Lifestyle Modification
Eating well, being physically active and maintaining a healthy weight can improve your overall health and may help reduce your risk of cancer returning.
Maintaining a healthy body weight
Weight gain after a cancer diagnosis is common, and may increase the risk of other health problems, including heart disease and type 2 diabetes. These conditions not only reduce quality of life, but they may also increase the risk of cancer recurrence.
Maintaining or achieving a normal body mass index (and waist circumference <80cm for women and <94cm for men) should be a priority for cancer survivors. Sometimes, changes in metabolism or body composition as a result of cancer treatment or menopause can mean that it is harder to lose or maintain weight. Specific attention to both diet and exercise is usually required.
Tracking caloric intake and physical activity has been shown to be an effective strategy for weight management. There are various free phone apps that you can download to help you (eg MyFitnessPal) as well as paid versions which offer coaching and personalised tips and advice.
Seeing an Accredited Practicing Dietician may also help to identify areas of improvement in your diet, and for tips and strategies to assist with weight loss and optimising metabolic health.
Alcohol and breast cancer recurrence
Alcohol is classified as a carcinogen and there is clear evidence linking alcohol consumption to multiple forms of cancer. Alcohol increases a woman’s risk of getting breast cancer, however, the evidence that alcohol is associated with an increase in the risk of recurrence is limited.
In the largest prospective research study, 1897 female breast cancer survivors participated in the Life After Cancer Epidemiology (LACE) study. Those who drank ≥6 grams of alcohol daily (equivalent to more than four ‘standard drinks’ of alcohol per week) had significantly higher rates of recurrence (34% more likely to have a recurrence) and death due to breast cancer (51% more likely to die from breast cancer) than those who drank <0.5 grams daily.
The increased risk of recurrence appeared to be greater among overweight and postmenopausal women. Further prospective studies are needed to confirm these findings, but some guidelines recommend limiting intake on the basis of these results.
NICE (National Institute for Health and Care Excellence in the UK) recommends people who have had breast cancer limit their alcohol intake to 4 units (40 grams) a week or less.
You can find out how many units are in your drinks by using an online unit calculator.
As an example, a 150mL glass of wine (standard restaurant serving) is 1.5 standard drinks (15g of alcohol), and a full-strength 375mL can or stubbie of beer is 1.4 standard drinks.
Can exercise help reduce cancer recurrence?
Regular physical activity is an important part of maintaining a healthy lifestyle and has been shown to reduce the risk of health conditions such as heart attacks, strokes and some cancers. It may also reduce the risk of breast cancer recurrence.
There is specific advice for people during and after cancer treatment.
The Clinical Oncology Society of Australia (COSA) recommends that all people who have had a cancer diagnosis participate in regular physical activity with the aim, as able, of reaching and maintaining:
at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic exercise each week; and
two to three muscle-strengthening resistance exercise sessions each week involving moderate to vigorous-intensity exercises targeting the major muscle groups.
Weight-bearing and osteogenic (bone strengthening) exercises are important to incorporate into your regular routine for bone health. Highly osteogenic exercises include basketball, netball, impact aerobics, gymnastics, tennis and skipping. Running, hill walking, stair climbing, and resistance training are moderately osteogenic. Whilst walking has only low osteogenic benefit, and swimming and cycling are non-osteogenic, these exercises do of course offer other health benefits. Read more about exercises for bone health.
Ask your GP about a referral to a qualified exercise physiologist with experience in cancer care who can recommend an exercise program tailored to you.
Nutrition and dietary recommendations
Eating a healthy diet can lower your risk of cancer. The following overview provides some advice on nutrition and dietary recommendations. Read more advice on food and nutrition for cancer prevention.
High-fibre foods
There is some evidence that a diet high in fibre may reduce the risk of breast cancer recurrence, but more research is needed. As a general rule, a diet high in vegetable and fruit (5 serves of vegetables and 2 serves of fruit per day, per population guidelines) can provide most of your daily fibre requirements, with wholemeal grains and legumes additional alternatives.
Limiting red meat consumption
The Cancer Council recommends limiting consumption of meat to a maximum of 455g of lean, cooked red meat and to avoid processed meat which are high in saturated fat and salt.
Refined sugars
Eating less refined sugar is recommended, although more research is needed to understand the relationship between cancer and dietary sugar intake. All kinds of cells in the body, including cancer cells, depend on sugar (glucose) for energy. Most cancer cells grow faster than normal cells and therefore require more energy, including from glucose. There is no evidence however that sugar actually makes cancer cells grow faster. Eating too much sugar however can lead to weight gain and increase the risk of diseases such as obesity, metabolic syndrome and diabetes, which in turn may increase the risk of cancer indirectly.
Vitamin D
Several studies have demonstrated a link between low levels of vitamin D and breast cancer. There is also some evidence that low levels are correlated with higher risk of breast cancer recurrence. While it is difficult to draw conclusions, there are benefits of adequate vitamin D more broadly (including for bone health). Taking a vitamin D supplement to ensure year-round levels that are higher than most of the population (ie >80 at the end of winter), may be advantageous.
Should I eat this? Common questions related to nutrition and diet
Foods that contain phytoestrogens
Soy foods such as soy milk and tofu contain natural compounds called phytoestrogens. Foods such as chickpeas and linseeds also contain phytoestrogens. Phytoestrogens have a chemical structure similar to the hormone oestrogen. As oestrogen can stimulate some breast cancers to grow, some people worry that foods or supplements containing phytoestrogens might have the same effect as oestrogen and increase the risk of recurrence. Current evidence suggests that a diet containing naturally occurring phytoestrogens is safe if you’ve had breast cancer and may be beneficial.
Organic foods
No association has been found between eating an organic diet (before or after diagnosis) and the risk of breast cancer recurrence.
Dairy
There is no evidence that the eating dairy products increases the risk of breast cancer. The Cancer Council Australia supports the Australian Dietary Guidelines, which encourage people to eat at least two and a half serves of dairy foods (milk, cheese and yoghurt) each day. Adequate calcium intake is particularly important for bone health, which is often a more significant issue during and after breast cancer treatment.
Supplements
There is little data to support the use of vitamins or other dietary supplements (except those advised for bone health) for the purposes of cancer recurrence or prevention.