Modern era systemic therapies: Expanding concepts of cure in early and locally advanced non-small cell lung cancer.

Cure of cancer is a sensitive and multidimensional concept that is challenging to define, difficult to assert at the individual patient level, and often surrounded by controversy. The notion of cure in non-small cell lung cancer (NSCLC) has changed and continues to evolve with improvements in diagnosis and treatment. Targeted and immune therapies have recently entered the treatment landscape of stage I-III NSCLC. While some initial pivotal trials of such agents failed to improve survival, recently approved epidermal growth factor receptor (EGFR) inhibitors (in EGFR-mutated NSCLC) and immune checkpoint inhibitors have shown delays in disease recurrence or progression and unprecedented survival gains compared to previous standards of care. Additional data is now emerging supporting the benefit of treatment strategies based on alternation-matched targeting (anaplastic lymphoma kinase [ALK] inhibition in ALK-altered disease) and immune checkpoint inhibition in stage I-III NSCLC. Similar to previous developments in the treatment of early and locally advanced NSCLC, it is expected that statistically significant and clinically meaningful trial-level benefits will translate into real-world benefits, including improvements in cure measures. Parallel advances in molecular testing (e.g., circulating tumor DNA analyses) are also allowing for a deeper and more comprehensive characterization of disease status and treatment response. Given the impact that curative-intent treatments have on survival, it is critical that various stakeholders, including clinicians and patients, are aware of new opportunities to pursue cure in stage I-III NSCLC.

Radiation dose for thymic tumours.

Thymomas and thymic carcinomas are rare epithelial cell tumours arising from the thymus. Definitive surgical resection continues to be the primary approach for the management of thymomas and thymic carcinomas. However, complete resection is not always achievable due to the complexity of the mediastinal anatomy and in rare cases local recurrences may occur which are often incurable. Therefore, the use of Post-Operative Radiotherapy (PORT) may be considered with the intent of improving local control while being judicious of toxicity in the setting of prolonged clinical trajectories and proximity to critical structures. There continues to be a paucity of literature surrounding the use of PORT for thymomas and thymic carcinomas and the optimal dose has not yet been established. This review aims to summarize the current literature regarding radiotherapy indications and to explore issues surrounding radiotherapy dose-response-relationships for thymomas and thymic carcinoma. Long-term prospective studies using contemporary surgical and radiotherapy techniques are needed to further elucidate the optimal radiation approach in the management of thymic tumours.

Radiation Therapy Quality Assurance (RTQA) of Concurrent Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer in the PROCLAIM Phase 3 Trial.

PURPOSE: Chemoradiation therapy trials of different tumors, including lung cancer, have shown a correlation between protocol deviations and adverse outcomes. Radiation therapy quality assurance (RTQA) was mandated for all patients treated in the PROCLAIM trial evaluating 2 different chemoradiation therapy regimens. The RTQA results were evaluated from the PROCLAIM study, and the impact of irradiation deviations on efficacy outcomes was investigated. METHODS AND MATERIALS: The study was conducted from 2008 to 2014. Review of the irradiation plan was mandated for all patients. Real-time review was performed prior to irradiation start for the first enrolled patient at each site and randomly in 20% of additional patients, with non-real-time review in the remainder. The RTQA criteria evaluated included planning target volume coverage, dose homogeneity, volume of lung receiving ≥20 Gy, and maximum point dose to spinal cord. RESULTS: Major RTQA violations occurred in 40 of 554 patients, treated at 28 sites. Seven sites treated ≥2 patients with major violations. Stage IIIB disease and larger planning target volume were observed more frequently in patients with major violations. Major violations were more prevalent in sites treating either <6 patients or >15 patients. Patients treated at sites enrolling ≥2 patients with major violations (n = 86) had lower median overall survival (21.1 months vs 29.8 months; hazard ratio, 1.442) and progression-free survival (7.3 months vs 11.3 months; hazard ratio, 1.345) than patients treated at sites without major violations. These findings remained significant for overall survival on multivariate analysis. CONCLUSIONS: Major violations in treatment plans were uncommon in the PROCLAIM study, possibly reflecting mandatory RTQA. The RTQA violations were more frequent in patients requiring more complex chemoradiation therapy plans. Poorer observed outcomes at centers with multiple major violations are hypothesis generating.

