Ablative Hypofractionated Radiation Therapy Enhances Non-Small Cell Lung Cancer Cell Killing via Preferential Stimulation of Necroptosis In Vitro and In Vivo.

PURPOSE: To investigate how necroptosis (ie, programmed necrosis) is involved in killing of non-small cell lung cancer (NSCLC) after ablative hypofractionated radiation therapy (HFRT). METHODS AND MATERIALS: Deoxyribonucleic acid damage, DNA repair, and the death form of NSCLC cells were assessed after radiation therapy. The overexpression and silencing of receptor-interacting protein kinases 3 (RIP3, a key protein involved activation of necroptosis)-stable NSCLC cell lines were successfully constructed. The form of cell death, the number and area of colonies, and the regulatory proteins of necroptosis were characterized after radiation therapy in vitro. Finally, NSCLC xenografts and patient specimens were used to examine involvement of necroptosis after ablative HFRT in vivo. RESULTS: Radiation therapy induced expected DNA damage and repair of NSCLC cell lines, but ablative HFRT at ≥10 Gy per fraction preferentially stimulated necroptosis in NSCLC cells and xenografts with high RIP3 expression, as characterized by induction and activation of RIP3 and mixed-lineage kinase domain-like protein and release of immune-activating chemokine high-mobility group box 1. In contrast, RNA interference of RIP3 attenuated ablative HFRT-induced necroptosis and activation of its regulatory proteins. Among central early-stage NSCLC patients receiving stereotactic body radiation therapy, high expression of RIP3 was associated with improved local control and progression-free survival (all P < .05). CONCLUSIONS: Ablative HFRT at ≥10 Gy per fraction enhances killing of NSCLC with high RIP3 expression via preferential stimulation of necroptosis. RIP3 may serve as a useful biomarker to predict favorable response to stereotactic body radiation therapy.

Early postoperative radiotherapy is associated with improved outcomes over late postoperative radiotherapy in the management of completely resected (R0) Stage IIIA-N2 non-small cell lung cancer.

AIMS: The aim of this study was to evaluate the ideal timing of PORT in the management of completely resected (R0) Stage IIIA-N2 NSCLC. PATIENTS AND METHODS: Between January 2008 and December 2015, patients with known histologies of pathologic Stage IIIA-N2 NSCLC who underwent R0 resection and received PORT concurrent with or prior to two sequential cycles of chemotherapy ("early PORT") or with PORT administered after two cycles of chemotherapy ("late PORT") at multiple hospitals. The primary endpoint was OS; secondary end points included pattern of the first failure, LRRFS, and DMFS. Kaplan-Meier OS, LRRFS, and DMFS curves were compared with the log-rank test. Cox regression analysis was used to determine prognosticators for OS, LRRFS, and DMFS. RESULTS: Of 112 included patients, 41 (36.6%) and 71 (63.4%) patients received early PORT and late PORT, respectively. The median OS, LRRFS, and DMFS were longer for those who received early PORT than for those who received late PORT at the median follow-up of 29.6 months (all p < 0.05). Uni- and multi-variate analyses showed that number of POCT cycles and the combination schedule of PORT and POCT were independent prognostic factors for OS, LRRFS, and DMFS. CONCLUSIONS: Early PORT is associated with improved outcomes in pathologic Stage IIIA-N2 R0 NSCLC patients.

Sublobar resection is associated with improved outcomes over radiotherapy in the management of high-risk elderly patients with Stage I non-small cell lung cancer: a systematic review and meta-analysis.

BACKGROUND AND AIM: A matched-pair comparison was performed to compare the efficacy and safety of sublobar resection versus radiotherapy for high-risk elderly patients with Stage I non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: We searched the Cochrane Library, MEDLINE, CENTRAL, EMBASE and manual searches. The meta-analysis was performed to compare overall survival, pattern of failure, and toxicity among the homogeneous studies. Subdivided analyses were also performed. RESULTS: Sixteen studies containing 11540 patients were included in the meta-analysis. Among these studies, 9 were propensity-score matched (PSM) cohort studies, and 7 were cohort studies. Sublobar resection, compared with radiotherapy (either conventional fraction radiation therapy or stereotactic body radiation therapy), significantly improved the overall survival regardless in both PSM and non-PSM analyses (all p < 0.05). However, the difference in the pattern of failure and toxicity were not significant (all p > 0.05). CONCLUSIONS: Sublobar resection was associated with improved outcomes in high-risk elderly patients with Stage I NSCLC, which supports the need to compare both treatments in large prospective, randomized, controlled clinical trials.

