Table 1.
Summary of ECT studies investigating the effects on the immune system.
| Species | Authors | Interventions (Type, n) | Cancer Types | Key Findings |
|---|---|---|---|---|
| Human | Gasljevic et al., 2017 [77] | ECT (bleomycin, 7) | Colorectal cancer | ECT induced coagulation necrosis. The majority of vessels >5 mm in diameter remained functional. |
| Bigi et al., 2016 [74] | ECT (bleomycin, 2) | Cutaneous melanoma | High prevalence of tumor-infiltrating CD8+ T cells and foci of NK cells 3 h to 1 month after ECT. Apoptotic cell death was followed by necrosis 48–72 h after ECT. | |
| Gerlini et al., 2013 [79] | ECT (bleomycin, 9) | Metastatic melanoma | ECT promoted Langerhans cell migration from the tumor to draining lymph nodes and DC recruitment to the tumor. Further, DCs found in low number before ECT greatly increased at day 7 to 14. | |
| Mouse | Tremble et al., 2019 [75] | ECT (cisplatin) | Colorectal cancer | ECT increased tumor infiltration of macrophages, neutrophils, B, NK, natural killer T cells, and DCs. Further, it decreased tumor growth of both treated and distal non-treated tumors. |
| Ursic et al., 2018 [72] | ECT (cisplatin/oxaliplatin) | Melanoma | ECT induced a 4-fold increase in tumor infiltration of NK cells and CD8+ T cells. | |
| Calvet et al., 2014 [71] | ECT (bleomycin) | Colon cancer | ECT induced ICD through the liberation of ATP and HMGB1 and the translocation of calreticulin to the cell surface. Seven out of 8 immunocompetent mice were disease-free 24 days after ECT treatment, whereas all immunodeficient mice presented PD. |
|
| Markelc et al., 2013 [80] | ECT (bleomycin) | Colorectal cancer | ECT induced a complete stop of the tumor blood vessels for up to 24 h. No damage to peritumoral normal blood vessels. | |
| Roux et al., 2008 [73] | ECT (bleomycin) | Sarcoma | ECT induced recruitment of tumor-infiltrating DCs and CD8+ T cells after 48–96 h, while the presence of CD4+ T cells remained stable. | |
| Torrero et al., 2006 [81] | ECT (bleomycin) | Breast cancer | ECT induced inhibition of angiogenesis in tumors but did not increase CD8+ T cell activity. | |
| Mekid et al., 2003 [82] | ECT (bleomycin) | Sarcoma | ECT increased the tumor infiltration of lymphocytes after 25, 50, and 75 h, in particular in the vicinity of apoptotic cells. | |
| Sersa et al., 1997 [70] | ECT (cisplatin) | Sarcoma | The tumor growth delay in immunocompetent mice was twice as long as in immunodeficient mice. Further, a high percentage of tumor cures was achieved in immunocompetent mice but none in immunodeficient mice. Of the mice cured after ECT, 75% rejected the tumor challenge, while none of the control mice did. |
|
| Cell | Fernandes et al., 2019 [83] | ECT (bleomycin/cisplatin/oxaliplatin) | Pancreatic cancer | ECT led to necroptosis. |
| Ali et al., 2018 [84] | ECT (bleomycin/cisplatin/oxaliplatin) | Pancreatic cancer | The ECT treatments induced changes in stemness inducing factors related to cancer stem cells. |
DC, dendritic cell; ECT, electrochemotherapy; ICD, immunogenic cell death; NK cells, natural killer cells; PD, progressive disease.