Phase I trial of radiation therapy and sorafenib in unresectable liver metastases.

BACKGROUND AND PURPOSE: To determine maximum tolerated dose (MTD) and toxicities of sorafenib combined with stereotactic radiotherapy (SBRT) or whole liver radiotherapy (WLRT) in patients with liver metastases. MATERIAL AND METHODS: Eligible patients had unresectable liver metastases. Sorafenib dose was escalated in 2 strata: I - SBRT: effective liver volume irradiated (Veff)<80% (30-60Gy in 6 fractions); II - WLRT: Veff>80% (21.6Gy in 6 fractions). Four weeks of sorafenib, with radiotherapy during weeks 2-3, was delivered at 3 escalating dose levels (200-400mg twice daily). Dose limiting toxicity was defined as any grade 3+ liver toxicity, or grade 4+ treatment-related toxicity. RESULTS: Thirty-three patients were treated: 18 in stratum I (median dose 42Gy), 15 in stratum II. The MTD was not reached. Grade 3+ toxicity was seen in 33% of patients, at a median of 10days. Two deaths from non-classic liver toxicity occurred post WLRT in stratum II. The median overall survival was 22.3 and 5.7months for strata I and II respectively. CONCLUSIONS: Sorafenib and 21.6Gy in 6 fraction WLRT resulted in unacceptably high rates of liver toxicity. Although sorafenib combined with SBRT was tolerable, the observed efficacy does not merit further clinical evaluation.

Phase 1/2 Study of the Addition of Cisplatin to Adjuvant Chemotherapy With Image Guided High-Precision Radiation Therapy for Completely Resected Gastric Cancer.

PURPOSE: Locoregional recurrence is common after surgery for gastric cancer. Adjuvant therapy improves outcomes but with toxicity. This phase 1/2 study investigated infusional 5-fluorouracil (5-FU) in combination with biweekly cisplatin delivered concurrently with image guided high-precision radiation therapy. METHODS AND MATERIALS: Eligible patients had completely resected stage IB to IV (Union for International Cancer Control TNM 6th edition) nonmetastatic gastric adenocarcinoma. Treatment constituted 12 weeks of infusional 5-FU (200 mg/m2/day) with cisplatin added in a standard 3 + 3 dose escalation protocol (0, 20, 30, and 40 mg/m2) during weeks 1, 3, 5, and 7, and an additional week 9 dose in the final cohort. Radiation therapy (45 Gy in 25 fractions) was delivered during weeks 3 to 7. Maximum tolerated dose (MTD) was determined in phase 1 and confirmed in phase 2. RESULTS: Among the 55 patients (median age, 54 years; range 28-77 years; 55% male), the median follow-up time was 3.0 years (range, 0.3-5.3 years). Five patients in phase 1 experienced dose-limiting toxicity, and MTD was determined as 4 cycles of 40 mg/m2 cisplatin. Twenty-seven patients were treated at MTD. Acute grade 3 to 4 toxicity rate was 37.0% at MTD and 29.1% across all dose levels. No treatment-related deaths occurred. Fourteen patients experienced recurrent disease. The 2-year overall survival (OS) and relapse-free survival were 85% and 74%, respectively. Median OS has not been reached. Quality of life (QOL) was impaired during treatment, but most scores recovered by 4 weeks. CONCLUSION: Cisplatin can be safely delivered with 5-FU-based chemoradiation therapy. Acute toxicity was acceptable, and patient-reported QOL showed the regimen was tolerable. Outcomes are encouraging and justify further study of this regimen.

Phase 1 Trial of Sorafenib and Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma.

