Keynote presentation by UBC's Rachel Murphy on the epidemiology of kidney cancer. Presented at the ON-DECK Knowledge Translation event in Vancouver, November 7th, 2017
3. Epidemiology of kidney cancer
Kidney cancer includes renal parenchyma (mainly
renal cell cancer) and renal pelvis tumors
10th most common cancer in Canada
– 6,600 Canadians will be diagnosed in 2017
– 2,400 women (2.3% of cancer cases)
– 4,200 men (4.1% of cancer cases)
4. Cancer prevention
Prevention is a critical part of cancer control and
reducing the burden of cancer on Canadians
Primary prevention: aims to prevent disease before
it occurs
– Preventing exposure to hazards
– Altering unhealthy or unsafe behaviours
5. Cancer prevention
Eating well, maintaining a healthy body weight and
being physically active prevents ~30% of cancers1
1Kushi LH et al. CA Cancer J Clin. 2012;62:30-67
2Tom Blackwell, nationalpost.com/features/is-
prevention-the-ultimate-cure-for-cancer
“…further curbing the population’s risk
will likely require broad, structural
changes, policies that make fresh produce
as cheap and accessible as Big Macs”
– John Spinelli
6. Risk factors for kidney cancer
Known risk factors
– Age
– Sex
– Cigarette smoking
– Body weight
– Genetic conditions
– End-stage kidney disease and dialysis
– Family history
– Exposure to trichloroethylene
– Alcohol
7. Risk factors
Possible risk factors
– Exposure to radiation
– Arsenic in drinking water
– Exposure to cadmium
– Exposure to printing processes
– History of thyroid cancer
– Horseshoe kidney
– Hysterectomy
– Diabetes
– Height
– Physical activity
– Hypertension
8. Modifiable risk factors
What factors can you change?
– Exposure to carcinogens?
– Cigarette smoking
– Body weight
– Alcohol
– Diabetes?
– Physical activity
9. Modifiable risk factors
Smoking
• Causal risk factor: DNA damage, genetic alterations, tissue
hypoxia and smoking related-conditions like COPD
• Risk is 50% higher in male and 20% higher in female
smokers
• Dose-response pattern
• Smoking cessation reduces risk IF quit for >10 years
10. Modifiable risk factors
Body weight
• Overweight and obesity account for >40% of renal cell
cancers in US and >30% in Europe1
• 24% increased risk (men) and 34% increased risk (women)
for every 5 kg/m2 increase in BMI
• Weight cycling, weight gain and abdominal obesity are all
risk factors
How?
• Insulin resistance, adipokines, inflammation,
oxidative stress
1Calle EE, Kaaks R. Nature Rev. 2004;4:579-591
11. Modifiable risk factors
Body weight
It’s not too late to reduce your risk!
• Losing >5% of body weight improves cancer risk markers
• Losing >5% of body weight reduces the risk of some cancers
by ~66%1
1Luo J et al. JCO; 35(11):1189-1193.
12. Modifiable risk factors
Physical activity
• Only a few studies have studied physical activity and kidney
cancer
• Greater physical activity is associated with lower risk
• Possible dose-response relationship
How?
• Indirect: body weight, blood pressure
• Direct: insulin sensitivity, inflammation, oxidative stress
13. Modifiable risk factors
Physical activity
What can we do?
• Adopt a physically active lifestyle
• Include at least 150 min of moderate intensity or 75
min of vigorous intensity activity each week1
• Limit sedentary time1
1Kushi LH et al. CA Cancer J Clin. 2012;62:30-67
14. Modifiable risk factors
Diet
• Mixed findings
– Greater fruits and vegetables are associated with decreased risk
– Antioxidants have protective or null associations
– Increased fat intake may be a risk factor but some studies are
null
– Increased energy intake positively associated (modestly)
– Increased processed meat intake positively associated
15. Modifiable risk factors
Diet
What can we do?
• Eat a healthy diet with an emphasis on plant foods
• >2.5 cups/d of fruit and vegetables
• Limit consumption of red and processed meats
• Choose whole grains
1Kushi LH et al. CA Cancer J Clin. 2012;62:30-67
20. Incidence trends
• Between 2012 and 2020, kidney cancer is expected to
increase globally by 22%
Causes?
• Population aging
• Increased prevalence of risk factors: overweight/obesity,
hypertension
• Smoking continues to be prevalent
21. Incidence trends in Canada
Canadian Cancer Society, 2017
• Between 2001-2010, the
annual % change in age-
standardized incidence
rates was 1.3%
• The % change in new
cases is expected to soar
by >90% in 2028-2032
vs. cases in 2003-2007
22. Topic #3: Mortality
• 12th most common cause of cancer-related death
• 1,900 Canadians will die from kidney cancer in 2017
– 1,200 men will die from kidney cancer
• 5-year survival is 67%
Improvements in treatment Increased survivors
• >24,000 Canadians who were diagnosed 10+ years
ago are alive today
Canadian Cancer Society, 2017
26. Rachel Murphy
Centre of Excellence in Cancer Prevention
Faculty of Medicine | School of Population and Public Health
The University of British Columbia
Rm-167 2206 East Mall | Vancouver, BC Canada V6T 1Z3
Phone 604 822 6108 | Fax 604 822 4994
Rachel.murphy@ubc.ca | @cancerprevent |
www.cancerprevent.ca | youtube.com/user/cancerprevent
Contact
Editor's Notes
Primary prevention is a an effective approach to reduce the burden of cancer and has the benefit of being likely to prevent other chronic diseases that share risk factors with cancer such as diabetes and cardiovascular disease.
Opportunities for prevention
If obesity and physical activity are associated with risk of kidney cancer, then it would stand to reason that diet which is intertwined with both obesity and physical activity is as well. However, findings have been mixed.
AICR guidelines call for >2.5 cups/d of fruit and vegetable, however this is less than what is recommended in Canada’s Food guide which is 7-8 servings for women and 8-10 servings for men. Whole grain is a grain that has all three of it’s original parts-the bran, germ and endosperm. When one or more is removed it’s considered to be a refined grain e.g. white rice is only the endosperm
Rates are generally high in Europe and North America and low in Asia and South America. Within a continent and within a country, rates also differ.
There is geographic variability in incidence rates,
The incidence of kidney cancer are similar to variation in risk factors. BC has lower rates of overweight/obesity and smoking compared to Nova Scotia and Newfoundland. This may mean that prevention efforts need to be context specific.
The incidence of kidney cancer are similar to variation in risk factors. BC has lower rates of overweight/obesity and smoking compared to Nova Scotia and Newfoundland. This may mean that prevention efforts need to be context specific.
Kidney cancer incidence has been rising in most countries over the past 3 decades.
This highlights the importance of prevention so that we can bend these curves