Rôle de la TEP au 18F-FDG dans l’évaluation des volumes cibles chez des patients atteints de CBNPC traités par radiochimiothérapie

Currently ¹⁸F-FDG-PET is the gold standard to evaluate tumor response after chemotherapy in patients with advanced or metastatic non-small cell lung cancer (NSCLC). PET can also determine the volumes to be treated by radiotherapy, in inoperable patients. The aim of our mixed (prospective and retrospective) study concerned 28 patients with NSCLC, was to quantify the variation of the metabolic activity of lesions and their volumes after chemotherapy. We also studied the impact of change of these volumes on the definition of radiotherapy target volumes. Patients with stage II–IV and inoperable NSCLC were included. Two PET scans were performed: before treatment (PET1), then after two to six courses of chemotherapy (PET2). Of the 28 patients included, we observed complete metabolic response in six patients (21%), partial metabolic response in 13 patients (46%), stable disease in seven patients (25%), and progressive metabolic disease in two patients (7%), according to the PERCIST criteria. We observed significant variation (P < 0.001) of metabolic activity (estimated by SULpeak or SUVmax) for primary tumor as well as for overall lesions between the two PET scans. Thus, the target volumes of radiotherapy decreased significantly (P < 0.01) in PET2. Our results confirm that ¹⁸F-FDG-PET is not only a powerful technique for treatment evaluation but also a useful tool for radiotherapy planning after chemotherapy, in the context of personalized treatments.     

Study of gold nanoparticles for mammography diagnostic and radiotherapy improvements

AimA study on the possibility to use gold nanoparticles in mammography, both for a better image diagnostics and radiotherapy, is presented and discussed. We evaluate quantitatively the increment of dose released to the tumor enriched with Au-NPs with respect to the near healthy tissues, finding that for X-rays the increase can reach two orders of greater intensity.BackgroundGold nanoparticles continue to be investigated for their potential to improve existing therapies and to develop novel therapies. They are simple to obtain, can be functionalized with different chemical approaches, are stable, non-toxic, non-immunogenic and have high permeability and retention effects in the tumor cells. The possibility to use these for breast calcified tumors to be better treated by radiotherapy is presented as a possible method to destroy the tumor.Materials and methodsThe nanoparticles can be generated in water using the top-down method, should have a size of the order of 10–20 nm and be treated to avoid their coalescence. Under diagnostic X-ray monitoring, the solution containing nanoparticles can be injected locally inside the tumor site avoiding injection in healthy tissues. The concentrations that can be used should be of the order of 10 mg/ml or higher.ResultsAn enhancement of the computerized tomography diagnostics using 80–150 keV energy is expected, due to the higher mass X-ray coefficient attenuation with respect to other contrast media. Due to the increment of the effective atomic number of the biological tissue containing the gold nanoparticles, also an improvement of the radiotherapy effect using about 30 keV X-ray energy is expected, due to the higher photoelectric cross sections involved.ConclusionsThe study carried out represents a feasibility proposal for the use of Au-nanoparticles for mammographic molecular imaging aimed at radiotherapy of tumor nodules but no clinical results are presented.     

The Pulmonary Fibrosis Associated MUC5B Promoter Polymorphism Is Prognostic of the Overall Survival in Patients with Non–Small Cell Lung Cancer (NSCLC) Receiving Definitive Radiotherapy

