Through the use of novel digitally scored vessel-density-related metrics, this exploratory study identifies stroma-normalised VD in the invasive margin as a candidate marker for benefit of adjuvant 5-FU-based chemotherapy in stage II/III colon cancer. The findings, indicating particular importance of vessels in the invasive margin, also suggest biological mechanisms for further exploration.

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.

Multi-parametric profiling of renal cell, colorectal, and ovarian cancer identifies tumour-type-specific stroma phenotypes and a novel vascular biomarker.

A novel set of integrated procedures for quantification of fibroblast-rich stroma and vascular characteristics has recently been presented allowing discovery of novel perivascular and stromal biomarkers in colorectal, renal cell, and ovarian cancer. In the present study, data obtained through these procedures from clinically well-annotated collections of these three tumour types have been used to address two novel questions. First, data have been used to investigate if the three tumour types demonstrate significant differences regarding features such as vessel diameter, vessel density, and perivascular marker expression. Second, analyses of the cohorts have been used to explore the prognostic significance of a novel vascular metric, 'vessel distance inter-quartile range (IQR)' that describes intra-case heterogeneity regarding vessel distribution. The comparisons between the three tumour types demonstrated a set of significant differences. Vessel density of renal cell cancer was statistically significantly higher than in colorectal and ovarian cancer. Vessel diameter was statistically significantly higher in ovarian cancer. Concerning perivascular status, colorectal cancer displayed significantly higher levels of perivascular PDGFR-ß expression than the other two tumour types. Intra-case heterogeneity of perivascular PDGFR-ß expression was also higher in colorectal cancer. Notably, these fibroblast-dominated stroma phenotypes matched previously described experimental tumour stroma characteristics, which have been linked to differential sensitivity to anti-VEGF drugs. High 'vessel distance IQR' was significantly associated with poor survival in both renal cell cancer and colorectal cancer. In renal cell cancer, this characteristic also acted as an independent prognostic marker according to multivariate analyses including standard clinico-pathological characteristics. Explorative subset analyses indicated particularly strong prognostic significance of 'vessel distance IQR' in T stage 4 of this cancer type. Together, these analyses identified tumour-type-specific vascular-stroma phenotypes of possible functional significance, and suggest 'vessel distance IQR' as a novel prognostic biomarker.

Image analysis-derived metrics of histomorphological complexity predicts prognosis and treatment response in stage II-III colon cancer.

The complexity of tumor histomorphology reflects underlying tumor biology impacting on natural course and response to treatment. This study presents a method of computer-aided analysis of tissue sections, relying on multifractal (MF) analyses, of cytokeratin-stained tumor sections which quantitatively evaluates of the morphological complexity of the tumor-stroma interface. This approach was applied to colon cancer collection, from an adjuvant treatment randomized study. Metrics obtained with the method acted as independent markers for natural course of the disease, and for benefit of adjuvant treatment. Comparative analyses demonstrated that MF metrics out-performed standard histomorphological features such as tumor grade, budding and configuration of invasive front. Notably, the MF analyses-derived "αmax" -metric constitutes the first response-predictive biomarker in stage II-III colon cancer showing significant interactions with treatment in analyses using a randomized trial-derived study population. Based on these results the method appears as an attractive and easy-to-implement tool for biomarker identification.

Epidemiology of cutaneous melanoma in Sweden-Stage-specific survival and rate of recurrence.

Cutaneous malignant melanoma (CMM) incidence is increasing globally, making a thorough understanding of the disease and its outcomes essential for optimizing care even more urgent. In this population-based, retrospective study, we investigated stage-specific survival and recurrence/progression rates of CMM among patients diagnosed in Stockholm County Council during 2005-2012, before the wide introduction of targeted therapy. A total of 3,554 CMM patients from the Stockholm Melanoma Register were included. Information on comorbidities, progression, death, and treatments was obtained from nationwide registers and hospital electronic medical records. Unadjusted 5-year survival varied from 91.4% for stage I to 24.6% for stage IV patients. Stage, age and gender were predictors of survival, with gender an independent predictor of survival for stages IA and IIA. 74.6% of patients remained recurrence/progression-free during follow-up, with 5-year recurrence/progression-free survival rates varying from 85.3% to 12.9% among stages I and IV patients, respectively. In addition to stage, male gender, and age, circulatory system comorbidities increased the risk for recurrence/progression. No statistically significant differences in progression rate for operated and non-operated patients could be detected, possibly due to high rate (98.9%) of surgery. Our estimates of survival and recurrence rates are consistent with historical and global expectations and can serve as a baseline to gauge population-level improvements with use of novel melanoma treatments.

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.

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.

The expression of CYP2W1: a prognostic marker in colon cancer.

