Colorectal cancer in Georgia: 2002-2006 [Sept. 2009]

Colorectal
in Georgia, 2002 - 2006
1

Acknowledgments
Georgia Department of Community Health Rhonda M. Medows, M.D., Commissioner and State Health Officer Division of Public Health Rhonda M. Medows, M.D., Acting Director Epidemiology Branch Susan Lance, D.V.M., Ph.D., Director Chronic Disease, Healthy Behaviors, and Injury Epidemiology Section A. Rana Bayakly, M.P.H., Acting Director Georgia Comprehensive Cancer Registry A. Rana Bayakly, M.P.H., Director Deepali Rane, M.B.B.S., M.P.H., Epidemiologist Health Promotion & Disease Prevention Branch Kimberly Redding, M.D, M.P.H., Director Georgia Comprehensive Cancer Control Program Tamira Moon, M.P.H, C.H.E.S., Manager Graphic Design Jimmy Clanton, Jr.
We would like to thank all the hospitals in Georgia who contributed data to the Georgia Comprehensive Cancer Registry. Without their hard work, this report would not have been possible.
Suggested Citation: Rane D., Bayakly AR., Moon, T., Colorectal Cancer in Georgia, 2002-2006. Georgia Department of Community Health, Division of Public Health, Chronic Disease, Healthy Behaviors, and Injury Epidemiology, September, 2009.
2

Figure 1. Anatomy of the Digestive System
Figure 2. Colon Polyp

Introduction
Colorectal cancer is a collective term for cancers of the colon and rectum. Since cancers of the colon and rectum share many common features, they are often referred as colorectal cancer. The colon and rectum are parts of the digestive system. Together, they form a long, muscular tube called the large intestine. The colon is the first four to five feet of the large intestine and the last four to five inches is the rectum (Figure 1).
Once food is chewed and swallowed, it travels through the esophagus to the stomach. In the stomach, it is partially digested and transferred to the small intestine. The small intestine continues digesting the food and absorbs most of the nutrients. The small intestine is connected to the large intestine. In the large intestine, the colon absorbs water and electrolytes from the food and serves as a storage place for waste products. The waste then moves from the colon into the rectum and passes out of the body through an opening called the anus during a bowel movement.
Colorectal cancers develop slowly over a period of several years. Most of them begin as a polyp, a growth of tissue protruding into the center of the colon or rectum (Figure 2). Polyps are also known as adenomas. Removing the polyp early may prevent it from becoming cancerous. Over 95 percent of colorectal cancers are adenocarcinomas, which arise from cells that line the inside of the colon and the rectum.
Colorectal cancer affects both men and women and most often occurs in people over 50 years of age. It is the third most commonly diagnosed cancer and cause of cancer death among Georgia men and women, respectively. The Georgia Comprehensive Cancer Registry estimates that, over 3,700 new cases of colorectal cancer will be diagnosed statewide in 2009 and about 1,300 Georgians will die from this disease.
Screening & Detection
Treatment is more likely to be successful if colorectal cancers are detected early. Several screening tests are available to detect the disease. The American Cancer Society recommends that people at average risk for colorectal cancer should begin screening at age 50.
Screening options include: Tests that find polyps and cancer
Flexible Sigmoidoscopy every 5 years Double contrast barium enema every 5 years CT colonography (virtual colonoscopy) every 5 years Colonoscopy every 10 years Tests that mainly find cancer Fecal occult blood test every year (FOBT)* Fecal immunochemical test every year (FIT)* Stool DNA test (sDNA), interval uncertain
*For FOBT or FIT used as a screening test, the take-home multiple sample method should be used.
3

