Electrochemotherapy is an effective and safe method for local treatment of cutaneous and subcutaneous tumours, where electric pulses cause increased permeability of cell membranes in the tumour mass, enabling dramatically enhanced effectiveness of bleomycin and other hydrophilic drugs. Here, we report results of a European multi-institutional prospective study of the effectiveness of electrochemotherapy in the treatment of skin cancer of the head and neck (HN) area, where standard treatments had either failed or were not deemed suitable or declined by the patient. A total of 105 patients affected by primary or recurrent skin cancer of the HN area were enrolled; of these, 99 were eligible for evaluation of tumour response. By far, the majority (82%) were treated only once, and 18% of patients had a second treatment. The objective response was highest for basal cell carcinoma (97%) and for other histologies was 74%. Small, primary, and treatment-naive carcinomas responded significantly better (p < 0.05), as investigated by univariate analysis. Electrochemotherapy was well tolerated and led to a significant improvement of quality of life, estimated by the European Organisation for Research and Treatment of Cancer quality of life questionnaires. At 1-year follow-up, the percentages of overall and disease-free survival were 76% and 89%, respectively. Electrochemotherapy is an effective option for skin cancers of the HN area and can be considered a feasible alternative to standard treatments when such an alternative is appropriate. The precise role for electrochemotherapy in the treatment algorithm for non-melanoma skin cancer of the HN region requires data from future randomised controlled studies. (ISRCTN registry N. 30427).

Intratumor heterogeneity may contribute to the ambiguous clinical results on PD-L1 status as a predictor for immunotherapy response in patients with HNSCC. This decreases the utility of PD-L1 expression from single tumour biopsies as a predictive biomarker. In this prospective study, intratumor heterogeneity of PD-L1 expression in HNSCC was investigated with both Tumour Proportion Score (TPS) and Combined Positive Score (CPS). Thirty-three whole surgical specimens from 28 patients with HNSCC were included. PD-L1 expression in six random core biopsies from each surgical specimen was used to assess the concordance between multiple biopsies and the negative predictive value of a single negative core biopsy. With 1% cut off, 36% of the specimens were concordant with TPS and 52% with CPS. With a 50% cut-off value the concordance was 70% with TPS and 55% with CPS. Defining a tumour as positive if just a single-one of the biopsies was positive, the negative predictive value (NPV) of a single negative core biopsy was 38.9 and 0% (1% cut off), and 79.9% and 62.8% (50% cut off) for TPS and CPS, respectively. In conclusion, PD-L1 positivity varies markedly within the tumour, both with TPS and CPS, challenging the utility of this biomarker.

No abstract