PURPOSE: To determine the maximally tolerated dose of sorafenib delivered before, during, and after stereotactic body radiation therapy (SBRT) in hepatocellular carinoma (HCC). METHODS AND MATERIALS: Eligible patients had locally advanced Child-Pugh class A HCC, showed Eastern Cooperative Oncology Group performance status 0-1, and were ineligible for standard local-regional therapies. Sorafenib was dose escalated in 2 strata: (1) low effective irradiated liver volume (veff) < 30% and (2) high veff 30%to 60%. Sorafenib (400 mg daily = dose level 1) was administered for 12 weeks, with 6 fractions SBRT delivered weeks 2 and 3, and escalation to full dose (400 mg twice daily) after 12 weeks as tolerated. Standard 3 + 3 cohorts with dose escalation of sorafenib were planned. RESULTS: Sixteen patients (4 low veff, median dose 51 Gy; 12 high veff, median dose 33 Gy) were treated at 2 sorafenib dose levels. Of those patients 75% were had Barcelona Clinic Liver Cancer stage C, and 63% had main branch portal vein invasion. In the low veff stratum, no dose-limiting toxicities (DLTs) were observed in 4 patients treated with SBRT and sorafenib 400 mg. Inb the high veff stratum: 2 of 3 evaluable patients treated with sorafenib 400 mg experienced DLT (grade 3 large bowel bleed and grade 4 bowel obstruction 51 and 27 days, respectively, after SBRT). One of 6 evaluable patients at dose level -1 (200 mg once daily) experienced a grade 3 tumor rupture at week 5. Median overall survival and in-field local progression have not been reached. Worsening of Child-Pugh liver function class was seen in 6 of 12 patients in the high veff stratum. CONCLUSIONS: Significant toxicity was observed in the high veff stratum, and concurrent SBRT with sorafenib is not recommended outside a clinical trial.

Tumor regression and positional changes in non-small cell lung cancer during radical radiotherapy.

INTRODUCTION: We have used respiratory-correlated cone beam computed tomography (rcCBCT) imaging to study the volumetric and positional changes that occur throughout the course of radical radiotherapy in non-small cell lung cancer (NSCLC). METHODS: Tumor volumes and centers of mass were recorded and analyzed on weekly serial rcCBCT images of NSCLC patients treated with radical radiotherapy to a dose ≥45 Gy with concurrent chemotherapy. RESULTS: Sixty patients with locally advanced NSCLC were included; in 31 patients, the primary tumor was peripheral and thus suitable for contouring. There was a mean percent decrease of 40.2% by fraction 15 and 51.1% by treatment completion. Among all 60 patients, 19 patients (32%) had more than 30% regression by fraction 15 and 25 patients (81%) by treatment completion. Statistically significant tumor migration in at least one direction between the first and the last 2 weeks was demonstrated in 14 of 27 patients. Clinically relevant changes (atelectasis and effusions) were noted in 11 of 29 visually assessed patients. CONCLUSIONS: Current rcCBCT image quality allows assessment of tumors located more peripherally. Significant tumor regression was documented in the majority of patients. In view of these observations, the suitability of adaptive radiotherapy in radical lung cancer treatment should be further investigated.

Radiation recall dermatitis triggered by multi-targeted tyrosine kinase inhibitors: sunitinib and sorafenib.

Small molecule tyrosine kinase inhibitors are rapidly being integrated into the management of cancer. This is the first report of sorafenib and sunitinib, both small molecule tyrosine kinase inhibitors of vascular endothelial growth factor and platelet-derived growth factor receptors, triggering radiation recall dermatitis. The pathophysiology of radiation recall is poorly understood, and several possible mechanisms have been proposed. The clinical presentations of these two cases were consistent with one hypothesized mechanism of radiation recall, an idiosyncratic drug hypersensitivity reaction.

Chest wall pain and rib fracture after stereotactic radiotherapy for peripheral non-small cell lung cancer.

Stereotactic body radiotherapy is an emerging treatment option for peripheral non-small cell lung cancer in medically inoperable patients. With high dose per fraction radiotherapy, late side effects are of possible concern. In our initial cohort of 42 patients treated with 54 to 60 Gy in three fractions, nine patients have rib fracture. The median dose to rib fracture sites was 46 to 50 Gy, depending on the method of dose calculation. We describe a typical case of poststereotactic radiotherapy rib fracture and present dosimetric analysis of patients with rib fracture.

