Supporting Patients During and After Cancer Treatment: Evidence-Informed Approach to Lifestyle and Behavior Change

Get Permission

Lorenzo Cohen, PhD

Lorenzo Cohen, PhD

Alison Jefferies, BA, MEd

Alison Jefferies, BA, MEd

The ASCO Post’s Integrative Oncology series is intended to facilitate the availability of evidence-based information on integrative and complementary therapies sometimes used by patients with cancer. In this installment, Lorenzo Cohen, PhD, and Alison Jefferies, BA, MEd, summarize research findings and emphasize the importance of counseling patients to play an active role in improving their quality of life and well-being through lifestyle modifications for health.

Confronted with a cancer diagnosis and treatment, patients often ask doctors what they can do to alleviate symptom burden and prevent recurrence. With increasing evidence to support lifestyle modifications for health, there is a clear need to communicate with cancer patients about adopting such measures.


During and after treatment for cancer, patients often ask what they can do to improve their outcomes—to decrease the side effects of treatment, reduce the chance of disease recurrence, and increase long-term survival. Well-intentioned physicians and clinical staff may reassure patients there is nothing they need to do; through the best practices of treatment and follow-up care, cancer progression or recurrence will be caught early and new treatment approaches considered. A typical comment is: “You don’t need to worry. You can go back to leading your life as you did before cancer, and we’ll see you in 6 months.

Unfortunately, this message removes an important aspect of control patients have over their cancer and the possibility of a second primary. It is also a lost opportunity for a teachable moment for patients and their loved ones, who typically accompany patients, to emphasize the importance of the link between lifestyle factors and cancer prevention and control and how to modify their risks. These same recommendations may also decrease other comorbidities patients often have, such as diabetes, hypertension, and cardiovascular disease.

Lifestyle Factors and Cancer

Although the evidence linking lifestyle factors to cancer is stronger in some areas than others, there is no debate that at least 50% of the most common cancers are attributable to lifestyle factors.1 These same factors also influence outcomes once someone has cancer.

These lifestyle factors can be categorized into physical and psychosocial categories: physical refers to diet, exercise/sedentary behavior, and exposure to environmental carcinogens and endocrine disruptors, as well as smoking, risky sexual behavior, and sun exposure; psychological refers to erosion of tight social support networks and chronic stress. These lifestyle factors have all independently been linked with cancer incidence and/or outcomes after a cancer diagnosis.1-3

With increasing evidence to support lifestyle modifications for health, there is a clear need to communicate with cancer patients about adopting such measures.

Tweet this quote

All these factors—diet, physical activity, environmental toxins, social support, and chronic stress—are linked with one or more key biologic hallmarks of cancer4 necessary for cancers to form, grow, and survive, such as tumor-promoting inflammation, avoiding immune destruction, inducing angiogenesis, and resisting cell death, to name a few.3,5-13 Furthermore, these lifestyle factors also interact with each other.

For example, we know that lack of social support makes it difficult to engage in healthy behaviors and manage chronic stress. Stress itself makes it difficult to engage in healthy behaviors and may lead to relapses in tobacco use,14 modified food choices,15 decreased beneficial effects of healthy foods,16 diminished interest in exercising,17 and disrupted sleep.18 (Sleep deprivation has also been linked with an increased cancer risk and cancer-specific and overall mortality.19,20) Sleep deprivation can modify food preferences21 as well as nutritional metabolic pathways,22 reduce energy for exercise, and may be linked with being overweight and obesity.20 Finally, exercise can influence stress,23 sleep,24 and metabolic processes.25

A More Comprehensive Approach

As the risk factors for developing cancer and those associated with better outcomes for people with cancer are multiple, modifying as many risk factors as possible simultaneously may result in greater risk reduction than modifying one or two risk factors alone. In fact, extensive epidemiologic research suggests the more guidelines followed for cancer prevention and control,26 the lower the risk of disease and cancer mortality.27 Clinical trials of individual lifestyle factors such as diet,28 exercise,29,30 and stress management31 have been found to improve clinical cancer outcomes. However, this research remains equivocal, as other studies have found limited benefit for recurrence of disease or survival outcomes when targeting modification of single lifestyle factors.32-34 Yet emerging data suggest there may be synergy between different lifestyle factors.35 For example, engaging in a healthy diet and being physically active together leads to a greater reduction in inflammatory markers relative to engaging in just one of the behaviors alone.36

Existing initial research of clinical trials focused on changing multiple lifestyle factors and behaviors shows evidence that this approach may, in fact, strengthen natural defenses, modify multiple cancer-specific biologic pathways, and have an impact on long-term outcomes.37-41 However, most previous lifestyle research modifies only one (eg, diet) or at the most two (eg, diet and exercise) behaviors, often resulting in limited effects.