Nucleophilic 1,1-Difluoroethylation with Fluorinated Phosphonium Salt.

The fluorinated phosphonium salt (Ph3P+CF2CH3 BF4-) was shown to act as a nucleophilic 1,1-difluoroethylation agent to enable difluoroethylation of aldehydes and imines.

Stereotactic body radiation therapy for patients with recurrent pancreatic adenocarcinoma at the abdominal lymph nodes or postoperative stump including pancreatic stump and other stump.

BACKGROUND AND AIM: The aim of this study is to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) using CyberKnife in the treatment of patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. PATIENTS AND METHODS: Between October 1, 2006 and May 1, 2015, patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery were enrolled and treated with SBRT at our hospital. The primary end point was local control rate after SBRT. Secondary end points were overall survival, time to symptom alleviation, and toxicity, assessed using the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Twenty-four patients with 24 lesions (17 abdominal lymph nodes and seven stumps) were treated with SBRT, of which five patients presented with abdominal lymph nodes and synchronous metastases in the liver and lung. The 6-, 12-, and 24-month actuarial local control rates were 95.2%, 83.8%, and 62.1%, respectively. For the entire cohort, the median overall survival from diagnosis and SBRT was 28.9 and 12.2 months, respectively. Symptom alleviation was observed in eleven of 14 patients (78.6%) within a median of 8 days (range, 1-14 days) after SBRT. Nine patients (37.5%) experienced Common Terminology Criteria for Adverse Events version 4.0 grade 1-2 acute toxicities; one patient experienced grade 3 acute toxicity due to thrombocytopenia. CONCLUSION: SBRT is a safe and effective treatment for patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. Further studies are needed before SBRT can be recommended routinely.

Mesenchymal stem cells generate pericytes to promote tumor recurrence via vasculogenesis after stereotactic body radiation therapy.

BACKGROUND: Stereotactic body radiation therapy (SBRT) is postulated to enhance the recruitment of mesenchymal stem cells (MSCs) into the tumor microenvironment, which promote tumor recurrence. The aim of this study is to determine the molecular mechanisms behind SBRT stimulating MSC migration and differentiation. METHODS: In vitro, mediated factors and migrated MSCs (post-SBRT) were generated. In vivo, bone-marrow derived MSCs were identified and harvested from green fluorescent protein (GFP)-expressing transgenic male mice and transplanted into sub-lethally irradiated recipient female mice to establish a model of bone marrow transplantation. Lewis lung carcinoma and malignant melanoma-bearing recipient mice were treated with SBRT, 14 Gy/1 fraction. The migration and differentiation potential of MSCs were characterized. RESULTS: SBRT increased the release of stromal cell derived factor-1α (SDF-1α) and platelet-derived growth factor-B (PDGF-B) by tumor cells; these ligands bound to chemokine (C-X-C motif) receptor 4 (CXCR4) and platelet-derived growth factor receptor-ß (PDGFR-ß), respectively, on circulating bone marrow-derived MSCs, resulting in engraftment of the MSCs into the tumor parenchyma. The newly-homed MSCs differentiated into pericytes, which induced the tumor vasculogenesis, and promoted tumor regrowth. Targeted therapies, AMD3100 and imatinib abrogated MSC homing, vasculogenesis, and tumor regrowth. CONCLUSION: Bone-marrow derived MSCs migrate to the tumor parenchyma and differentiate into pericytes, inducing tumor vasculogenesis after SBRT, and promoting tumor recurrence. MSC migration and maturation may be abrogated with AMD3100 and imatinib. This novel treatment strategy warrants clinical investigation.

Stereotactic radiation therapy for oligometastases or oligorecurrence within mediastinal lymph nodes.