AIM: The enzyme Cytochrome P450 2W1 (CYP2W1) is found in fetal colon tissue and is also detected in colorectal cancer but not in non-transformed tissue. In a pilot study, we reported that the immunohistochemically-detected expression of CYP2W1 might be of prognostic value since high expression of CYP2W1 was indicative of a worse prognosis. The aim of this study was to validate the pilot study's results using a larger, independent group of patients with colon cancer. MATERIALS AND METHODS: Immunohistochemical detection of CYP2W1 in 235 malignant colon tumors of stage II and III, was carried out using a polyclonal antibody. Grading of staining was carried out by two independent readers. The highest grade that involved more than 5% of the tumor area on each slide was used for the classification of CYP2W1 expression. RESULTS: CYP2W1 was expressed at high levels in 30% of the tumors. In the entire colon cancer group it was an independent prognostic factor in multivariate analysis (p=0.04), where high expression (grade 3) correlated with worse outcome. CYP2W1 expression was an independent prognostic factor in the subgroup of patients with colon cancer stage III (p=0.003), but not for those with stage II. In 107 cases, two slices from different areas of the same tumor were available, and no significant difference in CYP2W1 expression between the slices was observed (r=0.53, p<0.001). CONCLUSION: The results of the current study were in agreement with those of the previous pilot study and show that higher expression of CYP2W1 seems to be of prognostic value in colon cancer. Furthermore, we found equal expression in slices from two different areas of the same tumor. Since the CYP2W1 enzyme has been shown to catalytically activate compounds to cytotoxic products, the enzyme might be used as a novel drug target for the treatment of 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.

Clinical effects of a chimeric anti-EpCAM monoclonal antibody in combination with granulocyte-macrophage colony-stimulating factor in patients with metastatic colorectal carcinoma.

The EpCAM antigen is highly expressed on colorectal carcinoma (CRC) cells. Murine anti-EpCAM MAb (anti-EpCAM mMAb) alone or in combination with cytokines may induce clinical responses including long-lasting complete remissions (CR) in patients with metastatic disease. The chimeric variant of anti-EpCAM MAb (anti-EpCAM cMAb) interacts more efficiently with human effector cells (ADCC) than the murine counterpart in the killing of colorectal carcinoma cells in vitro, an important mechanism of action for antibody in vivo. Granulocyte-macrophage colony-stimulating factor (GM-CSF) augments immune effector cell functions in vivo and may enhance the therapeutic effect of MAbs. In this study, the therapeutic efficacy of the combination of anti-EpCAM cMAb and GM-CSF was evaluated in 24 patients with metastatic CRC. GM-CSF was given s.c. once daily for 10 consecutive days and on day 3, anti-EpCAM cMAb was given i.v. A treatment cycle was repeated every 4th week. Five patients achieved stable disease > 3 months (overall response rate 21%). Responding patients survived significantly longer than non-responding patients (p = 0.030). The frequency of patients with an immediate-type allergic reaction (ITAR) against anti-EpCAM cMAb at the 1st, 2nd, 3rd and 4th treatment cycles was as 13%, 29%, 25% and 19% respectively. Compared to a previous study where anti-EpCAM mMAb was used in a similar treatment regimen, the present protocol did not augment the overall or progression-free survival. The overall response rate was also similar to anti-EpCAM mMAb treated patients (6/22, 27%), but the anti-EpCAM mMAb treatment protocol induced two CR, one MR and three SD. Further studies are warranted to establish the role of EpCAM as a target for antibody therapy, specifically the significance of chimeric or humanized anti-EpCAM MAbs.

Anti-EpCAM monoclonal antibody (MAb17-1A) based treatment combined with alpha-interferon, 5-fluorouracil and granulocyte-macrophage colony-stimulating factor in patients with metastatic colorectal carcinoma.

Monoclonal antibodies (MAbs) have different modes of action and toxicity profile compared to chemotherapeutics, which makes it interesting to combine these drugs. Addition of cytokines to MAb therapy may also augment immune effector functions utilized by MAb. In an effort to improve the therapeutic effect of a MAb-based regimen in colorectal carcinoma (CRC) patients, the effects of a combination of alpha-interferon (alpha-IFN), 5-fluorouracil (5-FU), granulocyte-macrophage colony-stimulating factor (GM-CSF) and mouse MAb17-1A was evaluated in 27 patients with metastatic disease. alpha-IFN was given s.c. once daily for 5 consecutive days and at days 4 and 5, 5-FU was administered as a daily i.v. bolus injection. After 2 days rest, GM-CSF was given s.c. once daily, days 8-14 and on day 10, MAb17-1A was given i.v. The treatment cycle was repeated every 4th week. One patient achieved a partial remission and 13 patients showed a minor response or stable disease >3 months, inducing an overall response rate of 54%. Responding patients survived significantly longer than non-responding patients (p=0.021). Median overall survival time for all patients was 75 weeks and progression-free survival time 15 weeks. Adverse events related to alpha-IFN, GM-CSF and 5-FU were as expected. The frequency of patients with an immediate-type allergic reaction (ITAR) against MAb17-1A at the 1st, 2nd, 3rd and 4th treatment cycles was 11%, 52%, 62% and 64% respectively. The planned MAb17-1A dose had to be reduced by repeated infusions. No patient received full dose of MAb17-1A from the 3rd cycle and onward. Compared to historical control patients treated with MAb17-1A alone, the present combination regimen seemed to improve the response rate (54% vs 15%) as well as progression-free survival (15 vs 7 weeks; p<0.05).

