Leukocytosis and neutrophilia as independent prognostic immunological biomarkers for clinical outcome in the CAO/ARO/AIO-04 randomized phase 3 rectal cancer trial.

Peripheral blood leukocytosis and neutrophilia reflect cancer inflammation and have been proposed as prognostic immunological biomarkers in various malignancies. However, previous studies were limited by their retrospective nature and small patient numbers. Baseline peripheral blood leukocytes, neutrophils, hemoglobin, platelets, lactate dehydrogenase and carcinoembryonic antigen (CEA) were correlated with clinicopathologic characteristics, and clinical outcome in 1236 patients with rectal cancer treated with 5-FU-based preoperative chemoradiotherapy (CRT) alone or with oxaliplatin followed by surgery and adjuvant chemotherapy within the CAO/ARO/AIO-04 randomized phase 3 trial. Multivariable analyses were performed using Cox regression models. After a median follow-up of 50 months, baseline leukocytosis remained an independent adverse prognostic factor for disease-free survival (DFS; HR 1.457; 95% CI 1.163-1.825; p = 0.001), distant metastasis (HR 1.696; 95% CI 1.266-2.273; p < 0.001) and overall survival (OS; HR 1.716; 95% CI 1.264-2.329; p = 0.001) in multivariable analysis. Similar significant findings were observed for neutrophilia and high CEA levels. Conversely, treatment-induced leukopenia correlated with favorable DFS (p = 0.037), distant metastasis (p = 0.028) and OS (p = 0.012). Intriguingly, addition of oxaliplatin to 5-FU CRT resulted in a significant DFS improvement only in patients with neutrophilia and leukocytosis (p = 0.028 and p = 0.002). Our findings have important clinical implications and provide high-level evidence on the adverse prognostic role of leukocytes and neutrophils, and the impact of chemotherapy in the context of these biomarkers. These data could help guide patient stratification and should be further validated within prospective studies.

Combination of ionising irradiation and hyperthermia activates programmed apoptotic and necrotic cell death pathways in human colorectal carcinoma cells.

PURPOSE: The malignancy of tumor cells can be attenuated by interfering with cell death pathways. Since hyperthermia (HT) is a very potent radiosensitizer, the influence of HT (41.5 °C for 1 hour) alone and in combination with ionising irradiation (X-ray; 5 Gy or 10 Gy) on the form of cell death as well as on the expression of proteins known to be major components in tumor cells' apoptotic and necrotic pathways were examined in colorectal tumor cells. MATERIAL AND METHODS: The expression of proteins was analysed by western blot and the relative activity of caspases-3/7 by fluorescence- based assay. Colony formation was analysed using the clonogenic assay and cell death was determined with annexin V-FITC/propidium iodide staining. RESULTS: Combining X-ray with HT led to similar activation of caspase-3/7 and p53 expression in comparison to irradiation only while the amount of the pro-apoptotic proteins PUMA and Bax was increased in HCT15 and SW480 cells. HT alone or combinations with X-ray further resulted in a temporarily increased level of the anti-apoptotic protein Bcl-2. Irradiation plus HT further led to an up-regulation of IRF-5. The levels of RIP-1, a marker for programmed necrosis, increased in tumor cells which were treated with HT and/or X-ray. Combining 5 Gy irradiation with HT compared to irradiation resulted in a significantly increased number of necrotic tumor cells and in decreased colony formation. CONCLUSION: The combined treatment of colorectal tumor cells with X-ray and HT activates distinct tumor cell pathways and fosters the early appearance of a necrotic tumor cell phenotype.

The role of annexin A5 in the modulation of the immune response against dying and dead cells.

