620 likes | 805 Views
Carpe Diem: Time to Seize the Opportunity for Cancer Prevention. Graham A. Colditz, MD, DrPH ASCO: June 1, 2014. Department of Surgery Division of Public Health Sciences. Graham A. Colditz, MD DrPH. No Relevant Financial Relationships with Commercial Interests. Disclosures.
E N D
Carpe Diem: Time to Seize the Opportunity for Cancer Prevention Graham A. Colditz, MD, DrPH ASCO: June 1, 2014 Department of Surgery Division of Public Health Sciences
Graham A. Colditz, MD DrPH No Relevant Financial Relationships with Commercial Interests Disclosures
Goals of talk Focus = future and potential for prevention Local and global burden Review obstacles to prevention • Skepticism cancer can be prevented • Societal factors adding to complexity of prevention • Time frame Breast cancer example to integrate Tools and support to move forward Online tools and resources http://tinyurl.com/l4a4g2j
Aging US population Over 65 rising from 13% in 2012 to more than 20% of pop. in 2050 Cancer burden • Assume incidence per 100,000 holds steady at each age • Number of new cancer cases will double by 2050 simply due to aging population
Projected number of cases, USA Edwards, et al. Cancer 2002
Estimated new cancer cases, World, 1975 to 2050: Region New Cases 2012 already at 14M new cases diagnosed Bray and Moller Nat Rev Cancer 2006
Global burden, 2012 14 million new cases of cancer diagnosed 7.4M men; 6.6M women 1.7 Million new cases of breast cancer 25% of all cancer diagnosed in women Globocan 2012, IARC
Cancer care Cost – billions ($US 125b in 2010) Breast cancer: $US 16.6 b, or 13% in 2010 • 36% of this cost in the last year of life Increasing burden direct and indirect costs of cancer Lost productivity due to breast cancer $US 10.9b • Competition among drug manufacturers, surgical, radiation oncology, etc • What are system perspectives and patient perspectives? Hassett & Elkin, 2013
United States: New cases, women, 2014 Cancer Facts and Figures, 2014
Why aren’t we preventing cancer now? Multiple barriers: • Skepticism that cancer can be prevented • Short term focus of cancer research • Interventions deployed too late in life • Research focused on treatment not prevention • Debates among scientists • Societal factors ignored • Lack of transdisciplinary training • Complexity of implementation http://tinyurl.com/l4a4g2j Colditz et al SciTransl Med 2012: March 28
Why aren’t we preventing cancer now? Multiple barriers: • Skepticism that cancer can be prevented • Short term focus of cancer research http://tinyurl.com/l4a4g2j Colditz et al SciTransl Med 2012: March 28
Overcoming obstacles of skepticism and time frame • Must counter skepticism that cancer can be prevented • Arguments about endpoints of prevention: risk marker, premalignant lesion, invasive disease, death • Avoid exposure vs. remove later in life • Can we intervene if we don’t have the pathway defined? • Take into account time frame of cancer development
What Potentially Influences Cancer? Genetic factors telomere length Inherited mutations sporadic mutations Macro-level factors crime poverty availability of services Demographic factors age gender ancestry Individual-level factors diet health behaviors
Public health benefits Lie in the future Beneficiaries generally unknown Public has no idea what public health programs do. Thus, when people benefit from prevention they don’t recognize they have been helped Opposition to public health approaches that require societal change Hemenway D. Why we don’t spend enough on public health. NEJM 2010
What are the causes of cancer in society and which ones can be prevented?