Use of palliative radiotherapy trials for clinical biomarker development.

INTRODUCTION: Approximately one quarter of all cancer patients will require palliative radiation treatment at some point during the course of their disease, but only a minority of these patients are entered in clinical trials. ETHICAL ASSESSMENT OF BIOMARKERS IN PALLIATIVE RADIOTHERAPY TRIALS: We review the literature debating the ethics of inclusion of "palliative" patients on clinical trials. We suggest that these patients provide a potentially valuable resource that can be leveraged to facilitate the discovery and validation of biomarkers predictive of radiation response and toxicity. In addition, this patient population offers valuable opportunities to test combination of radiation and targeted therapies to screen for activity, toxicity and biomarkers in a relatively safe manner. CONCLUSION: Patients undergoing palliative radiation therapy may provide new opportunities for the development and testing of predictive radiotherapy biomarkers as well as affording opportunities to test combinations of radiation and targeted therapies.

Heat-directed tumor cell fusion.

In previous studies we demonstrated that a modified human HSP70b promoter (HSE.70b) directs high levels of gene expression to tumor cells after mild hyperthermia treatment in the range of 41.5-44 degrees C. This transcriptional targeting system exhibits low basal activity at 37 degrees C, is highly induced (950-fold) after mild heat treatment (43 degrees C/30 min), and returns to basal activity levels within 12-24 hours of activation. Here we describe heat-directed targeting of an activated form of the Gibbon ape leukemia virus env protein (GALV FMG) to tumor cells. GALV FMG mediates cell-cell fusion, and when expressed in tumor cells can produce bystander effects of up to 1:200. Transient transfection of a HSE70b.GALV FMG minigene caused extensive syncytia formation in HeLa and HT-1080 cells following mild heat treatment (44 degrees C/30 min). Stable transfection into HT-1080 cells produced a cell line (HG5) that exhibits massive syncytia formation and a 60% reduction in viability relative to a vector-only control (CI1) following heat treatment in vitro. Mild hyperthermia also resulted in syncytia formation, necrosis, and complete macroscopic regression of HG5 xenograft tumors grown in the footpads of mice with severe combined immunodeficiency disorders (SCID). Median survival increased from 12.5 (in heated CI1 controls) to 52 days after a single heat treatment. Heat-directed tumor cell fusion may prove to be a highly beneficial adjunct to existing cancer treatment strategies that take advantage of the synergistic interaction between mild hyperthermia and radiation or chemotherapeutic drugs.

Heat-directed suicide gene therapy for breast cancer.

Adjuvant hyperthermia can improve treatment outcome for locally recurrent breast cancer (LRBC). Previously, we demonstrated that infection of human breast cancer cells with a recombinant adenovirus expressing beta-galactosidase from the human hsp70b gene promoter (Ad.70b.betagal) results in 50- to 800-fold increases in reporter gene expression following heat treatment (30 minutes at 43 degrees C). Here, we describe a heat-directed suicide gene therapy strategy based on an adenoviral vector (Ad.70b.CDTK) in which expression of the dual prodrug-activating E. coli cytosine deaminase/herpes simplex virus thymidine kinase (CDTK) fusion gene is under the control of the hsp70b promoter. Treatment of T47D and MCF-7 breast cancer cells with mild hyperthermia (43 degrees C/30 minutes) and prodrugs (100 microg/ml 5-fluorocytosine and 10 microg/ml ganciclovir) following infection with Ad.70b.CDTK (10-100 PFU/cell) resulted in 30- to 60-fold decreases in clonogenic survival relative to control cultures treated with heat or prodrugs alone. Clonogenic survival declined even further (up to 240-fold) following heat treatment at 41.5 degrees C for 120 minutes. A decreased clonogenic survival was accompanied by tumor cell apoptosis. These results demonstrate that this combined treatment strategy can be highly effective against heat- and radiation-resistant breast tumor cells and supports the continued development of heat-directed CDTK suicide gene therapy strategies for LRBC.