Search

Purpose Chemotherapy and concurrent thoracic radiation therapy (CCTRT) followed by prophylactic cranial irradiation (PCI) is the standard of care for limited-stage small cell lung cancer (LS-SCLC). We aimed to compare the efficacy and toxicity of moderately hypofractionated once-daily CCTRT with that of a standard twice-daily regimen. Methods and Materials This multicenter, phase 2, randomized study enrolled patients aged 18 to 75 years old who had pathologically confirmed LS-SCLC and an Eastern Cooperative Oncology Group performance status of 0 to 1. Eligible patients received 4 to 6 cycles of etoposide-cisplatin chemotherapy and were randomized to receive twice-daily CCTRT at 45 Gray (Gy) in 30 fractions or once-daily CCTRT at 65 Gy in 26 fractions, commencing with cycles 1 to 3 of chemotherapy. PCI was given to good responders. The primary endpoint was progression-free survival (PFS). Results The analyses included 182 patients, with 94 in the twice-daily group and 88 in the once-daily group. CCTRT started with cycle 3 of chemotherapy for most patients (80.2%). At a median follow-up of 24.3 months, the median PFS was 13.4 months (95% confidence interval [CI], 10.8-16.0) in the twice-daily group versus 17.2 months (95% CI, 11.8-22.6) in the once-daily group (P = .031), with 2-year PFS rates of 28.4% (95% CI, 18.2-38.6) and 42.3% (95% CI, 31.1-53.5), respectively. The estimated overall survival was 33.6 months in the twice-daily group versus 39.3 months in the once-daily group (P = .137). The median locoregional PFS was 23.9 months in the twice-daily group and was not reached in the once-daily group (P = .017). The incidences of most toxicities were similar in both groups, except for a higher incidence of ≥grade 3 acute lymphopenia in the once-daily group (71.7% vs 40.2% in the twice-daily group; P Conclusions Moderately hypofractionated, once-daily CCTRT showed improved PFS and similar toxicities compared with twice-daily CCTRT in LS-SCLC. This regimen should be evaluated for comparison in a phase 3 randomized trial.

Purpose Telomerase is reactivated in non-small cell lung cancer (NSCLC), and it increases cell resistance to irradiation through protecting damaged telomeres and enhancing DNA damage repair. We investigated the radiosensitizing effect of BIBR1532, a highly selective telomerase inhibitor, and its corresponding mechanism in NSCLC. Methods and Materials Cell proliferation, telomerase activity, and telomere dysfunction-induced foci were measured with CCK-8 assay, real-time fluorescent quantitative polymerase chain reaction, and immunofluorescence. The effect of BIBR1532 on the response of NSCLC cells to radiation was analyzed using clonogenic survival and xenograft tumor assays. Cell death and cell senescence induced by BIBR1532 or ionizing radiation (IR), or both, were detected with western blotting, flow cytometry, and senescence-association β-galactosidase staining assay. Results We observed dose-dependent direct cytotoxicity of BIBR1532 at relatively high concentrations in NSCLC cells. Low concentrations of BIBR1532 did not appear toxic to NSCLC cells; however, they substantially increased the therapeutic efficacy of IR in vitro by enhancing IR-induced apoptosis, senescence, and mitotic catastrophe. Moreover, in a mouse xenograft model, BIBR1532 treatment synergized with IR at nontoxic dose levels promoted the antitumor efficacy of IR without toxicity to hematologic and internal organs. Mechanistically, lower concentrations of BIBR1532 effectively inhibited telomerase activity and increased IR-induced telomere dysfunction, resulting in disruption of chromosomal stability and inhibition of the ATM/CHK1 (ataxia-telangiectasia-mutated/Checkpoint kinase 1) pathway, which impaired DNA damage repair. Conclusions Our findings demonstrate that disturbances in telomerase function by nontoxic dose levels of BIBR1532 effectively enhance the radiosensitivity of NSCLC cells. This finding provides a rationale for the clinical assessment of BIBR1532 as a radiosensitizer.

