Cancer and lifestyle – research round up

Effects of physical exercise on breast cancer related secondary lymphedema: a systematic review 
Baumann FT et al. (2018) Breast Cancer Research and Treatment DOI: 10.1007/s10549-018-4725-y

Improvements in the early detection, diagnosis, and treatment of breast cancer over recent years has improved survival rates significantly. With increasing numbers of survivors attention must be paid to reducing the long term side effects of the disease and its treatments. Breast cancer related lymphedema (BCRL) is one of the commonest morbidities and results from an accumulation of fluid in the interstitial tissue due to damage to the lymphatic system. Patients experience a swollen upper limb, associated weakness and pain and if persistent impacts  negatively on quality of life. Overweight and obesity are risk factors for developing BCRL therefore weight loss and increased physical activity are desirable to reduce the risk of developing BCRL and managing the condition.

This review aimed to examine the effects of various types of exercise in women with BCRL. Included were 11 intervention studies (n=458) comprising several modes of exercise: resistance exercise, aerobic training, water-based exercise, Yoga, Tai Chi etc. Most studies found a significant improvement in lymphedema, grip strength and arm disability, shoulder strength, flexion and range of movement and weight loss. From this review of the evidence it can be concluded that physical  exercise is not contraindicated for women with BCRL and may in fact be beneficial.

Consumption of ultraprocessed foods and cancer risk: results from NutriNetSanté prospective cohort
Fiolet T et al. (2018) BMJ DOI:10.1136/bmj.k322

The consumption of ultra-processed foods has dramatically increased over recent decades and it is estimated that these foods may contribute up to 50% of total daily energy intake. This is concerning because ultra-processed foods often have a higher content of total fat, saturated fat, and added sugar and salt, along with a lower fibre and vitamin density making them obesogenic but also the processing itself may cause the formation of carcinogenic compounds. Additionally some contain carcinogenic additives and packaging.

This prospective cohort study examined the association between ultra-processed food intake and risk of overall, breast, prostate, and  colorectal cancer. Repeated web based food recall diaries were used to gather data on participants’ usual consumption for 3300 different food items. 104980 participants (78.3% women) were included in the study and the median follow-up period was 5 years. Results showed ultra-processed food intake was associated with increased risks of overall cancer (P<0.001) and postmenopausal breast cancer (P=0.04). Specifically ultra-processed fats and sauces (P=0.002) and sugary products (P=0.03) and drinks (P=0.005) were associated with an increased risk of overall cancer, and ultra-processed sugary products were associated with risk of breast cancer (P=0.006). No association was statistically significant for prostate and colorectal cancers.

Preoperative exercise halves the postoperative complication rate in patients with lung cancer: a systematic review of the effect of exercise on complications, length of stay and quality of life in patients with cancer
Steffens D et al (2108) British Journal of Sports Medicine DOI: 10.1136/bjsports-2017-098032

Preoperative exercise, ‘prehabilitation’, has been suggested as a way to improve postoperative recovery. This paper reports a systematic  review of 13 RCTs testing preoperative exercises interventions in patients undergoing oncological surgery and what effect they have on  postoperative complications, length of hospital stay and quality of life. Seventeen articles were included involving 806 individual participants
and 6 tumour types (colon, liver resection for colorectal metastatic disease, oesophageal, lung, mouth and prostate). The authors found  moderate-quality evidence that preoperative pulmonary rehabilitation was effective in reducing postoperative complications and length of hospital stay in patients undergoing lung cancer surgery. For other cancers results were uncertain due to the limited number of trials included and the low quality of evidence.