BACKGROUND: MUC5B is glycoprotein secreted by bronchial glands. A promoter variant in MUC5B, rs35705950, was previously found to be strongly associated with the incidence of idiopathic pulmonary fibrosis (IPF) and also the overall survival (OS) of such patients. Patients with IPF and patients with radiation pneumonitis (RP) have the similar pathologic process and clinical symptoms. However, the role of rs35705950 in patients receiving thoracic radiotherapy remains unclear. PATIENTS AND METHODS: In total, 664 patients with NSCLC receiving definitive radiotherapy (total dose ≥60 Gy) were included in our study. RP was scored via the Common Terminology Criteria for Adverse Events v3.0. OS was the second end point. MUC5B rs35705950 was genotyped, and Kaplan-Meier and Cox regression analyses were used to evaluate associations between MUC5B rs35705950 and the risk of RP or OS. RESULTS: The median patient age was 66 years (range 35-88); most (488 [73.2%]) had stage III of the disease. Until the last follow-up, 250 patients developed grade ≥ 2 RP, 82 patients developed grade ≥ 3 RP, and 440 patients died. The median mean lung dose was 17.9 Gy (range 0.15-32.74). No statistically significant associations were observed between genotypes of MUC5B rs35705950 and the incidence of RP ≥ grade 2 either in univariate analysis (hazard ratio [HR] 1.009, 95% confidence interval [CI] 0.728-1.399, P = .958) or in multivariate analysis (HR 0.921, 95% CI 0.645-1.315, P = .65). Similar results were also observed for RP ≥ grade 3, while TT/GT genotypes in MUC5B were significantly associated with poor OS in both univariate analysis (HR 1.287, 95% CI 1.009-1.640, P = .042) and multivariate analysis (HR 1.561, 95% CI 1.193-2.042, P = .001). CONCLUSION: MUC5B promoter polymorphism could be prognostic of the OS among NSCLC patients receiving definitive radiotherapy, although no significant associations were found with the risk of RP.     

Pulmonary CYP2A13 levels are associated with early occurrence of lung cancer—Its implication in mutagenesis of non-small cell lung carcinoma

CYP2A13, a human pulmonary specific cytochrome P450 enzyme, plays an important role in susceptibility to tobacco-specific nitrosamines (TSNAs)-induced lung cancer in humans. The pattern of CYP2A13 distribution in respiratory tract affects the susceptibility of the lung to carcinogens. CYP2A13 is expressed in the epithelium of trachea and bronchi; however its pattern of expression in human lung cancer remains largely unknown. This study aimed to determine the CYP2A13 expression in specimens from human non-small cell lung carcinomas (NSCLCs), i.e., adenocarcinoma and squamous carcinoma, by immunohistochemical (IHC) analysis and to identify the potential linkage between tumor CYP2A13 levels and some clinicopathological characteristics of NSCLC patients in Taiwan. The tumor CYP2A13 IHC staining signal was strong in 76% of the 112 study subjects. Study subjects (especially non-smoking or lung adenocarcinoma patients) with higher tumor CYP2A13 levels were younger. Multiple logistic regression analysis revealed that in younger subjects (age ≤ 66) and heavy smokers (pack-years ≥ 40), the odds ratio (OR) for positive tumor CYP2A13 staining was significantly higher than that for negative tumor CYP2A13 staining. Moreover, the association of EGFR gene mutations and positive tumor CYP2A13 staining was also revealed. In conclusion, these findings suggest the potential involvement of pulmonary CYP2A13 in the early occurrence of NSCLC as well as in the development of EGFR gene mutations.     

Nanoparticle-aided external beam radiotherapy leveraging the Čerenkov effect

This study investigates the feasibility of exploiting the Čerenkov radiation (CR) present during external beam radiotherapy (EBRT) for significant therapeutic gain, using titanium dioxide (titania) nanoparticles (NPs) delivered via newly designed radiotherapy biomaterials. Using Monte Carlo radiation transport simulations, we calculated the total CR yield inside a tumor volume during EBRT compared to that of the radionuclides. We also considered a novel approach for intratumoral titania delivery using radiotherapy biomaterials (e.g. fiducials) loaded with NPs. The intratumoral distribution/diffusion of titania released from the fiducials was calculated. To confirm the CR induced enhancement in EBRT experimentally, we used 6 MV radiation to irradiate human lung cancer cells with or without titania NPs and performed clonogenic assays. For a radiotherapy biomaterial loaded with 20 μg/g of 2-nm titania NPs, at least 1 μg/g could be delivered throughout a tumor sub-volume of 2-cm diameter after 14 days. This concentration level could inflict substantial damage to cancer cells during EBRT. The Monte Carlo results showed the CR yield by 6 MV radiation was higher than by the radionuclides of interest and hence greater damage might be obtained during EBRT. In vitro study showed significant enhancement with 6 MV radiation and titania NPs. These preliminary findings demonstrate a potential new approach that can be used to take advantage of the CR present during megavoltage EBRT to boost damage to cancer cells. The results provide significant impetus for further experimental studies towards the development of nanoparticle-aided EBRT powered by the Čerenkov effect.     

