Breast cancer is the most commonly diagnosed cancer in women, while cardiovascular disease remains the leading cause of death among women in Singapore. Together, they account for a large proportion of morbidity and mortality. The important thing to note is that they are connected in many ways, especially for breast cancer patients and survivors.
The strong link between heart health and cancer has led to the growth of cardio-oncology – a multidisciplinary approach dedicated to protecting the heart throughout the cancer journey and improving long-term survival for cancer survivors at higher risk of heart disease [1].
Why Breast Cancer Survivors Are at Higher Heart Risk
Treatment-related cardiac effects of cancer therapy play a major role. Some common breast cancer treatments can affect heart health:
- Anthracycline chemotherapy (e.g. doxorubicin) is linked to heart damage [2]. Risk increases with higher cumulative doses and in patients with pre-existing cardiovascular risk factors.
- Trastuzumab (Herceptin) can affect cardiac function, especially when combined with other agents that affect the heart [2]. Unlike anthracyclines, trastuzumab-related heart dysfunction is often reversible when detected early.
- Radiotherapy, especially to the left side of the chest, can unintentionally affect the heart [2]. Modern techniques have reduced but not eliminated this risk.
These effects may not appear immediately; slow, cumulative damage can develop years after treatment [2].
Heart-Healthy Strategies
1. Stay Active
Physical activity is one of the most powerful ways to reduce cardiovascular risk after breast cancer [3]:
- Survivors who are physically active have a significantly lower risk of cardiovascular death and all-cause mortality [3].
- Even adding ~2,500 extra steps per day or moderate exercise can reduce risk [3].
Guideline recommendation:
According to the Health Promotion Board (HPB) and World Health Organisation, aim for at least 150-300 minutes of moderate-intensity aerobic physical activity per week, or 75 minutes of vigorous activity, plus strength training on 2 days/week [3].
2. Eat a Heart-Healthy Diet
Nutrition plays a key role in cardiovascular health:
- Diets similar to DASH (Dietary Approaches to Stop Hypertension) or Mediterranean patterns are associated with lower risk of heart disease in breast cancer survivors. [4]
- Focus on fruits, vegetables, whole grains, lean proteins, and healthy fats, while minimising processed foods, added sugars, and excessive salt.[4] This supports healthy blood pressure and overall heart function.
3. Monitor Key Risk Factors
Regular monitoring of cardiovascular risk factors is essential:
- Blood pressure
- Blood cholesterol
- Blood sugar
- Weight
- Physical inactivity
- Smoking status
These factors contribute to cancer-related heart risk and can often be improved through lifestyle changes or medication [2].
4. Work with Your Healthcare Team
Collaborating with oncology and cardiology teams improves outcomes [1] [2]:
- Tailored cardiovascular risk assessments before, during, and after treatment – including heart imaging (such as echocardiograms) and functional evaluations when appropriate – help detect issues early [2].
- Shared-care models that involve oncologists, cardiologists, primary care, and rehabilitation professionals achieve the best long-term results [1].
5. Consider Structured Rehabilitation
Some programmes, called Cardio-Oncology Rehabilitation (CORE), integrate cardiovascular and cancer survivorship care [1] [3]:
- Exercise training
- Nutritional counselling
- Psychological support
- Education on risk factors
- Smoking cessation support
These programmes are similar to traditional cardiac rehabilitation programmes but adapted for cancer survivors, and can reduce long-term heart risk and support overall health.
Summary
Breast cancer survivors face elevated long-term risk for cardiovascular disease due to treatment effects and shared risk factors [1] [2]. The good news is that this risk can be managed and reduced through:
- Regular physical activity [3]
- Heart-healthy eating [4]
- Routine monitoring of cardiovascular risk factors [2]
- Close collaboration with healthcare providers [1]
Many cancer centres and breast surgeons in Singapore now work closely with cardiologists to monitor heart health during and after treatment. With proactive care, breast cancer survivors can improve long-term heart health and overall quality of life.
*Article reviewed by Dr Benji Lim, Interventional Cardiologist at Novena Heart Centre.
References
[3] Cardio-oncology, Exercise and cardiovascular health among breast cancer survivors: a scoping review