Effect of bisphosphonates and statins on the in vitro radiosensitivity of breast cancer cell lines

BACKGROUND

Early-stage breast cancer is usually treated with breast-conserving surgery followed by adjuvant radiation therapy. Acute skin toxicity is a common radiation-induced side effect experienced by many patients. Recently, a combination of bisphosphonates (zoledronic acid) and statins (pravastatin), or ZOPRA, was shown to radio-protect normal tissues by enhancing DNA double-strand breaks (DSB) repair mechanism. However, there are no studies assessing the effect of ZOPRA on cancerous cells. The purpose of this study is to characterize the in vitro effect of the zoledronic acid (ZO), pravastatin (PRA), and ZOPRA treatment on the molecular and cellular radiosensitivity of breast cancer cell lines.

MATERIALS

Two breast cancer cell lines, MDA MB 231 and MCF-7, were tested. Cells were treated with different concentrations of pravastatin (PRA), zoledronate (ZO), as well as their ZOPRA combination, before irradiation. Anti-γH2AX and anti-pATM immunofluorescence were performed to study DNA DSB repair kinetics. MTT assay was performed to assess cell proliferation and viability, and flow cytometry was performed to analyze the effect of the drugs on the cell cycle distribution. The clonogenic assay was used to assess cell survival.

RESULTS

ZO, PRA, and ZOPRA treatments were shown to increase the residual number of γH2AX foci for both cell lines. ZOPRA treatment was also shown to reduce the activity of the ATM kinase in MCF-7. ZOPRA induced a significant decrease in cell survival for both cell lines.

CONCLUSIONS

Our findings show that pretreatment with ZOPRA can decrease the radioresistance of breast cancer cells at the molecular and cellular levels. The fact that ZOPRA was previously shown to radioprotect normal tissues, makes it a good candidate to become a therapeutic window-widening drug.

Clinical and Pathological Characteristics of Breast Cancer Among Emirati National Patients

INTRODUCTION

Breast cancer is the most frequent cancer among Emirati women and is the second leading cause of death among women in the UAE. To date, published studies regarding breast cancer in the UAE have investigated a mixed population of different ethnicities with a low percentage of UAE nationals. This is the first study to highlight the clinical and pathological data of a large cohort of exclusively Emirati national breast cancer patients diagnosed at a tertiary care medical facility.

MATERIALS AND METHODS

This is a retrospective study involving breast cancer patients in UAE women who were evaluated and/or treated at the Cleveland Clinic Abu Dhabi during the period from May 2015 until June 2021.

RESULTS

This study initially included 372 participants. The median age at diagnosis was 48 years (24-86 years) and 12.3% of patients had screening detected tumors. 30% of patients presented with locally advanced disease and 20% had stage IV disease at presentation. 24% were 40 years or younger at the time of diagnosis.

DISCUSSION

To our knowledge, this is the largest study to date focusing exclusively on the presentation and characteristics of Emirati women with breast cancer. The median age of incidence was 48 years and the percentage of patients diagnosed with breast cancer at age 40 or younger years was 24%. This is an agreement with data published in the Middle East, but is significantly below what is reported in Caucasian women in the Western world. In this study, Emirati patients presented with advanced stages of disease. More advanced disease, and higher stage 4 at presentation is another reflection of the low screening rates, but also an indication of a higher patient thresholds for reporting breast health concerns to medical professionals for evaluation.

CONCLUSION

Findings of our study do suggest the need to focus efforts on continuing to understand the exact presentation of breast cancer among Emirati women and underscore the need to pursue efforts to improve public education, increase screening utilization and early detection to reduce the burden of disease and address an essential health care need for this unique population.

High rates of advanced prostate cancer in the Middle East: Analysis from a tertiary care center

Objectives:

Prostate cancer incidence is increasing in the Middle East (ME); however, the data of stage at the diagnosis and treatment outcomes are lacking. In developed countries, the incidence of de novo metastatic prostate cancer ranges between 4% and 14%. We hypothesized that the rates of presentation with advanced disease are significantly higher in the ME based on clinical observation. This study aims to examine the stage at the presentation of patients with prostate cancer at a large tertiary center in the ME.

Methods:

After Institutional Review Board approval, we identified the patients diagnosed with prostate adenocarcinoma and presented to a tertiary care center between January 2010 and July 2015. Clinical, demographic, and pathological characteristics were abstracted. Patients with advanced disease were stratified according to tumor volume based on definitions from practice changing clinical trials. Descriptive and Kaplan–Meier survival analysis was used.

Results:

A total of 559 patients were identified, with a median age at the diagnosis of 65 years and an age range of 39–94 years. Median prostate-specific antigen (PSA) at the presentation was 10 ng/ml, and almost a quarter of the men (23%) presented with metastatic disease. The most common site of metastasis was the bone (34/89, 38%). High-volume metastasis was present in 30.3%, 9%, and 5.2% of the cohort based on STAMPEDE, CHAARTED, and LATITUDE trial criteria, respectively.

Conclusion:

This is the first report showing the high proportion of men from ME presenting with de novo metastasis. This could be due to many factors, including the highly variable access to specialist multidisciplinary management, lack of awareness, and lack of PSA screening in the region. There is a clear need to raise the awareness about prostate cancer screening and early detection and to address the rising burden of advanced prostate cancer affecting men in the ME region.

