Characterization of a novel pesticide transporter and P-glycoprotein orthologues in Drosophila melanogaster.

Pesticides remain one of the most effective ways of controlling agricultural and public health insects, but much is still unknown regarding how these compounds reach their targets. Specifically, the role of ABC transporters in pesticide absorption and excretion is poorly understood, especially compared to the detailed knowledge about mammalian systems. Here, we present a comprehensive characterization of pesticide transporters in the model insect Drosophila melanogaster. An RNAi screen was performed, which knocked down individual ABCs in specific epithelial tissues and examined the subsequent changes in sensitivity to the pesticides spinosad and fipronil. This implicated a novel ABC drug transporter, CG4562, in spinosad transport, but also highlighted the P-glycoprotein orthologue Mdr65 as the most impactful ABC in terms of chemoprotection. Further characterization of the P-glycoprotein family was performed via transgenic overexpression and immunolocalization, finding that Mdr49 and Mdr50 play enigmatic roles in pesticide toxicology perhaps determined by their different subcellular localizations within the midgut. Lastly, transgenic Drosophila lines expressing P-glycoprotein from the major malaria vector Anopheles gambiae were used to establish a system for in vivo characterization of this transporter in non-model insects. This study provides the basis for establishing Drosophila as a model for toxicology research on drug transporters.

Using tissue specific P450 expression in Drosophila melanogaster larvae to understand the spatial distribution of pesticide metabolism in feeding assays.

Drug metabolizing enzymes such as cytochrome P450s have often been implicated in influencing levels of pesticide toxicology and resistance. Consequently, a variety of different P450 genes and variants have been linked to pesticide metabolism. Substantially less is known in regards to which tissues these P450s contribute to pesticide metabolism. Here, we isolate the effect of different tissues in pesticide toxicology by driving the model P450 Cyp6g1 in specific tissues of Drosophila melanogaster. Fluorescent and luminescent assays were used to compare the strength of GAL4 lines specific to the midgut (Mex-GAL4), Malpighian tubules (UO-GAL4) and the fat body (LSP2-GAL4) with the widely used HR-GAL4 line which drives GAL4 expression in all three tissues simultaneously. These data suggested that GAL4 drivers specific for the midgut and fat body were of approximately equal strength to the HR-GAL4 line, while the Malpighian tubule specific line was significantly weaker. Multiple toxicology assays using the pesticides bendiocarb, imidacloprid and malathion were then performed to assess which tissues provide the most chemoprotection. In the long-term feeding assay, transgenic expression of Cyp6g1 specifically in the midgut accounted for the majority of the resistance caused by Cyp6g1 overexpression with the HR-GAL4 driver. Real-time toxicology assays on third instar larvae were also performed and showed variable contributions of tissues to acute toxicology response depending on which pesticide was used. These data suggest a strong influence of bioassay parameters such as life stage and dosing method on outcome but suggest a prominent role for the midgut in larval toxicology.

Hellenic society of medical oncology (HESMO) guidelines for the management of anal cancer.

Despite considerable improvement in the management of anal cancer, there is a great deal of variation in the outcomes among European countries, and in particular among different hospital centres in Greece and Cyprus. The aim was to elaborate a consensus on the multidisciplinary management of anal cancer, based on European guidelines (European Society of Medical Oncologists-ESMO), considering local special characteristics of our healthcare system. Following discussion and online communication among members of an executive team, a consensus was developed. Guidelines are proposed along with algorithms of diagnosis and treatment. The importance of centralisation, care by a multidisciplinary team (MDT) and adherence to guidelines are emphasised.

A randomized study comparing two hypofractioned 3-D conformal radiotherapy for stage IIIb-IV non small cell lung cancer.

PURPOSE: We compared the safety and efficacy of two hypofractionated irradiation schedules for elderly and low performance status patients with inoperable symptomatic non-small cell lung cancer (NSCLC). METHODS: Patients that entered the study were either unfit or without response concerning chemotherapy. We randomized 14 patients (group A) vs 15 patients (group B) who underwent two different hypofractionated radiotherapy schedules. Group Α patients underwent a scheme of 13x3 Gy, while group B patients received 2x8.5 Gy and one fraction of 6 Gy one week apart. Efficacy was assessed in terms of disease-free survival (DFS), tumor response and overall survival (OS).Toxicity according to RTOG/EORTC criteria and duration of symptoms were also evaluated. RESULTS: Median follow up was 3 years. Median age was 64.5 years (group A) and 73 years (group B). Mean values for symptom palliation were higher for group B vs group A (3.20±1.21 vs 2.21±0.97, p=0.037), respectively. EORTC/RTOG toxicity was significantly higher (p=0.046) for group A (1.57±0.51) vs group B (1.13±0.35). Duration of toxicity was significantly lower in group B compared to group A (p=0.001). Median OS was similar between groups, while DFS was better in group B than group A (p=0.023). CONCLUSIONS: Although safe conclusions are difficult to be ascertained, hypofractionated schedule B might be an alternative scheme in elderly and low performance status patients offering adequate palliation, good tumor control and acceptable toxicity.