AIMS: This study evaluated the safety and efficacy of stereotactic radiation therapy (SRT) for the treatment of patients with oligometastases or oligorecurrence within mediastinal lymph nodes (MLNs) originating from different tumors. METHODS: Between October 2006 and May 2015, patients with MLN oligometastases or oligorecurrence were enrolled and treated with SRT at our hospital. The primary endpoint was MLN local control (LC). Secondary endpoints were time to symptom alleviation, overall survival (OS) after SRT, and toxicity using the Common Terminology Criteria for Adverse Events (CTCAE v4.0). RESULTS: Eighty-five patients with 98 MLN oligometastases or oligorecurrences were treated with SRT. For the entire cohort, the 1-year and 5-year actuarial LC rates were 97% and 77%, respectively. Of 53 symptomatic patients, symptom alleviation was observed in 47 (89%) after a median of 5 days (range, 3-30 days). The median OS was 27.2 months for all patients. For patients with non-small cell lung cancer, univariate and multivariate analyses revealed that a shorter interval between diagnosis of primary tumors and SRT and larger MLN SRT volume were associated with worse OS. CTCAE v4.0 ≥ Grade 3 toxicities occurred in six patients (7%), with Grade 5 in three patients (all with RT history to MLN station 7). CONCLUSIONS: SRT is a safe and efficacious treatment modality for patients with oligometastases or oligorecurrence to MLNs originating from different tumors, except for patients who received radiotherapy to MLN station 7. Further investigation is warranted to identify the patients who benefit most from this treatment modality.

Multimodality therapy is recommended for limited-stage combined small cell esophageal carcinoma.

BACKGROUND AND AIM: Limited-stage combined small cell esophageal carcinoma (LS-C-SCEC) is a rare, poorly understood, underdiagnosed disease, with components of both small cell esophageal cancer and non-small cell esophageal cancer. We investigated the optimal treatment strategy and prognostic factors in patients with LS-C-SCEC. PATIENTS AND METHODS: LS-C-SCEC patients included in the analysis (from our hospital and the literature) were treated between January 1966 and December 2013. Patient treatment strategies included surgery (S), chemotherapy (CT), and radiation therapy (RT). The primary end point was overall survival (OS); the secondary end points included tumor complete response rates, patterns of failure, and toxicity. Kaplan-Meier curves were compared with the log-rank test. Univariate and multivariate analyses were used to determine prognosticators for OS. RESULTS: A total of 72 patients were included in the analysis: 24 (33%) from our hospital and 48 (67%) from the literature. The median OS of all patients was 15.0 months. Patients who received CT had a significantly longer median OS than did those who did not (OS 22.8 months vs 10.0 months) (P=0.03). Patients treated with multimodality therapy (including RT+CT [18%], S+CT [40%], or S+RT+CT [17%]) vs monotherapy (typically, S [18%]) had significantly improved OS (15.5 months vs 9.3 months) (P=0.02) and complete response rates. On multivariate analysis, tumor location (upper third of the esophagus) and type of treatment (monotherapy) were the only factors predictive of poor OS. CONCLUSION: Multimodality therapy (including RT+CT, S+CT, or S+RT+CT) improves OS for patients with LS-C-SCEC compared with monotherapy (typically, S). Additional studies are necessary to personalize multimodal treatment approaches to individual patients.

Targeting pyruvate kinase M2 contributes to radiosensitivity of non-small cell lung cancer cells in vitro and in vivo.

Aerobic glycolysis, a metabolic hallmark of cancer, is associated with radioresistance in non-small cell lung cancer (NSCLC). Pyruvate kinase M2 isoform (PKM2), a key regulator of glycolysis, is expressed exclusively in cancers. However, the impact of PKM2 silencing on the radiosensitivity of NSCLC has not been explored. Here, we show a plasmid of shRNA-PKM2 for expressing a short hairpin RNA targeting PKM2 (pshRNA-PKM2) and demonstrate that treatment with pshRNA-PKM2 effectively inhibits PKM2 expression in NSCLC cell lines and xenografts. Silencing of PKM2 expression enhanced ionizing radiation (IR)-induced apoptosis and autophagy in vitro and in vivo, accompanied by inhibiting AKT and PDK1 phosphorylation, but enhanced ERK and GSK3ß phosphorylation. These results demonstrated that knockdown of PKM2 expression enhances the radiosensitivity of NSCLC cell lines and xenografts as well as may aid in the design of new therapies for the treatment of NSCLC.