Cell proliferation and apoptosis in stage III inoperable non-small cell lung carcinoma treated by radiotherapy

Apoptosis - Fueling the oncogenic fire

Apoptosis, the most extensively studied form of programmed cell death, is essential for organismal homeostasis. Apoptotic cell death has widely been reported as a tumor suppressor mechanism. However, recent studies have shown that apoptosis exerts noncanonical functions and may paradoxically promote tumor growth and metastasis. The hijacking of apoptosis by cancer cells may arise at different levels, either via the interaction of apoptotic cells with their local or distant microenvironment, or through the abnormal pro-oncogenic roles of the main apoptosis effectors, namely caspases and mitochondria, particularly upon failed apoptosis. In this review, we highlight some of the recently described mechanisms by which apoptosis and these effectors may promote cancer aggressiveness. We believe that a better understanding of the noncanonical roles of apoptosis may be crucial for developing more efficient cancer therapies.

Risk Stratification of Locally Advanced Non-Small Cell Lung Cancer (NSCLC) Patients Treated with Chemo-Radiotherapy: An Institutional Analysis

Background

The purpose of this study was to determine which factors predicted survival and to derive a risk prediction model for patients with locally advanced non-small cell lung cancer (NSCLC) receiving concurrent chemo-radiotherapy (cCRT).

Methods

This investigation included 149 patients with locally advanced NSCLC who were treated with cCRT at Stony Brook University Hospital between 2007 and 2015. A finite set of demographic, clinical, and treatment variables were evaluated as independent prognostic factors. Kaplan–Meier survival curves were generated, and log rank tests were used to evaluate difference in survival between groups. To derive a risk score for mortality, a machine learning approach was utilized. To maximize statistical power while examining replicability, the sample was split into discovery (n=99) and replication (n=50) subsamples. Elastic-net regression was used to identify a linear prediction model. Youden’s index was used to identify appropriate cutoffs. Cox proportional hazards regression was used to examine mortality risk; model concordance and hazards ratios were reported.

Results

One-quarter of the patients survived for three years after initiation of cCRT. Prognostic factors for survival in the discovery group included age, sex, smoking status, albumin, histology, largest tumor size, number of nodal stations, stage, induction therapy, and radiation dose. The derived model had good risk predictive accuracy (C=0.70). Median survival time was shorter in the high-risk group (0.93 years) vs the low-risk group (2.40 years). Similar findings were noted in the replication sample with strong model accuracy (C=0.69) and median survival time of 0.93 years and 2.03 years for the high- and low-risk groups, respectively.

Conclusion

This novel risk prediction model for overall survival in patients with stage III NSCLC highlights the importance of integrating patient, clinical, and treatment variables for accurately predicting outcomes. Clinicians can use this tool to make personalized treatment decisions for patients with locally advanced NSCLC treated with concurrent chemo-radiation.

18F-FDG PET metabolic-to-morphological volume ratio predicts PD-L1 tumour expression and response to PD-1 blockade in non-small-cell lung cancer

PURPOSE

Anti-PD-1/PD-L1 blockade can restore tumour-specific T-cell immunity and is an emerging therapy in non-small-cell lung cancer (NSCLC). We investigated the correlation between ¹⁸F-FDG PET/CT-based markers and tumour tissue expression of PD-L1, necrosis and clinical outcome in patients receiving checkpoint inhibitor treatment.

METHODS

PD-Li expression in biopsy or resection specimens from 49 patients with confirmed NSCLC was investigated by immunohistochemistry. Maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were obtained from ¹⁸F-FDG PET/CT images. The ratio of metabolic to morphological lesion volumes (MMVR) and its association with PD-L1 expression in each lesion were calculated. The associations between histologically reported necrosis and ¹⁸F-FDG PET imaging patterns and radiological outcome (evaluated by iRECIST) following anti-PD-1/PD-L1 therapy were also analysed. In 14 patients, the association between necrosis and MMVR and tumour immune contexture were analysed by multiple immunofluorescent (IF) staining for CD8, PD-1, granzyme B (GrzB) and NFATC2.

