Impact of COVID-19 on Radiation Oncology, an Austrian Experience.

The COVID-19 pandemic has an unprecedented impact on cancer treatment worldwide. We aimed to evaluate the effects of the pandemic on the radiation treatment of patients in order to provide data for future management of such crises. We compared the number of performed radiotherapy sessions of the pandemic period from February 2020 until May 2021 with those of 2018 and 2019 for reference.

Rac1 as a potential therapeutic target for chemo-radioresistant head and neck squamous cell carcinomas (HNSCC).

Background: In order to improve therapy for HNSCC patients, novel methods to predict and combat local and/or distant tumour relapses are urgently needed. This study has been dedicated to the hypothesis that Rac1, a Rho GTPase, is implicated in HNSCC insensitivity to chemo-radiotherapy resulting in tumour recurrence development.

Methods: Parental and radiation-resistant (IRR) HNSCC cells were used to support this hypothesis.

Antibodies attenuate the capacity of dendritic cells to stimulate HIV-specific cytotoxic T lymphocytes.

Background: Control of HIV is suggested to depend on potent effector functions of the virus-specific CD8(+) T-cell response. Antigen opsonization can modulate the capture of antigen, its presentation, and the priming of specific CD8(+) T-cell responses.

Objective: We have previously shown that opsonization of retroviruses acts as an endogenous adjuvant for dendritic cell (DC)-mediated induction of specific cytotoxic T lymphocytes (CTLs).

Radioresistant head and neck squamous cell carcinoma cells: intracellular signaling, putative biomarkers for tumor recurrences and possible therapeutic targets.

Purpose: Treatment of local and distant head and neck cancer recurrences after radiotherapy remains an unsolved problem. In order to identify potential targets for use in effective therapy of recurrent tumors, we have investigated protein patterns in radioresistant (FaDu-IRR and SCC25-IRR, "IRR cells") as compared to parental (FaDu and SCC25) head and neck carcinoma cells.

Methods And Materials: Radiation resistant IRR cells were derived from parental cells after repeated exposure to ionizing radiation 10 times every two weeks at a single dose of 10 Gy, resulting in a total dose of 100 Gy.

Epithelial-to-mesenchymal transition and c-myc expression are the determinants of cetuximab-induced enhancement of squamous cell carcinoma radioresponse.

Purpose: Radiation therapy cures malignant tumors of the head and neck region more effectively when it is combined with application of the anti-EGFR monoclonal antibody cetuximab. Despite the successes achieved, we still do not know how to select patients who will respond to this combination of anti-EGFR monoclonal antibody and radiation. This study was conducted to elucidate possible mechanisms which cause the combined treatment with cetuximab and irradiation to fail in some cases of squamous cell carcinomas.