Although thedata to date from randomized clinical trials of comprehensive lifestyle change are limited, it is important to weigh the risks of doing nothing, when it is known that people may be engaging in unhealthy habits that could lead to ill health and disease. Patients can still be counseled about some of the accepted and safe parameters to support healthy living. We need to guide patients in a direction we know is safe and would likely improve multiple other health indices and quality of life.

Modifying as many risk factors as possible simultaneously may result in greater risk reduction than modifying one or two risk factors alone.

Tweet this quote

The World Cancer Research Fund,42 the American Cancer Society,43 and the American Institute of Cancer Research (AICR)26 all have similar guidelines for cancer prevention, and they recommend cancer survivors follow these same guidelines. Here are the AICR guidelines: maintain a healthy weight; eat a primarily plant-based diet with a variety of vegetables, fruits, whole grains, and legumes such as beans; limit red meats and avoid processed meat; avoid sugary drinks and limit consumption of energy-dense foods; if consumed at all, limit alcohol to 1 drink a day for women and 2 for men; and be physically active for at least 30 minutes a day and limit sedentary behavior.26

When it comes to mind-body practices, there are many options, including the movement-based practices such as yoga, tai chi, or qigong and the hundreds to thousands of different meditation practices. Ultimately, the ideal program is one people are willing to do each day to reduce sympathetic nervous system activation and to create calm in their lives.

Finally, in the area of environmental factors, in the absence of clear evidence, it is ideal to follow the precautionary principle and to try to decrease exposure to endocrine disruptors and carcinogenic substances. There are a number of valuable resources to achieve this goal, including from the Environmental Working Group44 and the Breast Cancer Prevention Partners.45

If we truly want to win the “war” on cancer, we need to increase our focus on cancer prevention and start to implement lifestyle strategies we believe will reduce cancer risk and improve outcomes for those with cancer. It is time to modify the parting words cancer patients hear at the end of treatment—“See you in 6 months”—and use the encounter as a teachable moment to counsel them on the important role they can play in their future health and well-being.

DISCLOSURE: Dr. Cohen has received honoraria for certified continuing education from Teva and is an uncompensated consultant/advisor for Cancer Treatment Centers of America. Dr. Cohen and Ms. Jefferies are coauthors of Anticancer Living: Transform Your Life and Health With the Mix of Six.


1. American Association for Cancer Research (AACR): AACR Cancer Progress Report 2016: Saving Lives Through Research. Available at Accessed May 2, 2018.

2. World Health Organization/United Nations Environment Programme: State of the science of endocrine disrupting chemicals—2012. Available at Accessed May 2, 2018.

3. Cole SW, et al: Sympathetic nervous system regulation of the tumour microenvironment. Nat Rev Cancer 15:563-572, 2015.

4. Hanahan D, et al: Hallmarks of cancer. Cell 144:646-674, 2011.

5. Tabung FK, et al: Associations between adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations and biomarkers of inflammation, hormonal, and insulin response. Int J Cancer 140:764-776, 2017.

6. Figueiredo JC, et al: Genome-wide diet-gene interaction analyses for risk of colorectal cancer. PLoS Genet 10:e1004228, 2014.

7. Pedersen L, et al: Voluntary running suppresses tumor growth through epinephrine- and IL-6-dependent NK cell mobilization and redistribution. Cell Metab 23:554-562, 2016.

8. Saito R, et al: Aryl hydrocarbon receptor induced intratumoral aromatase in breast cancer. Breast Cancer Res Treat 161:399-407, 2017.

9. Lutgendorf SK, et al: Biobehavioral approaches to cancer progression and survival. Am Psychol 70:186-197, 2015.

10. Ruiz-Casado A, et al: Exercise and the hallmarks of cancer. Trends Cancer 3:423-441, 2017.

11. LoConte NK, et al: Alcohol and Cancer: A statement of the American Society of Clinical Oncology. J Clin Oncol 36:83-93, 2018.

12. Gray JM, et al: State of the evidence 2017: An update on the connection between breast cancer and the environment. Environ Health 16:94, 2017.

13. National Toxicology Program: 14th Report on Carcinogens. U.S. Department of Health and Human Services, Public Health Service, 2016. Available at Accessed May 2, 2018.

