Proton beam therapy was used to treat breast cancer patients in a world-first NHS trial to establish its promise as an alternative to radiotherapy.
According to Professor Charlotte Coles, oncology consultant at Addenbrooke’s Hospital, standard radiotherapy is very effective and produces few side effects for most of the 30,000 breast cancer patients treated each year.
However, for a small minority of about 500 patients each year, radiotherapy may pose a potential risk of at least two percent or more for lifetime heart problems, occurring in less than 1 percent of recipients.
This group will be offered to take part in Parable, the new NHS trial led by Prof Coles, set to include 192 patients at 22 UK facilities, to determine whether proton beam therapy would be a “better option”.
Proton beam therapy uses charged particles instead of X-rays to more precisely target tumors, and the researchers hope this will allow doctors to deliver the required dose of radiotherapy where it’s needed while minimizing the radiation delivered to the heart and without increasing the risk. early side effects such as skin redness and changes in breast appearance.
It is currently only available to NHS cancer patients at two centers in London and Manchester and is much more expensive than standard radiotherapy. Mainly used to treat children with brain tumors, no large-scale trials have been conducted for breast cancer patients so far.
Participants in the experiment will receive either standard radiotherapy or proton beam therapy and will record their experience using questionnaires so researchers can assess side effects such as skin reactions, breast pain and swelling.
The trial will measure the dose of radiation delivered to the heart as an early indicator of possible heart problems, ensuring that many years of long follow-up are not required before results are available.
“Using this early predictor will allow us to reveal the potential benefits of using proton beam therapy for long-term heart health years, rather than decades,” said Professor Judith Bliss of the Institute for Cancer Research.
One of the first recruits, Kim Jones, 44, from Ely, Cambridgeshire, was diagnosed with cancer last February after noticing some thickening of her skin and painful chest pains.
Having received chemotherapy, mastectomy and lymph node removal at Addenbrooke’s, Ms. Jones was accepted into the Parable trial and began proton beam therapy at The Christie NHS Foundation Trust in Manchester on 24 October.
“When I was told that I had been accepted into the trial, I felt very lucky to have had the opportunity to receive this treatment,” said Kim. “Clinical trials are incredibly important as they are the best way to evaluate which treatments work best.”
The risk of radiotherapy causing heart problems later in life is very low and is typically because patients have breast tissue and lymph nodes located close to the heart or are already at an increased risk of developing heart problems.
However, the average dose of radiotherapy the heart is likely to receive can be estimated, and this information, along with age and other medical history, is used to estimate the potential lifetime risk of minor heart problems.
Although proton beam therapy has been used to treat breast cancer in other countries, the number of participants in these trials was small and no studies were reported directly comparing proton beam therapy with standard radiotherapy.
Prof Coles said: “Although only a very small group of people are affected by a higher risk of heart problems later in life, it can still be a serious problem.
“Most patients treated with radiotherapy have decades of wellness ahead of them, and we must do everything we can to avoid potential heart problems in the future associated with treatment.”