Incidence and Mortality
The overall age-adjusted colorectal cancer incidence rate in Georgia is 49 per 100,000 in males and females combined. Males are 40% more likely to be diagnosed with colorectal cancer than females (age-adjusted rate 59/100,000 vs. 42/100,000)
The overall age-adjusted colorectal cancer mortality rate in Georgia is 18 per 100,000 in males and females combined. Males are 47% more likely to die of colorectal cancer than females (age-adjusted rate 22/100,000 vs.15/100,000)
In Georgia and the United States, black males are more likely than white males to be diagnosed with colorectal cancer. Similarly, black females are more likely than white females to be diagnosed with this disease (Figure 3)
Black males are more likely than white males to die from colorectal cancer in Georgia and the United States. Similarly, black females are more likely than white females to die from this disease (Figure 4)
Figure 3. Age-adjusted Incidence Rate by Race and Sex, 2002-2006

100

Georgia 2002-2006 United States 2002-2006

69 70
50

57 59

53 52

39 43

Rate per 100,000

0 Black Males

White Males Black Females White Females

Figure 4. Age-adjusted Mortality Rate by Race and Sex, 2002-2006

100

Georgia 2002-2006 United States 2002-2006

Rate per 100,000

50
30 31

20 21

21 22

13 15

0
Black Males

White Males Black Females White Females

4

Causes and Risk Factors
Everyone is at risk for colorectal cancer, some more than others. Different cancers have different risk factors. A risk factor is anything that increases a person's chance of getting a disease such as cancer. Some get colorectal cancer in the absence of any apparent risk factors. Although, it is hard to measure the contribution of a risk factor or know the exact cause for the development of precancerous polyps or cancer, researchers have found factors that can increase the risk of colorectal cancer.
Risk Factors You Can Change
Diet: People who eat a diet similar to that of Western countries, such as United States and Europe, have a higher risk of developing colon cancer then do people who eat diets typically seen in developing countries. The higher risk may be associated with a diet high in animal fat and processed meat, which is low in fiber. Diets high in vegetables and fruits have been linked with a decreased risk of colorectal cancer. The American Cancer Society recommends choosing most of your food from plant sources and limiting the amount of high-fat foods
Physical inactivity: If you are not active, there is a greater chance of developing colorectal cancer. Getting regular physical activity may reduce your risk. To gain substantial health benefits, the U.S. Department of Health and Human Services recommends 60 minutes, five times a week of moderate-intensity aerobic physical activity for adults
Obesity: People who are obese have an increased risk of developing colon cancer and an increased risk of dying of colon cancer when compared with people who are considered to be at normal weight
Smoking: Long term smokers are more likely than nonsmokers to develop and die from colorectal cancer
Alcohol Consumption: Heavy use of alcohol may increase the odds of getting colorectal cancer. The American Cancer Society recommends that alcohol use should be limited to no more than two drinks per day for men and one drink per day for women
5

Risk Factors You Cannot Change

Age: The risk of developing colorectal polyps and cancer Figure 5. Familial Adenomatous Polyposis

increases with age. More than 90% of people diagnosed with colorectal cancer are older

Familial

than 50

adenomatous

Family History: Parents, siblings, and children of a person who have

polyposis

colorectal adenomas or cancer

are at least two to three

times more likely to develop

colorectal cancer themselves.

The risk increases even further

if any first-degree relative

is affected before the age

of 60, or if two or more

first-degree relatives are

affected. Cancers within

the same family may result

from inherited genes, shared

exposure to an environmental

carcinogen, diet, or lifestyle

factors. Also, certain genetic syndromes

passed

through generations of a person's family can increase one's

risk of developing colorectal cancer. These syndromes cause

5% of all colon cancers. The two most common syndromes

are Familial Adenomatous Polyposis (FAP) and Hereditary

Non-Polyposis Colorectal Cancer (HNPCC). People with FAP

(Figure 5) develop hundreds or thousands of polyps in their

colon and rectum in their teens or early adulthood. Cancer

may develop in these polyps as early as age 20. Similar to FAP,

HNPCC develops when people are relatively young. However,

individuals with HNPCC have fewer polyps and develop

colorectal cancers at an average age of 44. These genetic

syndromes can be detected through genetic testing. For

those who have changes in their genes or have family history

of colorectal cancer, health care providers suggest reducing

the risk of colorectal cancer by implementing strategies

such as receiving regular screenings, eating a healthy diet,

exercising, and other preventive measures at an early age

Racial and Ethnic Background: African Americans have the

highest colorectal cancer incidence and mortality rates of all

racial groups in the United States. The reason for this is not

yet understood

Personal history of Colorectal Cancer or Polyps: Once

a person suffers from colorectal cancer, it is likely to recur.

