Diabetes and breast cancer: Q&A with a breast surgeon

In the U.S. 266,400 people are diagnosed each year with breast cancer according to the Centers for Disease Control and Prevention (CDC). It’s not surprising that individuals with a breast cancer diagnosis could also have pre-existing conditions that can affect their breast cancer treatment. One such condition, diabetes, is reported by the CDC to affect 11.3% of the U.S. population with an additional 48.8% of adults over the age of 65 identified as prediabetic.

To share what diabetic and pre-diabetic patients should know about a breast cancer diagnosis, Sasa Espino, MD, FACS, a breast surgeon within our greater HCA Healthcare family, joins us for a question and answer post. More information on Dr. Espino can be found at the bottom of the page.

Q:If a diabetic or pre-diabetic patient has just been diagnosed with breast cancer, what should that person do first?

Dr. Espino: Meet with their primary care physician and make sure their diabetes is under control. A patient who has recently received a breast cancer diagnosis will probably go through additional tests and procedures, which may impact their diabetes management. Getting diabetes under control will ensure the patient’s breast cancer journey, and road to recovery, is as smooth and fast as possible.

Q: Does having diabetes mean a patient’s breast cancer is going to be more aggressive than breast cancer in a non-diabetic person?

Dr. Espino: Not necessarily. Diabetes affects almost 1/3 of patients with breast cancer, and while there is some data that previously showed diabetics have a higher mortality than nondiabetics, more detailed studies have shown a higher breast cancer-specific mortality only in women with longer-standing diabetes and cardiovascular disease. This may be because more aggressive disease can result from higher levels of estrogen in women with diabetes, obesity, and insulin resistance. This means that patients who are able to get their diabetes and other comorbidities under control can potentially expect to have the same prognosis as a nondiabetic.

Q: How would a diabetic or pre-diabetic patient’s breast cancer treatment plan be impacted by the patient’s pre-existing condition. Would certain treatments not be available to them?

Dr. Espino: Women with diabetes and comorbidities related to diabetes tend to receive less aggressive breast cancer treatments primarily because of the potential side effects of the treatment. For example, diabetic patients may receive less aggressive chemotherapy because of its potential cardiovascular adverse effects. This doesn’t mean that the patient will not receive adequate treatment, but it does mean that there may be less options from which their physician may choose. Another example is radiation therapy. While diabetic patients can still get radiation, having left-sided breast cancer (more directly over the heart) may impact the decision for duration and strength of radiation, given the potential for long-term cardiotoxicity.

Q: If a breast cancer patient is diabetic or pre-diabetic, what can that patient do to best prepare their body for cancer treatments?

Dr. Espino: It is vital that the patient educates herself or himself with their current medical status, including making sure they are up to date on medication changes, physician visits, and tests and procedures. I always tell patients that whatever is good for their body is good for their breasts, which means that healthy eating and being active will make their body strong enough to face whatever breast cancer treatments they may need.

Q: What are the typical side effects from breast cancer treatment and how might a diabetic or pre-diabetic breast cancer patient’s experience differ?

Dr. Espino: Patients have different reactions to treatments, and it is important for patients to be aware of their own bodies even before treatment begins.

Some cancer treatments can cause significant swings in blood glucose, thereby making their diabetes worse. People with uncontrolled diabetes may have more severe treatment side effects, with increased likelihood for infections and hospital stays during their treatments. Vomiting and diarrhea can occur during chemotherapy, leading to dehydration. Dehydration can adversely affect treatment recovery and can be life-threatening, which is why an important way in which patients can ensure they keep their diabetes under control is to stay hydrated and regularly check their blood sugar.

Some of the treatments that more directly affect the patient’s blood glucose include chemotherapy, steroid medications, immunotherapies and hormone therapies, which can cause blood sugars to spike directly and can also lead to weight gain, which can result in a higher blood sugar.

Ways to control diabetes during such treatment side effects include following a healthy eating plan, getting exercise, managing stress, staying hydrated and continue talking to your healthcare team about how to manage your diabetes during cancer treatment.

Q: If a diabetic or pre-diabetic breast cancer patient needs surgery, are they more at risk for complications and, if so, what are those complications?

Dr. Espino: Patients with diabetes area at increased risk for infections after surgery, slower wound healing, fluid and electrolyte problems, as well as heart problems. The perioperative period may also include unpredictable blood glucose level spikes and dips. This starts with not having anything to eat for hours before the surgery, as well as potential stress hormones leading to higher blood glucose postoperatively.

Patients with diabetes should check their blood sugar often. This is especially important if patients have more trouble controlling their blood sugar because of postoperative nausea, vomiting, stress, pain, and postoperative medications.

Patients who have diabetes should expect that they will likely take more time to heal than patients without diabetes. Signs to watch out for include fevers, incisions that are red, hot to touch, swollen, more painful than usual, or oozing.

Finally, it is not uncommon for patients to want to lay in bed all day after surgery. This is the complete opposite of what I tell patients to do. Patients need to be active, prevent bedsores (which can be much worse in diabetics), prevent blood clots and pneumonias. I need you up and about and ready to take on the world.

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