Chloé Rancoule

Nanoparticles in radiation oncology: From bench-side to bedside

Nanoparticles (NP) are in vogue in medical research. Pre-clinical studies accumulate evidence of NP enhancing radiation therapy. On one hand, NP, selected for their intrinsic physicochemical characteristics, are radio-sensitizers. Thus, when NP accumulate in cancer cells, they increase the radiation absorption coefficient specifically in tumour tissue, sparing healthy surrounding tissue from toxicity. On the other hand, NP, by being drug vectors, can carry radio-sensitizer therapeutics to cancer cells. Finally, NP present theranostic effects. Indeed they are used in imaging as contrast agents. NP therefore can be multi-tasking and have promising prospect in radiotherapy field. In spite of the numerous encouraging preclinical evidence, the very small number of clinical trials investigating NP possible involvement in the radiotherapy clinical practice suggests a physicians unwillingness. Many prerequisites seem necessary including define biological mechanisms of NP radiosensitization pathways and of NP clearance. NP biocompatibility and toxicities should be better investigated to select, among the extensive range of possible systems, the harmless and most efficient one, and to finally come to a safe and successful clinical use. The present review focuses on the various interests of NP in the radiotherapy area and proposes a discussion about their role in the future clinical practice.

Optimize and refine therapeutic index in radiation therapy: Overview of a century.

In 1936, Holthusen theorized the probability of achieving tumor control and of developing normal tissue complications after radiotherapy as a function of radiation dose. This concept was formalized and further developed in 1975. Several concepts for improving the therapeutic gain had been anticipated, including the possibility of modulating the tumor/normal tissue differential response. Eight decades later, it is possible to review and analyze progress achieved in the knowledge of radiation-induced toxicity. The clinical developments using new technologies and biological modulators of radiation response have corroborated a posteriori this model, however, many questions remain unanswered. A few randomized trials have validated the benefit of modern irradiation techniques for improving the therapeutic index; but the level I evidence of a survival improvement is still lacking. In the field of bio-modulation, large meta-analyses have shown that concurrent chemotherapy improves local control in many cancer types. Clinical investigations using molecularly targeted therapies have been rather disappointing, with only one exception: head and neck squamous cell carcinoma. Numerous recent biological findings question the possibility to target tumor tissue without impacting normal tissue response. Moreover, the abscopal and bystander effects suggest that normal tissue irradiation should not be perceived only as a source of toxicity, but may also result in downstream therapeutic effects. This paper reexamines the multiple efforts made to modulate the tumor versus normal tissue differential response, which have translated into incremental therapeutic gain and highlights the ongoing effort to better understand the optimal integration of radiation biology, chemotherapeutic, novel drugs and novel technologies.

Risk of second cancers in the era of modern radiation therapy: does the risk/benefit analysis overcome theoretical models?

In the era of modern radiation therapy, the compromise between the reductions in deterministic radiation-induced toxicities through highly conformal devices may be impacting the stochastic risk of second malignancies. We reviewed the clinical literature and evolving theoretical models evaluating the impact of intensity-modulated radiation therapy (IMRT) on the risk of second cancers, as a consequence of the increase in volumes of normal tissues receiving low doses. The risk increase (if any) is not as high as theoretical models have predicted in adults. Moreover, the increase in out-of-field radiation doses with IMRT could be counterbalanced by the decrease in volumes receiving high doses. Clinical studies with short follow-up have not corroborated the hypothesis that IMRT would drastically increase the incidence of second cancers. In children, the risk of radiation-induced carcinogenesis increases from low doses and consequently the relative risk of second cancers after IMRT could be higher than in adults, justifying current developments of proton therapy with priority given to this population. Although only longer follow-up will allow a true assessment of the real impact of these modern techniques on radiation-induced carcinogenesis, a comprehensive risk-adapted strategy will help minimize the probability of second cancers.

Preclinical models in HNSCC: A comprehensive review.