Translational and rotational localization errors in cone-beam CT based image-guided lung stereotactic radiotherapy

PurposeAccurate localization is crucial in delivering safe and effective stereotactic body radiation therapy (SBRT). The aim of this study was to analyse the accuracy of image-guidance using the cone-beam computed tomography (CBCT) of the VERO system in 57 patients treated for lung SBRT and to calculate the treatment margins.Materials and methodsThe internal target volume (ITV) was obtained by contouring the tumor on maximum and mean intensity projection CT images reconstructed from a respiration correlated 4D-CT. Translational and rotational tumor localization errors were identified by comparing the manual registration of the ITV to the motion-blurred tumor on the CBCT and they were corrected by means of the robotic couch and the ring rotation. A verification CBCT was acquired after correction in order to evaluate residual errors.ResultsThe mean 3D vector at initial set-up was 6.6 ± 2.3 mm, which was significantly reduced to 1.6 ± 0.8 mm after 6D automatic correction. 94% of the rotational errors were within 3°. The PTV margins used to compensate for residual tumor localization errors were 3.1, 3.5 and 3.3 mm in the LR, SI and AP directions, respectively.ConclusionsOn-line image guidance with the ITV–CBCT matching technique and automatic 6D correction of the VERO system allowed a very accurate tumor localization in lung SBRT.     

Pirfenidone inhibits motility of NSCLC cells by interfering with the urokinase system

Pirfenidone (PFD) is an orally available synthetic drug which has been approved for the treatment of idiopathic pulmonary fibrosis. In addition to its anti-fibrotic properties, PFD also exerts anti-tumor effects in cancer models by inducing alterations in the tumor microenvironment. Here, we demonstrate that PFD reduces proliferation, 2D- and 3D-migration as well as colony formation of the non-small-cell lung carcinoma (NSCLC) cells. On a molecular level, we show that PFD on the one hand interacts with plasminogen activator inhibitor-1 (PAI-1; K_d of 46.2 ± 11.3 nM) and affects its inhibitory potency, but on the other hand it also increases PAI-1 expression; in both cases consequently leading to the reduction of urokinase (uPA) activity. Finally, we report that the effect of PFD on 2D-migration of NSCLC cells depends on PAI-1 expression and thus on the activity of the uPA system whereas the PFD-induced changes in cancer cell proliferation, 3D-migration and colony formation are PAI-1 independent. To conclude, a direct interference of PFD with the uPA-PAI-1 system may deregulate pericellular proteolytic activity and thereby influence the stability of the tumor blood vessels and the matrix architecture within tumor stroma.     

Tolerability and toxicity of prophylactic cranial irradiation in patients with non-small cell lung cancer – Results of a phase II study (with estimation of hematological toxicity,pituitary function and magnetic resonance spectra changes)

AimTo evaluate the tolerability and toxicity of PCI in patients with NSCLC.BackgroundProphylactic cranial irradiation (PCI) is a standard treatment for patients with small cell lung cancer. There are data showing a decreasing ratio of brain metastases after PCI for non-small cell lung cancer (NSCLC-non small cell lung cancer) patients but, so far, there is no evidence for increasing overall survival. The main concern in this setting is the tolerance and toxicity of the treatment.Materials and methodsFrom 1999 to 2007, 50 patients with NSCLC treated with radical intent underwent PCI (30 Gy in 15 fractions). Mean follow-up was 2.8 years. The tolerability and hematological toxicity were evaluated in all patients, a part of participants had done neuropsychological tests, magnetic resonance imaging with ¹H nuclear magnetic resonance spectra, and estimation of pituitary function.ResultsDuring follow-up, 20 patients developed distant metastases, 4-brain metastases. Fourteen (30%) patients had acute side effects: (headache, nausea, erythema of the skin). The symptoms did not require treatment breaks. Six patients complained of late side effects (vertigo, nausea, anxiety, lower extremity weakness, deterioration of hearing and olfactory hyperesthesia). Hematological complications were not observed. Testosterone levels tended to decrease (p = 0.062). Visual-motor function deteriorated after treatment (p < 0.059). Performance IQ decreased (p < 0.025) and the difference between performance IQ and verbal IQ increased (p < 0.011). Degenerative periventricular vascular changes were observed in two patients. Analysis of the spectroscopic data showed metabolic but reversible alterations after PCI.ConclusionPCI in the current series was well tolerated and associated with a relatively low toxicity.     

