Recent advances in radiotherapy for thoracic tumours

Management of non-small cell lung cancer with EGFR mutation: the role of radiotherapy in the era of tyrosine kinase inhibitor therapy-opportunities and challenges

In recent years, the treatment of advanced non-small cell lung cancer (NSCLC) was greatly promoted by the discovery of oncogenic drivers and the development of targeted therapies specific for these drivers. Somatic mutations in epidermal growth factor receptor (EGFR) are the most common type in patients with NSCLC. Small-molecule tyrosine kinase inhibitor (TKI) targeting EGFR produced relatively high response rate and long duration with acceptable toxicity profile. Also, the life expectancy in patients with active EGFR mutation has been significantly prolonged than the past. Additionally, evolution of advanced imaging and radiation techniques has expanded the indications for radiotherapy in complex clinical situation. All of those factors contributed to the widely use of radiotherapy for advanced NSCLC treated with TKI therapy. In this review, we will discuss how to integrate radiotherapy into the comprehensive treatment of patients with TKI therapy in order to maximize the therapeutics effect.

The potential role of brachytherapy in the irradiation of patients with lung cancer: a systematic review

To review the use of brachytherapy as an adjuvant therapy to reduce recurrences after sublobar resections and as a palliation to patients with inoperable disease. Α review of all published studies was performed to identify the recurrence rate after brachytherapy adjuvant to sublobar resection and assess the palliation of symptoms and the complications of brachytherapy as a palliative treatment. Most of the studies that we found about brachytherapy as an adjuvant therapy to sublobar resection due to patient's poor cardiopulmonary reserve showed that brachytherapy offered low recurrence rate with low toxicity. Ten studies concerning palliative brachytherapy showed improvement of symptoms with good tolerance and good endoscopic response rates. Literature suggests that brachytherapy for inoperable symptomatic disease can be delivered for symptom improvement with acceptable toxicity. Brachytherapy as an alternative treatment option for lung cancer needs more investigation with more prospective trials.

The HSP90 Inhibitor Ganetespib Radiosensitizes Human Lung Adenocarcinoma Cells

The molecular chaperone HSP90 is involved in stabilization and function of multiple client proteins, many of which represent important oncogenic drivers in NSCLC. Utilization of HSP90 inhibitors as radiosensitizing agents is a promising approach. The antitumor activity of ganetespib, HSP90 inhibitor, was evaluated in human lung adenocarcinoma (AC) cells for its ability to potentiate the effects of IR treatment in both in vitro and in vivo. The cytotoxic effects of ganetespib included; G2/M cell cycle arrest, inhibition of DNA repair, apoptosis induction, and promotion of senescence. All of these antitumor effects were both concentration- and time-dependent. Both pretreatment and post-radiation treatment with ganetespib at low nanomolar concentrations induced radiosensitization in lung AC cells in vitro. Ganetespib may impart radiosensitization through multiple mechanisms: such as down regulation of the PI3K/Akt pathway; diminished DNA repair capacity and promotion of cellular senescence. In vivo, ganetespib reduced growth of T2821 tumor xenografts in mice and sensitized tumors to IR. Tumor irradiation led to dramatic upregulation of β-catenin expression in tumor tissues, an effect that was mitigated in T2821 xenografts when ganetespib was combined with IR treatments. These data highlight the promise of combining ganetespib with IR therapies in the treatment of AC lung tumors.