Annika Ålgars

Type and location of tumor‐infiltrating macrophages and lymphatic vessels predict survival of colorectal cancer patients

The type of tumor‐infiltrating macrophages may be decisive in tumor immunity, lymphangiogenesis and in the clinical outcome of cancer. Here, we elucidated the prognostic significance of lymphatic vessels, different types of macrophages and the balance between different macrophage types in colorectal cancer. We analyzed the impact of density, type and location of macrophages on the clinical behavior of 159 primary colorectal carcinomas using CD68 as a pan‐macrophage marker and CLEVER‐1/Stabilin‐1 as a marker for regulatory/suppressive macrophages. Podoplanin was used as a pan‐lymphatic vessel marker. A high number of CLEVER‐1/Stabilin‐1+ peritumoral macrophages positively correlated with survival (p = 0.04). However, in more advanced disease (Stage IV), the patients with a high number of peritumoral or intratumoral CLEVER‐1/Stabilin‐1+ macrophages had a shorter disease‐specific survival (p = 0.05, and p = 0.008, respectively). Moreover, a low number of suppressive intratumoral CLEVER‐1/Stabilin‐1+ macrophages among high numbers of CD68+ macrophages correlated with a low number of distant recurrences (p = 0.01) and to fewer disease relapses exclusively in the liver as well (p = 0.006). A high number of intratumoral lymphatics correlated with poor survival (p = 0.03). The results of this work suggest that the type of macrophages, number of lymphatic vessels and their location contribute to the clinical behavior of colorectal cancer in a disease stage‐specific manner.

EGFR gene copy number assessment from areas with highest EGFR expression predicts response to anti-EGFR therapy in colorectal cancer

Background:Only 40–70% of metastatic colorectal cancers (mCRCs) with wild-type (WT) KRAS oncogene respond to anti-epidermal growth factor receptor (anti-EGFR) antibody treatment. EGFR amplification has been suggested as an additional marker to predict the response. However, improved methods for bringing the EGFR analysis into routine laboratory are needed.Methods:The material consisted of 80 patients with mCRC, 54 of them receiving anti-EGFR therapy. EGFR gene copy number (GCN) was analysed by automated silver in situ hybridisation (SISH). Immunohistochemical EGFR protein analysis was used to guide SISH assessment.Results:Clinical benefit was seen in 73% of high (⩾4.0) EGFR GCN patients, in comparison with 59% of KRAS WT patients. Only 20% of low EGFR GCN patients responded to therapy. A high EGFR GCN number associated with longer progression-free survival (P<0.0001) and overall survival (P=0.004). Together with KRAS analysis, EGFR GCN identified the responsive patients to anti-EGFR therapy more accurately than either test alone. The clinical benefit rate of KRAS WT/high EGFR GCN tumours was 82%.Conclusion:Our results show that automated EGFR SISH, in combination with KRAS mutation analysis, can be a useful and easily applicable technique in routine diagnostic practise for selecting patients for anti-EGFR therapy.

Increased C-reactive protein implies a poorer stage-specific prognosis in colon cancer

Abstract Background. To characterize the stage-specific prognostic relevance of preoperative systemic inflammatory response, defined by C-reactive protein (CRP), in colon cancer (CC) patients. Material and methods. Data from CC patients operated on from 1998 to 2007 at three hospitals from three different Nordic countries were collected retrospectively from national registries, local databases and/or patient records. Patients with emergency surgery, infection or auto-immune disease were excluded. Associations between clinical or histopathological variables and CRP were assessed. Patients were followed from the date of surgery to death or end of follow-up. Disease-specific survival (DSS) was the main endpoint. Results. In total, 525 patients with age and stage distributions which were representative for CC patients were included. None of the patients was lost to follow-up. Age, TNM Stage, WHO differentiation grade and right-sided tumor location significantly associated with elevated CRP values, in contrast to postoperative morbidity, which did not. CRP levels were found to be a strong prognostic factor for DSS in CC. The risk of death due to CC was augmented with increasing levels of CRP in every stage of operated CC. Both short- and long-term DSS were impaired. The sub-hazard ratios for CRP-levels above 60 mg/L were 7.37 (CI 2.65–20.5) for stage I+ II, compared to 3.29 (CI 1.30–8.29) for stage III and 2.24 (CI 1.16–4.35) for stage IV. Conclusion. Increase of CRP concentrations correlate with clinically relevant poorer disease-specific survival in each stage of CC.

