Scientists investigating risk factors behind increasing rates of early- onset cancer – those occurring before age 50 – have found lifestyle factors starting in early life and young adulthood are the likely major influences.
The large study by US researchers, published in Clinical Oncology, analysed global data from 2000-2012 on the incidence of 14 cancer types which have increased in incidence among adults under 50, including: breast, colorectal, endometrial, esophageal, head and neck, kidney, multiple myeloma, pancreatic, prostate, stomach and thyroid.
The researchers then examined multiple previous investigations into risk factors, alongside literature describing the clinical and biological tumour characteristics of early and later-onset cancers – and confirmed ‘lifestyle factors early in life such as diet, obesity and environmental exposure’ may contribute to early- onset risks.
The study noted specific lifestyle factors that may increase cancer risk include:
- Westernised diet (high in saturated fats, red meat, processed meat, sugar and ultra-processed foods while low in fruits, vegetables, whole gains and fibre);
- lower breastfeeding rates and increased formula milk consumption;
- increased alcohol consumption;
- smoking habits;
- reduced sleep among children due to bright lights during the night;
- night shift work (which increases incidence of obesity and diabetes);
- reproductive changes (including reduced age of menarche, reduced number of births, increased age at first and last birth, increased oral contraceptive use);
- physical inactivity and sedentary lifestyle;
- increased rates of Type 2 diabetes.
In addition, the researchers reported 8 of the 14 cancers related to the digestive system – ‘indicating the importance of oral and intestinal microbiome in cancer risk’ and highlighting ‘higher antibiotic use’ as a factor affecting the microbiome and increasing cancer risk.
The researchers concluded the early-onset cancer risk factors ‘are likely linked to the environmental exposures in early life and young adulthood from the mid-20th century onwards’, summed up medicalnewstoday.com.