Radiosensitizing Effect of Curcumin on Human Bladder Cancer Cell Lines: Impact on DNA Repair Mechanisms

Chemo-radiotherapy is one of the promising approaches to treat bladder cancer, but its effectiveness is limited to sensitive patients. Polyphenol curcumin has shown anticancer and radiosensitizing potentials, but the mechanism is not fully understood. Here, the In Vitro response of UM-UC5 and UM-UC6 bladder cell lines to curcumin and radiation treatments was evaluated. The effect of curcumin on the DNA double-strand breaks repair system after treatment with ionizing radiation (2 Gy) was determined by immunofluorescence. Cell viability, proliferation, and survival were performed using trypan blue, MTT, clonogenic, and sphere-forming assays. The migratory ability of both cells was assessed by wound healing. We showed that curcumin treatment increased the radiosensitivity by modifying the DNA double-strand breaks repair kinetics of the most radioresistant cells UM-UC6 without affecting the radiosensitive UM-UC5. Moreover, UM-UC6 cell survival and proliferation was significantly decreased after the combination of curcumin with radiation. Bladder cell migration was also inhibited considerably. Curcumin was also shown to reduce the number and the volume of bladder cancer spheres of both cell lines. This study revealed that curcumin was able to radiosensitize resistant bladder cell line without affecting the sensitive one with minimal side effects through enhancing DNA damage signaling and repair pathway.

Post-lumpectomy radiation therapy boost in breast cancer patients: evidence revisited

Purpose

Radiation therapy is an integral part in the management of breast cancer after breast conservative surgery. In selected patients at high risk for local recurrence (LR), a boost radiation dose is commonly applied to the tumour bed.

Methods

We performed a review of the English literature using PubMed, Medline and Google Scholar for published manuscripts addressing the effect of boost radiation in breast cancer patients, focusing mainly on LR and overall survival (OS).

Results

A total of seven studies were included in our review. Most studies (6/7, 85.7%) showed a significant improvement in local control independent of age (hazard ratios ranging between 0.34 and 0.73), with the largest absolute benefit in younger patients. None of the studies, however, was able to demonstrate an improvement in OS.

Conclusions

With lack of sufficient studies addressing the role of boost radiation, individualised treatment decisions are recommended, taking into account the risk factors for LR, including tumour biology. Real-life data are sorely needed to better assess the role of tumour bed boost in the contemporary era.

Cystectomy vs. bladder preservation after neoadjuvant chemotherapy in muscle-invasive bladder cancer: A tertiary medical center experience

BACKGROUND

Radical cystectomy (RC) remains the standard of care for muscle-invasive bladder cancer (MIBC). Because of the higher overall risks associated with RC, particularly in the elderly patients with multiple comorbidities, other less invasive bladder preservation strategies have been considered.

METHODS

This is a retrospective chart review of patients diagnosed with MIBC, pT2-4N0-2M0, at the American University of Beirut Medical Center between 2007 and 2017.

RESULTS

98 patients, 85 (86.7%) males and 13 (13.3%) females, were included. Of the 98 patients, 19 (19.3%) patients were treated with upfront CRT, 35 (35.7%) were treated with upfront RC and 44 (45%) were treated with NAC. 26 (26.5%) patients underwent RC after NAC and 18 (18.4%) received CRT after NAC. The mean overall survival (OS) for the different treatment modalities was 69.4, 60.4, 56.1 and 44.2 months for RC, CRT, RC post-NAC and CRT post-NAC, respectively (p = 0.83). The median disease-free survival (DFS) was 29, 22, 21 and 16 months for RC, CRT, RC post-NAC and CRT post-NAC, respectively (p = 0.49). Patients with pT3/T4 had a higher risk of death by 3.335 folds compared to pT2 (95% CI [1.321-8.422], p<0.05).

CONCLUSIONS

No difference was noted in the OS and DFS between the groups who underwent RC post-NAC and CRT post-NAC. These findings further support the possibility of bladder preservation after the treatment with NAC for MIBC. The pathologic T stage at diagnosis is an important prognostic factor regardless of treatment modality.

Efficacy and safety-in analysis of short-course radiation followed by mFOLFOX-6 plus avelumab for locally advanced rectal adenocarcinoma

Background

Neoadjuvant chemotherapy and short-course radiotherapy followed by resection has been gaining recognition in the treatment of rectal cancer. Avelumab is a fully human immunoglobulin that binds Programmed Death-Ligand 1 (PD-L1) and prevents the suppression of the cytotoxic T cell immune response. This phase II trial evaluates the safety and pathologic response rate of short-course radiation followed by 6 cycles of mFOLFOX6 with avelumab in patients with locally advanced rectal cancer (LARC).

Methods

This study is prospective single-arm, multicenter phase II trial adopting Simon’s two-stage. Short-course radiation is given over 5 fractions to a total dose of 25 Gy. mFOLFOX6 plus avelumab (10 mg/kg) are given every 2 weeks for 6 cycles. Total mesorectal excision is performed 3–4 weeks after the last cycle of avelumab. Follow up after surgery is done every 3 months to a total of 36 months. Adverse event data collection is recorded at every visit.

Results

13 out of 44 patients with LARC were enrolled in the first stage of the study (30% from total sample size). All patients met the inclusion criteria and received the full short-course radiation course followed by 6 cycles of mFOLFOX6 plus avelumab. 12 out of the 13 patients completed TME while one patient had progression of disease and was dropped out of the study. The sample consisted of 9 (69%) males and 4 (31%) females with median age of 62 (33–73) years. The first interim analysis revealed that 3 (25%) patients achieved pathologic complete response (pCR) (tumor regression grade, TRG 0) out of 12. While 3 (25%) patients had near pCR with TRG 1. In total, 6 out of 12 patients (50%) had a major pathologic response. All patients were found to be MMR proficient. The protocol regimen was well tolerated with no serious adverse events of grade 4 reported.

Conclusion

In patients with LARC, neoadjuvant radiation followed by mFOLFOX6 with avelumab is safe with a promising pathologic response rate.

Trial Registration Number and Date of Registration ClinicalTrials.gov NCT03503630, April 20, 2018. https://clinicaltrials.gov/ct2/show/NCT03503630?term=NCT03503630&draw=2&rank=1.

