Success of hyperthermia in cervical cancer

Dr Carrie Minnaar explains why hyperthermia is heating up the field of oncology as it gains more attention with recent cervical cancer studies.

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Cancer treatment is a tough journey, with treatments often having side effects that can be very challenging to deal with, but there are new treatment methods that bring hope. One of these is heat treatment, also known as hyperthermia. Using heat to treat cancer has been around since Hippocrates’ times and this ancient tool has recently been reinvented and modernised to be a potentially powerful tool in cancer treatment.

A technique called modulated electro-hyperthermia, developed in Hungary in 2006, involves gently heating cancer cells to make them more responsive to traditional treatments like radiation and chemotherapy. This technique is also highly targeted, so that there is minimal damage to healthy tissues, and it’s a comfortable and safe procedure for patients. 

How heat makes treatment more potent

Radiation

At mild temperatures (39 – 40°C), hyperthermia can make radiation therapy much more effective. Firstly, heat increases blood flow to the tumour, which means more oxygen gets delivered to the cancer cells. This extra oxygen helps radiation therapy work better by forming extra reactive oxygen species (ROS) during treatment. These ROS cause damage to the tumour. 

Secondly, after radiation therapy, cancer cells will try to repair their damaged DNA. However, the increased oxygen from hyperthermia can slow down this repair process, which works best in low-oxygen conditions. The repair processes happen within two hours after radiation, so it’s important to time the radiation and hyperthermia to ensure the maximum amount of oxygen is present at the time of radiation and during the repair processes.

Lastly, mild hyperthermia affects various cellular processes like enzyme activity, protein stability, and cell membrane fluidity. These changes can lead to better treatment outcomes when hyperthermia is combined with radiation. 

Chemotherapy

Hyperthermia also works well with certain types of chemotherapy. The increased blood flow to the tumour helps deliver more chemotherapy drugs to the cancer cells, and heat can make the cancer cell membranes more porous, allowing more of the drug to enter the cells and increase its effectiveness.

Cervical cancer findings

Modulated electro-hyperthermia uses low frequency radio waves to create an electromagnetic field which boosts the treatment’s impact. One remarkable aspect of the treatment is its ability to stimulate an immune response against cancer cells when combined with radiation. 

This was observed in women with metastatic cervical cancer treated with chemoradiation and hyperthermia. 

In about a quarter of these women, a complete response to the disease was seen six months after treatment, and they remained disease-free five years later, aside from two women who unfortunately passed away due to unrelated causes. 

A nine-year trial testing this treatment on women with locally advanced cervical cancer has recently been completed. A total of 210 women participated, receiving either chemoradiation alone or combined with hyperthermia. The results, which were presented at a conference in Glasgow in May this year, showed that the five-year disease-free survival rate was more than doubled in the group who received the hyperthermia treatment. There was no increase in side effects with the addition of hyperthermia, meaning it was very safe, and the quality of life was significantly higherin women treated with hyperthermia.

Available in SA

The treatment is already available in SA and with the promising results from the cervical trial, there is hope that this could become more widely available. Additional trials on different tumour types are already being developed. 

For more information and to see if you could be eligible for this treatment, speak to your oncologist.

Visit onc-hyperthermia.co.za for more info.

References

Minnaar, C. A., Kotzen, J. A., Akinwale, O., et al. (2019). The effect of modulated electro-hyperthermia on local disease control in HIV-positive and -negative cervical cancer women in South Africa: Early results from a phase III randomized controlled trial. PLoS ONE, 14(6), e0217894.

Minnaar, C. A., Maposa, I., Kotzen, J. A., & Baeyens, A. (2022). Effects of Modulated Electro-Hyperthermia (mEHT) on Two and Three Year Survival of Locally Advanced Cervical Cancer Patients. Cancers (Basel), 14(3), 656. https://doi.org/10.3390/cancers14030656

Minnaar, C. A., Kotzen, J. A., Ayeni, O. A., et al. (2020). Potentiation of the Abscopal Effect by Modulated Electro-Hyperthermia in Locally Advanced Cervical Cancer Patients. Frontiers in Oncology, 10, 376. https://doi.org/10.3389/fonc.2020.00376

Minnaar, C. A., Kotzen, J. A., Naidoo, T., et al. (2020). Analysis of the effects of mEHT on the treatment-related toxicity and quality of life of HIV-positive cervical cancer patients. International Journal of Hyperthermia, 37(1), 263-272. https://doi.org/10.1080/02656736.2020.1737253

Horsman, M. R., & Overgaard, J. (2007). Hyperthermia: a potent enhancer of radiotherapy. Clinical Oncology, 19(6), 418-426.

Kampinga, H. H. (2006). Cell biological effects of hyperthermia alone or combined with radiation or drugs: a short introduction to newcomers in the field. International Journal of Hyperthermia, 22(3), 191-196.

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