Response to Chemotherapy (Irinotecan plus 5-Fluorouracil) in Colorectal Carcinoma Can Be Predicted by Tumour DNA Content

Objective: The aim of this study was to identify markers that might predict response to chemotherapy. Postoperative chemotherapy improves the outcome in stage III colon cancer and is widely accepted as a standard therapy, but there are currently no reliable predictors to identify and select patients that will benefit. Methods: Using DNA image cytometry, the DNA content was determined from the isolated nuclei of 56 primary colorectal carcinomas of patients who received chemotherapy (either irinotecan or irinotecan plus 5-fluorouracil and folinic acid) for advanced disease. Response to chemotherapy could be reliably evaluated in 53 patients. Results: The modal DNA content (ploidy status) of the tumour correlated with the observed response to chemotherapy (p = 0.01). An objective response was observed in 56% of patients whose tumour histograms displayed tetraploid, peri-tetraploid or multiploid patterns of peaks, compared with 19% in patients with diploid, peri-diploid or aneuploid peaks. Notably, 86% (6/7) of patients whose tumours displayed a multiploid peak pattern showed an objective response and 1 patient had stable disease. Conclusion: This study suggests that modal DNA content can be used to predict a patient’s response to chemotherapy in advanced colorectal carcinoma. This may help in identifying patients who will benefit most from therapy for advanced colorectal cancer.

Tumor-Associated Macrophages Provide Significant Prognostic Information in Urothelial Bladder Cancer

Inflammation is an important feature of carcinogenesis. Tumor-associated macrophages (TAMs) can be associated with either poor or improved prognosis, depending on their properties and polarization. Current knowledge of the prognostic significance of TAMs in bladder cancer is limited and was investigated in this study. We analyzed 184 urothelial bladder cancer patients undergoing transurethral resection of a bladder tumor or radical cystectomy. CD68 (pan-macrophage marker), MAC387 (polarized towards type 1 macrophages), and CLEVER-1/Stabilin-1 (type 2 macrophages and lymphatic/blood vessels) were detected immunohistochemically. The median follow-up time was 6.0 years. High macrophage counts associated with a higher pT category and grade. Among patients undergoing transurethral resection, all studied markers apart from CLEVER-1/Stabilin-1 were associated with increased risk of progression and poorer disease-specific and overall survival in univariate analyses. High levels of two macrophage markers (CD68/MAC387+/+ or CD68/CLEVER-1+/+ groups) had an independent prognostic role after transurethral resection in multivariate analyses. In the cystectomy cohort, MAC387, alone and in combination with CD68, was associated with poorer survival in univariate analyses, but none of the markers were independent predictors of outcome in multivariate analyses. In conclusion, this study demonstrates that macrophage phenotypes provide significant independent prognostic information, particularly in bladder cancers undergoing transurethral resection.

Heterogeneous EGFR Gene Copy Number Increase Is Common in Colorectal Cancer and Defines Response to Anti-EGFR Therapy

Anti-EGFR therapy is commonly used to treat colorectal cancer (CRC), although only a subset of patients benefit from the treatment. While KRAS mutation predicts non-responsiveness, positive predictive markers are not in clinical practice. We previously showed that immunohistochemistry (IHC)-guided EGFR gene copy number (GCN) analysis may identify CRC patients benefiting from anti-EGFR treatment. Here we tested the predictive value of such analysis in chemorefractory metastatic CRC, elucidated EGFR GCN heterogeneity within the tumors, and evaluated the association between EGFR GCN, KRAS status, and anti-EGFR antibody response in CRC cell lines. The chemorefractory patient cohort consisted of 54 KRAS wild-type (WT) metastatic CRC patients. EGFR GCN status was analyzed by silver in situ hybridization using a cut-off value of 4.0 EGFR gene copies/cell. KRAS-WT and KRAS mutant CRC cell lines with different EGFR GCN were used in in vitro studies. The chemorefractory CRC tumors with EGFR GCN increase (≥4.0) responded better to anti-EGFR therapy than EGFR GCN (<4.0) tumors (clinical benefit, P = 0.0004; PFS, HR = 0.23, 95% CI 0.12–0.46). EGFR GCN counted using EGFR IHC guidance was significantly higher than the value from randomly selected areas verifying intratumoral EGFR GCN heterogeneity. In CRC cell lines, EGFR GCN correlated with EGFR expression. Best anti-EGFR response was seen with KRAS-WT, EGFR GCN = 4 cells and poorest response with KRAS-WT, EGFR GCN = 2 cells. Anti-EGFR response was associated with AKT and ERK1/2 phosphorylation, which was effectively inhibited only in cells with KRAS-WT and increased EGFR GCN. In conclusion, IHC-guided EGFR GCN is a promising predictor of anti-EGFR treatment efficacy in chemorefractory CRC.