Short-course radiation followed by mFOLFOX-6 plus avelumab for locally-advanced rectal adenocarcinoma

BACKGROUND

Current standard practice for locally advanced rectal cancer (LARC) entails a multidisciplinary approach that includes preoperative chemoradiotherapy, followed by total mesorectal excision, and then adjuvant chemotherapy. The latter has been accompanied by low compliance rates and no survival benefit in phase III randomized trials, so the strategy of administering neoadjuvant, rather than adjuvant, chemotherapy has been adapted by many trials, with improvement in pathologic complete response. Induction chemotherapy with oxaliplatin has been shown to have increased efficacy in rectal cancer, while short-course radiation therapy with consolidation chemotherapy increased short-term overall survival rate and decreased toxicity levels, making it cheaper and more convenient than long-course radiation therapy. This led to recognition of total neoadjuvant therapy as a valid treatment approach in many guidelines despite limited available survival data. With the upregulation (PDL-1) expression in rectal tumors after radiotherapy and the increased use of in malignant melanoma, the novel approach of combining immunotherapy with chemotherapy after radiation may have a role in further increasing pCR and improving overall outcomes in rectal cancer.

METHODS

The study is an open label single arm multi- center phase II trial. Forty-four recruited LARC patients will receive 5Gy x 5fractions of SCRT, followed by 6 cycles of mFOLFOX-6 plus avelumab, before TME is performed. The hypothesis is that the addition of avelumab to mFOLFOX-6, administered following SCRT, will improve pCR and overall outcomes. The primary outcome measure is the proportion of patients who achieve a pCR, defined as no viable tumor cells on the excised specimen. Secondary objectives are to evaluate 3-year progression-free survival, tumor response to treatment (tumor regression grades 0 & 1), density of tumor-infiltrating lymphocytes, correlation of baseline Immunoscore with pCR rates and changes in PD-L1 expression.

DISCUSSION

Recent studies show an increase in PD-L1 expression and density of CD8+ TILs after CRT in rectal cancer patients, implying a potential role for combinatory strategies using PD-L1- and programmed-death- 1 inhibiting drugs. We aim through this study to evaluate pCR following SCRT, followed by mFOLFOX-6 with avelumab, and then TME procedure in patients with LARC.

TRIAL REGISTRATION

Trial Registration Number and Date of Registration: ClinicalTrials.gov NCT03503630, April 20, 2018.

De-intensifying Radiation Therapy in HER-2 Positive Breast Cancer: To Boost or Not to Boost?

PURPOSE

Radiation therapy is fundamental in the management of breast cancer. After whole breast irradiation, an additional boost dose is often applied to the primary tumor bed. Here, we analyze the effect of radiation therapy boost on local control in patients with HER-2 positive breast cancer.

METHODS AND MATERIALS

We studied 1082 patients with HER-2 positive breast cancer who were originally enrolled in the Herceptin Adjuvant Trial and treated with breast-conserving surgery, radiation therapy, and adjuvant chemotherapy with trastuzumab. The primary endpoint of the study was to determine the effect of a radiation boost on local recurrence. Kaplan-Meier curves were generated, and hazard ratios were estimated using Cox regression.

RESULTS

Our analysis included 441 patients (40.8%) who received radiation therapy boost and 641 patients (59.2%) who did not, after completion of whole breast radiation. Patients from both groups had similar baseline characteristics in terms of age, nodal involvement, and grade. At a median follow-up of 11 years, local control was 93% (confidence interval, 90%-95%) in the radiation boost group compared with 91% (confidence interval, 89%-93%) in the no-boost group (P = .33). When analyzing patients by age, patients <40 years of age had a higher risk for local recurrence; however, this was not significantly lowered by the addition of boost. Furthermore, no local control benefit for boost was noted in both hormone receptor (HR) subtypes (HR+: P = .11; HR-: P = .98).

CONCLUSIONS

Patients with HER-2 positive breast cancer treated with breast-conserving surgery, whole breast radiation, and trastuzumab have excellent local control. Delivery of an additional radiation boost in this patient population was not shown to improve local control. Future studies are needed to identify subgroups of HER-2 positive patients who derive a clinically relevant benefit from radiation boost.

Comparison of Nodal Target Volume Definition in Breast Cancer Radiation Therapy According to RTOG Versus ESTRO Atlases: A Practical Review From the TransAtlantic Radiation Oncology Network (TRONE)

Regional nodal irradiation has gained interest in recent years with the publication of several important randomized trials and the availability of more conformal techniques. Target volume delineation represents a critical step in the radiation planning process. Adequate coverage of the microscopic tumor spread to regional lymph nodes must be weighed against exposure of critical structures such as the heart and lungs. Among available guidelines for delineating the clinical target volume for the breast/chest wall and regional nodes, the Radiation Therapy Oncology Group and European Society for Radiotherapy and Oncology guidelines are the most widely used internationally. These guidelines have been formulated based on anatomic boundaries of areas historically covered in 2-dimensional field-based radiation therapy but have not been validated by patterns-of-failure studies. In recent years, an important body of data has emerged from mapping studies documenting patterns of local and regional recurrence. We aim to review, discuss, and compare contouring guidelines for breast cancer radiation therapy in the context of contemporary data on locoregional relapse to improve their implementation in modern practice.

Demographics and outcomes of meningioma patients treated at a tertiary care center in the Middle East

OBJECTIVE

Meningioma is the most common intracranial primary brain tumor. Risk factors such as age and exposure to radiation as well as prognostic factors such as grade, location, and extent of surgical resection have been reported in the literature worldwide; however, to our knowledge, data from the Middle East is still warranted. In this study, we aim to identify the characteristics, risk factors and outcomes of meningioma patients treated at a multidisciplinary regional referral center in the Middle East.

PATIENTS AND METHODS

This is a retrospective chart review with a prospective follow up of outcomes. It included patients diagnosed with meningioma between January 2005 and December 2015 at the American University of Beirut Medical Center. Patient's demographics, risk factors and outcomes were first retrospectively collected. Then, we conducted phone calls to all included alive patients to update their disease status and outcomes.