14. Buczkowski K, et al: Motivations toward smoking cessation, reasons for relapse, and modes of quitting. Patient Prefer Adherence 8:1353-1363, 2014.

15. Yau YH, Potenza MN: Stress and eating behaviors. Minerva Endocrinol 38:255-267, 2013.

16. Kiecolt-Glaser JK, et al: Depression, daily stressors and inflammatory responses to high-fat meals. Mol Psychiatry 22:476-482, 2017.

17. Stults-Kolehmainen MA, Sinha R: The effects of stress on physical activity and exercise. Sports Med 44:81-121, 2014.

18. Hall MH, et al: Chronic stress is prospectively associated with sleep in midlife women. Sleep 38:1645-1654, 2015.

19. Thompson CL, et al: Short duration of sleep increases risk of colorectal adenoma. Cancer 117:841-847, 2011.

20. Buysse DJ: Sleep health. Sleep 37:9-17, 2014.

21. Greer SM, et al: The impact of sleep deprivation on food desire in the human brain. Nature Commun 4:2259, 2013.

22. Knutson KL, et al: The metabolic consequences of sleep deprivation. Sleep Med Rev 11:163-178, 2007.

23. Conn VS: Anxiety outcomes after physical activity interventions: Meta-analysis findings. Nurs Res 59:224-231, 2010.

24. Kredlow MA, et al: The effects of physical activity on sleep. J Behav Med 38:427-449, 2015.

25. De Feo P, et al: Metabolic response to exercise. J Endocrinol Invest 26:851-854, 2003.

26. American Institute for Cancer Research (AICR): AICR’s Guidelines for Cancer Survivors. Available at Accessed May 2, 2018.

27. Kohler LN, et al: Adherence to diet and physical activity cancer prevention guidelines and cancer outcomes. Cancer Epidemiol Biomarkers Prev 25:1018-1028, 2016.

28. Toledo E, et al: Mediterranean diet and invasive breast cancer risk among women at high cardiovascular risk in the PREDIMED trial. JAMA Intern Med 175:1752-1760, 2015.

29. Ballard-Barbash R, et al: Physical activity, biomarkers, and disease outcomes in cancer survivors. J Natl Cancer Inst 104:815-840, 2012.

30. Buffart LM, et al: Effects and moderators of exercise on quality of life and physical function in patients with cancer. Cancer Treat Rev 52:91-104, 2017.

31. Stagl JM, et al: A randomized controlled trial of cognitive-behavioral stress management in breast cancer. Breast Cancer Res Treat 154:319-328, 2015.

32. Pierce JP, et al: Influence of a diet very high in vegetables, fruit, and fiber and low in fat on prognosis following treatment for breast cancer. JAMA 298:289-298, 2007.

33. Goodwin PJ, et al: The effect of group psychosocial support on survival in metastatic breast cancer. N Engl J Med 345:1719-1726, 2001.

34. Courneya KS, et al: Effects of exercise during adjuvant chemotherapy on breast cancer outcomes. Med Sci Sports Exerc 46:1744-1751, 2014.

35. Pierce JP, et al: Greater survival after breast cancer in physically active women with high vegetable-fruit intake regardless of obesity. J Clin Oncol 25:2345-2351, 2007.

36. Abbenhardt C, et al: Effects of individual and combined dietary weight loss and exercise interventions in postmenopausal women on adiponectin and leptin levels. J Intern Med 274:163-175, 2013.

37. Andersen BL, et al: Psychologic intervention improves survival for breast cancer patients. Cancer 113:3450-3458, 2008.

38. Ornish D, et al: Increased telomerase activity and comprehensive lifestyle changes. Lancet Oncol 9:1048-1057, 2008.

39. Ornish D, et al: Changes in prostate gene expression in men undergoing an intensive nutrition and lifestyle intervention. Proc Natl Acad Sci U S A 105:8369-8374, 2008.

40. Ornish D, et al: Intensive lifestyle changes may affect the progression of prostate cancer. J Urol 174:1065-1070, 2005.

41. Saxe GA, et al: Potential attenuation of disease progression in recurrent prostate cancer with plant-based diet and stress reduction. Integr Cancer Ther 5:206-213, 2006.

42. World Cancer Research Fund International: Our Cancer Prevention Recommendations. Available at Accessed May 2, 2018.

43. Kushi LH, et al: American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: Reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin 62:30-67, 2012.

44. Environmental Working Group: Available at Accessed May 2, 2018.

45. Breast Cancer Prevention Partners: Available at Accessed May 2, 2018.