Background: Head-and-neck squamous cell carcinoma (HNSCC) is one of the most common malignancies globally, and the number of elderly patients diagnosed with HNSCC is increasing. However, as elderly HNSCC patients are underrepresented in clinical trials, current clinical decision making for this cohort largely lacks clinical evidence.Methods: Elderly patients (≥65 years) with HNSCC undergoing (chemo)radiotherapy from 2010 to 2018 at Freiburg University Medical Center were assessed for patterns of care, locoregional control (LRC), progression-free (PFS) and overall survival (OS) regarding definitive and adjuvant treatments. Acute and late therapy-associated toxicities were quantified according to CTCAE v5.0.Results: Two hundred forty-six patients were included in this analysis, of whom 166 received definitive and 80 adjuvant treatment. Two-year rates for OS, PFS and LRC were 56.9, 44.9 and 75.5%, respectively. Survival differed significantly between age groups with an OS of 40 and 22 months and a PFS of 23 and 12 months for patients aged 65–74 or ≥ 75 years, respectively (p < 0.05). Concomitant chemotherapy resulted in improved OS in patients aged 65–74 years compared to radiotherapy alone (p < 0.05) for definitive treatments, while patients ≥75 years did not benefit (p = 0.904). For adjuvant chemoradiotherapy, a trend towards superior OS rates was observed for patients aged 65–74 years (p = 0.151). Low performance status (HR = 2.584, 95% CI 1.561–4.274;p < 0.001) and smoking (HR = 1.960, 95% CI 1.109–3.464,p < 0.05) were the strongest independent prognostic factor in the multivariate analysis for decreased OS. One hundred thirty-eight patients (56.1%) experienced acute grade 3/4 and 45 patients (19.9%) chronic grade 3 toxicities.Conclusion: Radiotherapy is a feasible treatment modality for elderly HNSCC patients. The relatively low OS compared to high LRC may reflect age and comorbidities. Concomitant chemotherapy should be critically discussed in elderly HNSCC patients.

Mesenchymal stem cells (MSCs) have been shown to attenuate pulmonary damage induced by bleomycin-based anticancer treatments, but the influence of bleomycin on the stem cells themselves remains largely unknown. Here, we demonstrate that human bone marrow-derived MSCs are relatively sensitive to bleomycin exposure compared to adult fibroblasts. MSCs revealed increased levels of apoptosis after bleomycin treatment, while cellular morphology, stem cell surface marker expression and the ability for adhesion and migration remained unchanged. Bleomycin treatment also resulted in a reduced adipogenic differentiation potential of these stem cells. MSCs were found to efficiently repair DNA double strand breaks induced by bleomycin, mostly through non-homologous end joining repair. Low mRNA and protein expression levels of the inactivating enzyme bleomycin hydrolase were detected in MSCs that may contribute to the observed bleomycin-sensitive phenotype of these cells. The sensitivity of MSCs against bleomycin needs to be taken into consideration for ongoing and future treatment protocols investigating these stem cells as a potential treatment option for bleomycin-induced pulmonary damage in the clinic.

Tumor hypoxia is associated with radiation resistance and can be longitudinally monitored by ¹⁸F-fluoromisonidazole (¹⁸F-FMISO)-PET/CT. Our study aimed at evaluating radiomics dynamics of ¹⁸F-FMISO-hypoxia imaging during chemo-radiotherapy (CRT) as predictors for treatment outcome in head-and-neck squamous cell carcinoma (HNSCC) patients. We prospectively recruited 35 HNSCC patients undergoing definitive CRT and longitudinal ¹⁸F-FMISO-PET/CT scans at weeks 0, 2 and 5 (W0/W2/W5). Patients were classified based on peritherapeutic variations of the hypoxic sub-volume (HSV) size (increasing/stable/decreasing) and location (geographically-static/geographically-dynamic) by a new objective classification parameter (CP) accounting for spatial overlap. Additionally, 130 radiomic features (RF) were extracted from HSV at W0, and their variations during CRT were quantified by relative deviations (∆_RF). Prediction of treatment outcome was considered statistically relevant after being corrected for multiple testing and confirmed for the two ¹⁸F-FMISO-PET/CT time-points and for a validation cohort. HSV decreased in 64% of patients at W2 and in 80% at W5. CP distinguished earlier disease progression (geographically-dynamic) from later disease progression (geographically-static) in both time-points and cohorts. The texture feature low grey-level zone emphasis predicted local recurrence with AUC_W2 = 0.82 and AUC_W5 = 0.81 in initial cohort (N = 25) and AUC_W2 = 0.79 and AUC_W5 = 0.80 in validation cohort. Radiomics analysis of ¹⁸F-FMISO-derived hypoxia dynamics was able to predict outcome of HNSCC patients after CRT.

Oncological outcomes for head-and-neck squamous cell carcinoma (HNSCC) patients are still unsatisfactory, especially for advanced tumor stages. Besides the moderate survival rates, the prevalence of severe treatment-induced normal tissue toxicities is high after multimodal cancer treatments, both causing significant morbidity and decreasing quality of life of surviving patients. Therefore, risk-adapted and individualized treatment approaches are urgently needed for HNSCC patients to optimize the therapeutic gain. It has been a well-known fact that especially HPV-positive oropharyngeal squamous cell carcinoma (OSCC) patients exhibit an excellent prognosis and may therefore be subject to overtreatment, resulting in long-term treatment-related toxicities. Regarding the superior prognosis of HPV-positive OSCC patients, treatment de-escalation strategies are currently investigated in several clinical trials, and HPV-positive OSCC may potentially serve as a model for treatment de-escalation also for other types of HNSCC. We performed a literature search for both published and ongoing clinical trials and critically discussed the presented concepts and results. Radiotherapy dose or volume reduction, omission or modification of concomitant chemotherapy, and usage of induction chemotherapy are common treatment de-escalation strategies that are pursued in clinical trials for biologically selected subgroups of HNSCC patients. While promising data have been reported from various Phase II trials, evidence from Phase III de-escalation trials is either lacking or has failed to demonstrate comparable outcomes for de-escalated treatments. Therefore, further data and a refinement of biological HNSCC stratification are required before deescalated radiation treatments can be recommended outside of clinical trials.

Mesenchymal stem cells (MSCs) aid the regeneration of tissues damaged by treatment with cisplatin. However, the effects of this cytotoxic drug on the stem cells have been largely unknown. Here we demonstrate that human bone marrow-derived MSCs are relatively resistant to cisplatin treatment and show resistance levels comparable to these of differentiated fibroblasts. Cisplatin did not affect cellular morphology, adhesion or induction of apoptosis in MSCs. The potential for differentiation was preserved after exposure to cisplatin and established MSC surface markers were observed to be stably expressed irrespective of cisplatin treatment. Cytoskeletal rearrangements and high expression levels of individual heat shock proteins were detected in MSCs and may be partly responsible for the observed cisplatin resistance. The cisplatin-resistant phenotype of human MSCs supports the concept of further investigating these stem cells as a potential treatment option for cisplatin-induced tissue damage.