Also, some types of polyps, such as adenomatous polyps and

hyperplastic polyps increase the risk of colorectal cancer

Personal history of bowel disease: Inflammatory Bowel

Disease (IBD), which includes Ulcerative Colitis or Crohn's

disease, is a condition in which the colon is inflamed over a

long period of time. People with IBD have an increased risk of

developing colorectal cancer and they should be screened for

colorectal cancer on a more frequent basis

Diabetes: People with Type 2 diabetes have an increased

risk of developing colorectal cancer. The disease may also

develop more aggressively in these patients

6

Prevalence of Behavioral Risk Factors

Table 1: Prevalence(%), Behavioral Risk Factor Surveillance System (BRFSS), 2008

Georgia

United States

Risk Factors

All

Males Females All Males Females

Obesity

28

28

28

27

27

26

Smoking

20

22

17

18

20

17

Physical Inactivity

23

20

26

25

23

27

According to the Georgia 2008 Behavioral Risk Factor Surveillance System (Table1):
The prevalence of obesity in males and females is similar Males (22%) are more likely to be current smokers than
females (17%), however this difference is not significant Females (26%) are significantly more likely to be physically
inactive than males (20%)

Symptoms
In the early stages of colorectal cancer, individuals with the disease may not have any symptoms. When symptoms appear, they vary depending on the location and size of the cancer in the large intestine. Signs and symptoms of colorectal cancer include:
A change in bowel habits such as diarrhea, constipation, or change in the consistency of the stool that lasts for more than a couple of weeks
A feeling that the bowel does not empty completely Rectal bleeding or blood in the stool Persistent cramping abdominal pain Abdominal pain during a bowel movement Weakness and fatigue Unexplained weight loss Other conditions such as hemorrhoids and inflammatory bowel disease may also have symptoms that mimic colorectal cancer. If you have any of the above symptoms, it is very important to talk to your doctor because it could be a sign of a serious medical condition such as colorectal cancer.

Colorectal cancer is the third most commonly diagnosed cancer and cause of cancer death among males and females in Georgia.

Leading Causes of Cancer Incidence and

Mortality

Table 2: Leading Causes of Cancer Incidence and Mortality, Georgia 2002-2006

Top 5 Causes of Cancer Incidence

Top 5 Causes of Cancer Mortality

Males

Females

Males

Females

Prostate

Breast

Lung & bronchus Lung & Bronchus

Lung & Bronchus Lung & Bronchus Prostate

Breast

Colorectal

Colorectal

Colorectal

Colorectal

Bladder

Uterus

Pancreas

Pancreas

Melanoma

Melanoma

Leukemia

Ovary

7

Age at Diagnosis
Figure 6. Age-specific Colorectal Cancer Incidence and Mortality Rates by Sex, Georgia 2002-2006
Males

Rrate per 100,000

500
400
300
200
100 21
0 0-39

Incidence Mortality

26 7 40-49

86 23

185 58

50-59

60-69

Age Group

373 297
217
107

70-79

80+

Females

Rate per 100,000

500
400
300
200
100 21
0 0-39

Incidence Mortality

23 6 40-49

64 16

121 34

50-59

60-69

Age Group

212 79
70-79

267 147
80+

The incidence and mortality rates of colorectal cancer increases with age for both males and females (Figure 6)
The risk of being diagnosed with colorectal cancer increases sharply between ages 50-59 years for both males and females
Similarly, the risk of dying from colorectal cancer increases sharply between ages 50-59 years for both males and females
Fewer than 70 cases and 35 deaths due to colorectal cancer occur each year in individuals less than 40
years of age in both males and females