Trends in smoking and lung cancer, USA Cigarette consumption Lung cancerMen Lung cancerwomen
Time course: lung & total mortality Current smoker: continuing
Preventing Cancer: Tobacco • Killed 100 million people globally in last century • Projected to kill 1 billion by end of this century • Causes at least 11 different types of cancer • Yet, single biggest public health success story of past 50 years • Smoking rates in United States more than cut in half since 1964. • Nearly 20% of people in US still smoke
Preventing Cancer Tobacco - Approaches • Work toward an “Endgame” • Maintain and expand current tobacco control polices • Initiate innovative new policies • Continue to promote and support cessation • Regulate electronic cigarettes as tobacco products
Source: Institute of Medicine, Accelerating Progress in Obesity Prevention, 2012
Preventing Cancer Overweight & Obesity - Approaches • Provide reimbursement and incentives for better integrating weight counseling into primary care delivery • Improve access to high-quality food in communities, schools, and workplaces • Improve education and self-efficacy on healthy weight issues • Create infrastructure and surroundings that support physical activity
Why aren’t we preventing cancer now? Multiple barriers: • Skepticism that cancer can be prevented • Short term focus of cancer research • Ignores decades-long time course for cancer development Colditz et al SciTransl Med 2012: March 28
Model of breast cancer evolution Wellings-Jensen Model (JNCI 55:231, 1975) Time (decades) Diversity LCIS ALH Invasion CCH s Adhesion & Polarity Growth ADH IBC DCIS TDLU
Lifestyle: high income countries Colditz, Wolin, Gehlert. Sci Trans Med 2012
Time course of benefits:Cost effectiveness considerations Universal Hepatitis B vaccination saves lives and dollars through reducing sequalae of infection • Primary prevention saves dollars! • Hung, Taiwan 2009 • China data show same benefit, extend life & save dollars, Lu 2013 • Hung and Chen. Vaccine 2009;27:6770-6 • Lu SQ, et al. Vaccine 2013;31:1864– 1869
The Value of Childhood Vaccination: Benefits Accrue across Time Broad Community externalities Improved outcomes in unvaccinated community members Behavior-related productivity gains Improvement of child health and survival changes household behavior Scope of benefits Outcome-related productivity gains Increased productivity due to improved cognition, physical strength, and school attainment Care-related productivity gains Parents’ productivity increases because need to take care of sick child is avoided Health care cost savings Savings of medical expenditures because illness is prevented Health gains Reduction in morbidity and mortality Narrow Time since Vaccination Adapted from Barnighausen, T., et al. "Accounting for the full benefits of childhood vaccination in South Africa: SAMJ forum." South African Medical Journal 98.11 (2008): 842-844.
What works: beyond smoking cessation and vaccines? • ACS guidelines NPA: not overweight, eat a plant based diet, limit alcohol, be active • Avoid alcohol between adolescence and first birth Reduced cancer incidence by: • Breast 22% • Colon 52% Reduced mortality • Thomson et al 2014 • Reduce premalignant and invasive breast cancer • Liu Y, et al JNCI 2013
Breast Cancer incidence:Pike model – Nature 1983 To accommodate the higher incidence with late first birth, we add a constant representing an increase in risk with FFTP (+b) in figure Pike, et al. Nature 1983
Breast Cancer:Multiple birth model 2.5% /yr 9% /yr Menarche First birth Menopause Rosner, Colditz, Willett, Am J Epidemiology 1994;139:826
Change in age at menarche Finland Norway Sweden
Change in menarche, Korea 30 years Cho EurJ Pediatr 2009
Trends in Fertility Calendar year Ito et al NEBR, 2008
Breast Cancer Incidence, Korea 1998 4o, born 1958 2008 40, born 1968 Jung et al, J Breast Ca, 2011
Risk factors account for 76% discrepancy China vs. USA • Compared age specific incidence in Shanghai prospective cohort vs. SEER. • Then fit Rosner-Colditz model to account for risk factors • Age at menarche, age at first and subsequent births, height, weight at 18 and through adult life, alcohol, menopause, type of menopause (natural, surgical), use of postmenopausal hormone therapy (E alone, E+P), benign breast disease, family history breast ca. • 76% of the US excess incidence controlled away with the established risk factors. • Leaves 24% not included in our models Linos,…,Colditz JNCI 2008;100:1352-60
Age at menarche, China LewingtonInt J Epi 2014
Parity, China LewingtonInt J Epi 2014
Age at first birth, China LewingtonInt J Epi 2014
Model of breast cancer evolution Wellings-Jensen Model (JNCI 55:231, 1975) Time (decades) Diversity LCIS ALH Invasion CCH s Adhesion & Polarity Growth ADH IBC DCIS TDLU
Adolescent fiber & BBD: NHSII Su et al, Cancer Causes Control, March 2010