RESULTS

One-hundred and ninety-five patients were included. 69 % had grade I tumors and around 31 % with grades II and III meningiomas. The means of the overall survival and progression free survival (PFS) were 198 and 126 months, respectively. The residence area (city vs. countryside), occupation, alcohol use, oral contraceptive use, family history of meningioma, previous head trauma, radiation exposure for head/brain imaging, cell phone use, and finally, the tumor Ki-67 protein level did not correlate with the survival outcomes. The meningioma grade and extent of resection were significant predictors of the PFS on the univariate analysis, whereas, in the multivariate analysis only previous radiotherapy was significant in prolonging PFS.

CONCLUSION

In our study cohort, that included around 30 % grades II and III tumors, previous radiotherapy use was the only significant prognostic factor for longer PFS in patients diagnosed with meningioma. Future prospective studies should be conducted to evaluate genetic and molecular factors that could possibly be linked to meningioma grade and prognosis in our population of Middle Eastern patients.

HPV-related oropharyngeal cancer prevalence in a middle eastern population using E6/E7 PCR

Background

Given the paucity of data and widely variable rates that have been reported, the main objective of this study was to examine the prevalence of HPV-positivity in oropharyngeal squamous cell carcinoma (OPSCC) in Middle Eastern patients presenting to one of the region's largest tertiary care centers using polymerase chain reaction (PCR) amplification of the HPV E6/E7 oncogenes, a highly sensitive and specific method of detection.

Methods

Medical charts and archived pathological specimens were obtained for patients diagnosed with biopsy proven oropharyngeal cancer who presented to the American University of Beirut Medical Center between 1972 and 2017. DNA was extracted from paraffin-embedded specimens and tested for 30 high-risk and low-risk papilloma viruses using the PCR-based EUROarray HPV kit (EuroImmun).

Results

A total of 57 patients with oropharyngeal cancer were initially identified; only 34 met inclusion/exclusion criteria and were included in the present study. Most patients were males (73.5%) from Lebanon (79.4%). The most common primary tumor site was in the base of tongue (50%), followed by the tonsil (41.2%). The majority of patients (85.3%) tested positive for HPV DNA.

Conclusion

The prevalence of HPV-positivity amongst Middle Eastern OPSCC patients, specifically those from Lebanon, may be far greater than previously thought. The Lebanese population and other neighboring Middle Eastern countries may require a more vigilant approach towards HPV detection and awareness. On an international level, further research is required to better elucidate non-classical mechanisms of HPV exposure and transmission.

AROME-ESO Oncology Consensus Conference: access to cancer care innovations in countries with limited resources. Association of Radiotherapy and Oncology of the Mediterranean Area (AROME-Paris) and European School of Oncology (ESO - Milan)

PURPOSE

Cancer is a leading cause of mortality worldwide. Its incidence is still increasing, particularly in developing countries. Recent progresses further strengthen the differences between low/middle and high-income countries. This situation calls for joint action to reduce inequities in cancer outcomes among the patients. The Association of Radiotherapy and Oncology of the Mediterranean Area (AROME) and the European School of Oncology (ESO), have initiated joint conferences devoted to access to innovations in oncology in the Mediterranean area. The heterogeneity of the economic, political and cultural situations of the different participating countries, offers the opportunity to develop consensus conference.

METHODS

Cancer prevention and treatment strategies were discussed according to existing international guidelines. The Scientific committee prepared 111 questions with an objective to prioritize the access to treatments and innovations in low/middle-income Mediterranean countries. The results from the votes of 65 oncology experts, coming from 16 countries and 33 institutions have been analysed and access priorities classified accordingly.

RESULTS

Ninety six percent of the proposed general recommendations concerning national health care strategies, oncology education, and treatment organization were considered to be high priorities. Regarding access to systemic treatments, 41% of the drugs without validated predictive markers and 53% of those with validated predictive markers were considered to be 1st level priority. Only 4 biological tests were considered to be 1st level priority to access to innovation.

CONCLUSIONS

AROME-ESO consensus offers to cancer specialists from developing countries a basis for discussion with health authorities and payers on the prioritization of access to innovations in cancer care.

Prognostic significance of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation and isocitrate dehydrogenase-1 (IDH-1) mutation in glioblastoma multiforme patients: A single-center experience in the Middle East region

OBJECTIVES

To determine the prevalence and prognostic value of MGMT promoter methylation and IDH1 mutation in glioblastoma multiforme (GBM) patients from the Middle East.

PATIENTS AND METHODS

Records of patients diagnosed between 2003 and 2015 were reviewed. MGMT promoter methylation was measured using methylation-specific polymerase chain reaction and IDH-1 mutation was reported. The primary endpoint was overall survival (OS).

RESULTS

A total of 110 patients were included. The median age was 51 years and 71 patients (64.5%) were males. The median diameter of GBM was 4.6 cm and 29 patients (26.4%) had multifocal disease. Gross total resection was achieved in 38 patients (24.9%). All patients received adjuvant radiation therapy, and 96 patients (91.4%) received concomitant temozolomide. At a median follow up of 13.6 months, the median OS was 17.2 months, and the OS at 1 and 2 years were 71.6% and 34.8%, respectively. On multivariate analysis, age at diagnosis (HR 1.019; P = 0.044) and multifocality (HR 2.373; P = 0.001) were the only independent prognostic variables. MGMT promoter methylation was found in 28.2% of patients but did not significantly correlate with survival (HR 1.160; P = 0.635). IDH-1 mutation was found in 10% of patients was associated with a non-significant trend for survival improvement (HR 0.502; P = 0.151).

CONCLUSION

Patients with GBM from the Middle East have adequate survival outcomes when given the optimal treatment. In our patient population, MGMT promoter methylation did not seem to correlate with outcomes, but patients with IDH1 mutation had numerically higher survival outcomes.

