Tumor size and effectiveness of electrochemotherapy

Abstract

BackgroundElectrochemotherapy (ECT) is an effective and safe method for local treatment of tumors. However, relatively large variability in effectiveness of ECT has been observed, which likely results from different treatment conditions and tumor characteristics. The aim of this study was to investigate the relationship between tumor size and effectiveness of a single-session ECT.Materials and methodsA systematic search of various bibliographic databases was performed and nine studies eligible for this study were extracted. Different statistical methods including meta-analysis were applied to analyze the data.ResultsThe results of analysis based on data from 1466 tumors of any histotype show significantly lower effectiveness of ECT on tumors with maximal diameter equal to or larger than 3 cm (complete response (CR) of 33.3%, objective response (OR) of 68.2%) in comparison to smaller tumors (CR% of 59.5%, OR% of 85.7%). The results of meta-analysis indicated that ECT performed on tumors smaller than 3 cm statistically significantly increases the probability of CR by 31.0% and OR by 24.9% on average in comparison to larger tumors. The analysis of raw data about the size and response of tumors showed statistically significant decrease in effectiveness of ECT progressively with increasing tumor diameter. The biggest drop in CR% was detected at tumor diameters as small as 2 cm.ConclusionsThe standard operating procedures for ECT should be reexamined and refined for the treatment of large tumors. We propose that future clinical trials should include accurate ECT treatment planning and/or multiple ECT cycles, besides a prolonged observation for tumor response evaluation.

Outcomes of Bleomycin-based electrochemotherapy in patients with repeated loco-regional recurrences of vulvar cancer

“…Some patients underwent up to three treatments because of new lesions, but maintained superficial tumor control. After a median follow-up of 12 (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) months, only one patient experienced relapse in the treatment field, localized in the same treated site. Mapping of the lesions showed that disease was present in the vulva in 100% of cases.…”

“…The results of meta-analysis indicated that ECT performed on tumors smaller than 3 cm statistically significantly increases the probability of CR by 31.0% and OR by 24.9% on average in comparison to larger tumors. The analysis of raw data about the size and response of tumors showed statistically significant decrease in effectiveness of ECT progressively with increasing tumor diameter [20,21]. Partial responders and new lesions can be handled with additional ECT albeit increasing local pain and skin toxicity [22].…”

Electroporation-Based Technologies for Medicine: Principles, Applications, and Challenges

“…The procedure can, however, be repeated with similar effectiveness (70). Another recent review and clinical study (71) suggested that the SOP may need refinement, as the current SOP for ECT may not be suitable for tumors bigger than 3 cm in diameter, which require multiple, consecutive ECT treatments. Several ongoing ECT studies are targeting superficial tumors, predominantly melanoma but also chest wall breast cancer recurrences (72)(73)(74) and head and neck cancers (75).…”

Gene electrotransfer of plasmid AMEP, an integrin-targeted therapy, has antitumor and antiangiogenic action in murine B16 melanoma

“…In addition, its antiproliferative and antimetastatic effects were shown in vitro on melanoma cell lines. 7 Electroporation was used as a delivery system, as it is safe and effective for the introduction of small molecules, such as bleomycin or cisplatin, [12][13][14][15][16][17][18][19][20][21][22] as well as larger molecules, such as plasmid DNA or small noncoding RNA. 7,23-30 In a recent study, it was shown that GET of Plasmid AMEP in a combined modality treatment with radiation had a radiosensitizing effect based on the normalization of tumor vasculature and consequently on improved tumor oxygenation.…”