RESULTS

In total, 25 adenocarcinomas and 24 squamous cell carcinomas were analysed. All tumours showed metabolic ¹⁸F-FDG PET uptake. MMVR was correlated inversely with PD-L1 expression in tumour cells. Furthermore, PD-L1 expression and low MMVR were significantly correlated with clinical benefit. Necrosis was correlated negatively with MMVR. Multiplex IF staining showed a greater frequency of activated CD8⁺ cells in necrotic tumours than in nonnecrotic tumours in both stromal and epithelial tumour compartments.

CONCLUSION

This study introduces MMVR as a new imaging biomarker and its ability to noninvasively capture increased PD-L1 tumour expression and predict clinical benefit from checkpoint blockade in NSCLC should be further evaluated.

Computed tomography morphologic features of pulmonary adenocarcinoma with brain/bone metastasis

BACKGROUND/AIMS

Brain and bone metastases are common in patients with lung cancer. The development of metastasis is associated with poor survival in lung cancer patients. Although tumor morphologic features on radiographs are routinely assessed for differentiation between benign and malignant lung nodules, they are not used to predict metastasis. We assessed morphologic features of pulmonary adenocarcinomas with brain/bone metastasis on computed tomography (CT) to identify related factors for metastasis.

METHODS

We performed a retrospective analysis of initial chest CT findings (size, type of contour, percentage of necrosis, enhancement, presence or absence of calcification, and air cavity) from 2009 to 2010 of patients with brain or bone metastasis and compared the findings with those of patients without metastases.

RESULTS

In total, 128 patients were included (78 men, 52 women; mean age 69 years; range, 36 to 87). Nineteen patients had brain metastases and 32 had bone metastases. Morphologic features associated with brain metastasis included size ≥ 50 mm (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.24 to 9.17; p = 0.013), necrosis ≥ 30% (OR, 4.51; 95% CI, 1.62 to 12.55; p =0.002), and presence of calcification (OR, 3.97; 95% CI, 1.16 to 13.55; p = 0.035). Morphologic features associated with bone metastasis included necrosis ≥ 30% (OR, 4.639; 95% CI, 1.98 to 10.82; p < 0.001) and T 3 to 4 stage (OR, 2.53; 95% CI, 1.07 to 6.00; p = 0.031).

CONCLUSIONS

We found that necrosis ≥ 30% was associated with pulmonary adenocarcinoma with brain and bone metastasis at initial chest CT morphologic feature. To validate these results, further research should be conducted.

Primary tumor standardized uptake value measured on F18-Fluorodeoxyglucose positron emission tomography is of prediction value for survival and local control in non-small-cell lung cancer receiving radiotherapy: meta-analysis

INTRODUCTION

The 2-[18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) has become an imaging tool for clinical assessment of tumor, node, metastasis in non-small-cell lung cancer (NSCLC). Primary tumor maximum standardized uptake value (SUV(max)) on (18)F-FDG PET/CT before and after radiation therapy (RT) has been studied as a potential prognostic factor for NSCLC patients receiving radiotherapy. However, the sample sizes of most studies were small, and the results of the prediction value of SUV(max) remained undetermined, which lead us to perform a meta-analysis to improve the precision in estimating its effect.

METHODS

We performed a meta-analysis of published literature for primary tumor SUV(max)-based biomarkers of the outcome of NSCLC receiving radiotherapy. The required data for estimation of individual hazard ratios (HRs) to compare patients with a low and a high SUV(max) were extracted from each publication. A combined HR was calculated by Stata statistical software (Version 11). All of the results were verified by two persons to ensure its accuracy.

RESULTS

Thirteen studies were finally included into this meta-analysis; data are available in 13 studies for pre-RT primary tumor SUV(max) and in five studies for post-RT. For overall survival, the combined HR estimate was 1.05 (95% confidence interval [CI], 1.02-1.08) and 1.32 (95% CI, 1.15-1.51) for pre-RT SUV(max) and post-RT SUV(max), respectively; 1.26 (95% CI, 1.05-1.52) and 2.01 (95% CI, 1.16-3.46) for local control (LC). In stereotactic body radiotherapy (SBRT) group, HR for LC was 1.11 (95% CI, 1.06-1.18) and 2.19 (95% CI, 1.34-3.60) for pre-SBRT SUV(max) and post-SBRT SUV(max), respectively.

CONCLUSION

Both pre-RT and post-RT primary tumor SUV(max) can predict the outcome of patients with NSCLC treated with radiotherapy. Patients with high levels of pre-RT SUV(max) seemed to have poorer overall survival and LC.