Consensus statement of the Hellenic and Cypriot Gastric Cancer Study Group on the diagnosis, staging and management of gastric cancer.

Gastric Cancer epidemics have changed over recent decades, declining in incidence, shifting from distal to proximal location, transforming from intestinal to diffuse histology. Novel chemotherapeutic agents combined with modern surgical operations hardly changed overall disease related survival. This may be attributed to a substantial inherent geographical variation of disease genetics, but also to a failure to standardize and implement treatment protocols in clinical practice. To overcome these drawbacks in Greece and Cyprus, a Gastric Cancer Study Group under the auspices of the Hellenic Society of Medical Oncology (HeSMO) and Gastrointestinal Cancer Study Group (GIC-SG) merged their efforts to produce a consensus considering ethnic parameters of healthcare system and the international proposals as well. Utilizing structured meetings of experts, a consensus was reached. To achieve further consensus, statements were subjected to the Delphi methodology by invited multidisciplinary national and international experts. Sentences were considered of high or low consensus if they were voted by ≥ 80%, or < 80%, respectively; those obtaining a low consensus level after both voting rounds were rejected. Forty-five statements were developed and voted by 71 experts. The median rate of abstention per statement was 9.9% (range: 0-53.5%). At the end of the process, one statement was rejected, another revised, and all the remaining achieved a high consensus. Forty-four recommendations covering all aspects of the management of gastric cancer and concise treatment algorithms are proposed by the Hellenic and Cypriot Gastric Cancer Study Group. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and individualization are emphasized.

Stereotactic radiosurgery and radiotherapy for acoustic neuromas.

Neuromas are benign intracranial tumors with indolent natural history. Surgery is the mainstay of treatment and only after the introduction of single-fraction stereotactic radiosurgery (SRS), radiotherapy emerged as an alternative viable option. In this review, we focused on SRS or conventionally fractionated stereotactic radiotherapeutic (FSRT) approaches. We described the results of different doses used for SRS and FSRT, the current status, and a comparison between the two radiotherapy approaches. Stereotactic radiotherapy techniques aim to control tumor growth with minimal toxicity. SRS using either a cobalt unit or a linear accelerator has given high rates of tumor control and of cranial nerve function preservation with marginal doses range of 12-14 Gy. Fractionated stereotactic radiotherapy (FSRT) is optimal for tumors larger than 3 cm. Doses as low as 50.4 Gy provide excellent control rates and low morbidity. Overall, both SRS and FSRT are equally effective and safe options for neuroma patients who do not need immediate surgical decompression.

Consensus statement of the Hellenic and Cypriot Oesophageal Cancer Study Group on the diagnosis, staging and management of oesophageal cancer.

In spite of recent advances in the diagnosis and management of oesophageal cancer, the overall survival of the disease worldwide remains disappointingly low. In Greece and Cyprus, this may be partly due to a failure of health care providers to implement standardised treatment protocols in clinical practice. Development of clinical practice guidelines was undertaken as a joint project between the Hellenic Society of Medical Oncology (HeSMO) and Gastro-Intestinal Cancer Study Group (GIC-SG) in an effort to provide guidance for Greek and Cypriot clinicians in all aspects of the management of oesophageal cancer. A study group was formed comprising clinicians from different disciplines with a special interest in the management of oesophageal cancer. Following extensive review of the literature, the members of the group met in person and consensus statements were developed, which were later subjected to the Delphi survey process by invited national and international experts. Statements that achieved a rate of voting consensus > 80% were adopted. Those that reached a voting consensus of < 80% were revised or rejected. In total, 46 sentences were developed and subjected to the voting process. Of those, 45 sentences achieved a rate of consensus > 80% during the first voting round. One sentence that did not reach a satisfactory rate of consensus was revised by the members of the study group and subsequently incorporated to the final statement. Forty-six recommendations covering all aspects of the management of oesophageal cancer and concise treatment algorithms are proposed by the Hellenic and Cypriot Oesophageal Cancer Study Group. In particular, centralisation of services, care by multidisciplinary teams and adherence to clinical guidelines are strongly recommended.

A five split-field three dimensional conformal technique versus an anterior-posterior on in postoperative radiotherapy for gastric carcinoma: a multicenter comparative study using quality of life measurements as well as clinical and dosimetric parameters.

