The fight against breast cancer – research advances over 40 years highlight how far we’ve come

Early detection, more personalised treatment and more knowledge about the causes and risk factors behind breast cancer mean that more people are surviving the disease than ever before.

In marking Breast Cancer Awareness Month this October, we've looked back on 40 years of breast cancer in Ireland to see the advances that have been made in the prevention, diagnosis, treatment and survivorship associated with this disease.

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Forty years ago the outlook for a breast cancer patient was vastly different from today:

In 1976, almost half of women diagnosed with breast cancer died from the disease. Today, survival rates for breast cancer have increased to almost 82% over five years.

Advances in breast cancer prevention

We can’t learn how to prevent cancer without knowing the major risk factors. While the world began to learn of the dangers of smoking, many other major risk factors related to breast and other cancers were still unknown in 1976.

Scientists have recognised the impact of body weight on cancer. Women who are overweight or obese after menopause have a 30-60% higher breast cancer risk than those who are of a healthier weight.

There is also growing evidence of a link between alcohol and some cancers, including breast cancer.

Approximately 12% of all breast cancers in Ireland (300 cases per year) are associated with alcohol consumption. Having one standard drink per day increases the risk of developing breast cancer by 7%, while consuming three to six standard drinks per day increases the risk by 41%.

We know now that genetics has a role to play in breast cancer. But many of the changes in genes linked to breast cancer are not inherited from a parent. About 5-10% of breast cancers are thought to be hereditary.

Researchers have also found that the risk of developing breast cancer is moderately increased for women who are using combined hormone replacement therapy (HRT) over prolonged periods.

However, the increased risk is minimal compared to other factors such as weight, alcohol and smoking.

Advances in the detection of breast cancer

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Fast forward to 2016 and the prevalence of breast cancer screening programmes across Ireland means that early diagnosis is far more common.

In Ireland the BreastCheck screening programme began in February 2000 and since then over 450,000 women have been screened. The public now has more information than ever before about the signs of breast cancer, meaning that increasingly women will find a lump themselves and contact their doctor.

Advances in breast cancer treatment

Over the past 40 years Ireland has gone from harsh, one-size-fits-all approaches to breast cancer treatment to more specific, often less invasive approaches delivered by teams of clinicians in specialist centres.

In 1976 mastectomy was the only surgical option recommended to women with breast cancer, involving removal of the full breast, underarm lymph nodes and chest wall muscles. Now, a simpler lumpectomy is the more common surgery, directly removing the tumour and having less impact on the patient’s body.

Partial mastectomies and breast reconstruction post-surgery are now options for patients that could only be dreamed of 40 years ago.

In the 1970s the causes and characteristics of breast cancer were only beginning to be understood. But when researchers found that the hormones oestrogen and progesterone are commonly linked to breast cancer growth, testing soon began on the drug Tamoxifen, which helps prevent the disease returning by blocking the effects of oestrogen. From Irish oncologist and radiotherapist Dr Moya Cole pioneering a clinical trial of the drug to 46 women with advanced breast cancer in 1969, Tamoxifen is now routinely used as part of a treatment plan after surgery, chemotherapy and radiation are finished.

In 1998, after researchers discovered that high levels of the human epidermal growth factor 2 (HER2) protein was found in cancer cells in 25-30% of cases, the first targeted anti breast cancer drug – Herceptin – was introduced to treat this HER2-positive breast cancer. Used with chemotherapy, Herceptin can lower the risk of HER2-positive breast cancer recurring by about 50% compared to chemotherapy alone.

Understanding the links between breast cancer and genes has also been a huge factor in treating the disease more successfully. In the mid-1990s scientists discovered that women who have changes in the genes BRCA1 and BRCA2 have a 50-80% increased risk of developing breast cancer and ovarian cancers. As a result, clinical trials are underway on new drugs that may be able to treat cancers that involve these genetic mutations.

The recent introduction of genetic testing to determine how effective chemotherapy would be as part of an individual cancer patient’s treatment plan has led to more personalised treatment for many women with early stage breast cancer. Since the ‘Oncotype DX’ test was introduced in Ireland in 2011, the use of chemotherapy has dropped significantly in those women.

Breast cancer survivorship

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Recent developments

The last five years alone have seen research discoveries that will profoundly change the way scientists see cancer in the future.

In 2012 researchers announced an important finding- that the majority of breast cancers can be grouped into a number of subtypes. Researchers had looked at the genetics of the tumour cells - which genes had been mutated, which genes were working in overdrive, which were being shut down. This molecular classification of breast cancers is a huge advance because it allows better prediction of the likely outcome for the patient and points the way for new treatments that will work better in those particular sub-types.

The future

In 2016 breast cancer patients are being diagnosed earlier, undergoing less invasive surgery and receiving more targeted therapies.

We now know that every breast cancer is different. Future research will focus on personalised treatment that is even better equipped to save lives and get patients back to full health.

The Irish Cancer Society is funding a €7.5 million collaborative cancer research centre called BREAST-PREDICT that is working to achieve the development of personalised medicine. BREAST-PREDICT commenced in 2013 and is made up of approximately 50 breast cancer researchers based all around Ireland. BREAST-PREDICT aims to test new treatment strategies for breast cancer patients, understand how patients respond to certain medicines, study the evolution of breast cancer and determine if exposure to commonly utilised medicines has an impact on breast cancer patient outcomes. This world class research is giving us a better understanding of why patients respond differently to treatments and helping to develop treatments based on each individual patient.

As part of the Irish Cancer Society’s ‘Paint it Pink’ campaign, taking place throughout Breast Cancer Awareness Month, people across Ireland are encouraged to raise vital life-saving funds that will support our continued investment in breast cancer research, advocacy and services. Learn more or get involved at www.paintitpink.ie.