No diagnostic impact of routinely use of respiratory gating to characterize lung nodules with 18F-FDG PET/CT

Purpose

To evaluate diagnostic impact of routinely use of respiratory gated (RG) ¹⁸FDG PET/CT to distinguish benign and malignant lung nodules.

Pituitary Hormone Dysfunction After Proton Beam Radiation Therapy in Children with Brain Tumors

Objectiveo characterize endocrine dysfunction in pediatric patients with brain tumors who received proton beam (PB) radiation therapy and to compare those treated with PB radiotherapy only versus combined conventional and PB irradiation.MethodsA retrospective review of medical records of patients ≤ 18 years of age who received PB radiation therapy for a brain tumor between 2000 and 2008 was performed. Variables analyzed included patient demographics, tumor type, therapeutic modalities, radiation doses, and types and timing of endocrine dysfunction.ResultsThirty-eight patients were identified, of whom 31 (19 boys and 12 girls; mean age, 11.9 ± 3.3 years) had undergone endocrine evaluation. Of these patients, 19 received PB radiotherapy only and 12 received conventional plus PB irradiation. Before irradiation, a cranial surgical procedure was performed in 28 study subjects, and 22 received chemotherapy. The mean duration of follow-up after radiation therapy was 1.8 ± 0.8 years. Nine patients (47%) in the PB only group and 4 (33%) in the conventional plus PB group developed endocrine dysfunction (no significant difference) after cranial irradiation. Children with endocrine sequelae treated with PB irradiation alone received fewer cobalt gray equivalents than those treated with conventional plus PB irradiation (5,384 ± 268 versus 5,775 ± 226, respectively; P < .02), and pituitary hormone deficiencies were detected later during follow-up in those who received PB radiotherapy only versus conventional plus PB irradiation (1.17 ± 0.4 years versus 0.33 ± 0.11 year, respectively; P < .01).ConclusionA high rate of endocrine sequelae was seen in our study. Children with brain tumors treated with conventional plus PB irradiation developed endocrine dysfunction faster and received a higher radiation dose than those receiving PB radiotherapy only. Prior surgical treatment and chemotherapy were additional risk factors. Large prospective studies are needed to evaluate further the incidence of endocrine sequelae after PB irradiation in children. (Endocr Pract. 2011;17:891-896)     

Incidence of radiation toxicity in cervical cancer and endometrial cancer patients treated with radiotherapy alone versus adjuvant radiotherapy

AimThe study was made to evaluate early and late toxicity in a diversified group of patients receiving definitive or adjuvant radiotherapy in terms of clinical diagnosis and treatment methods.BackgroundRadiotherapy is a standard way of treatment in cervical and endometrial cancer patients, both as definitive and adjuvant therapy. But every radiation treatment may be involved with toxicity.Materials and methodsA detailed analysis was performed of 263 patients with gynaecological cancer treated with definitive (90 patients with cervical cancer received radiochemotherapy or radiotherapy exclusively) and adjuvant radiotherapy (38 with cervical and 135 with endometrial cancer).ResultsAcute reactions were found in 51.3% and late reactions were found in 14.8% of patients. It was stated that early (p < 0.007) and late (p < 0.003) post radiation reaction appear more frequently in women treated with definitive than adjuvant radiotherapy. The analysis of the whole group revealed higher rate of toxicity, both early and late, in the gastrointestinal tract than in the urinary system (p < 0.004). Comparing the subgroups, it was found that intestinal reactions occurred more frequently in the definitive radiotherapy group than in the adjuvant one.The occurrence of side effects was associated with the prolongation of total irradiation time due to necessary interruptions of radiotherapy. The comparison of the subgroups showed that interruptions occurred more frequently in patients receiving definitive rather than adjuvant radiotherapy (17.7–2.9%).ConclusionsDefinitive radiotherapy compared with adjuvant treatment may by associated with higher percentage of side effects caused by dose of therapy and correlation with chemotherapy.     