PURPOSE: Several adjuvant approaches are regarded as available options in the management of localized, resectable gastric cancer .The objective of our study was to evaluate multiple field and anteroposterior conformal technique. METHODS: Ninety-seven patients received three dimensional conformal (3DCRT) postoperative adjuvant radiation therapy for gastric carcinoma. Thirty-five patients received anteroposterior (AP/PA) fields (Group B), while 62 patients were irradiated with multifield technique (Group A). Their ages ranged between 29-85 years. The objective of the study was to evaluate the quality of life (QoL) for all patients after the completion of radiotherapy using the QLQ-C30 of the EORTC questionnaire (European Organization for Research and Treatment of Cancer) and to investigate any measurable differences between those two radiation techniques according to QUANTEC criteria and the radiotoxicity. RESULTS: In terms of QUANTEC criteria, the multifield technique was superior concerning the left kidney (p=0.025), right kidney (p<0.001), spinal cord (p<0.001) and planning target volume (PTV) coverage (p<0.001). According to EORTC/ RTOG toxicity criteria, the rate of diarrhea was higher in AP/ PA technique (p=0.028). In terms of QLQ-C30, the multifield technique was superior concerning appetite loss (p=0.022), diarrhea (p=0.046) and global QoL (p<0.001). CONCLUSION: On the basis of QLQ-C30 questionnaire, EORTC/ RTOG toxicity and dosimetric parameters, the present report has shown that the three dimensional multifield conformal radiotherapy is superior compared to AP-PA techniques.

A Retrospective Analysis of Toxicity and Efficacy for 2 Hypofractionated Irradiation Schedules Versus a Conventional One for Post-Mastectomy Adjuvant Radiotherapy in Breast Cancer.

INTRODUCTION: The aim of this analysis was a retrospective evaluation of the efficacy and toxicity of 2 hypofractionated irradiation schedules compared to conventional therapy in post-mastectomy patients. METHODS: 3 irradiation schedules were analyzed: 48.30 Gy in 21 fractions (group A, n = 60), 42.56 Gy in 16 fractions (group B, n = 27) and 50 Gy in 25 fractions (group C, n = 30) of the front chest wall. All groups were also treated with a supraclavicular field, with 39.10 Gy in 17 fractions (group A), 37.24 Gy in 14 fractions (group B) or 45 Gy in 25 fractions (group C). RESULTS: No local recurrences were noted in any group during 36 months of follow-up. Acute skin toxicity presented in all groups, with 58.3%, 70.4% and 60% of grade I; 35%, 25.9% and 40% of grade II; 6.7%, 3.7% and 0% of grade III being seen in groups A, B and C, respectively. Late skin toxicity was noted only as grade I in 16.7%, 25.9% and 26.7% of groups A, B and C, respectively. No significant difference was noted among all groups for either acute or late skin toxicity, or for radio-pneumonitis (chi2 test, p > 0.05). CONCLUSION: All schedules were equally effective with equivalent toxicity. A prospective randomized study is needed to confirm our results.

Role of radiotherapy in the management of hepatocellular carcinoma: A systematic review.

Many patients with hepatocellular carcinoma (HCC) present with advanced disease, not amenable to curative therapies such as surgery, transplantation or radiofrequency ablation. Treatment options for this group of patients include transarterial chemoembolization (TACE) and radiation therapy. Especially TACE, delivering a highly concentrated dose of chemotherapy to tumor cells while minimizing systemic toxicity of chemotherapy, has given favorable results on local control and survival. Radiotherapy, as a therapeutic modality of internal radiation therapy with radioisotopes, has also achieved efficacious tumor control in advanced disease. On the contrary, the role of external beam radiotherapy for HCC has been limited in the past, due to the low tolerance of surrounding normal liver parenchyma. However, technological innovations in the field of radiotherapy treatment planning and delivery, have provided the means of delivering radical doses to the tumor, while sparing normal tissues. Advanced and highly conformal radiotherapy approaches such as stereotactic body radiotherapy and proton therapy, evaluated for efficacy and safety for HCC, report encouraging results. In this review, we present the role of radiotherapy in hepatocellular carcinoma patients not suitable for radical treatment.

Challenges and choices in prostate cancer irradiation: from the three dimensional conformal radiotherapy to the era of intensity modulated, image-guided and adaptive radiation treatment.

In the last decades the status of radiotherapy was tremendously increased in terms of conformity to the target as well as image-guided techniques in conjunction with intensity-modulated radiotherapy (IMRT). The technological improvement had a significant clinical outcome for better response and lower toxicity to the surrounding normal tissues. Nowadays the incidence of rectal toxicity has been significantly decreased, especially with image guided radiation therapy (IGRT), whereas the dose escalation to the prostate has driven the clinical practice to the fact that radical radiotherapy for low or intermediate risk prostate cancer is definitely equivalent to surgery. The treatment volume can be reduced by reducing the size of the necessary margins to count for inaccuracies in target position and patient setup. This can be achieved either by improving the daily localization of the target before treatment or by adapting the treatment in response to feedback. This is the goal of image-guided and adaptive radiotherapy, respectively. These techniques improve the accuracy of dose delivery with a significant impact on clinical outcome and toxicity. 

