New research from the University of Aberdeen has revealed that the incidence of male breast cancer in Scotland has almost doubled from 0.8 cases per 100,000 men in 1992 to 1.3 cases per 100,000 men in 2017.
Researchers found that the trend was most pronounced in the north of Scotland and in rural areas – possibly linked with the use of chemicals in the agricultural industry.
The study, published in The European Journal of Surgical Oncology, found that male breast cancer accounted for 0.36 per cent of all breast cancers diagnosed in 1992, rising to 0.65 per cent of all breast cancers in 2017.
This is the first time Scottish data has been analysed in this way, but the increase follows a similar pattern to that seen across the world in countries including the USA where male breast cancer diagnosis is also on the rise.
Male breast cancer is still relatively rare with around 25 cases diagnosed in Scotland per year.
The study, led by Professor Valerie Speirs, used publicly available data from the Information Services Division Scotland to monitor trends in the number of men living in Scotland receiving a breast cancer diagnosis.
Prof Speirs explained: “With this type of data, it’s hard to say if this is a real rise or just that men are becoming more aware and presenting with symptoms.
“Maybe 25 years ago, they would have just ignored it then either died with the disease without even knowing they had it or before it became a bigger problem.
“Plus, we are living longer, and cancer is associated with ageing, so the rise may reflect this.
“Importantly, our findings emphasise the need for a better understanding of male breast cancer. We need to determine the risk factors of the disease so that improved prevention policies can be applied.
“Going forward there may also be a call to design bespoke treatment for men so we can target molecules expressed by male breast cancer.
“It goes without saying that with numbers rising it is important to raise awareness in the general public that breast cancer doesn’t just affect women.”
There are a number of possible causes of breast cancer in men including family history, higher than normal levels of the hormone oestrogen, age and previous medical treatments. Men, who have had previous radiotherapy to the chest, for example to treat Hodgkin lymphoma, may have a slightly increased risk of developing breast cancer.
Environmental factors could also play a part.
Prof Speirs added: “We can only speculate why there are more cases in rural areas as the study didn’t address this, specifically. It was an observational study.
“It may be due to use of pesticides associated with farming in rural areas. But this is speculation – we don’t have any data to support this.
“It’s also possible that environmental compounds that mimic oestrogens (so-called Endocrine-Disrupting Chemicals [EDCs]) might be exacerbated in areas of higher agricultural activity, with potential adverse health consequences.
“Lifetime exposure to oestrogen is a well-established risk factor for breast cancer, so it is reasonable to speculate that EDCs might contribute to this too. But studies that specifically address these points are challenging.”
Dr Kotryna Temcinaite, research communications manager at Breast Cancer Now, the research and care charity, said: “These important figures illustrate just how much there is still to do to tackle breast cancer in men. With this study showing incidence has risen in Scotland over the last 25 years, research will be crucial to gaining a better understanding of its causes, how it differs to the disease in women and how best to treat it.
“While it’s an interesting pattern that more breast cancers have been diagnosed in men in rural areas of Scotland, more research is needed before we can speculate about any potential causes, particularly given the small numbers of cases involved.
“Our Male Breast Cancer Study is now trying to pinpoint the genetic, environmental and lifestyle causes of breast cancer in men, which could enable us to identify those who are at greater risk and what could be done to help lower the chances of developing the disease.”
Breast cancer in men is rare – around 370 men in the UK are diagnosed with breast cancer each year. And while it can be diagnosed in men at any age, it is more common in older men, typically from 65 years onwards.
Men have a small amount of breast tissue and health professionals are encouraging men to be more aware of the symptoms. The most common is a lump, often painless, in the chest.
Other symptoms may include a liquid discharge, that comes from the nipple without squeezing and which may be blood-stained; a tender or inverted (pulled in) nipple; ulcers (sores) on the chest or nipple area; and swelling of the chest area and occasionally the lymph nodes under the arm.
Remember that most lumps found in males are benign and 80 per cent are not cancerous.
If you notice a change you should see your GP as soon as possible. Your GP will examine you and then decide whether to refer you to a breast clinic for further examination. These may include a mammogram, an ultrasound scan and a needle biopsy.
Dr Temcinaite added: “It’s so important that all men know to get any unusual changes to their breasts checked out by their GP as soon as possible.”
Anyone with questions or concerns about breast cancer can call Breast Cancer Now’s free Helpline on 0808 800 6000 to speak to one of their expert nurses.