Curcumin induces apoptosis and inhibits growth of orthotopic human non-small cell lung cancer xenografts

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality. Curcumin is involved in various biological pathways leading to inhibition of NSCLC growth. The purpose of this study was to evaluate the effect of curcumin on expression of nuclear factor κB-related proteins in vitro and in vivo and on growth and metastasis in an intralung tumor mouse model.H1975 NSCLC cells were treated with curcumin (0–50 μM) alone, or combined with gemcitabine or cisplatin. The effects of curcumin were evaluated in cell cultures and in vivo, using ectopic and orthotopic lung tumor mouse models. Twenty mice were randomly selected into two equal groups, one that received AIN-076 control diet and one that received the same food but with the addition of 0.6% curcumin 14 days prior to cell implantation and until the end of the experiment. To generate orthotopic tumor, lung cancer cells in Matrigel were injected percutaneously into the left lung of CD-1 nude mice. Western blot analysis showed that the expressions of IkB, nuclear p65, cyclooxygenase 2 (COX-2) and p-ERK1/2 were down-regulated by curcumin in vitro. Curcumin potentiated the gemcitabine- or cisplatin-mediated antitumor effects. Curcumin reduced COX-2 expression in subcutaneous tumors in vivo and caused a 36% decrease in weight of intralung tumors (P=.048) accompanied by a significant survival rate increase (hazard ratio=2.728, P=.036). Curcumin inhibition of COX-2, p65 expression and ERK1/2 activity in NSCLC cells was associated with decreased survival and increased induction of apoptosis. Curcumin significantly reduced tumor growth of orthotopic human NSCLC xenografts and increased survival of treated athymic mice. To evaluate the role of curcumin in chemoprevention and treatment of NSCLC, further clinical trials are required.     

Monte Carlo study on the secondary cancer risk estimations for patients undergoing prostate radiotherapy: A humanoid phantom study

AimThe aim of this study was to estimate the secondary malignancy risk from the radiation in FFB prostate linac-based radiotherapy for different organs of the patient.BackgroundRadiation therapy is one of the main procedures of cancer treatment. However, the application the radiation may impose dose to organs of the patient which can be the cause of some malignancies.Materials and methodsMonte Carlo (MC) simulation was used to calculate radiation doses to patient organs in 18 MV linear accelerator (linac) based radiotherapy. A humanoid MC phantom was used to calculate the equivalent dose s for different organs and probability of secondary cancer, fatal and nonfatal risk, and other risks and parameters related to megavoltage radiation therapy. In out-of-field radiation calculation, it could be seen that neutrons imparted a higher dose to distant organs, and the dose to surrounding organs was mainly due to absorbed scattered photons and electron contamination.ResultsOur results showed that the bladder and skin with 54.89 × 10⁻³ mSv/Gy and 46.09 × 10⁻³ mSv/Gy, respectively, absorbed the highest equivalent dose s from photoneutrons, while a lower dose was absorbed by the lung at 3.42 × 10⁻³ mSv/Gy. The large intestine and bladder absorbed 55.00 × 10⁻³ mSv/Gy and 49.08 × 10⁻³, respectively, which were the highest equivalent dose s due to photons. The brain absorbed the lowest out-of-field dose, at 1.87 × 10⁻³ mSv/Gy.ConclusionsWe concluded that secondary neutron portion was higher than other radiation. Then, we recommended more attention to neutrons in the radiation protection in linac based high energy radiotherapy.     