Assessing Radiosensitivity of Bladder Cancer in vitro: A 2D vs. 3D Approach

Background: Bladder cancer is the fourth most commonly diagnosed cancer among males worldwide. Current treatment strategies established for bladder cancer mainly consist of cystectomy yet advances in radiation therapy have pointed to the value of organ-preserving strategies in preserving patients' quality of life. Aim: To study and compare the radiosensitivity in two-dimension (2D) and physiologically-relevant three-dimension (3D) in vitro culture of three human bladder cancer cell lines, RT4, T24, and UM-UC-3. Materials and Methods: Clonogenic assay was performed to assess cells' radiosensitivity in 2D. Employing the 3D Matrigel™-based cultures to enrich for cancer stem cells (CSCs) allowed us to assess the survival of this subpopulation of cells via evaluating the number, i.e., sphere forming unit (SFU), and the sizes of cultured spheres, formed from cells exposed to different radiation doses compared to non-irradiated cells. Results: Irradiating cells with increasing radiation doses revealed highest survival rates with RT4 cells in 2D, followed by T24 and UM-UC-3. In 3D, however, UM-UC-3 cells were shown to be the most radio-resistant as evidenced by the number of spheres formed, yet they displayed the least efficient volume reduction/regression (VR), whilst the volume decreased significantly for both RT4 and T24 cells. Sphere VR and sphere ratio (SR) values were then plotted against each other demonstrating a linear correlation between volume and number with RT4 and UM-UC-3 cell lines, but not T24. Lastly, multiple regression model was employed to evaluate the possibility of obtaining a function combining both 3D parameters, SR and VR, with the surviving fraction (SF) in 2D, and showed a linear regression for T24 cells only, with a correlation coefficient of 0.97 for the combined parameters. Conclusion: We were able to radiobiologically characterize 3 human bladder cancer cell lines showing differential effects of radiation between 2D and 3D culture systems, paving the way for achieving better assessment of radiosensitivity of bladder cancer in vitro.

Predictors of Cardiac Sparing in Deep Inspiration Breath-Hold for Patients With Left Sided Breast Cancer

Purpose: The purpose of this study was to evaluate patient-related non-dosimetric predictors of cardiac sparing with the use of deep inspiration breath-hold (DIBH) in patients with left-sided breast cancer undergoing irradiation (RT).

Materials and Methods: We retrospectively reviewed charts and treatment plans of one-hundred and three patients with left-sided breast cancer. All patients had both free-breathing (FB) and DIBH (with body surface tracking) plans available. (MHD) and V4 (heart volume receiving at least 4 Gy) were extracted from dose volume histograms. Fisher's exact and Chi-square tests were used to identify predictors of reductions in MHD and V4 after DIBH.

Results: One-hundred and three patients were identified and most underwent mastectomy. MHD and V4 decreased significantly in DIBH plans (0.74 ± 0.25 Gy vs. 1.72 ± 0.98 Gy, p < 0.0001 for MHD; 4 ± 4.98 cc vs. 20.79 ± 18.2 cc, p < 0.0001 for V4). Body mass index (BMI), smoking and timing of CT simulation (spring/winter vs. summer/fall) were significant predictors of reduction in MHD whereas BMI, field size, chemotherapy, axillary dissection, and timing of CT simulation predicted reduction in V4. On multivariate analysis, BMI, and timing of CT simulation remained significant predictors of the heart-sparing effect of DIBH.

Conclusions: In the setting of limited resources, identifying patients who will benefit the most from DIBH is extremely important. Prior studies have identified multiple dosimetric predictors of cardiac sparing and hereby we identified new non-dosimetric factors such as BMI and timing of treatments.

Swine Atrioventricular Node Ablation Using Stereotactic Radiosurgery: Methods and In Vivo Feasibility Investigation for Catheter-Free Ablation of Cardiac Arrhythmias

Background

Linear accelerator–based stereotactic radiosurgery delivered to cardiac arrhythmogenic foci could be a promising catheter‐free ablation modality. We tested the feasibility of in vivo atrioventricular (AV) node ablation in swine using stereotactic radiosurgery.

Methods and Results

Five Large White breed swine (weight 40–75 kg; 4 females) were studied. Single‐chamber St Jude pacemakers were implanted in each pig. The pigs were placed under general anesthesia, and coronary/cardiac computed tomography simulation scans were performed to localize the AV node. Cone beam computed tomography was used for target positioning. Stereotactic radiosurgery doses ranging from 35 to 40 Gy were delivered by a linear accelerator to the AV node, and the pigs were followed up with weekly pacemaker interrogations to observe for potential electrocardiographic changes. Once changes were observed, the pigs were euthanized, and pathology specimens of various tissues, including the AV node and tissues surrounding the AV node, were taken to study the effects of radiation. All 5 pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic inspection did not reveal damage to the myocardium, and pigs had preserved systolic function on echocardiography. Immunostaining revealed fibrosis in the target region of the AV node, whereas no fibrosis was detected in the nontargeted regions.

Conclusions

Catheter‐free radioablation using linear accelerator–based stereotactic radiosurgery is feasible in an intact swine model.

Optimizing tumor immune response through combination of radiation and immunotherapy

Radiation therapy and immunotherapy are two highly evolving modalities for the treatment of solid tumors. Immunotherapeutic drugs can either stimulate the immune system via immunogenic pathways or target co-inhibitory checkpoints. An augmented tumor cell recognition by host immune cells can be achieved post-irradiation, as irradiated tissues can release chemical signals which are sensed by the immune system resulting in its activation. Different strategies combining both treatment modalities were tested in order to achieve a better therapeutic response and longer tumor control. Both regimens act synergistically to one another with complimentary mechanisms. In this review, we explore the scientific basis behind such a combination, starting initially with a brief historical overview behind utilizing radiation and immunotherapies for solid tumors, followed by the different types of these two modalities, and the biological concept behind their synergistic effect. We also shed light on the common side effects and toxicities associated with radiation and immunotherapy. Finally, we discuss previous clinical trials tackling this multimodality combination and highlight future ongoing research.