8

Screening
According to the Georgia Behavioral Risk Factor Surveillance System (BRFSS):
The percent of screening by sigmoidoscopy /colonoscopy is similar among both men and women 50 years of age and older (Figure 7)
Adult males, 50 years of age and older have a significantly higher prevalence of receiving the fecal occult blood test in the past 12 months when compared to adult females 50 years of age and older (Figure 8)

Figure 7. Percent of Adults age 50+, who ever had a Sigmoidoscopy/Colonoscopy by Sex, Georgia 2002-2008
100

51

50

42

Percent

0 Males

Females

Figure 8. Percent of Adults age 50+, who had a Fecal Occult Blood Test (FOBT) in the past 12 months, by Sex, Georgia 20022008
100

56

57

50

Percent

0 Males

Females

9

Treatment
Different types of treatment are available for patients with colon cancer. The choice of treatment depends on a variety of factors such as age, overall health, and type and stage of colorectal cancer. Staging is a standardized way to summarize information about how far a cancer has spread from its point of origin. The three standard types of treatment used in colorectal cancer are surgery, radiation therapy, and chemotherapy. Depending on the stage of cancer, multiple treatment modalities may be used at the same time or one after another.
Surgery: This is the main treatment for early stage colorectal cancer. If the cancer is at an early stage the doctor removes it without cutting through the abdominal wall, with a colonoscope (a tube that is inserted through the rectum into the colon, to cut the cancer out). This is called a local excision. If the cancer is found in a polyp, the operation is called a polypectomy. If the cancer is larger, the doctor removes a length of the large intestine on either side of the cancer including some lymph nodes and sews the healthy parts of the intestine together. This is termed as a colectomy. If the doctor is not able to sew the ends of the colon back together, an opening is made outside of the body for the waste to pass through. This procedure is called as a colostomy. A bag is placed around the stoma to collect the waste
Radiation Therapy: This treatment uses high energy x-rays or other type of radiation to kill cancer cells. There are two types of radiation therapies: external radiation and internal radiation. External radiation comes from a machine and is directed at the cancer. For internal radiation therapy, radioactive material/implants are put directly into or near the cancer. This therapy is used when the cancer is attached to an internal organ or lining of the abdomen. In such instances the cancer may not be completely removed by surgery. Radiation therapy then helps to kill any cancer cells remaining after surgery
Chemotherapy: This treatment uses drugs to stop the growth of cancer cells. Systemic chemotherapy uses drugs that are injected into a vein, muscle or taken by mouth. These drugs enter the blood stream and reach cancer cells throughout the body. In regional chemotherapy, drugs are placed directly into an artery leading to a part of the body containing the tumor. Chemotherapy is used in a variety of situations to treat colorectal cancers
Adjuvant and Neoadjuvant Therapy: Chemotherapy may be used after surgery even when there is no evidence of cancer remaining, to kill cancer cells that may have escaped from the primary tumor and settled in other parts of the body. This is called as adjuvant chemotherapy. Neoadjuvant chemotherapy is used for some rectal cancers before surgery (along with radiation), to shrink the tumor size. Chemotherapy in advanced cancers helps to shrink tumors and relieve symptoms from the tumor. Although it is unlikely this procedure will completely remove the cancer, it helps to increase the survival time
10

Survival
Early detection saves lives. Individuals diagnosed at an early stage (localized) have a better chance of surviving five years after diagnosis than those diagnosed at a later stage (Figure 9)

Figure 9. Colorectal Cancer Five-Year Survival Rates by Sex, Race and Stage, United States, 1999-2005

100

92859187

White Males

Black Males

66 66 56 57

70 70

White Females

63 63 Black Females

50

Percent

0 All Stages Localized

Regional

11 7 13 9 Distant

Percent

100

91 91

65 65

70 69

50

Males Females

11 12
0
All Stages Localized Regional Distant
Overall, five-year survival rate is 65% for both males and females at all stages of the disease. However, when detected at a localized stage the five-year survival rate increases to 91%
Overall, the five year survival rates for white males and females (66% each) for all stages are higher than those for blacks (56% for males, 57% for females)
Black males (85%) and black females (87%) diagnosed at a localized stage have a lower five-year survival rate than white males (92%) and white females (91%)
Five-year survival rates drop significantly for all individuals when diagnosed at a distant stage