Purpose Clinical tools are unavailable for accurate prediction of pathologic responses to chemoradiation therapy (CRT) among patients with esophageal squamous cell carcinoma (ESCC) before surgery. We evaluated tumor remission and tumor-infiltrating lymphocytes (TILs) during CRT as predictors of pathologic response and prognostic markers for patients with locally advanced ESCC treated with neoadjuvant CRT (neo-CRT) or definitive CRT. Methods and Materials We analyzed patients with locally advanced ESCC (N = 164) who underwent neo-CRT (N = 48) or definitive CRT (N = 116). Patients underwent endoscopic ultrasonography and biopsies when induction CRT finished. Tumor remission characteristics were designated minor (–/+) to excellent remission (ER) (+++). TILs were determined in 10% increments. Tumor remission, TILs, or both were associated with pathologic complete response (pCR) and survival in the neo-CRT group and then analyzed in the definitive CRT group. Results ER and lymphocyte-predominant ESCC (LPE; ≥60% TILs) were identified according to the pCR rate and disease-free survival. We built a prediction model for pCR incorporating ER and LPE. The area under the receiver operating characteristic curve was 0.877, and sensitivity and specificity were 86.7% and 90.9%, respectively. Furthermore, this model identified pathologic response with an excellent calibration. Disease-free survival of patients with ER and LPE tumors was significantly longer than that of other patients. Conclusions When we included tumor remission and TILs during CRT, our model predicted pCR with high probability and helped stratify prognostic subgroups, thereby guiding future therapy decisions for patients with locally advanced ESCC. Validation of this model in larger, prospective, multicenter studies is essential.

SummaryHeat-shock protein isa biomarker of radiosensi-tivity. Patients with lungcancer and the HSPB1 CCgenotype at rs2868371 havebeen shown to be at higherrisk of radiation-inducedesophagitis and shortsurvival. We found thatpatients with this genotypewere also more likely to havesevere radiation-inducedpneumonitis after chemo-radiation. This SNP might be Purpose: To date, no biomarkers have been found to predict, before treatment, which patientswill develop radiation pneumonitis (RP), a potentially fatal toxicity, after chemoradiation forlung cancer. We investigated potential associations between single nucleotide polymorphisms(SNPs) in HSPB1 and risk of RP after chemoradiation for non-small cell lung cancer(NSCLC).Methods and Materials: Subjects were patients with NSCLC treated with chemoradiation at 1institution. The training data set comprised 146 patients treated from 1999 to July 2004; thevalidation data set was 125 patients treated from August 2004 to March 2010. We genotyped2 functional SNPs of HSPB1 (rs2868370 and rs2868371) from all patients. We used Kaplan-Meier analysis to assess the risk of grade 2or 3 RP in both data sets and a parametric log-logistic survival model to evaluate the association of HSPB1 genotypes with that risk.Results: Grade 3 RP was experienced by 13% of those with CG/GG and 29% of those withCC genotype of HSPB1 rs2868371 in the training data set (PZ.028); corresponding rates inthe validation data set were 2% CG/GG and 14% CC (PZ.02). Univariate and multivariateanalysis confirmed the association of CC of HSPB1 rs2868371 with higher risk of grade 3RP than CG/GG after adjustment for sex, age, performance status, and lung mean dose. Thisassociation was validated both in the validation data set and with Harrell’s C statistic.

Purpose/Objectives: It is reported that halofuginone can inhibit the transforming growth factor-beta1 (TGF-β1 ) signaling pathway. TGF-β1 signaling plays an important role in the invasive and metastatic behavior in many kind of malignancy. Radiation therapy may result in increased expression of TGF--β1 in tumor and surrounding tissues. We hypothesized that halofuginone may enhance the anti-tumor effect of radiation therapy in lung cancer.