Nicotinic modulation of therapeutic response in vitro and in vivo.

Tobacco use significantly increases the risk of developing cancer. Moreover, there is growing evidence that tobacco use decreases survival in cancer patients. Nicotine, a systemically available component of tobacco, is associated with tumor promotion and decreased apoptosis in cell culture; however, the role of nicotine on response to radiotherapy (RT) or chemoradiotherapy (CRT) in vivo has not been evaluated. Our study evaluated the effects of nicotine administration on cancer cell survival in cell culture and mouse models. Nicotine increased survival in two cell lines following RT in vitro. Nicotine administration in mice during fractionated RT or CRT increased xenograft regrowth as compared to RT or CRT alone. Nicotine increased hypoxia-inducible factor 1-alpha (HIF-1α) expression in tumor xenografts without altering expression of carbonic-anhydrase, a clinical marker of tumor hypoxia. The effects of nicotine on HIF-1α expression were transient, returning to baseline levels within 2-3 days after nicotine removal. Further mechanistic studies indicated that inhibition of phosphoinositide-3-kinase (PI3K) prevented nicotine-mediated increases in HIF-1α expression as well as the prosurvival effects of nicotine on RT. These findings imply that during tobacco use, nicotine may function as a systemic agent through acute and reversible regulation of HIF-1α expression and a decreased therapeutic response.

An International Consensus on the Design of Prospective Clinical-Translational Trials in Spatially Fractionated Radiation Therapy.

PURPOSE: Spatially fractionated radiation therapy (SFRT), which delivers highly nonuniform dose distributions instead of conventionally practiced homogeneous tumor dose, has shown high rates of clinical response with minimal toxicities in large-volume primary or metastatic malignancies. However, prospective multi-institutional clinical trials in SFRT are lacking, and SFRT techniques and dose parameters remain variable. Agreement on dose prescription, technical administration, and clinical and translational design parameters for SFRT trials is essential to enable broad participation and successful accrual to rigorously test the SFRT approach. We aimed to develop a consensus for the design of multi-institutional clinical trials in SFRT, tailored to specific primary tumor sites, to help facilitate development and enhance the feasibility of such trials. METHODS AND MATERIALS: Primary tumor sites with sufficient pilot experience in SFRT were identified, and fundamental trial design questions were determined. For each tumor site, a comprehensive consensus effort was established through disease-specific expert panels. Clinical trial design criteria included eligibility, SFRT technology and technique, dose and fractionation, target- and normal-tissue dose parameters, systemic therapies, clinical trial endpoints, and translational science considerations. Iterative appropriateness rank voting, expert panel consensus reviews and discussions, and public comment posting were used for consensus development. RESULTS: Clinical trial criteria were developed for head and neck cancer and soft-tissue sarcoma. Final consensus among the 22 trial design categories each (a total of 163 criteria) was high to moderate overall. Uniform patient cohorts of advanced bulky disease, standardization of SFRT technologies and dosimetry and physics parameters, and collection of translational correlates were considered essential to trial design. Final guideline recommendations and the degree of agreement are presented and discussed. CONCLUSIONS: This consensus provides design guidelines for the development of prospective multi-institutional clinical trials testing SFRT in advanced head and neck cancer and soft-tissue sarcoma through in-advance harmonization of the fundamental clinical trial design among SFRT experts, potential investigators, and the SFRT community.

Evaluation of antioxidant network proteins as novel prognostic biomarkers for head and neck cancer patients.

OBJECTIVES: Recurrence rates for head and neck squamous cell carcinoma (HNSCC) approach 50% at 5 years. Current staging fails to identify patients with a worse prognosis who might benefit from intensified treatment, which warrants improved prognostic biomarkers. The purpose of this retrospective case study is to identify potential prognostic biomarkers in patients with HNSCC including APE1 (DNA repair/redox gene regulator), NRF2 and PPARGC1A (redox gene regulators), SOD3 and DCN (antioxidant proteins). MATERIALS AND METHODS: Differential protein expression between benign, carcinoma in situ (CIS), and invasive HNSCC tissue specimens from 77 patients was assessed using immunohistochemistry. Protein expression was analyzed with multivariate, pair-wise, and Kaplan-Meier survival analyses to identify potential prognostic biomarkers. Utilizing The Cancer Genome Atlas's transcriptome database, pair-wise and survival analysis was performed to identify potential prognostic biomarkers. RESULTS: APE1, NRF2, PPARGC1A, SOD3, and DCN expression in HNSCC in relation to, lymph node invasion, and patient survival were examined. Elevated APE1 protein expression in CIS corresponded with reduced survival (p = 0.0243). Increased APE1 gene expression in stage T4a HNSCC was associated with reduced patient survival (p < 0.015). Increased PPARGC1A in invasive tumor correlated with reduced survival (p = 0.0281). Patients with lymph node invasion at diagnosis had significantly increased APE1 protein in the primary sites (p < 0.05). Patients with poorly differentiated invasive tumors had reduced PPARGC1A in CIS proximal to the invasive tumor and had elevated DCN and SOD3 in proximal benign tissue (p < 0.05). CONCLUSIONS: The expression of APE1, DCN, and SOD3 is a potential prognostic signature that identifies patients with worsened survival.

