Efficacy of Electrochemotherapy in Breast Cancer Patients of Different Receptor Status: The INSPECT Experience

Abstract

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.

Electrochemotherapy combined with immunotherapy – a promising potential in the treatment of cancer

“…There are various histologic types of breast cancer that differ in microscopic appearance and receptor expression, leading to differences in response to the treatment. Recently, a multicentric study investigating the efficacy of electrochemotherapy in breast cancer patients with different receptor statuses was published ( 54 ). The study demonstrated that electrochemotherapy is equally effective in the treatment of breast cancer metastases, regardless of receptor status.…”

“…The response and local tumor control were better in multiple smaller lesions than in larger lesions, as previously observed. Local progression-free survival was, however, significantly lower in triple-negative type, probably due to the more aggressive cancer type and smaller choice of systemic treatments ( 54 ).…”