Head and neck cancer remains a significant public health concern. About 60% of patients die within 5years due to local recurrence. Head and neck squamous cell carcinoma (HNSCC) cell lines are important preclinical models in the search for new therapies against this disease. Furthermore, there is a need to test novel drugs before introduction into clinical practice. A preclinical model that closely resembles the in vivo situation would be highly valuable. In the last few decades, a multicellular spheroid model has gained attention as its behavior was comparable to in vivo tumors. Basic research is necessary to achieve an understanding of the normal and pathological state but cannot, in itself, provide sufficient information for clinical applications. Indeed, animal models are an inevitable prelude to assess the efficacy of new therapeutic approaches in HNSCC. The present review proposes an overview of HNSCC pre-clinical models in order to further understand the oncogenic properties for HNSCC and translate these findings into clinic for patients.

Immunotherapy in head and neck cancer: Harnessing profit on a system disruption

Immune system deregulation and evasion play a key role in cancers evolution and progression, including squamous cell carcinoma of the head and neck (SCCHN). Development of basic research proposed a whole new vision of cancer treatment, based on a strong biological rational, and targeting intrinsic deregulations. Immunotherapies provide an encouraging strategy for patients improved outcomes. Immune-based therapies could act on cancer growth and/or development throughout many pathways. If cetuximab is for now the only monoclonal antibody approved for SCCHN management, other strategies, e.g. immune checkpoints openers, are arousing enthusiasm. Clinical trials are multiplying in patients with recurrent/metastatic SCCHN and primary results offer promising outcomes. Prospects of combining various immunotherapies with more established treatments, such as chemotherapy and radiotherapy, seem very encouraging and could provide synergistic benefits. Ongoing phase III clinical trials should soon enlighten us on the next standard of care for SCCHN. In the present review we summarized the different immunotherapy strategies that are currently under clinical investigation for SCCHN medical care.

Carbon ion irradiation withstands cancer stem cells’ migration/invasion process in Head and Neck Squamous Cell Carcinoma (HNSCC)

Cancer Stem Cells (CSCs) in Head and Neck Squamous Cell Carcinoma (HNSCC) have extremely aggressive profile (high migratory and invasive potential). These characteristics can explain their resistance to conventional treatment. Efficacy of photon and carbon ion irradiation with addition of cetuximab (5 nM) is studied on clonogenic death, migration and invasion of two HNSCC populations: SQ20B and SQ20B/CSCs. SQ20B express E-cadherin and overexpress EGFR while SQ20B/CSCs express N-cadherin and low EGFR. Cetuximab strongly inhibits SQ20B proliferation but has no effect on SQ20B/CSCs. 2 Gy photon irradiation enhances migration and invasiveness in both populations (p < 0.05), while cetuximab only stops SQ20B migration (p < 0.005). Carbon irradiation significantly inhibits invasion in both populations (p < 0.05), and the association with cetuximab significantly inhibits invasion in both populations (p < 0.005). These results highlight CSCs characteristics: EGFRLow, cetuximab-resistant, and highly migratory. Carbon ion irradiation appears to be a very promising therapeutic modality counteracting migration/invasion process in both parental cells and CSCs in contrast to photon irradiation.

Thirty years of phase I radiochemotherapy trials: Latest development

Radiochemotherapy is undergoing a complete expansion. Currently, possibilities of treatment combination are skyrocketting, with different anticancer and targeted molecules, different radiotherapy techniques, and dose escalation with each therapy. The development of a modern phase I radiochemotherapy trial becomes more and more complex and should be fully investigated. In the literature, there are no exhaustive reviews describing the necessity of their characteristics. The present article explores historical and current phase I clinical trials involving a combination of radiation therapy and anticancer therapies. Selected trials were identified by searching in PubMed databases. A total of 228 studies were identified in the last three decades, and a portrait of their characteristics is presented. As expected, most frequently studied malignancies were head and neck cancers, followed by non-small cell lung cancer and brain cancer. Toxicity is reported in more than 90% of the studies. Most studies were published since 2010, at the area of targeted therapies, but mainly concerned classical chemotherapies (cisplatin and 5-fluorouracil). The present review highlights some limits. Indeed, methodology seems not optimised and could be based on more accurate methods of dose-escalation. The present portrait of phase I radiochemotherapy trials suggests that radiochemotherapy notion must be reinvented and trials should be adapted to its complexity. Step by step method does not sound like an option anymore. Let us build the future of radiochemotherapy on past evidences.