Fluorouracil vs gemcitabine chemotherapy before and after fluorouracil-based chemoradiation following resection of pancreatic adenocarcinoma: a randomized controlled trial.

CONTEXT: Among patients with locally advanced metastatic pancreatic adenocarcinoma, gemcitabine has been shown to improve outcomes compared with fluorouracil. OBJECTIVE: To determine if the addition of gemcitabine to adjuvant fluorouracil chemoradiation (chemotherapy plus radiation) improves survival for patients with resected pancreatic adenocarcinoma. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled phase 3 trial of patients with complete gross total resection of pancreatic adenocarcinoma and no prior radiation or chemotherapy enrolled between July 1998 and July 2002 with follow-up through August 18, 2006, at 164 US and Canadian institutions. INTERVENTION: Chemotherapy with either fluorouracil (continuous infusion of 250 mg/m2 per day; n = 230) or gemcitabine (30-minute infusion of 1000 mg/m2 once per week; n = 221) for 3 weeks prior to chemoradiation therapy and for 12 weeks after chemoradiation therapy. Chemoradiation with a continuous infusion of fluorouracil (250 mg/m2 per day) was the same for all patients (50.4 Gy). MAIN OUTCOME MEASURES: Survival for all patients and survival for patients with pancreatic head tumors were the primary end points. Secondary end points included toxicity. RESULTS: A total of 451 patients were randomized, eligible, and analyzable. Patients with pancreatic head tumors (n = 388) had a median survival of 20.5 months and a 3-year survival of 31% in the gemcitabine group vs a median survival of 16.9 months and a 3-year survival of 22% in the fluorouracil group (hazard ratio, 0.82 [95% confidence interval, 0.65-1.03]; P = .09). The treatment effect was strengthened on multivariate analysis (hazard ratio, 0.80 [95% confidence interval, 0.63-1.00]; P = .05). Grade 4 hematologic toxicity was 1% in the fluorouracil group and 14% in the gemcitabine group (P < .001) without a difference in febrile neutropenia or infection. There were no differences in the ability to complete chemotherapy or radiation therapy (>85%). CONCLUSIONS: The addition of gemcitabine to adjuvant fluorouracil-based chemoradiation was associated with a survival benefit for patients with resected pancreatic cancer, although this improvement was not statistically significant. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00003216.

Development and Validation of Nomograms Predictive of Overall and Progression-Free Survival in Patients With Oropharyngeal Cancer.

Purpose Treatment of oropharyngeal squamous cell carcinoma (OPSCC) is evolving toward risk-based modification of therapeutic intensity, which requires patient-specific estimates of overall survival (OS) and progression-free survival (PFS). Methods To develop and validate nomograms for OS and PFS, we used a derivation cohort of 493 patients with OPSCC with known p16 tumor status (surrogate of human papillomavirus) and cigarette smoking history (pack-years) randomly assigned to clinical trials using platinum-based chemoradiotherapy (NRG Oncology Radiation Therapy Oncology Group [RTOG] 0129 and 0522). Nomograms were created from Cox models and internally validated by use of bootstrap and cross-validation. Model discrimination was measured by calibration plots and the concordance index. Nomograms were externally validated in a cohort of 153 patients with OPSCC randomly assigned to a third trial, NRG Oncology RTOG 9003. Results Both models included age, Zubrod performance status, pack-years, education, p16 status, and T and N stage; the OS model also included anemia and age × pack-years interaction; and the PFS model also included marital status, weight loss, and p16 × Zubrod interaction. Predictions correlated well with observed 2-year and 5-year outcomes. The uncorrected concordance index was 0.76 (95% CI, 0.72 to 0.80) for OS and 0.70 (95% CI, 0.66 to 0.74) for PFS, and bias-corrected indices were similar. In the validation set, OS and PFS models were well calibrated, and OS and PFS were significantly different across tertiles of nomogram scores (log-rank P = .003;< .001). Conclusion The validated nomograms provided useful prediction of OS and PFS for patients with OPSCC treated with primary radiation-based therapy.

Accuracy of self-reported tobacco assessments in a head and neck cancer treatment population.

Prospective analysis was performed of self-reported and biochemically confirmed tobacco use in 50 head and neck cancer patients during treatment. With 93.5% compliance to complete weekly self-report and biochemical confirmatory tests, 29.4% of smokers required biochemical assessment for identification. Accuracy increased by 14.9% with weekly vs. baseline self-reported assessments. Data confirm that head and neck cancer patients misrepresent true tobacco use during treatment.