非小细胞肺癌患者血清淀粉样蛋白A水平与放射性肺炎的相关性研究

目的:评估非小细胞肺癌患者血清淀粉样蛋白A(SAA)水平与发生放射性肺炎(RP)的相关性。方法:选取我院确诊为非小细胞肺进行肺部病灶放射治疗的患者118例,评价是否发生放射性肺炎,并在放疗前及放疗剂量达到43 GY时分别抽取患者血清样本,应用酶联免疫法(ELISA)检测患者血清淀粉样蛋白A含量。结果:43例患者发生了放射性肺炎,发生放射性肺炎组患者的放疗前血清淀粉样蛋白A水平明显高于未发生放射性肺炎组,两组对比,差异有统计学意义(P0.05)。而在放疗剂量达到43Gy时,发生放射性肺炎组患者的血清淀粉样蛋白A水平与未发生放射性肺炎组患者相比,差别无统计学意义。结论:对于非小细胞肺癌患者,通过检测放疗前血清淀粉样蛋白A水平可以预测放射性肺炎的发生。     

P2X7 receptor as predictor gene for glioma radiosensitivity and median survival

Glioblastoma multiforme (GBM) is considered the most lethal intracranial tumor and the median survival time is approximately 14 months. Although some glioma cells present radioresistance, radiotherapy has been the mainstay of therapy for patients with malignant glioma. The activation of P2X7 receptor (P2X7R) is responsible for ATP-induced death in various cell types. In this study, we analyzed the importance of ATP-P2X7R pathway in the radiotherapy response P2X7R silenced cell lines, in vivo and human tumor samples. Both glioma cell lines used in this study present a functional P2X7R and the P2X7R silencing reduced P2X7R pore activity by ethidium bromide uptake. Gamma radiation (2 Gy) treatment reduced cell number in a P2X7R-dependent way, since both P2X7R antagonist and P2X7R silencing blocked the cell cytotoxicity caused by irradiation after 24 h. The activation of P2X7R is time-dependent, as EtBr uptake significantly increased after 24 h of irradiation. The radiotherapy plus ATP incubation significantly increased annexin V incorporation, compared with radiotherapy alone, suggesting that ATP acts synergistically with radiotherapy. Of note, GL261 P2X7R silenced-bearing mice failed in respond to radiotherapy (8 Gy) and GL261 WT-bearing mice, that constitutively express P2X7R, presented a significant reduction in tumor volume after radiotherapy, showing in vivo that functional P2X7R expression is essential for an efficient radiotherapy response in gliomas. We also showed that a high P2X7R expression is a good prognostic factor for glioma radiosensitivity and survival probability in humans. Our data revealed the relevance of P2X7R expression in glioma cells to a successful radiotherapy response, and shed new light on this receptor as a useful predictor of the sensitivity of cancer patients to radiotherapy and median survival.     

Detection of risk factors that influence weight loss in patients undergoing radiotherapy

AimTo identify risk factors that influence weight loss in patients receiving radiotherapy.BackgroundIt is a well-known fact that cancer patients can be affected by malnutrition at the onset of the disease and during treatment due to the toxicity. Pretreatment weight loss alone does not predict those who will need nutritional supplementation. Instead, a variety of nutritional and tumor related factors needs to be taken into account.Material and methodsA retrospective study was conducted on 129 patients with different tumor locations. Weight loss was evaluated during radiotherapy and one month after treatment. The impact of age, ECOG, chemotherapy, pretreatment weight loss, tumor location, previous surgery and TNM were analyzed. We aimed to identify a high-risk group of patients before starting treatment.ResultsThe average net weight loss during radiotherapy and one month after treatment for this group of patients was 0.68 kg and 1.6 kg, respectively. Median weight loss during radiotherapy was 2.6 kg for head and neck (HN) patients and 0.27  kg for other tumor sites (p = 0.028). Median weight loss one month after radiotherapy was 3.7 kg for HN patients and 1.1 kg for the rest of the patients (p = 0.034). The median weight loss one month after treatment was 3.2 kg for patients receiving chemotherapy and 0.5 kg for those patients who did not receive chemotherapy (p < 0.001). A regression analysis determined that HN tumor location and the use of chemotherapy were independent risk factors.ConclusionsNutritional status must be monitored and managed before, during and after treatment. A variety of nutritional and tumor-related factors must be considered. According to our results, head and neck tumors and the use of chemotherapy are the only two factors considered statistically significant. Because patients continue to lose weight after treatment, we recommend close surveillance after radiotherapy.     