Intensity-modulated salvage radiotherapy with simultaneous integrated boost for local recurrence of prostate carcinoma: a pilot study on the place of PET-choline for guiding target volume delineation

OBJECTIVEnThe aim of this study was to report the first cases of salvage radiotherapy (RT) using the intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) targeted on choline positron emission tomography (PET) uptake in a local recurrent prostate cancer, after a radical prostatectomy.nnnMETHODSnFour patients received salvage irradiation for biochemical relapse that occurred after the initial radical prostatectomy. The relapse occurred from 10 months to 6 years with PSA levels ranging from 2.35 to 4.86u2009ngu2009ml(-1). For each patient, an (18)F-choline PET-CT showed a focal choline uptake in prostatic fossa, with standardized uptake value calculated on the basis of predicted lean body mass (SUL) max of 3.3-6.8. No involved lymph node or distant metastases were diagnosed. IMRT doses were of 62.7u2009Gy (1.9u2009Gy/fraction, 33 fractions), with a SIB of 69.3u2009Gy (2.1u2009Gy/fraction, 33 fractions) to a PET-guided target volume.nnnRESULTSnAcute toxicities were limited. We observed no gastrointestinal toxicity ≥grade 2 and only one grade 2 genitourinary toxicity. At 1-month follow-up evaluation, no complication and a decrease in PSA level (6.8-43.8% of the pre-therapeutic level) were reported. After 4 months, a decrease in PSA level was obtained for all the patients, ranging from 30% to 70%. At a median follow-up of 15 months, PSA level was controlled for all the patients, but one of them experienced a distant lymph node recurrence.nnnCONCLUSIONnSalvage irradiation to the prostate bed with SIB guided by PET-CT is feasible, with biological efficacy and no major acute toxicity.nnnADVANCES IN KNOWLEDGEnIMRT with PET-oriented SIB for salvage treatment of prostate cancer is possible, without major acute toxicity.

Novel predictive biomarkers for cervical cancer prognosis

High hypoxic, glycolytic and acidosis metabolisms characterize cervical cancer tumors and have been described to be involved in chemoradioresistance mechanisms. Based on these observations, the present study assessed four selected novel biomarkers on the prognosis of locally advanced cervical carcinoma. A total of 66 patients with stage IIB/IIIB cervical cancer were retrospectively included. The protein expression levels of glucose transporter 1 (GLUT1), carbonic anhydrase 9 (CAIX) and hexokinase 1 (HKII) were investigated by immunohistochemistry on tumor biopsies, hemoglobin was measured and the disease outcome was monitored. A total of 53 patients (80.3%) presented a complete response. For these patients, the protein expression levels of GLUT1, CAIX and HKII were overexpressed. A significant difference was observed (P=0.0127) for hemoglobin levels (≤11 g/dl) in responsive compared with non-responsive patients. The expression of GLUT1 is associated with a lower rate of both overall and disease-free survival, with a trend of decreased risk of 1.1x and 1.5x, respectively. Co-expression of GLUT1 and HKII is associated with a decreased trend risk of 1.6x for overall survival. Patients with hemoglobin levels ≤11 g/dl had a 4.3-fold risk (P=0.02) in decreasing both to the rate of overall and disease-free survival. The presence of anemic hypoxia (hemoglobin ≤11 g/dl) and the expression of GLUT1 and/or HKII influence treatment response and are associated with a lower overall and disease-free survival. The present results demonstrated that these biomarkers may be used as predictive markers and suggested that these metabolic pathways can be used as potential novel therapeutic targets.

Radiosensibilité et/ou résistance des cancers ORL : aspects biologiques

Radiation therapy is a cornerstone of head and neck cancer management. Technological improvements in recent years in radiation therapy, with intensity-modulated techniques, reinforce even more its role. However, both local and locoregional relapses are still observed. Understanding biological mechanisms of treatment resistance is a topic of major interest. From the cancer cell itself, its ability to repair and proliferate, its microenvironment and oxygenation conditions, migratory and invasive capacity, to biological parameters related to the patient, there are many mechanisms involving radiosensitivity and/or radioresistance of head and neck cancer. The present study explores the main biological mechanisms involved in radiation resistance of head and neck cancer, and describes promising therapeutic approaches.