Short-course hypofractionated radiochemotherapy for unresectable locally advanced cancer of the base of tongue: palliation only? A case report and short review of the literature.

We present a case of unresectable cancer of the base of tongue treated with hypofractionated 3D conformal radiotherapy and concomitant chemotherapy. Based on the excellent tumour response in this radiotherapy regimen and international experience in short course treatments we shortly reviewed, we propose that this therapeutic approach could be considered in a curative setting for patients unsuitable for the a standard long course radiochemotherapy schedule.

Assessment of contralateral mammary gland dose in the treatment of breast cancer using accelerated hypofractionated radiotherapy.

AIM: To measure the dose distribution, related to the treatment planning calculations, in the contralateral mammary gland of breast cancer patients treated with accelerated hypofractionated 3-dimensional conformal radiotherapy. METHODS: Thirty-four prospectively selected female patients with right breast cancer (pN0, negative surgical margins) were treated with breast-conserving surgery. A total dose of 42.5 Gy (2.66 Gy/fraction) was prescribed; it was requested that planning target volumes be covered by the 95% isodose line. The contralateral mammary gland was defined on CT simulation. The dose received was evaluated by dose volume histograms. RESULTS: The measured contralateral breast doses were: (1) Dose maximum: 290-448 cGy [Equivalent (Eq) 337-522 cGy]; (2) Mean dose: 45-70 cGy (Eq 524-815 cGy); and (3) Median dose: 29-47 cGy (337-547 cGy) for total primary breast dose of 42.5 Gy in 16 equal fractions. The spearman rho correlation showed statistical significance between the contralateral breast volume and maximum dose (P = 0.0292), as well as mean dose (P = 0.0025) and median dose (P = 0.046) to the breast. CONCLUSION: Minimizing the dose to the contralateral breast has to be one of the priorities of the radiation oncologist when using short schedules because of the radiosensitivity of this organ at risk. Further study is necessary to assess the long-term clinical impact of this schedule.

Accelerated hypofractionated radiotherapy schedules in breast cancer: a review of the current literature.

Lumpectomy followed by breast irradiation is an alternative to mastectomy for patients with early-stage breast cancer. The purpose of radiation treatment following lumpectomy is to minimize the risk of recurrent cancer in the treated breast with as little toxicity as possible so that good cosmesis and function are maintained. Conventional fractionation schedules for postlumpectomy radiotherapy give 50 Gy in 2 Gy daily fractions, often with an additional boost to the tumor bed, resulting in treatment being given over 5-7 weeks. Delivering postoperative radiotherapy in a shorter period of time, provided it is as effective as longer treatment regiments, could result in greater convenience for patients. Moreover, given the high incidence of breast cancer, the use of a shorter fractionation schedule would decrease waiting lists in busy radiotherapy departments. We searched the medline (pubmed) and we reviewed all the relevant publications. We concluded that the accelerated hypofractionated schedules are safe in terms of cosmesis and effective in terms of local control.

Long-term results of LINAC-based stereotactic radiosurgery for acoustic neuroma: the Greek experience.

PURPOSE: To estimate the value of LINAC-based stereotactic radiosurgery (SRS) for the long-term local control of unilateral acoustic neuromas. MATERIALS AND METHODS: Twenty patients (median age 66; range 57-80 years) with unilateral acoustic neuroma underwent LINAC-based SRS from May 2000 through June 2004 with a dose of 11-12 Gy. The follow-up period ranged from 36 to 84 months (median follow-up period: 55 months). Before SRS none of the patients had useful hearing. The follow-up consisted of repeat imaging studies and clinical examination for assessment of facial and trigeminal nerve function at 6-month intervals for the first year and yearly thereafter. RESULTS: Eleven tumors (58%) decreased in size and eight (42%) remained stable. One tumor showed a minor increase in size on the MRI done 6 months after SRS in comparison with the pretreatment MRI; however, a subsequent decrease was noticed on the next radiographic assessment and the tumor remained stable from then on. None of the tumors increased in size in the long-term follow-up, thus giving an overall growth control of 100% for the patients in this study. None of the patients had useful hearing before SRS, so hearing level was not assessed during follow-up. No patient developed new, permanent facial or trigeminal neuropathy. CONCLUSION: LINAC-based SRS with 11-12 Gy provides excellent tumor control in acoustic neuroma and has low toxicity even after long-term follow-up.