Exercise and resistance to neoplasia

Area of Science:

• Oncology
• Preventive Medicine
• Exercise Physiology

Background:

• Epidemiological studies show an inverse relationship between physical activity and cancer incidence/mortality.
• This association is strongest for colon cancer and estrogen-dependent cancers (breast, ovary, endometrium).
• Confounding factors like lifestyle and body composition complicate definitive conclusions from human studies.

Purpose of the Study:

• To review epidemiological and experimental evidence on the role of physical activity in cancer prevention.
• To explore potential physiological mechanisms linking exercise to reduced cancer risk.
• To identify research gaps regarding exercise dosage and cancer prevention.

Main Methods:

• Review of epidemiological data assessing physical activity through various methods (recall, fitness).
• Analysis of experimental animal studies investigating exercise effects on tumor development and progression.
• Examination of proposed biological mechanisms, including hormonal, metabolic, and immune pathways.

Main Results:

• Consistent epidemiological evidence supports physical activity's protective role against several cancers.
• Animal studies suggest exercise can retard or prevent tumor incidence, progression, and spread.
• Potential mechanisms include altered hormone levels, reduced body fat, improved gut motility, enhanced antioxidant defenses, and stimulated anti-tumor immunity.

Conclusions:

• Moderate exercise is a safe and effective adjunct to diet for cancer prevention.
• Further research is needed to clarify optimal exercise dosages and elucidate underlying biological mechanisms.
• More investigation is required to determine the impact of exercise on cancer patients' prognosis.