5-FU split dose; a phase I/II and pharmacokinetic study of a different schedule of the Nordic regimen in advanced colorectal carcinoma.

PURPOSE: Despite more than four decades of fluoro-pyrimidine treatment in different cancers, the optimal schedule is still not known. The plasma half-life of 5-fluorouracil (5-FU) is extremely short and continuous infusion has gained popularity. In this study we explored whether repeated bolus 5-FU injections could improve the results. PATIENTS AND METHODS: Forty-three patients with advanced gastrointestinal carcinoma, where no standard treatment was available, were included in the phase I study. The initial dose of 5-FU was 250 mg/m2 with 30 mg/m2 leucovorin, repeated three hours later. Treatments were repeated every week. Twenty-six patients were recruited in the following phase II after maximal-tolerated dose (MTD) was reached. Plasma was collected for 5-FU pharmacokinetics. RESULTS: Diarrhoea was the dose-limiting toxicity (DLT), and was reached at 450 mg/m2. One complete and three partial responses (24%) were seen in the phase II study at 400 mg/m2. In addition, several patients had lasting subjective improvements. The treatments were well-tolerated but accumulated toxicity was seen after several months. Dose intensity was 89% after four months of treatment. A great interpatient variability was seen in 5-FU pharmacokinetics. The plasma AUC correlated with the 5-FU dose and toxicity, but not with the tumour response. CONCLUSION: A split of the 5-FU push bolus injection is possible with maintained treatment activity and surprisingly high doses can be tolerated; a weekly dose intensity of 800 mg/m2 could be reached compared with 500 mg/m2 in the standard Nordic FLv schedule.

Natural killer (NK) cell function is a strong prognostic factor in colorectal carcinoma patients treated with the monoclonal antibody 17-1A.

Tumor cells might be susceptible to different effector functions of the immune system. This cytotoxic capacity has been utilized to analyze the prognostic significance of peripheral blood mononuclear cells (PBMC) in patients with metastatic colorectal carcinoma (CRC) treated with the monoclonal antibody (MAb)17-1A. Such analysis might form the basis for future patient selection and may lead to improvements in therapeutic strategies. Between 1986 and 1998, 73 patients were treated with regimens containing MAb17-1A. Prior to therapy, the lytic capability of PBMC was assayed against: K562 (4 hr assay), the CRC cell line SW948 (4 hr and 18 hr assays) and antibody-dependent cellular cytotoxicity (ADCC, 18 hr assay). Since the study was performed over 13 years, the assays were checked for time-related bias. Reproducibility over time was satisfactory. Patients exhibited a significantly higher cytotoxic capability in all 4 assays compared to healthy control donors. No correlation to clinical outcome was noted for 18 hr ADCC and 18 hr spontaneous cytotoxicity. Pretreatment natural killer (NK) cell cytotoxicity (K562) was significantly related to overall survival (OS), progression-free survival (PFS), and response rate. OS for patients with high and low NK cell cytotoxicity was 71 vs. 30 weeks, respectively (p = 0.007). NK cell cytotoxicity (K562) was an independent prognostic factor for OS (p = 0.016). Pretreatment NK cell activity is a strong prognostic factor for patients with metastatic CRC receiving MAb17-1A therapy and is a predictor for OS, PFS and response. These results should be considered when designing antibody-based therapeutic protocols.

MAb17-1A and cytokines for the treatment of patients with colorectal carcinoma.

CO17-1A/GA73-3/EpCam/KSA is a cellular adhesion molecule expressed on the majority of tumor cells in most patients with colorectal carcinoma. One of the first mouse monoclonal antibodies (MAbs) for therapeutic use was produced against this particular tumor associated antigen (MAb17-1A). MAb17-1A has served as a model for the development of antibody therapy. It exerts therapeutic effects through antibody dependent cellular cytotoxicity (ADCC), induction of an idiotypic network cascade and maybe also by complement activation. Addition of cytokines that augment these functions, mainly granulocyte macrophage-cerebrospinal fluid (GM-CSF), seemed to improve the clinical efficacy as well as chemotherapeutic agents (5-Fu). In advanced disease the clinical effect is, however, modest while the most beneficial clinical situation seems to be the adjuvant setting. Twenty years have passed since the EpCam antigen was identified as a target structure for immunotherapy, but still we do not know how to optimally use this target. The antigen might, however, be a rewarding structure to utilize for therapy. Preclinical and clinical trials are ongoing aimed at improving passive and active immunotherapy using CO17-1A/EpCam as a target antigen in colorectal carcinoma.