Low-dose boost of radiotherapy keeps young breast cancer patients recurrence-free

In In The News by Barbara Jacoby

Source: European Organisation for Research and Treatment of Cancer
From: news-medical.net
The vast majority of young patients given a low-dose boost of radiotherapy to the site where their breast cancer was removed in addition to whole breast radiotherapy, remained free of local recurrence after ten years, according to results of the ‘Young boost trial’ presented at the 14th European Breast Cancer Conference.

Patients treated with a high-dose boost had an even lower risk of recurrence; however, they were much more likely to develop scar tissue in the breast, resulting in hardening of the breast.

The research was presented by Dr Sophie Bosma, a radiation oncologist at The Netherlands Cancer Institute in Amsterdam. She said: “Young breast cancer patients generally have a worse prognosis than older patients. However, because breast cancer is more common in older women, younger women are under-represented in most breast cancer studies.

“We know that in young patients, there is a higher chance of the breast cancer returning in the same place following breast-conserving treatment. In this trial we were aiming to lower that risk by giving patients a high radiotherapy boost directed at the site of the tumor. We were also comparing a higher and lower dose to see which one worked best for young patients in terms of local control and cosmetic outcome.”

The trial included 2421 patients who were all aged 50 or younger, with an average age of around 45, and being treated at one of 32 centers in The Netherlands, France, or Germany. Following surgery to remove their tumors and whole breast radiotherapy, the patients were randomly assigned to be treated with either the low-dose (16 grays) or high-dose (26 grays) radiotherapy boost. The majority of patients also received chemotherapy.

Patients were monitored for an average of 11 to 12 years and during that time, 109 patients suffered a recurrence in the same breast. Among patients who received a low-dose boost, there were 61 recurrences, equating to a ten-year local recurrence rate of 4.4%. In those who received a high-dose boost, there were 48 recurrences with a ten-year local recurrence rate of 2.8%.

However, 48% of patients who received the high dose experienced severe or moderate fibrosis (scar tissue) in the breast, compared with 27% of patients who received the low dose. Overall, the researchers conclude that the ‘benefit does not justify the increased impact on cosmetic outcomes’.