Intraoperative Radiation Therapy: A Promising Treatment Modality in Head and Neck Cancer

Every year, almost 62,000 are diagnosed with a head and neck cancer (HNC) and 13,000 will succumb to their disease. In the primary setting, intraoperative radiation therapy (IORT) can be used as a boost in select patients in order to optimize local control. Addition of external beam radiation to limited volumes results in improved disease control over surgery and IORT alone. In the recurrent setting, IORT can improve outcomes from salvage surgery especially in patients previously treated with external beam radiation. The use of IORT remains limited to select institutions with various modalities being currently employed including orthovoltage, electrons, and high-dose rate brachytherapy. Practically, execution of IORT requires a coordinated effort and careful planning by a multidisciplinary team involving the head and neck surgeon, radiation oncologist, and physicist. The current review summarizes common uses, outcomes, toxicities, and technical aspects of IORT in HNC patients.

Analytical model for out-of-field dose in photon craniospinal irradiation

The prediction of late effects after radiotherapy in organs outside a treatment field requires accurate estimations of out-of-field dose. However, out-of-field dose is not calculated accurately by commercial treatment planning systems (TPSs). The purpose of this study was to develop and test an analytical model for out-of-field dose during craniospinal irradiation (CSI) from photon beams produced by a linear accelerator. In two separate evaluations of the model, we measured absorbed dose for a 6 MV CSI using thermoluminescent dosimeters placed throughout an anthropomorphic phantom and fit the measured data to an analytical model of absorbed dose versus distance outside of the composite field edge. These measurements were performed in two separate clinics-the University of Texas MD Anderson Cancer Center (MD Anderson) and the American University of Beirut Medical Center (AUBMC)-using the same phantom but different linear accelerators and TPSs commissioned for patient treatments. The measurement at AUBMC also included in-field locations. Measured dose values were compared to those predicted by TPSs and parameters were fit to the model in each setting. In each clinic, 95% of the measured data were contained within a factor of 0.2 and one root mean square deviation of the model-based values. The root mean square deviations of the mathematical model were 0.91 cGy Gy(-1) and 1.67 cGy Gy(-1) in the MD Anderson and AUBMC clinics, respectively. The TPS predictions agreed poorly with measurements in regions of sharp dose gradient, e.g., near the field edge. At distances greater than 1 cm from the field edge, the TPS underestimated the dose by an average of 14% ± 24% and 44% ± 19% in the MD Anderson and AUBMC clinics, respectively. The in-field measured dose values of the measurement at AUBMC matched the dose values calculated by the TPS to within 2%. Dose algorithms in TPSs systematically underestimated the actual out-of-field dose. Therefore, it is important to use an improved model based on measurements when estimating out-of-field dose. The model proposed in this study performed well for this purpose in two clinics and may be applicable in other clinics with similar treatment field configurations.

Fight against cancer around the Mediterranean area: "Many hands make light work!"

The geopolitical and strategic importance of the Mediterranean area is evident since a long time. In terms of health programs and means for cancer care, significant disparities have been reported between countries that borders the Mediterranean basin. AROME project began modestly in 2006 with a group of leaders who recognized the need to promote practical training of young people and, thus, contribute to reduce these inacceptable inequalities in terms of early diagnosis and management. Moreover, our project has been built from our belief that the socio-cultural specificity of this region, its epidemiology, availability of means for diagnosis and treatment, should impose a sustained regional research and better knowledge of tumor biology and identify the specificities that may require particular strategies of care that should not be based only on Western and Asian research data. We must thus take advantage of advances in the identification of intimate biological tumors to provide answers to our ignorance of the specific Mediterranean biology. In this paper, we illustrate this issue describing some particular cancers in this region such as breast and nasopharyngeal cancers.

Poster - Thur Eve - 36: Out-of-Field dose in craniospinal irradiation

The risk of radiotherapy induced secondary cancer depends on the integral dose delivered to the patient where the dose delivered within the radiation field is accounted for, as well as dose to out-of-field organs from scattered and leakage radiation. While commercial treatment planning systems allow accurate determination of in-field dose, they are generally not capable of accurate out-of-field dose prediction. Secondary cancer risk is especially an issue in craniospinal treatments where involved patients are often children or young adults. In this work we therefore propose a mathematical model that accurately predicts out-of-field dose for patients treated by craniospinal irradiation at the American University of Beirut Medical Center. An anthropomorphic phantom was imaged, planned and treated, with thermoluminescent dosimeters inserted in the phantom at in-field and out-of-field locations. The measurements showed that our treatment planning system calculated accurately (within 2%) dose inside the field, but did not perform well at points just outside the field edge and consistently underestimated the dose at points further away from the field edge. From the out-of-field measured data, a model was developed that predicts out-of-field dose at a point in the patient based on the distance of that point to the treatment field edge. The developed model is of the double-gaussian type; it contains parameters that can be tuned to make it applicable in other centers where linac geometry and treatment techniques may differ.

Outcome of thyroid associated ophthalmopathy treated by radiation therapy

Thyroid associated orbitopathy is a common manifestation of Graves disease. Many options can be considered for treatment. In this case series, we reviewed the medical records of 17 patients who received radiation therapy (RT) for GO in a tertiary care center between 1997 and 2007. All patients received 20 Gy to both orbits and 12 of them (71%) had already received one or more trials of steroid therapy prior to RT. After a median follow-up of 2 years, a subjective improvement in exophthalmos and vision was reported by all patients at the end of RT but only 3 patients reported a decrease in their diplopia immediately after therapy. Symptoms continued to improve with time in many patients: 22% had complete reversal of their symptoms and signs, and the remaining 78% had partial improvement. Two patients developed recurrent signs and symptoms, both of them were smokers who continued to smoke after treatment. About 60-65% of patients responded favorably to RT alone which increased to 87-97% when RT is combined with steroids. No patients developed late toxicity during the follow-up period. We conclude that RT is an effective treatment option in GO even in patients who failed previous treatment with steroids or surgical decompression. Based on our own clinical experiences and the literature data, the combination of RT and intravenous corticosteroid administration may improve the response rate.

