Electrochemotherapy has been proven to be an efficient treatment for cutaneous metastases of various cancers. Data on breast cancer (BC) patients with cutaneous metastases were retrieved from the INSPECT database. Patients were divided by their receptor status: HER2+, HR+ (ER/PgR+), and TN (triple negative). Groups were similar for histological subtype and location of the nodules. Most patients were previously treated with surgery/systemic therapy/radiotherapy. We found no differences in the three groups in terms of response ratio (OR per patient 86% HER2+, 80% HR+, 76% TN, p = 0.8664). The only factor positively affecting the complete response rate in all groups was small tumor size (<3 cm, p = 0.0105, p = 0.0001, p = 0.0266, respectively). Local progression-free survival was positively impacted by the achievement of complete response in HER2+ (p = 0.0297) and HR+ (p = 0.0094), while overall survival was affected by time to local progression in all groups (p = 0.0065 in HER2+, p < 0.0001 in HR+, p = 0.0363 in TN). ECT treatment is equally effective among groups, despite different receptor status. Response and local tumor control seem to be better in multiple small lesions than in big armor-like lesions, suggesting that treating smaller, even multiple, lesions at the time of occurrence is more effective than treating bigger long-lasting armor-like cutaneous lesions.

The aim of this multicenter study was to evaluate the effectiveness and safety of electrochemotherapy (ECT) for the treatment of mucosal tumors in the head and neck. A total of 71 patients with 84 nodules of different histologies in the oral cavity, pharynx and larynx treated by ECT were evaluated. The data were collected from the InspECT database from 10 participating centers throughout Europe. Primary and recurrent/secondary tumors of different histologies were treated. The overall response rate was 65 %, with a 33 % complete response rate with limited side effects. The response rates of the primary and secondary tumors were not different. However, smaller tumors responded better than tumors larger than 3 cm in diameter. Furthermore, the tumors that were treated with curative intent responded significantly better than those treated with palliative intent. This study demonstrated the feasibility, safety and effectiveness of ECT in a larger cohort of patients with mucosal lesions in the head and neck region. Based on the available data, ECT can be used for the treatment of recurrent and, in some cases, primary mucosal tumors located in the oral cavity, larynx, and pharynx. A better response was obtained in patients with smaller primary tumors treated with curative intent.

Electrochemotherapy (ECT) is a local treatment combining chemotherapy with electroporation. This prospective multicentre study aimed to evaluate the efficacy of ECT in the treatment of patients with skin metastases from breast cancer and confirm whether “luminal A-like” tumors are more responsive to treatment. One-hundred and ninety-five patients were included in the analysis. 55% achieved complete response, 27% partial response (objective response OR 82%); 12% stable disease and 5% experienced progressive disease. The analysis by tumor phenotype showed a significant better response rate in Luminal A-like (p = 0.0060) and Luminal B-like (p = 0.0271) groups compared to Triple-Negative. Patients were divided into 4 groups based on the number and size of cutaneous metastases. Higher response rate was observed in patients with small (≤ 3 cm), single or multiple, metastases (OR rate 95% and 90%, respectively); larger tumors (> 3 cm) showed an OR rate of 85%. Tumor response was not affected by the presence of distant metastases, whereas patients with large cutaneous lesions and distant metastases showed a OR rate of 58%. One-year local progression-free survival (LPFS) was 86% (C.I. 82-89%). In the multivariate analysis, patient age and response to ECT were significantly associated with longer LPFS. This study confirms the efficacy of ECT in small-volume cutaneous metastases from breast cancer regardless the presence of systemic disease and suggests higher efficacy in patients with luminal A- and luminal B-like tumors. ECT can be utilized not only as a palliative measure but also as an alternative treatment for patients not eligible for standard treatments, or in combination with them. Trial registered on https://clinicaltrials.gov/study/NCT06683404 (date of registration 11/11/2024) retrospectively registered.