Some men with breast cancer may be having unnecessary radiotherapy, according to new research published (Wednesday 22 June) in Annals of Oncology.
A study carried out at the British Columbia Cancer Agency in Vancouver, British Columbia, Canada, showed that men whose cancer had not spread beyond the breast were almost six times more likely to be given radiotherapy than were women with the equivalent stage of disease.
Many men receive radiotherapy routinely after a mastectomy because the smaller male breast makes it harder for surgeons to leave a clear margin of healthy tissue when they remove the tumour, so men are perceived to be more at risk of the tumour recurring in the breast area.
But an analysis of 60 male breast cancer patients and more than 4,000 female control patients, showed that gender was not a prognostic factor in recurrence, breast cancer survival or overall survival.
"What this means is that if we do have presumptions about prognosis purely on the basis of sex we would do better to ditch them and apply the same guidelines for radiotherapy treatment to men as we do for women," said lead author, Dr Graham Macdonald, a consultant in clinical oncology at Aberdeen Royal Infirmary, Scotland, who was a fellow in radiation oncology in Vancouver at the time the study was carried out.
He said that there was an ongoing debate whether post-mastectomy radiotherapy in men should be guided by the same principles used in women or given routinely to all men with breast cancer, but the new results were consistent with there being no influence of gender on the main outcomes once other known prognostic variables were taken into account.
However, he emphasised that because of the low numbers of male breast cancer patients available for analysis, the power of the study to detect possible small differences was low.
The study drew on men and women diagnosed in British Columbia between the start of 1989 and the end of 1998 who had undergone total mastectomy, excluding certain categories of patients. This left 60 men and 4,181 women where direct comparisons could be made with a median follow-up of 8.4 years (men) and 10 years (women).
"Statistically significant predictors for receiving radiotherapy after surgery included tumour size, the status of the margins around the tumour, whether chemotherapy was given and whether the nodes were affected," said Dr Macdonald.