Cell death by the quinoxaline dioxide DCQ in human colon cancer cells is enhanced under hypoxia and is independent of p53 and p21

INTRODUCTION

We have shown that the radio sensitizer DCQ enhances sensitivity of HCT116 human colon cancer cells to hypoxia. However, it is not known whether the p53 or p21 genes influence cellular response to DCQ. In this study, we used HCT116 that are either wildtype for p53 and p21, null for p53 or null for p21 to understand the role of these genes in DCQ toxicity.

METHODS

HCT116 cells were exposed to DCQ and incubated under normoxia or hypoxia and the viability, colony forming ability, DNA damage and apoptotic responses of these cells was determined, in addition to the modulation of HIF-1α and of p53, p21, caspase-2, and of the ataxia telangiectasia mutated (ATM) target PIDD-C.

RESULTS

DCQ decreased colony forming ability and viability of all HCT116 cells to a greater extent under hypoxia than normoxia and the p21-/-cell line was most sensitive. Cells had different HIF-1α responses to hypoxia and/or drug treatment. In p53+/+, DCQ significantly inhibited the hypoxia-induced increases in HIF-1α protein, in contrast to the absence of a significant HIF-1α increase or modulation by DCQ in p21-/- cells. In p53-/- cells, 10 μM DCQ significantly reduced HIF-1α expression, especially under hypoxia, despite the constitutive expression of this protein in control cells. Higher DCQ doses induced PreG1-phase increase and apoptosis, however, lower doses caused mitotic catastrophe. In p53+/+ cells, apoptosis correlated with the increased expression of the pro-apoptotic caspase-2 and inhibition of the pro-survival protein PIDD-C. Exposure of p53+/+ cells to DCQ induced single strand breaks and triggered the activation of the nuclear kinase ATM by phosphorylation at Ser-1981 in all cell cycle phases. On the other hand, no drug toxicity to normal FHs74 Int human intestinal cell line was observed.

CONCLUSIONS

Collectively, our findings indicate that DCQ reduces the colony survival of HCT116 and induces apoptosis even in cells that are null for p53 or p21, which makes it a molecule of clinical significance, since many resistant colon tumors harbor mutations in p53.

The radiosensitizer 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide induces DNA damage in EMT-6 mammary carcinoma cells

Background

DCQ (2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide), a synthetic quinoxaline 1,4-dioxide, enhances the cytotoxic effect of ionizing radiation (IR) in vivo and in vitro. We sought to clarify whether increased radiation-induced DNA damage, decreased rate of damage repair, and the generation of reactive oxygen species (ROS) contribute to DCQ enhancement of IR.

Methods

Murine mammary adenocarcinoma EMT-6 cells were treated with DCQ for 4 h before exposure to 10 Gy IR. Treated cells were monitored for modulations in cell cycle, induction of DNA damage, and generation of ROS.

Results

Combined DCQ and IR treatments (DCQ+IR) induced rapid cell-cycle arrests in EMT-6 cells, particularly in S and G₂/M phases. Alkaline comet assays revealed high levels of DNA damage in cells after exposure to DCQ+IR, consistent with damage-induced arrest. Unlike IR-only and DCQ-only treated cells, the damage induced by combined DCQ+IR was repaired at a slower rate. Combined treatment, compared to separate DCQ and IR treatments, activated DNA-protein kinase and induced more p-ATM, supporting a role for double strand breaks (DSBs), which are more toxic and difficult to repair than single strand breaks (SSBs). Contributing factors to DCQ radiosensitization appear to be the induction of ROS and DSBs.

Conclusion

Collectively, our findings indicate that radiosensitization by DCQ is mediated by DNA damage and decreased repair and that ROS are at least partially responsible.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with early breast cancer

e22084

Background: The status of the axillary lymph nodes (ALN) in early (stage I and II) breast cancer (BC) patients remains the single most important determinant of overall survival (OS). While the absolute number of positive ALN has been demonstrated to have a significant prognostic impact, new emerging data supports the role of axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. Methods: We conducted a single-center retrospective review of 1,255 BC patients and analyzed 930 patients with early BC admitted to American University of Beirut Medical Center between 1983 and 2001. Data included age at diagnosis, type of mastectomy, ALN involvement, use of chemotherapy, hormonal therapy, post-operative radiation therapy, tumor size, histological type and grade, lympho-vascular invasion status, hormonal receptor status, and Her-2/neu overexpression and the calculated ALNR (number of positive ALN / total number of excised ALN). Patients were subdivided into 3 groups according to ALNR value (< 0.25, 0.25–0.49, 0.50–1.00). The status of the axillary lymph nodes was analyzed with respect to 5- and 10-year OS. Results: On univariate analysis both the absolute number of positive ALN and the ALNR were significant predictors of OS .The 5- year OS of patients with ALNRs of < 0.25, 0.25–0.49 and 0.50–1.00 was 88%, 72% and 65 % respectively and the 10-year OS was 83%,54% and 51 % respectively . On multivariate analysis only the ALNR remained an independent predictor of overall survival, with a 2.7- and 3.16-fold risk of dying at ALNRs of 0.25 and 0.5, respectively. Conclusions: Our study demonstrated that the ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes. ALNR may aid in subdividing patients with positive ALN into low and high risk groups, with potential implications on their subsequent adjuvant management.

No significant financial relationships to disclose.

Tongue carcinoma in an adult Down's syndrome patient: a case report

BACKGROUND

Cancer of the oral cavity is rare and unusual in Down's syndrome patient. The over all risk is similar to that in adult population.

CASE PRESENTATION

This case report describes a 27 years old male with Down's syndrome, non-smoker, who developed a poorly differentiated squamous cell carcinoma of the tongue. The patient underwent a hemiglossectomy without neck dissection followed by a postoperative locoregional radiation therapy to a total tumor-bed dose of 56 Gy and 45 Gy to the neck. Three months later, the patient presented with local tongue recurrence and was treated by Docetaxel and Carboplatin chemotherapy with no significant response. The patient died one month later, 9 months after his initial diagnosis.