11

Colorectal Cancer by Stage of Disease

Table 3: Percent of Colorectal Cancer found by Stage of Disease, Sex and Race, Georgia (2002-2006) and United States (1999-2005)

US Males

Localized Regional (%) Distant (%) Unstaged/

(%)

Unknown (%)

39

37

19

4

GA Males

39

37

19

5

US Females

38

38

19

5

GA Females

40

37

18

6

US Black Males

34

36

25

5

GA Black Males

37

34

24

5

US White Males

40

37

19

4

GA White Males

40

38

18

4

US Black Females

34

35

24

6

GA Black Females

39

34

21

6

US White Females

38

38

19

5

GA White Females

40

38

17

6

The distribution of stage at diagnosis for colorectal cancer patients in Georgia is similar to the colorectal cancer patients in the U.S.

12

Urban vs. Rural Georgia

Figure 10-1. Urban -Rural Counties, Georgia, 2003

Figure 10-2. Counties by Poverty Level, Georgia, 2005

Rate per 100,000 Rate per 100,000

Based on the U.S Department of Agriculture, Georgia has 89 rural counties and 70 urban counties.

Georgia has 79 counties at high poverty level, 69 counties at medium poverty level and 11 counties at low poverty level.

Figure 11. Age-adjusted Colorectal Cancer Incidence and Mortality Rate by Geography, Race and Sex, Georgia, 2002-2006

100
69 52
50

Incidence

Males Females

56 39

69 55

63 42

0 Urban Black

Urban White

Rural Black

Rural White

Mortality

100

Males Females

50 30 21
0 Urban Black

20 13
Urban White

30 20
Rural Black

22 14
Rural White

The age-adjusted colorectal cancer incidence and mortality rates are consistently higher among blacks than among whites living in urban and/or rural areas (Figure 11)
Colorectal cancer incidence and mortality rates are significantly higher among urban black males and females than among urban white males and females
Incidence rates are not significantly different between rural black males and rural white males Mortality rates are significantly different between rural black males and rural white males Colorectal cancer incidence and mortality rates are significantly higher among rural black
females than among rural white females

13

Associations between Poverty and Geography

Table 4. Age-adjusted Colorectal Cancer Incidence Rates by Sex, Urban-Rural and Poverty, Georgia 2002-2006

Males

Females

Level of Poverty Low Medium High

Urban 52 57* 68*

Rural *** 63* 63*

Urban 41 42 45

Rural *** 47* 44

Urban and rural males living in medium and high poverty level areas have significantly higher incidence rates when compared to urban males living in low poverty areas (Table 4)
Rural females living in medium poverty areas have a significantly higher incidence rate when compared to urban females living in low poverty areas

Table 5. Age-adjusted Colorectal Cancer Incidence Rates by Sex, Race, Urban-Rural and Poverty, Georgia 2002-2006

Males

Females

Level of Poverty
Low Medium High

Urban White
53
56
62*

Rural White
***
63*
62*

Urban Black
62
66*
83*

Rural Black
***
68*
69*

Urban White
40
38*
39*

Rural White
***
44*
40*

Urban Black
47
53
53

Rural Black
***
65*
52

Urban white males living in high poverty areas as well as rural white males living in medium and high poverty areas have significantly higher incidence rates when compared to the urban white males living in low poverty areas (Table 5)
Urban and rural black males living in medium and high poverty areas have a significantly higher incidence rate than urban white males living in low poverty areas
Urban black males living in high poverty areas have a significantly higher incidence rate than urban black males living in low poverty areas
Urban and rural white females living in medium and high poverty areas have significantly higher incidence rates when compared to urban white females living in low poverty areas
Rural black females living in medium poverty areas have significantly higher incidence rate when compared to urban black females living in low poverty areas

