Ask the Doctor: ‘I have just been diagnosed with breast cancer — what can I expect next?’

“I have just been diagnosed with breast cancer — what can I expect next?”

Answer from Professor Catherine Kelly, a Consultant Medical Oncologist at Mater Private Network, Dublin.

Prof. Kelly served as the breast medical oncology lead for the Mater Misericordiae University Hospital from 2010 until 2021. She served as the medical director of the Mater Cancer Trials Unit and was the clinical lead for Ireland East Hospital Group Cancer Cluster. Prof. Kelly was also the chair of the Cancer Trials Ireland Breast Cancer Group from 2014 to 2021. She completed her undergraduate training at the Royal College of Surgeons in Ireland and her specialist oncology training in Ireland and the UK (The Royal Marsden and St Bartholomew’s Hospital, London) before gaining further fellowships and qualifications from the Odette Cancer Center, Sunnybrook Hospital, Toronto, Canada and MD Anderson Cancer Center, Houston, Texas USA.

Firstly, it’s important for you to know that you are not alone. 1 in 9 women in Ireland will be diagnosed with breast cancer in their lifetime and there are 3,700 new cases annually. It is one of the most common cancers for Irish women and for that reason it’s so important that we use opportunities like Breast Cancer Awareness month, to educate ourselves on how and when to check our breasts, but also to find out more about the exciting developments in breast cancer diagnosis and treatment that are having a significant impact on the lives of breast cancer patients. While the diagnosis is daunting, when caught early, breast cancer has one of the highest survival rates.

Following an initial diagnosis, the expert-led breast team at Mater Private Network will first work out what type of breast cancer you have. We will get this information from the biopsy, which is the sample of the cancer taken out of the breast with a needle. The three main types of breast cancer are estrogen-sensitive breast cancer, which is the most common type, HER2-positive breast cancer, which makes up 20% of cases, and triple-negative breast cancer, which makes up only about 10% of cases.

Some other questions the team will be trying to answer to determine what type of treatment you will need will be; ‘How big is the lump? or ‘How big is the abnormal area on the mammogram’, ‘Do the lymph nodes under your arm have any cancer cells in them?’. Some patients will need to have a scan of their body to see if there is breast cancer anywhere else. Not all patients need a body scan, especially if the cancer is small and hasn’t spread to the lymph nodes. We can work out the ‘stage’ of the cancer by understanding its size and if it is anywhere else in the body.

It is reassuring to know that most patients will have early-stage breast cancer. This means the cancer is just in the breast and/or lymph nodes under the arm. A small proportion of patients will be found to have cancer that has travelled from the breast and lymph nodes to other parts of the body. These patients have metastatic breast cancer and sometimes people call this stage IV or secondary breast cancer.

Once your doctor knows the stage and type of cancer you have, treatment will vary depending on your needs. Some patients will have surgery, radiation. Others will need to see a medical oncologist. The medical oncologist’s job is to work out if the patients need any type of chemotherapy or if they need to take a hormone tablet.

Some patients will need chemotherapy, while others will not. It is important to know that there are many types of chemotherapy. Two patients with similar-sized breast cancers can be sitting beside each other on the cancer day ward but be getting entirely different chemotherapy treatments. Some may have three months of chemotherapy and nothing else, while others could have treatments that go on for a year. This will all depend on the type of cancer you have, the stage of cancer you have, or if you have any pre-existing medical conditions.

For the most common type of breast cancer — called estrogen-sensitive or estrogen receptor-positive breast cancer — new types of tests called genomic tests can help us work out who can safely avoid chemotherapy. In these situations, we focus on giving the patient a tablet that either lowers the amount of estrogen in their body or does not allow estrogen to stimulate cancer cells. Most patients receive five years of the hormone tablet, although some may need it for longer. For patients who present with metastatic breast cancer that is estrogen sensitive, they also take similar hormone tablets, and a relatively new drug called a CDK4/6 inhibitor (e.g. ribociclib, or Palbociclib). These patients are usually on the medication for several years before they need to change to a different medication.

For patients with HER2-positive breast cancer, the improvements in survival for early-stage and for metastatic breast cancer are remarkable. These amazing improvements are down to many highly active anti-HER2 drugs. Most patients with early-stage HER2-positive breast cancer do not relapse and for those with metastatic breast cancer, we see women surviving for many years on treatment.

For patients with triple-negative breast cancer, most will require chemotherapy. This tends to be given before surgery so we can work out how sensitive the cancer cells are to the treatment. For more than half of these patients, the chemotherapy kills the cancer. When these patients have surgery, the breast cancer cannot be seen, just the ‘tumour bed’ which is the place where the tumour had been. We call this a pathological complete response, and this means all of the tumour in the breast and lymph nodes has been eradicated.

When patients do not have a pathological complete response, we usually give more chemotherapy after their breast surgery. For those with early-stage and metastatic triple-negative breast cancer, immunotherapy drugs are having a positive impact. There are also new drugs called antibody-drug conjugates that are increasingly being used to treat this type of breast cancer.

Although this might be a lot of information to take in at first, your breast team will work closely with you to determine what your cancer looks like, the best course of action, and ensure that you fully understand all of your options. Most patients with early-stage breast cancer survive and go back to living full and healthy lives. It’s so important to know that across all the different types of breast cancer, there have been hugely significant improvements. This means that patients with metastatic breast cancer are also living better, longer lives than ever before. Research is continuing into breast cancer of all types and stages at an amazing pace and all breast teams, both at the Mater Private Network and beyond, would strongly encourage everyone diagnosed with breast cancer to ask about clinical trials and consider being a part of one if you can.

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