Necrosis and apoptotic index as prognostic factors in non-small cell lung carcinoma: a review

Necrosis and apoptosis represent two pathogenetically distinct types of cell death. Necrosis is associated with pathologic conditions while apoptosis is a physiological process of programmed cell death, which is associated with normal tissue growth and is frequently impaired in various forms of cancer. Tumor necrosis and apoptotic index (AI) have been previously evaluated as prognostic biomarkers in lung cancer, but their exact clinical value remains unclear. The aim of this study was to perform a systematic review of the MEDLINE literature on the prognostic significance of these histopathological markers in patients with non-small cell lung carcinoma (NSCLC). Although a substantial body of evidence suggests that tumor necrosis may be a strong predictor of aggressive tumor behavior and reduced survival in patients with NSCLC, the independent prognostic value of this biomarker remains to be firmly established. Furthermore, previous data on the prognostic significance of apoptotic index in NSCLC are relatively limited and largely controversial. More prospective studies are necessary in order to further validate tumor necrosis and AI as prognostic markers in NSCLC.

Integrative radiogenomic profiling of squamous cell lung cancer

Radiotherapy is one of the mainstays of anticancer treatment, but the relationship between the radiosensitivity of cancer cells and their genomic characteristics is still not well defined. Here, we report the development of a high-throughput platform for measuring radiation survival in vitro and its validation in comparison with conventional clonogenic radiation survival analysis. We combined results from this high-throughput assay with genomic parameters in cell lines from squamous cell lung carcinoma, which is standardly treated by radiotherapy, to identify parameters that predict radiation sensitivity. We showed that activation of NFE2L2, a frequent event in lung squamous cancers, confers radiation resistance. An expression-based, in silico screen nominated inhibitors of phosphoinositide 3-kinase (PI3K) as NFE2L2 antagonists. We showed that the selective PI3K inhibitor, NVP-BKM120, both decreased NRF2 protein levels and sensitized NFE2L2 or KEAP1-mutant cells to radiation. We then combined results from this high-throughput assay with single-sample gene set enrichment analysis of gene expression data. The resulting analysis identified pathways implicated in cell survival, genotoxic stress, detoxification, and innate and adaptive immunity as key correlates of radiation sensitivity. The integrative and high-throughput methods shown here for large-scale profiling of radiation survival and genomic features of solid-tumor-derived cell lines should facilitate tumor radiogenomics and the discovery of genotype-selective radiation sensitizers and protective agents.

Prognostic factors in stage III non-small cell lung cancer: a review of conventional, metabolic and new biological variables

Lung cancer is one of the most frequently occurring neoplasms and usually has a poor prognosis because most of the patients present with advanced or metastatic disease at the time of diagnosis. Numerous prognostic factors (PFs) have been studied, but the two most prominent, having both prognostic and operational values, are disease stage and performance status. Even if the literature on PFs in lung cancer is impressive, the number of publications specifically dealing with PFs in stage III non-small cell lung cancer (NSCLC) is limited. We reviewed the literature on this topic and separated the available information into three groups: conventional PFs, metabolic criteria (standardized uptake value [SUV] measured on(18)F-FDG-PET) and new biomarkers. Performance status and the distinction between stage IIIA and IIIB confirmed their prognostic value in stage III NSCLC. Other conventional PFs have been suggested such as age, weight loss, response to treatment and some characteristics describing the locoregional extension of the tumour. There is a place for the SUV as a PF for survival in early NSCLC, but its role in stage III NSCLC has to be further assessed. Some new biomarkers involved in cell cycle regulation or in apoptosis have been shown to have potential value. Their role needs to be confirmed in large prospective studies including conventional PFs to determine their independent value as a PF in stage III NSCLC. In conclusion, few PFs have been well evaluated in stage III NSCLC. New studies, taking into account the modifications derived from the 7th international staging system of the UICC, have to be performed.

Bax, cytochrome c, and caspase-8 staining in parotid cancer patients: Markers of susceptibility in radiotherapy?

Objective: Negative bcl-2 and HLA-DR protein expression have been associated with responsiveness to adjuvant radiotherapy in surgically treated parotid cancer patients. The aim of this study was to investigate the prognostic significance of bax, cytochrome c, and caspase-8 protein expression in a group of surgically treated patients to determine whether they also suggest markers of responsiveness to adjuvant radiotherapy.

