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High risk prostate cancer (HR-PrCa) is a subset of localized PrCa with significant potential for morbidity and mortality associated with disease recurrence and metastasis. Radiotherapy combined with Androgen Deprivation Therapy has been the standard of care for many years in HR-PrCa. In recent years, dose escalation, hypo-fractionation and high precision delivery with immobilization and image-guidance have substantially changed the face of modern PrCa radiotherapy, improving treatment convenience and outcomes. Ultra-hypo-fractionated radiotherapy delivered with high precision in the form of stereotactic body radiation therapy (SBRT) combines delivery of high biologically equivalent dose radiotherapy with the convenience of a shorter treatment schedule, as well as the promise of similar efficacy and reduced toxicity compared to conventional radiotherapy. However, rigorous investigation of SBRT in HR-PrCa remains limited. Here, we review the changes in HR-PrCa radiotherapy through dose escalation, hypo- and ultra-hypo-fractionated radiotherapy boost treatments, and the radiobiological basis of these treatments. We focus on completed and on-going trials in this disease utilizing SBRT as a sole radiation modality or as boost therapy following pelvic radiation., (Copyright © 2021. Published by Elsevier Inc.)

Standard therapy for high-risk (HR) prostate cancer (PrCa) involves androgen deprivation therapy (ADT) and pelvic conventional fractionation (CF) external beam radiotherapy (EBRT) followed by boost CF-EBRT treatment to prostate for a total of 78 to 80 Gy in 39 to 40 fractions. This is a long and inconvenient treatment for patients. Brachytherapy boost treatment studies indicate that escalation of biological dose of radiotherapy (RT) can improve outcomes in HR-PrCa. However, brachytherapy is an invasive treatment associated with increased toxicity and requires specialized resources. Stereotactic body radiotherapy (SBRT) is a promising, non-invasive alternative to brachytherapy. However, its impact on patient quality of life (QoL) and RT-associated toxicity has not been investigated in a randomized setting. In this study, we investigate SBRT as a boost treatment, following pelvic CF-EBRT, in patients with HR-PrCa treated with ADT. One hundred patients with locally advanced PrCa will be randomized to receive daily CF-EBRT of 45 to 46 Gy in 23 to 25 fractions followed by either daily CF-EBRT of 32 to 33 Gy in 15 to 16 fractions (control arm) or SBRT boost treatment of 19.5 to 21 Gy in 3 fractions (1 fraction per week) (experimental arm). The primary objective of the PBS trial is early bowel and urinary QoL (expanded prostate index composite [EPIC], up to 6 months after RT). This phase II randomized study (PBS) provides an appropriate setting to investigate effectively the impact of SBRT boost on QoL and toxicity in patients with HR-PrCa, before this modality can be compared against the current standard of care in larger phase III protocols., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Despite improved staging and surgical techniques, the rate of incomplete resection (R1) of non-small-cell lung cancer (NSCLC) has not significantly decreased. Patients with R1 resection have worse survival compared with those with complete resection (R0). Stereotactic body radiotherapy (SBRT) is a rapid and convenient radiotherapy treatment that delivers high-dose radiotherapy to tumors with high precision while sparing normal organs. Although its efficacy in treating small lung tumors is documented, its use as neoadjuvant therapy for locally advanced (LA) NSCLC has not been examined. We hypothesized that a short course of preoperative SBRT is feasible and can be delivered safely as a neoadjuvant therapy in patients at risk for incomplete resection., Methods: In this phase I study, 20 patients with cT3 to 4, N0 to 1, M0 NSCLC at risk for incomplete resection will be treated with neoadjuvant SBRT followed by surgery and adjuvant chemotherapy. Four groups of 5 patients will be treated with escalating doses (35, 40, 45, and 50 Gy) in 10 daily fractions. The primary outcome is feasibility (ie, the ability to complete SBRT and surgery as planned; within 7 weeks). Secondary outcomes include acute and late adverse events; R0, R1, and R2 rates; and secondary surrogates of feasibility and safety., Relevance: This study is an important first step in introducing a new therapeutic modality to patients with LA NSCLC that could improve surgical outcomes in the future. If neoadjuvant SBRT is found to be feasible and safe for LA NSCLC, its effect in achieving R0 resection could be investigated in randomized trials., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We describe a Canadian phase III randomized controlled trial of stereotactic body radiotherapy (SBRT) versus conventionally hypofractionated radiotherapy (CRT) for the treatment of stage I medically inoperable non-small-cell lung cancer (OCOG-LUSTRE Trial). Eligible patients are randomized in a 2:1 fashion to either SBRT (48 Gy in 4 fractions for peripherally located lesions; 60 Gy in 8 fractions for centrally located lesions) or CRT (60 Gy in 15 fractions). The primary outcome of the study is 3-year local control, which we hypothesize will improve from 75% with CRT to 87.5% with SBRT. With 85% power to detect a difference of this magnitude (hazard ratio = 0.46), a 2-sided α = 0.05 and a 2:1 randomization, we require a sample size of 324 patients (216 SBRT, 108 CRT). Important secondary outcomes include overall survival, disease-free survival, toxicity, radiation-related treatment death, quality of life, and cost-effectiveness. A robust radiation therapy quality assurance program has been established to assure consistent and high quality SBRT and CRT delivery. Despite widespread interest and adoption of SBRT, there still remains a concern regarding long-term control and risks of toxicity (particularly in patients with centrally located lesions). The OCOG-LUSTRE study is the only randomized phase III trial testing SBRT in a medically inoperable population, and the results of this trial will attempt to prove that the benefits of SBRT outweigh the potential risks., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: The downstream signaling pathways of the epidermal growth factor receptor might influence radiation resistance. Data from preclinical work support the hypothesis that erlotinib concurrent with radiation therapy (RT) might increase cancer cell killing. The present trial was designed to examine the efficacy and toxicity of combined erlotinib and palliative chest thoracic RT in non-small-cell lung cancer (NSCLC)., Materials and Methods: Patients with newly diagnosed stage III-IV (American Joint Committee on Cancer, version 6) or recurrent NSCLC received 3 weeks of erlotinib at a dose of 150 mg daily, starting 1 week before palliative thoracic RT to 30 Gy in 10 fractions within 2 weeks. The primary outcome was a change in the quality of life, as measured by the Lung Cancer Symptom Scale (LCSS) question on the "symptoms of lung cancer" from baseline to 4 weeks after treatment., Results: A total of 40 patients were recruited from 2 institutions. Of the 40 patients, 22 (55%) were men, with an average age of 71 years, and 60% had stage IV disease. A total of 26 patients (65%) completed the full course of erlotinib, and 35 (88%) completed the planned RT. Twenty-five patients (62.5%) reported LCSS scores at 4 weeks after treatment, with an average change (improvement) of -12.5 U (95% confidence interval, -23.0 to -1.9; 2P = .023). This was less than the a priori hypothesis of a change of -17.5 U. The median overall and progression-free survival was 5.2 and 3.2 months, respectively., Conclusion: The present single-arm, phase II trial did not demonstrate additional symptomatic benefit from concurrent erlotinib therapy with standard palliative thoracic RT for patients with locally advanced or metastatic NSCLC., (Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.)