Radiosensitization of Pancreatic Cancer Cells In Vitro and In Vivo through Poly (ADP-ribose) Polymerase Inhibition with ABT-888

OBJECTIVESTo determine whether poly (ADP-ribose) polymerase-1/2 (PARP-1/2) inhibition enhances radiation-induced cytotoxicity of pancreatic adenocarcinoma in vitro and in vivo, and the mechanism by which this occurs.MethodsPancreatic carcinoma cells were treated with ABT-888, radiation, or both. In vitro cell viability, apoptosis, and PARP activity were measured. Orthotopic xenografts were generated in athymic mice and treated with ABT-888 (25 mg/kg), radiation (5 Gy), both, or no treatment. Mice were monitored with bioluminescence imaging.RESULTSIn vitro, treatment with ABT-888 and radiation led to higher rates of cell death after 8 days (P < .01). Co-treatment with 5 Gy and 1, 10 or 100 μmol/l of ABT-888 led to dose enhancement factors of 1.29, 1.41 and 2.36, respectively. Caspase activity was not significantly increased when treated with ABT-888 (10 μmol/l) alone (1.28-fold, P = .08), but became significant when radiation was added (2.03-fold, P < .01). PARP activity increased post-radiation and was abrogated following co-treatment with ABT-888. In vivo, treatment with ABT-888, radiation or both led to tumor growth inhibition (TGI) of 8, 30 and 39 days, and survival at 60 days of 0%, 0% and 40%, respectively.CONCLUSIONSABT-888 with radiation significantly enhanced tumor response in vitro and in vivo. ABT-888 inhibited PAR protein polymerization resulting in dose-dependent feedback up-regulation of PARP and p-ATM suggesting increased DNA damage. This translated into enhancement in TGI and survival with radiation in vivo. In vitro PAR levels correlated with levels of tumor apoptosis suggesting potential as a predictive biomarker. These data are being used to support a Phase I study in locally advanced pancreatic cancer.     

Comparison of neoadjuvant oral chemotherapy with UFT plus Folinic acid or Capecitabine concomitant with radiotherapy on locally advanced rectal cancer

AimTo evaluate the differences in treatment response and the impact on survival with both oral agents (UFT and Capecitabine) as neoadjuvant chemotherapy administered concomitantly with radiotherapy.BackgroundThere are still no studies comparing the use of neoadjuvant oral chemotherapy either with UFT plus Folinic acid or Capecitabine concomitant with radiotherapy in locally advanced rectal cancer (LARC).Materials and methodsA set of 112 patients with LARC were treated preoperatively. GROUP 1 – 61 patients underwent concomitant oral chemotherapy with Capecitabine (825 mg/m² twice daily). GROUP 2 – 51 patients submitted to concomitant oral chemotherapy with UFT (300 mg/m²/d) + Folinic acid (90 mg/d) and radiotherapy. 57.1% of patients were submitted to adjuvant chemotherapy.ResultsGROUP 1: acute toxicity – 80.3%; pathological complete response (pCR) – 10.5%; tumor downstaging (TD) – 49.1%; nodal downstaging (ND) – 76.5%; loco-regional response (LRR) – 71.9%; toxicity to adjuvant chemotherapy – 75%. GROUP 2: acute toxicity – 80.4%; pCR – 28%; TD – 62%; ND – 75.6%; LRR – 78%; toxicity to adjuvant chemotherapy – 56%. There was no difference in survival nor loco-regional control between the groups.ConclusionsPatients treated with neoadjuvant oral UFT + Folinic acid had a higher rate of pathologic complete response than patients treated with Capecitabine concomitant with radiotherapy. There were no differences in downstaging, LRR, toxicity, survival or loco-regional control between both groups. There was a trend to a higher rate of toxicity to adjuvant chemotherapy in the Capecitabine group.