Study Design: Historical cohort study.

Setting: Otolaryngology department in a university hospital.

Subjects and Methods: The immunohistochemical expression of bax, cytochrome c, and caspase-8 were studied in paraffin-embedded tissue specimens originating from 27 surgically treated parotid cancer patients and nine patients with Warthin parotid tumors (control group) and correlated with the patients' clinicopathological characteristics and clinical outcome.

Results: Caspase-8 negative staining was more frequently observed in higher TNM stages and in tumors measuring more than 4 cm ( P = 0.009 and P = 0.018, respectively). Caspase-8 (−)/cytochrome c (−) patients carried low-grade lesions without nodal involvement ( P = 0.01 and P = 0.05, respectively). Caspase-8 (−) patients who received postoperative radiotherapy presented a significantly increased disease-free survival compared to those who did not ( P = 0.04). Patients bearing bax (−) tumors who received postoperative radiotherapy presented an improved four-year disease-free survival compared to bax (−) patients who did not receive any type of adjuvant radiotherapy ( P = 0.017).

Conclusion: Bax, cytochrome c, and caspase-8 protein expression failed to independently predict survival in parotid cancer patients. However, patients with bax (−) or caspase-8 (−) tumors should be considered as candidates for adjuvant radiotherapy in order to achieve better local disease control.

EGFR, TTF-1 and Mdm2 expression in stage III non-small cell lung cancer: a positive association

New biological factors have not been extensively studied in stage III NSCLC as yet. The aim of this retrospective study was to assess the association between the expression and the prognostic role on survival of four biological markers in stage III NSCLC. Clinical characteristics were retrieved from the patients charts. EGF-R, Mdm2, p53 and TTF-1 expressions were evaluated by immunohistochemistry by three independent observers. Cox multivariate model was used to assess the impact of clinical and biological factors on patients' survival. A total of 84 stage III NSCLC patients, treated between 03/1987 and 08/2003, were included in the study. There was a statistically significant association between the expression of TTF-1 and EGFR (p=0.01) or TTF-1 and Mdm2 (p=0.04). Positive expressions for EGFR or TTF-1 were almost mutually exclusive. The status EGFR+/TTF-1--was mainly found in squamous cell carcinoma (18 among 19tumours). In multivariate analysis, only treatment with curative intent was independently associated with better survival (p=0.0004). In stage III NSCLC, there was a significant association between TTF-1 and EGFR or TTF-1 and Mdm2. The status EGFR+/TTF-1--was associated with squamous cell carcinoma.

Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

PURPOSE

Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer.

METHODS AND MATERIALS

Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated.

RESULTS

The COX-2 expression rate of the pretreatment samples was 46.1% +/- 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% +/- 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p = 0.06).

CONCLUSIONS

To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.

Clinical significance of apoptotic index in non-small cell lung cancer: correlation with p53, mdm2, pRb and p21WAF1/CIP1 protein expression

PURPOSE

The aim of this study was to assess the prognostic relevance of apoptotic index (AI), considered alone or together with expression of several proteins controlling G1 check point (p53, mdm2, pRb and p21WAF1/CIP1) in non-small cell lung cancer (NSCLC) patients.

METHODS

Study group included 50 NSCLC patients who underwent curative pulmonary resection. Apoptosis was detected with the use of TUNEL technique and AI was defined as the number of apoptotic cells per 1,000 tumor cells. The expression of p53, mdm2, pRb and p21WAF1/CIP1 was assessed immunohistochemically.

RESULTS

The mean and median AI calculated for all 50 patients was 14 and 9, respectively. Patients with lower (<14) and higher (> or =14) AI constituted 35 (70%) and 15 (30%) of cases, respectively. AI was not correlated with patient clinical characteristics, and expression of p53, pRb and p21WAF1/CIP1 . However, lower AI was correlated with over-expression of mdm2 protein (P=0.04). Median survival for patients with lower and higher AI was 43 months and 22 months, respectively, and 5-year survival probability-60 and 25%, respectively (P=0.03). In multivariate analysis, the only variable associated with shortened survival was AI (P=0.03, HR=2.9, 95% CI 1.95-3.86).

CONCLUSIONS

These results suggest that AI correlates with mdm2 protein expression and influences survival in NSCLC.