CONCLUSION

To our knowledge, this is the first case of tongue carcinoma arising in a patient with Down's syndrome. This unique case might not be sufficient to make a significant conclusion on the prognosis and survival of these patients but will increase the awareness about this possibility and will help in the appropriate management of Down's syndrome patients.

Radiosensitization of EMT6 mammary carcinoma cells by 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide

BACKGROUND AND PURPOSE

Previously, we have reported that 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ) is a radiosensitizer. Here, we investigate the mechanism of radiosensitization.

MATERIALS AND METHODS

EMT6 cells were treated with DCQ for 4h prior to ionizing radiation (IR). Flow cytometry, clonogenic assay, TUNEL, and Western blotting were performed to assess the effect of treatment on cells.

RESULTS

Propidium iodide staining of EMT6 cells treated with IR+/-DCQ revealed high numbers of cells with decreased DNA, consistent with an apoptotic response. TUNEL assay revealed apoptosis was 4%, 38%, and 49% 24h after treatment with IR alone, DCQ alone, and DCQ+IR, respectively. Clonogenic assays revealed that the survival of irradiated EMT6 cells was significantly reduced by DCQ treatment. DCQ treatment abrogated the radiation-induced expression of p21 and p53. The increased apoptosis observed in DCQ+IR-treated cells was correlated to suppression of radiation-induced phosphorylation of Akt and the expression of Bcl-X(L). DCQ also caused the phosphorylation of mitogen-activated protein kinases Erk and Jnk.

CONCLUSIONS

The radiosensitization effect of DCQ occurs through enhancement of radiation-induced apoptosis, which correlates to the inhibition of p-Akt kinase and Bcl-X(L) and the activation of Erk and Jnk kinases, but appears independent of p53 induction or modulation of Bax/Bcl-2 gene expression. These data suggest DCQ should be tested as a radiosensitizer in vivo and has potential in the treatment of human solid tumors.

Radiosensitization by 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide under oxia and hypoxia in human colon cancer cells

Background

The sensitizing effects of 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ) and ionizing radiation (IR) were determined in four colon cancer cells and in FHs74Int normal intestinal cells.

Methods

Cell cycle modulation, TUNEL assay, clonogenic survival and DNA damage were examined under oxia or hypoxia. Effects on apoptotic molecules and on p-Akt and Cox-2 protein expression were investigated.

Results

The four cell lines responded differently to DCQ+IR; HT-29 cells were most resistant. Combination treatment caused significant increases in preG₁ (apoptosis) in HCT-116, while G₂/M arrest occurred in DLD-1. DCQ potentiated IR effects more so under hypoxia than oxia. Pre-exposure of DLD-1 to hypoxia induced 30% apoptosis, and G₂/M arrest in oxia. The survival rate was 50% lower in DCQ+IR than DCQ alone and this rate further decreased under hypoxia. FHs74Int normal intestinal cells were more resistant to DCQ+IR than cancer cells.Greater ssDNA damage occurred in DLD-1 exposed to DCQ+IR under hypoxia than oxia. In oxia, p-Akt protein expression increased upon IR exposure and drug pre-treatment inhibited this increase. In contrast, in hypoxia, exposure to IR reduced p-Akt protein and DCQ restored its expression to the untreated control. Apoptosis induced in hypoxic DLD-1 cells was independent of p53-p21 modulation but was associated with an increase in Bax/Bcl-2 ratio and the inhibition of the Cox-2 protein.

Conclusion

DCQ is a hypoxic cell radiosensitizer in DLD-1 human colon cancer cells.

The value of EUS in predicting the response of gastric mucosa-associated lymphoid tissue lymphoma to Helicobacter pylori eradication

BACKGROUND

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is associated with Helicobacter pylori infection, and regression of the tumor has been described after its eradication.

OBJECTIVE

To determine the value of EUS, in addition to other clinical/endoscopic features, in predicting the response of low-grade MALT lymphoma to H pylori eradication.

DESIGN

A retrospective, single-center study.

SETTING AND PATIENTS

Twenty-two patients with primary gastric MALT lymphoma were identified through a retrospective review of charts of patients seen at the American University of Beirut Medical Center. Only 19 patients with histopathologically confirmed gastric MALT lymphoma and H pylori infection who had EUS staging were included in the study.

MAIN OUTCOME MEASUREMENTS

Regression of the gastric MALT lymphoma as determined by follow-up endoscopy and mucosal biopsies.

RESULTS

Patients with disease restricted to the gastric mucosa had a significantly higher rate of complete remission after H pylori eradication compared with patients who had disease infiltrating into the gastric submucosa (77.8% vs 12.5%, P value .007). There was no statistical difference in terms of the mean follow-up time to achieve such response (P value .212). Age, sex, location of the tumor within the stomach, and endoscopic appearance did not correlate with the probability of complete remission of the MALT lymphoma.

LIMITATIONS

The limitations include a retrospective design and a relatively small sample population.

CONCLUSION

EUS determination of the invasion depth of gastric MALT lymphoma helps predict a complete response to H pylori eradication.

Long-term survival following aggressive surgery and radiotherapy for pelvic fibromatosis

Desmoid tumors of the female pelvis are rare. The efficacy of the available treatment modalities in improving survival and decreasing recurrence remains controversial. A 32-year-old woman presented with an asymptomatic large ischeorectal mass. Computed tomography scan revealed a large tumor adherent to the pubic bone and impinging on the bladder neck and the rectum. Aggressive surgical removal of the mass including partial osteotomy of the pubic bone was followed by radiotherapy. The patient is still alive 6 years later with no evidence of disease. Aggressive surgical management followed by radiotherapy is an acceptable means of treatment of locally invasive desmoid tumor of the female pelvis.