14

Table 6. Age-adjusted Colorectal Cancer Mortality Rates by Sex, Urban-Rural and Poverty, Georgia 2002-2006

Males

Females

Level of Poverty Low Medium High

Urban 21 22 23

Rural *** 22 26*

Urban 14 15 17*

Rural *** 16 15

Rural males living in high poverty areas have significantly higher mortality rates when compared to urban males living in low poverty areas (Table 6)
Urban females living in high poverty areas have significantly higher mortality rates when compared to urban females living in low poverty areas

Table 7. Age-adjusted Colorectal Cancer Mortality Rates by Sex, Race, Urban-Rural and Poverty, Georgia 2002-2006

Males

Females

Level of Poverty
Low Medium High

Urban White
21 20 20

Rural Urban White Black

***

27

21

29*

24

32*

Rural
Black *** 29 31 *

Urban White
13 13 15

Rural White
*** 15 14

Urban Rural Black Black

20*

***

22*

25*

19*

19*

Urban black males living in medium and high poverty areas as well as rural black males living in high poverty areas have significantly higher mortality rates when compared to urban white males living in low poverty areas (Table 7)
Urban black females living in low, medium and high poverty areas as well as rural black females living in medium and high poverty areas have significantly higher mortality rates when compared to urban white females living in low poverty areas
***There are no rural counties in Georgia with low poverty levels.

15

Rate per 100,000 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Mortality Trends

Figure 12. Age-adjusted Colorectal Cancer Mortality Rate among Males by Race, Georgia (1980-2006) vs. United States (1980-2005)

50

US Black Males

US White Males

GA Black Males

GA White Males

40

30

20

10

0

From 1980 to 2005, the U.S. colorectal cancer mortality rate decreased at an average annual rate of 0.2% for black males and 1.96 % for white males (Figure 12)
In Georgia from 1980 to 2006, the colorectal cancer mortality rate increased at an average annual rate of 1.9% for black males while it decreased by 0.76% for white males
Since 2000, the colorectal cancer mortality rate decreased at an average annual rate of 3% for U.S. black males and 3.5% for U.S. white males; in Georgia the average annual rate decreased by 2.2% for both black and white males

Rate per 100,000 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Figure 13. Age-adjusted Colorectal Cancer Mortality Rate among Females by Race, Georgia (1980-2006) vs. United States (1980-2005)

50

US Black Females

US White Females

GA Black Females

GA White Females

40

30

20

10

0

Mortality rates among white females have been generally lower than those in black females, both in Georgia and in the U.S. (Figure 13)
From 1980 to 2005, the colorectal cancer mortality rate decreased at an average annual rate of 0.7% for U.S. black females and 2% for U.S. white females, whereas in Georgia there was a slight increase at an average annual rate of 0.5% among black females and decrease at an average annual rate of 1.2% among white females
Since 2000, there has been a decrease at an average annual rate in colorectal cancer mortality rates among females for both U.S. and Georgia (2.4% in U.S. black females, 3.7% in U.S. white females vs. 3.3% in Georgia black females and 1.7% in Georgia white females

16

Colorectal Cancer: Resources
You can learn more about colorectal cancer from the following organizations: American Cancer Society Telephone: 1-800-ACS-2345 www.cancer.org
Centers for Disease Control & Prevention Telephone: 1-800-CDC-INFO www.cdc.gov
National Cancer Institute, Cancer Information Service Telephone: 1-800-4-CANCER http://www.nci.nih.gov
National Colorectal Cancer Research Alliance Telephone: 818-760-7722 http://www.eifoundation.org/national/nccra/splash/
Cancer Research and Prevention Foundation Telephone: 1-800-227-2732 http://www.preventcancer.org
Cancer Control Planet http://cancercontrolplanet.cancer.gov/
17