The role of p53 in treatment responses of lung cancer

Resistance to radio- and chemotherapy is a major problem in treatment responses of lung cancer. In this disease, biological markers, that can be predictive of response to treatment for guiding clinical practice, still need to be validated. Radiotherapy and most chemotherapeutic agents directly target DNA and in response to such therapies, p53 functions as a coordinator of the DNA repair process, cell cycle arrest, and apoptosis. In fact, it participates in the main DNA repair systems operative in cells, including NHEJ, HRR, NER, BER, and MMR. Given the high p53 mutation frequency in lung cancer which likely impairs some of the p53-mediated functions, a role of p53 as a predictive marker for treatment responses has been suggested. In this review, we summarize the conflicting results coming from preclinical and clinical studies on the role of p53 as a predictive marker of responses to chemotherapy or radiotherapy in lung cancer.

Heterogeneity of immunostaining for tumour markers in non-small cell lung carcinoma

Lung carcinoma is a leading cause of death. However, there are few indicators that can aid in prediction and prognosis. Many tumour markers are available, but their reliability is questionable. For example, Ki-67 expression has been associated with increased as well as decreased survival or with no clinical significance. The varying results have been attributed to the methodology, relative intensity of staining, variety of marking and statistical methods. To determine whether differential expression of markers within tumours may be a contributory factor to this lack of agreement, we used two marking methods to evaluate the level of expression of Ki-67, p53 and bcl-2, in addition to the apoptotic index, in serial sections of non-small cell carcinoma. All stains exhibited a degree of heterogeneity. This small study highlights the importance of standardisation of marking methods and interpretation of results if tumour markers are to be used as predictive or prognostic factors.

Imbalance between proliferation and apoptosis may be responsible for treatment failure after postoperative radiotherapy in squamous cell carcinoma of the oropharynx

To assess the prognostic value of apoptosis, proliferation and clinical factors in squamous cell carcinoma of the oropharynx after radical surgery and postoperative radiotherapy (RT). Between 1985 and 1995, a total of 82 patients with 84 tumors were entered onto the study. Forty-two primary tumors (50%) involved the tonsils, 23 (27%) the soft palate, and 19 (23%) the base of the tongue. Median age was 52 years (range, 36-73 years). The pT- and pN-categories (UICC 1997) were: T1 (24), T2 (36), T3 (18), T4 (6), N0 (31), N1 (12), N2 (38), NX (8). Histologically clear margins were achieved in all patients by initial surgery. Postoperative RT to the primary and regional lymphatics was given with 60 Gy in 6 weeks and single daily fractions of 2 Gy. The expression of the nuclear Ki-67 labeling index (LI) was investigated by immunostaining using the monoclonal antibody MIB 1 and apoptotic carcinoma cells were identified using the terminal deoxynucleotidyltransferase-(TdT)-mediated dUTP nick end labeling (TUNEL) technique. Median follow-up was 43 months (range, 14-132 months). Overall survival, disease-free survival, and locoregional tumor control rates were 59, 70 and 76% at 5 years. Median values for apoptotic index and Ki-67 labeling were 1.6% (range 0-4.7%), and 20% (range, 0-79%), respectively. Apoptotic index <or=1.6% had a profound negative impact when associated with higher proliferation rates (5-year disease-free survival: 26%) as compared to all other patients with a balance between apoptosis and proliferation (5-year disease-free survival: 66-86%, P=0.003). Additional significant prognostic factors for disease-free survival were: tumor site (tonsils: 83% vs soft palate: 66% vs base of tongue: 49%, P=0.02), duration of RT (<or=47 days: 83% vs >47 days: 55%, P=0.03), Ki-67 LI (<or=20%: 84% vs >20%: 56%, P=0.006). A significant prognostic impact on locoregional control was noted for the duration of RT (P=0.01), tumor site (P=0.02), and the Ki-67 LI (P=0.02). A low apoptotic index together with higher proliferation rates led to unfavourable local control as low as 25% compared to the patients with higher apoptotic index (70-80%, P=0.009). An imbalance between apoptotic index and proliferation may identify patients with squamous cell carcinoma at high risk for local recurrence after surgery and postoperative RT. Prospective observation of these factors in clinical trials is warranted to further elucidate this phenomenon.