Introduction: In this study, we investigated the effect of the 3-hydroxy-3-methylgutaryl-CoA reductase inhibitor lovastatin, as a sensitizer of lung cancer cells to ionizing radiation (IR)., Methods: A549 lung adenocarcinoma cells were treated with 0 to 50 μM lovastatin alone or in combination with 0 to 8 Gy IR and subjected to clonogenic survival and proliferation assays. To assess the mechanism of drug action, we examined the effects of lovastatin and IR on the epidermal growth factor (EGF) receptor and AMP-activated kinase (AMPK) pathways and on apoptotic markers and the cell cycle., Results: Lovastatin inhibited basal clonogenic survival and proliferation of A549 cells and sensitized them to IR. This was reversed by mevalonate, the product of 3-hydroxy-3-methylgutaryl-CoA reductase. Lovastatin attenuated selectively EGF-induced phosphorylation of EGF receptor and Akt, and IR-induced Akt phosphorylation, in a mevalonate-sensitive fashion, without inhibition on extracellular signal-regulated kinase 1/2 phosphorylation by either stimulus. IR phosphorylated and activated the metabolic sensor and tumor suppressor AMPK, but lovastatin enhanced basal and IR-induced AMPK phosphorylation. The drug inhibited IR-induced expression of p53 and the cyclin-dependent kinase inhibitors p21(cip1) and p27(kip1), but caused a redistribution of cells from G1-S phase (control and radiated cells) and G2-M phase (radiated cells) of cell cycle into apoptosis. The latter was also evident by induction of nuclear fragmentation and cleavage of caspase 3 by lovastatin in both control and radiated cells., Conclusions: We suggest that lovastatin inhibits survival and induces radiosensitization of lung cancer cells through induction of apoptosis, which may be mediated by a simultaneous inhibition of the Akt and activation of the AMPK signaling pathways.

Introduction: The epidermal growth factor receptor (EGFR) and its downstream effector kinases are thought to have important roles in lung cancer cell proliferation and response to treatment., Methods: In a prospective cohort of patients with locally advanced non-small cell lung cancer (NSCLC) undergoing high-dose radiotherapy with or without chemotherapy, we examined by immunohistochemistry (IHC) the tumor levels of EGFR and phosphorylated/ activated-EGFR (P-EGFR), P-Erk, P-Akt, P-Stat3, and the cell cycle marker Ki67. We examined the relationships among marker expression, at the plasma membrane (M), cytoplasm (C) and nucleus, as well as the radiologic tumor response, and overall survival (OS)., Results: Fifty patients were recruited in this study. Their median survival was 18.3 months. No correlation was detected between total EGFR and P-EGFR levels in any subcellular compartment. M P-EGFR correlated positively with C P-Akt (p = 0.01). C P-Erk correlated negatively with radiologic response (p = 0.022), and on univariate regression analysis, this approached significance (p = 0.059). M and C P-EGFR correlated negatively with OS (p = 0.020), and on univariate analysis higher M P-EGFR predicted for poor OS (p = 0.001). Patients with high M P-EGFR levels had median survival of 7.8 months versus 17.7 months for patients with low M P-EGFR., Conclusions: Our results support a role of activated M P-EGFR, (but not total EGFR), as a predictor of OS in locally advanced-NSCLC. It is suggested that detailed evaluation of the subcellular distribution and activation state of EGFR and its downstream effectors is required to unravel the predictive value of these markers in NSCLC.