In February 2017, the Chinese Journal of Surgery published the “Lifestyle Guidelines for Chinese Breast Cancer Patients”, which provides recommendations and suggestions for daily life for breast cancer patients and provides guidance for medical professionals, breast cancer patients and their families.
Recommendations for lifestyle improvement for breast cancer patients
Recommended evidence for lifestyle improvement for breast cancer patients
I. Achieving and maintaining a healthy weight
1. Weight gain is common among Chinese breast cancer patients.
According to statistics, more than 60% of patients have a higher weight 1.5 years after diagnosis than before diagnosis. In the past, more patients were diagnosed with advanced disease and the main problem was underweight; while most breast cancer patients are now diagnosed with early disease and some have reached overweight or obesity; some patients after neoadjuvant chemotherapy also show weight gain and are in overweight or obese state when they enter the recovery period after treatment.
2. Overweight and obesity are important factors for poor prognosis of breast cancer patients.
The results of two meta-analyses and four prospective studies confirmed that the relative risk of overall death and breast cancer death for those who were overweight and obese after diagnosis was 1.31 to 1.33. Overweight and obesity were also associated with the occurrence of contralateral breast cancer, lymph node metastasis, tumor recurrence, and complications. the results of the NHS study showed that compared to those with unchanged weight, breast cancer patients who had an increase in body mass index of 0.5 to The results of the NHS study showed that if the body mass index of breast cancer patients increased by 0.5 to 2.0 kg/m2 after diagnosis, the risk of recurrence increased by 40%; an increase of 2.0 kg/m2 or more increased the risk of recurrence by 53%. In China, if the weight of breast cancer patients increases by 5 kg 1.5 years after diagnosis, the risk of death increases by 65%. Weight gain is not only associated with breast cancer prognosis, but also increases the risk of developing and dying from other diseases and brings overall health damage.
Interventions to maintain a healthy weight can be beneficial for breast cancer patients.
Regardless of their weight at diagnosis, breast cancer patients benefit from achieving or maintaining a normal weight during treatment and recovery. Results from the Women’s Nutrition Intervention Study (WINS) showed that an average weight reduction of 0.45 kg (sic 6 lbs) through a low-fat diet significantly reduced the risk of recurrence in postmenopausal breast cancer patients, a benefit that was even more pronounced in patients who were estrogen receptor negative.
Results from the Exercise and Nutrition for Recovery and Good Health (ENERGY) study also confirm that the use of exercise and low-calorie diet management in overweight and obese cancer patients can significantly reduce body weight, improve quality of life, and improve physical function and hormone levels. For overweight and obese people in general, health gains can be achieved by reducing body weight by 5-10%, and such findings should also apply to breast cancer patients.
II. Regular participation in physical activities
1. Physical activity in breast cancer patients after diagnosis is associated with reduced breast cancer recurrence rates, breast cancer mortality and overall morbidity and mortality, as well as improved patient fitness, patient self-reported health status, and reduced lymphedema and complications.
Eight prospective studies evaluated the relationship between physical activity and overall morbidity and mortality in breast cancer patients, four of which assessed its association with breast cancer morbidity and mortality, showing that adherence to physical activity after diagnosis reduced the risk of breast cancer death by 34% and the risk of breast cancer recurrence by 41%.
The results of the Aggregate Cancer Post-Phase Program (ACPP) study showed that physical activity of up to 10 metabolic equivalent-h per week in breast cancer patients could reduce the overall morbidity and mortality rate by 27% and breast cancer morbidity and mortality rate by 25%.
2. Physical activity and physical exercise can improve the physical fitness of cancer patients.
Moderate intensity aerobic and endurance training for breast cancer patients can increase bone density, improve cardiopulmonary function, muscle strength, and increase lean body mass. Physical exercise can also improve patients’ quality of life, relieve tension and depression, and improve self-awareness.
3. Breast cancer-related conditions and many factors during treatment can diminish patients’ ability to be physically active and physically active.
To avoid exercise-related injuries, breast cancer patients with anemia, impaired immune function, fatigue, tube placement and uncontrolled complications must seek professional guidance in choosing and performing exercise.
III. Proper nutrition and diet
Dietary structure and food choices are indeed related to disease progression, risk of recurrence, and overall survival of breast cancer patients.
1. Fat: The results of studies have shown that fat intake is associated with breast cancer survival, but the results are not entirely consistent across studies. Some studies showed that fat intake was negatively correlated with breast cancer recurrence and survival, and the above correlation disappeared after adjusting energy intake. The WINS study showed that a low-fat diet (less than 15% of total calories from fat) was associated with recurrence-free breast cancer survival. Every 20% reduction in dietary energy reduces the risk of breast cancer recurrence by 24%.
2. Protein: A moderate amount of protein intake is important in the process of treatment, recovery and long-term survival of cancer patients. Foods such as fish, lean meat, skinless poultry, eggs, low-fat and fat-free dairy products, nuts and legumes are sources of high-quality protein and can also provide unsaturated fatty acids. The dietary structure based on vegetables and fruits should be supplemented with sufficient fish, milk and other high-quality proteins.