Expression of the cell‐cell adhesion molecule β‐catenin in colorectal carcinomas and their metastases

To study the dynamic events leading to impaired cell‐cell adhesion upon transition to the invasive phenotype of colorectal cancer (CRC), we examined three distinct β‐catenin expression patterns (membranous, cytoplasmic, and nuclear) in the paired samples of the primary tumours (P) and their metastatic lesions (M). β‐catenin expression was detected by immunohistochemistry (IHC) in 33 pairs of the primary CRC and their metastases. In a pair‐wise (P‐M) comparison, the membranous index (MI) was significantly different between P and M (p=0.036, Wilcoxon Signed‐Ranks test), while cytoplasmic index (CI) and nuclear index (NI) values did not significantly deviate between P and M. MI in primary tumours was inversely related to the patients age (p=0.04) and tumour grade (p=0.03), while patients with low MI in M had a high rate of metastasis at diagnosis (p=0.06). CI in P was lower in patients with LN involvement (p=0.02) and in advanced tumour stage (p=0.002). Tumours of the ascending colon had the highest CI in their M (p=0.04). Interestingly, high MI of the M lesions was a significant predictor of favourable overall survival (OS) in univariate (Kaplan‐Meier) survival analysis (p=0.035). In conclusion, significant aberrations in β‐catenin expression probably take place in CRC cells during the development of metastatic phenotype, but a change from membrane expression to cytoplamic and/or nuclear expression is not a prerequisite for metastasis in all cases.

DNA Image Cytometry Is a Useful Adjunct Tool in the Prediction of Disease Outcome in Patients with Stage II and Stage III Colorectal Cancer

Background: We assessed the prognostic value of the nuclear DNA content measured in the primary tumours of 123 patients with stage II or stage III colorectal cancer (CRC). Methods: Isolated nuclei from paraffin sections were stained with the Feulgen reaction, and DNA was measured using a computer-assisted image analysis cytometry system. We applied 4 different approaches in the analysis of DNA histograms: the ABCDE approach, histogram range, peak evaluation and DNA cut-off values. Results: Using the histogram range, the narrow range was rare (3.7%) in patients who died of disease (n = 28) as compared with 16.4% among those alive (n = 74; p = 0.017). Modal peak evaluation was a significant predictor of disease-free survival (DFS; Kaplan-Meier log-rank p = 0.0235). In the range evaluation, the 1st set (low-start gates) was a significant predictor of DFS (log-rank p = 0.0121), where disease recurrence was closely associated with the widest range (1.8–>10c; c = haploid DNA content) gates. Recurrence-free survival was 3 times better in narrow-gate histograms than wide-range histograms (p < 0.03). The 1st set also proved to be a significant predictor of disease-specific survival (DSS; log-rank p = 0.0045), which was markedly better (77.8–90.0%) among the patients with the narrow-gate histograms. Grading of the histogram range into 2 categories (with 6.0c as cut-off), was a powerful predictor of both DSS (log-rank p = 0.0092) and 5-year DFS (p = 0.0106) in the whole series, and separately in stage III (but not stage II) disease, with p = 0.0131 and p = 0.0201, respectively. Conclusion: The DNA image cytometry with careful analysis of the histograms may provide valuable prognostic information in CRC, with potential clinical implications in patient management, particularly in predicting the patients at high risk for recurrence who should be considered as candidates for adjuvant therapy.

Thymidylate synthase expression in primary colorectal tumours is correlated with its expression in metastases

Objective. Thymidylate synthase (TS) is the rate-limiting enzyme in the synthesis of pyrimidine nucleotides and as such a critical target for fluoropyrimidines, which are widely used in the treatment of colorectal cancer (CRC). The purpose of this study was to investigate TS expression in the primary tumours (PTs) and their metastases (M) in advanced CRC. Material and methods. TS expression was determined immunohistochemically in paraffin-embedded biopsies of PT-M pairs in 39 CRC patients, as related to the clinical data. Results. There was no difference in the mean TS index of PTs compared with that of M, 1.25 and 1.14, respectively (p=0.12). TS expression of PTs was above the mean more often than that of M (61.5% and 41.0%, respectively, p=0.035). High TS expression in PTs was significantly related to high expression in M (the Fisher exact test, p=0.001). Using the absolute index values, TS expression in PT and M was significantly correlated (Pearson R=0.501, p=0.001). In 29/39 (74.3%) pairs, PT and M had concordant expression levels (Cohens kappa 0.508, 95% CI 0.260–0.756, p=0.001; intraclass correlation coefficient (ICC) = 0.679, 95% CI 0.358–0.836, p=0.0001). No significant association was found between TS expression and any of the clinicopathological variables, disease outcome (DFS, DSS) or its response to treatment in univariate or multivariate analysis. Conclusions. Albeit usually higher, TS expression in PT was closely correlated with TS expression in M. This suggests that measurement of TS in primary CRC accurately predicts TS expression in subsequent metastases, which may help in selecting those patients most likely to respond to 5-FU-based regimens.

Reply: EGFR alterations and response to anti-EGFR therapy: is it a matter of gene amplification or gene copy number gain?

Reply: EGFR alterations and response to anti-EGFR therapy: is it a matter of gene amplification or gene copy number gain?