Technical Notes
Definitions: Age-Adjusted Rate is calculated in a manner that minimizes the effects of differences in age composition when comparing rates derived from populations with different age structures. It is expressed per 100,000 population.
Cancer Incidence Rate is a measure of the development of new cancer cases in a population within a specified period of time. It is expressed as a rate per 100,000 persons.
Cancer Mortality Rate is defined as the number of deaths, due to cancer, occurring in a specified population during a specified period of time. It is also expressed as a rate per 100,000 population.
Average Risk Population includes most people who develop colorectal cancer and have no identifiable risk factors. People at increased risk of colorectal cancer consist of those with personal or family history of colorectal cancer, those with colorectal cancer symptoms or those who already have inflammatory bowel disease or certain genetic conditions.
Data Sources: The number of deaths and mortality rates for the State of Georgia were obtained from the Georgia Department of Human Resources, Division of Public Health, Vital Records Branch. The number of deaths and mortality rates for the United States were obtained from the National Center for Health Statistics, Centers for Disease Control and Prevention (CDC). Mortality data were coded using ICD-9 codes (1980-1998) and ICD-10 codes (1999-2005). The ICD-9 codes for colorectal cancer are 153.0154.1, 159.0, while the ICD-10 codes for colorectal cancer are C180:C209, C260.
The number of new cases and incidence rates for the state of Georgia were obtained from the Georgia Department of Human Resources, Division of Public Health, Georgia Comprehensive Cancer Registry. Incidence rates are calculated for the non-hispanic black and white population for the State of Georgia. The number of new cases and incidence rates for the United States were obtained from the North American Association of Central Cancer Registries (NAACCR). Incidence data were coded using ICD-O3 codes. The ICD-O3 codes used for colorectal cancer are C180:C209, C260.
Cancer stage and survival data for the United States were obtained from the Surveillance, Epidemiology, and End Results (SEER) program, National Cancer Institute.
Prevalence of risk factors, such as obesity, smoking and physical inactivity (for the year 2008) and screening for colorectal cancer (average of years 2002, 2004, 2005 2006, 2008) in Georgia was analyzed from the Behavioral Risk Factor Surveillance System, Office of Epidemiology, Health Information and Evaluation, Georgia Department of Community Health. National data for the prevalence of similar risk factors was retrieved from Centers for Disease Control and Prevention at www.cdc.gov/brfss/
Clinical information on colorectal cancer was retrieved from the Mayo Clinic at www.mayoclinic.com , Colorectal Cancer Medline Plus at www.nlm.nih. gov/medlineplus, National Cancer Institute at www.cancer.gov and the American Cancer Society at www.cancer.org
18

Methods: Mortality rates were calculated per 100,000 population and ageadjusted by the direct method to the 2000 US standard population. Except where calculated to show trends, the mortality rates are fiveyear average annual rates for the period 2002 through 2006. Incidence rates were calculated per 100,000 population and ageadjusted by the direct method to the 2000 US standard population. Rates were calculated for 2002-2006, as these are the years in which Cancer Registry data are greater than 95% complete. The estimated number of cases for 2009 was calculated by multiplying age-specific incidence rates for 2002-2006 by age-specific population projections for 2009. The estimated number of deaths for 2009 was calculated by multiplying age-specific mortality rates for 2002-2006 by age-specific population projections for 2009. The Rural-Urban classification of Georgia counties was based on the 2003 Rural-Urban Continuum Codes from the United States Department of Agriculture, Economic Research Service. Information about the Rural-Urban Continuum Codes can be retrieved from http://www.ers.usda.gov/Data/RuralUrbanContinuumCodes/. Poverty data for Georgia was retrieved from the U.S Census Bureau's Small Area Income and Poverty Estimates (SAIPE) Program at http:// www.census.gov/did/www/saipe/. The Georgia Comprehensive Cancer Registry further categorized the poverty percent into three groups, low poverty areas (less than 10% of county's population is below United States poverty level), medium poverty areas (10%-19% of county's population is below United States poverty level) and high poverty areas (20% or more of county's population is below United States poverty level) for the data analysis.
19

20