We learn more about the new treatment, hyperthermia, and its benefits when applied in conjunction with chemotherapy and radiation for the treatment of breast cancer.
In oncology, hyperthermia is the heating up of tumours to above 39°C. Hyperthermia is sometimes applied to tumours that are particularly difficult to treat, to sensitise the tumours to the prescribed treatments (radiotherapy or chemotherapy).
Hyperthermia is sometimes used to treat a local recurrence in the chest wall from breast cancer after prior treatment with radiotherapy to the region has failed.
Several changes begin to happen in a tumour that has been heated, which results in an increase in the sensitivity of the tumour to either chemotherapy or radiotherapy.
The first change that begins to happen is an increase in the blood flow to the tumour. This is helpful when given in combination with chemotherapy as the increased blood flow increases the delivery and concentration of chemotherapy in the tumour.
Radiation works best in tissues that have adequate levels of oxygen in them. Very large tumours, or tumours that have recurred in a previously treated region often have low levels of oxygen.
The increased blood flow from the heating also increases the amount of oxygen in the tumour which helps the radiation to be more effective at killing the tumour. When combined with radiation, hyperthermia is usually given once or twice a week, after the radiotherapy appointment.
Other benefits of heating include an inhibition of the tumour cells’ ability to repair from the damage done by the chemotherapy or radiotherapy, and a stimulation of the immune response at the heated site.
Tumours in the breast are considered to be superficial. This means that they are easily targeted with a variety of hyperthermia technologies, and can be fairly easily heated, without heating the surrounding tissues.
The standard treatment for breast cancer is chemotherapy, surgery, and radiotherapy. This combination usually works very well, especially if the cancer is detected early enough. The need for hyperthermia in the early stages of breast cancer is therefore very low.
Hyperthermia may still be beneficial in instances where breast tumours are very large and difficult to operate on, and which don’t respond well to chemotherapy. In these cases, there may be a benefit to adding hyperthermia to radiotherapy treatment.
The most well-known indication for hyperthermia in the management of breast cancer is for recurrent tumours. In cases where there is a recurrence in the skin or lymph nodes in the chest area which was previously treated with radiotherapy, the recurrent tumours may be resistant to radiotherapy.
It can be dangerous to give more radiation to an area that has already been treated with radiotherapy, as the healthy tissues are at risk of over exposure. There is a lot of research indicating that giving a lowered dose of radiotherapy, combined with hyperthermia, to the recurrent area, is an effective way to manage these difficult to treat cases.
What kinds of hyperthermia can be used for breast cancer?
Superficial heating techniques for breast tumours include using water-filtered infrared-light, or radiofrequency waves, to heat the area.
The biggest risk is the accidental burning of the skin during the heating process, although the safety of the newer technologies has reduced this risk to below 1%.
Infrared-heating needs to be applied immediately before radiotherapy and there can only be a gap of five minutes between the heating and the start of the radiotherapy.
In SA only radiofrequency heating is currently available. This involves the placement of an electrode over the affected area, for 30 to 60 minutes, after radiotherapy.
Are you eligible for hyperthermia?
Your oncologist needs to decide if you could benefit from it. If you’re eligible, then he/she will prescribe the treatment and refer you to a hyperthermia unit.
The treatments are currently only available at the Wits Donald Gordon Medical Centre and, unfortunately, the treatments are not yet covered by medical schemes.
For more information: www. onc-hyperthermia.co.za
- Datta NR et al (2016) Hyperthermia and radiotherapy in loco-regional recurrent breast cancers: A systematic review and met analysis Int J of Rad Onc, Bio, Phys. Vol. 94, No.5, pp:1073-1087
- Kouloulias V et al. Hyperthermia is now included in the NCCN clinical practice guidelines for breast cancer recurrences: An analysis of existing data. Breast Care. 2015;10(2):109-116.
- Linthorst M et al. Local control rate after the combination of re-irradiation and hyperthermia for irresectable recurrent breast cancer: Results in 248 patients. Radiother Oncol. 2015;117(2):217–22
- Linthorst M et al. Re-irradiation and hyperthermia after surgery for recurrent breast cancer. Radiother Oncol 2013;109:188-193
- Oldenborg S et al. Reirradiation and hyperthermia for irresectable locoregional recurrent breast cancer in previously irradiated area: Size matters. Radiother Oncol. 2015;117(2):223–8.
- Vernon CC et al. Radiotherapy with or without hyperthermia for superficial breast cancer: Results from five randomized controlled trials. Int J of Rad Onc, Bio, Phys. 1996;35(4):731-744
Photo by Bence Szemerey | szemerey.com
MEET OUR EXPERT – Dr Carrie Minnaar
Dr Carrie Minnaar first studied hyperthermia in Germany in 2009 and completed her PhD on hyperthermia in oncology at Wits in 2019. Currently, Dr Minnaar practices oncologic hyperthermia at the Wits Donald Gordon Medical Centre.