Annexins are characterized by the ability to bind phospholipids of membranes in the presence of Ca2+. Annexin A5 represents a typical member of this protein family and is a natural occurring highly specific ligand for phosphatidylserine (PS). The exposure of PS is one major "eat me" signal for phagocytes of apoptotic and necrotic cells. Apoptotic cells are normally cleared via an anti-inflammatory pathway. In contrast, the uptake and removal of necrotic cells normally involves inflammation and an immune response. Interestingly, the lack of endogenous annexin A5 also leads to a reduced inflammatory potential of necrotic cells. Annexin A5 may interfere in vivo with the immunosuppressive effects of apoptotic cells since it preferentially binds PS with high affinity and inhibits apoptotic cell uptake by macrophages. In this review we focus on how defects in the clearance process can lead to chronic autoimmunity. Furthermore, the role of annexin A5 as important adjuvant for apoptotic cell-based tumour vaccines is discussed. The mechanism of how the immunogenicity of apoptotic cells can be restored by blocking their PS-dependent clearance is outlined in detail. Taken together, annexin A5 is an important modulator of the immune response against PS-exposing particles like apoptotic cells, necrotic cells, and certain viruses.

P27 does not predict histopathological response to radiochemotherapy in rectal cancer.

BACKGROUND: Tumor response to radiochemotherapy (RCT) varies considerably, even among patients treated in accordance with the same protocol. The aim of the present study was to test the predictive value of the cell-cycle inhibitor p27kip1 with regard to neoadjuvant RCT response in rectal cancer. MATERIALS AND METHODS: P27kip1 was evaluated by immunohistochemistry in pretreatment biopsy material obtained from 42 patients with rectal cancer treated uniformly in accordance with an identical prospective neoadjuvant RCT protocol (CAO/AIO/ARO-94). Four expression patterns (staining intensity [-,+,++,+++] and the percentage of positive cells, evaluated separately for nuclei and cytoplasm) of p27kip1 were investigated for correlation with tumor response, which was assessed in the resected surgical specimen using a histopathological five-point grading system. Additionally, p27(kip1) expression was investigated for correlation with several pathological features, overall survival, and disease-free survival. RESULTS: p27kip1 expression was as follows: nuclear intensity: -: 8, +: 19, ++: 11, +++: 4 cases, median percentage of positive cells: 18.75%; cytoplasmic intensity: -: 0, +: 25, ++: 12, +++: 3 cases, median percentage of positive cells: 70%. Histopathological tumor regression was acceptable in 30 patients (3 complete; 27 good) and inadequate in 12 patients (7 moderate; 5 minimal). No tumor failed to show some regression. No significant correlation was found between any of the p27kip1 expression patterns and RCT response, tumor differentiation (low grade versus high grade), cT- and ypT-category, UICC stage, overall survival, and disease-free survival. CONCLUSIONS: p27kip1 cannot aid the individualization of multimodal treatment strategies in rectal cancer, nor can it serve as a predictor of survival.

Apoptosis as a cellular predictor for histopathologic response to neoadjuvant radiochemotherapy in patients with rectal cancer.

BACKGROUND: Tumor shrinkage by preoperative radiochemotherapy (RCT) can markedly improve surgery in locally advanced (T4) rectal cancer with clear resection margins and may enable sphincter preservation in low-lying tumors. However, tumor response varies considerably, even among tumors treated according to the same protocol. If one is able to identify patients with highly radio-responsive tumors at the time of diagnosis, a selective and individualized policy of preoperative RCT might be pursued. METHODS: The apoptotic index (AI), Ki-67, p53, and bcl-2 were evaluated by immunohistochemistry on pretreatment biopsies from 44 patients treated uniformly according to a prospective neoadjuvant RCT protocol (CAO/AIO/ARO-94). Treatment response was assessed histopathologically in the resected surgical specimen, using a five-point grading system. Expression of each marker was correlated with tumor response and relapse-free survival after curative surgery. RESULTS: Tumors with complete (n = 3) or good (n = 28) response to RCT showed significantly higher pretreatment levels of apoptosis (mean AI: 2.06%) than tumors with moderate (n = 7), minimal (n = 5), or no regression (n = 1) from RCT (AI: 1.44%, p = 0.003). The AI was significantly related to Ki-67 (p = 0.05), but not to p53 and bcl-2 status. Tumor regression and AI best predicted relapse-free survival after combined modality treatment and curative surgery. CONCLUSION: Spontaneous apoptosis in rectal cancer may serve as an important predictor of tumor regression from RCT in rectal cancer and as a significant prognosticator of relapse-free survival. Thus, this molecular marker may finally help to tailor therapy with regard to (neo-) adjuvant treatment of rectal cancer.