Male Breast Cancer: symptoms, risk factors, and treatment options
Do men get breast cancer? To mark the beginning of Breast Cancer Awareness month, Editorial Community Manager Sarah Theissen sat down with breast cancer expert Ian Fentiman to discuss the rare but still serious case of Male Breast Cancer (MBC). Here’s everything you need to know.
Do men get breast cancer (MBC)?
Yes, but it’s rare. In 2014 there were 55,222 new cases of breast cancer in the UK of whom 389 (7%) were male (for more info visit Cancer Research UK). There has been a significant increase between the 1990s and 2000s in all age groups suggesting that the rise is not simply due to longevity, but possibly related to the obesity epidemic.
What causes MBC?
In most cases, we don’t know. We know that increased age and obesity increase risk whereas smoking and drinking appear unrelated. Certain very specific correlations have been recorded, for example, male/female incidence ratios are highest in sub-Saharan Africa where 1 in 8 men are hepatitis B +ve with impaired steroid hormone degradation leading to raised estrogen levels. Among men with Klinefelter’s syndrome (where the sex chromosomes are XXY), there is a 50-fold increased risk of MBC. Occupations involving working in high ambient temperatures inhibit testicular function and increase risk as does post-pubertal mumps orchitis, epididymitis, and undescended testis. Total body irradiation for childhood cancers increases the risk of breast cancer in both men and women but all of these risk factors are relatively rare.
What about having a family history – is that important?
We think for most men it’s not very important. In women breast cancer risk is increased by having mutations of the BRCA1 or BRCA2 genes) which can be established by genetic testing. In the case of MBC, BrCa1 abnormalities are rare whereas 10% arise from BRCa2 mutations. The current advice is that genetic testing is recommended for only men having one first-degree relative with MBC and one or more with female breast or ovarian cancer.
A painless breast lump is the commonest symptom, followed by nipple discharge, with or without blood. Most men referred to breast clinics have benign conditions, frequently true or pseudo–gynaecomastia, (enlargement of the glandular tissue or surrounding fat) which normally needs no treatment other than reassurance and dietary advice.
How is MBC diagnosed?
This is usually done initially with breast ultrasound which can show whether this is a case of simple gynaecomastia or MBC. Sometimes mammography (an x-ray of the breast) is also used. The most reliable way of making a diagnosis is with a core biopsy (extracting a small amount of tissue from the affected area with a special needle and examining the cells under a microscope).
How is MBC treated?
Unfortunately, most men are slow to visit their GP’s with a problem, especially when this is in the breast area, and so nearly half of patients with MBC are diagnosed and treated when the disease has been present for some time. This means that is “locally advanced” (has invaded a large area of the breast tissue) or even “metastatic” (has moved into other areas of the body).
The traditional treatment, when the disease can be treated with surgery, has been mastectomy (total removal of the affected breast) irrespective of the psychological impact of a changed body image. Nowadays a number of patients can be treated by BCS (breast-conserving surgery) just as women with breast cancer are. In this case, only the affected area is removed.
Sentinel node biopsy – with a blue dye and/or radioactive isotope and widely available in the treatment of female breast cancer – is used to determine if the cancer has spread to other areas. This involves testing a few cells from the lymph glands in the armpit rather than removing the whole area, as was done previously, which carries the risk of an incapacitating condition called lymphoedema.
If more extensive surgery is required then a body image may be retained via reconstruction using skin flaps. Transverse rectus abdominis (TRAM) flaps are useful because they not only replace the skin and fat but also provide hair-bearing cover similar to the male breast skin.
DCIS (Ductal carcinoma in situ), a pre-cancerous condition normally requiring treatment, affects up to 10% of MBC patients and usually presents as a lump or nipple discharge. Nipple preserving surgery is often a valid option for some of these patients and should be followed by breast irradiation (radiotherapy).
Men with locally advanced or metastatic cancer will usually be given a hormone-based treatment, such as tamoxifen since almost all have estrogen receptor-positive tumors. This may be used as a neoadjuvant treatment (treatment given before surgery) or as palliative treatment for those with metastatic disease. Radiotherapy is also given after surgery to reduce the chances of recurrence of the cancer in the breast tissue.
What MBC trials have been carried out?
None. All the local and systemic therapies for MBC have been based on results from randomised controlled trials (RCTs) in female breast cancer. This has led to problems. Closer examination of available data reveals significant differences in both the development and treatment of the two diseases. Important biological differences point the way to the development of new treatments for male breast cancer based on these differences rather than similarities with female breast cancer (FBC).
In comparison with FBC there is a larger proportion of BRCA2 tumors, (present in 14% of MBC), and underrepresentation of BRCA1 tumors (in only 1% of MBC). Comparison at a molecular level reveals striking and potentially exploitable differences with more than 90% of MBC being ER+ve compared with 70% of FBC. The molecular subtypes of MBC are predominantly luminal A, sometimes luminal B, rarely basal and very rarely HER2.
With evidence in FBC that aromatase inhibitors are more effective than tamoxifen in the postmenopausal, these were used for adjuvant treatment MBC. Unfortunately, in prospective but non-randomized studies, overall survival in MBC was significantly better after adjuvant treatment with tamoxifen compared to an aromatase inhibitor. Approximately 15% of estradiol is derived from the testis and when peripheral synthesis is reduced by AIs there is a feedback surge of the testicular estrogen causing tumor stimulation.
What about the future?
The only way to improve the treatment of MBC is by setting up collaborative clinical and research networks based around a few directing hubs. At present, while prevention is not a feasible option, health education has an important role in dispelling ignorance and encouraging men with potential signs of male breast cancer to seek medical help. There needs to be a greater emphasis on neoadjuvant treatment, mostly endocrine in nature, to shrink primary tumors and enable more men to have less mutilating surgery. Sophisticated molecular analyses are now identifying multiple striking differences and the exploitation of these will in time lead to better prognostic models and new tailored therapies for male breast cancer.
Ian Fentiman is Emeritus Professor of Surgical Oncology at Guy’s, King’s & St Thomas’ Medical School and was appointed as a Consultant Surgeon Guy’s Hospital in 1982. He specializes in the diagnosis and treatment of breast diseases, particularly, breast cancer. He has published over 400 papers and is the author of 8 books on this subject, the most recent on male breast cancer. As well as being a Fellow of the Royal College of Surgeons, he has been awarded a Doctorate of Medicine and a Doctorate of Science from the University of London. He was Head of Service for Breast Surgery and Chairman of the SE London Cancer Network Breast Cancer Tumour Working Group and is now in private practice in London.
Opinions in this blog post are that of the author, and not necessarily that of Hindawi. Profile photo credit: Ian Fentiman. The text in this blog post is by Ian Fentiman and is distributed under the Creative Commons Attribution License (CC-BY). Illustration by Hindawi and is also CC-BY.