3. Carbohydrates: In a healthy dietary structure, carbohydrates should come from foods rich in essential nutrients and dietary fiber, such as vegetables, fruits, whole grains and legumes. Whole grains contain a variety of vitamins, minerals and other nutrients that can reduce the risk of cancer and cardiovascular disease. Refined grains, on the other hand, contain far fewer vitamins, minerals and dietary fiber than whole grains. Sugar and sugary drinks (soft drinks and juice drinks) can increase dietary energy intake and make weight gain, and should be limited.
4, vegetables and fruits: vegetables and fruits contain a large number of essential vitamins, minerals, bioactive phytochemicals and dietary fiber, and are low-energy density food, can help maintain a healthy weight. Fruits (not fruit juices) can provide dietary fiber and reduce the energy intake of food. If the patient can not intake fresh fruit, it is recommended to choose pure fruit juice.
5. Soy products: Soy products are rich in soy isoflavones, which have estrogen-like effects and can reduce the level of estrogen in human blood and have the effect of preventing breast cancer. The results of the Shanghai Breast Cancer Survival Cohort Study, which targeted 5,000 breast cancer patients in Shanghai, showed that the risk of death from breast cancer was reduced by 29% and the risk of recurrence was reduced by 32% in the highest soy protein intake group. Results from a joint US-China study showed that soy intake reduced the risk of breast cancer recurrence by 25%, with a more pronounced protective effect in estrogen receptor-negative patients. Based on the above research evidence, it is recommended that soy products are safe to consume in moderation as part of a healthy diet. However, due to the lack of evidence, supplements containing soy isoflavones are not recommended for breast cancer patients to reduce the risk of recurrence.
In summary, there is growing evidence that a diet rich in vegetables and fruits can improve overall survival in cancer patients. It is also important to recognize that the adverse effects of a patient’s diet for many years prior to diagnosis may offset the benefits of dietary structure changes for a short period of time after diagnosis. In addition to vegetables and fruits, a healthy dietary structure should include abundant fish and poultry rather than red and processed meats, low-fat dairy rather than full-fat milk, whole grains rather than refined grains, and vegetable oils rather than other fats. The Dietary Guidelines for Chinese Residents 2016 is also fully applicable to breast cancer patients.
4. Use health care products with caution
Nutraceuticals are foods that claim to have specific health functions or are intended to supplement vitamins and minerals, and are generally known as “dietary supplements” in Europe and the United States, including vitamins, minerals, herbs, amino acids, etc. According to the Shanghai Breast Cancer Survival Cohort Study, 97.2% of patients took dietary supplements or Chinese herbal medicine. To date, neither observational studies nor clinical trials have confirmed that supplements improve the prognosis of cancer patients, and may instead increase the risk of death.
Various dietary supplements and multivitamins have not been associated with recurrence, breast cancer morbidity and overall morbidity and mortality after early breast cancer diagnosis. In contrast, the results of the Chinese Breast Cancer Patient Study showed a mild reduction (18% to 22%) in the risk of death and recurrence in patients using antioxidants (vitamin E, vitamin C, or multivitamins), with the most significant reduction in the risk of death and recurrence especially in patients who used vitamin C and vitamin E for a prolonged period of time. Since the findings of the Chinese Breast Cancer Patient Study need to be validated by more research results, the use of dietary supplements for breast cancer patients should follow the recommendations of Food, Nutrition, Physical Activity and Cancer Prevention for cancer patients.
V. Other lifestyle recommendations
1. Smoking: Breast cancer patients who smoked at the time of diagnosis had a two-fold higher risk of death from breast cancer and a four-fold higher risk of death from non-breast cancer than nonsmokers. The risk of dying from breast cancer in smokers is also related to the intensity and duration of smoking. The rate of active smoking among Chinese women is only 2.5%, but overall exposure to secondhand smoke is 71.6%. Some studies have shown that passive smoking is weakly associated with death from breast cancer and all-cause mortality in women, and that passive smoking puts postmenopausal or obese breast cancer patients at higher risk of poor prognosis. Therefore, it is recommended that breast cancer patients should avoid smoking and passive smoking as much as possible. Breast cancer patients who smoke should quit smoking early.
2. Alcohol consumption: Available evidence has confirmed the association between ethanol intake and a variety of cancers (e.g. oral, liver, pharyngeal, laryngeal, breast, esophageal and colorectal cancers). Patients who have been diagnosed with cancer have an increased risk of developing a second primary cancer. Ethanol has the ability to increase peripheral blood estrogen concentrations, which theoretically raises the risk of breast cancer recurrence. Therefore, breast cancer patients should avoid ethanol intake as much as possible.
In conclusion, disease-free survival of breast cancer patients is a favorable time to improve lifestyle. The advice and recommendations in this guideline can help breast cancer patients to form healthy dietary habits, good physical activity habits, and achieve and maintain normal weight to promote overall health status, improved prognosis, and quality long-term survival.