Welcome to the California Cancer Registry

Colorectal Cancer in California, 1988-2007: Questions and Answers

Key points:

  • Colorectal cancer kills more Californians than any other cancer except lung cancer, yet it is one of the most preventable cancers.
  • From 1988-2007 colorectal cancer incidence rates in California have decreased significantly by 29.9 percent for men and by 24.9 percent
    for women. These decreases could be even more dramatic if every adult age 50 years and up participated in a program of routine screening for colorectal cancer and precancerous growths.
  • African Americans have the highest colorectal cancer rates – about 25 percent higher than non-Hispanic whites.
  • Colorectal cancer rates are dropping in California among non-Hispanic whites, African Americans, and Asians but rates for Hispanics are not changing. If these trends continue, colorectal cancer incidence rates among Hispanics will be higher than those for non-Hispanic whites for the first time ever.
  • Colorectal cancer rates among Asian subgroups in California vary greatly. Rates are substantially higher among Japanese than other Asian subgroups, and South Asian rates are substantially lower.
  • Contrary to the overall state trend of declining rates, colorectal cancer rates are actually increasing for some California groups. Korean men and women are experiencing a dramatic increase in colorectal cancer incidence. Vietnamese and Filipina women are also experiencing a smaller but significant increase in colorectal cancer rates.

  1. What is the purpose of this report and who created it?
  2. What are the sources of data for this report?
  3. What is happening with colorectal cancer incidence trends in California?
  4. What is happening with colorectal cancer mortality trends in California?
  5. Why are rates going down for some groups and not others?
  6. Who has the highest colorectal cancer rates in California? Who has the lowest?
  7. How does California compare with the rest of the United States with regard to colorectal cancer rates?
  8. How many Californians are being diagnosed with late-stage colorectal cancer?
  9. What are the five-year survival rates for patients diagnosed with colorectal cancer?
  10. Where can I get information on cancer rates in California counties?


1. What is the purpose of this report and who created it?
This report provides an overview of colorectal cancer incidence (new cases)and death rates and other statistics in California over the 20 year period 1988-2007. The report was created by the California Cancer Registry (CCR), a program of the Cancer Surveillance and Research Branch in the California Department of Public Health.

2. What are the sources of data for this report?
Information on newly diagnosed colorectal cancers occurring among California residents is based on data collected by the CCR. The CCR is California statewide, population-based cancer registry. Cancer mortality information is based on data contained in death certificates and filed by Vital Statistics. Data on race/ethnicity is based upon information contained in the medical record as abstracted by the cancer registry, and supplemented by algorithms based upon surname and place of birth designed to more accurately ascertain Hispanic ethnicity.


3. What is happening with colorectal cancer incidence trends in California?
Overall, colorectal cancer incidence rates (the number of new cases diagnosed among every 100,000 people) have been steadily decreasing for the past twenty years in California. From 1988-2007 colorectal cancer incidence rates in California have decreased significantly by 1.8 percent per year for men and by 1.4 percent for women. The most likely explanation for this decline is increased use of colorectal cancer screening, which prevents cancer by detecting precancerous growths so that they can be removed before cancer develops. Non-Hispanic whites have experienced the greatest decline in colorectal cancer incidence (2.0 percent per year for men, 1.4 percent for women), followed by African Americans (1.3 percent per year for men, 0.9 percent per year for women), and Asian/Pacific Islanders (1.3 percent per year for men, 0.5 percent for women). Among Hispanics, there has been a statistically significant decline among Hispanic women (0.5 percent per year), but among Hispanic men there has been only a small decline that is not statistically different from zero.

Contrary to the overall state trend of declining rates, colorectal cancer rates are actually increasing for some California groups. Korean men and women are experiencing a dramatic increase in colorectal cancer incidence. Rates have increased rapidly by over 3 percent per year for Korean men and over 2 percent for Korean women. Vietnamese and Filipina women are also experiencing a smaller but significant increase in colorectal cancer rates.

4. What is happening with colorectal cancer mortality trends in California?
Colorectal cancer mortality rates have decreased in tandem with the decrease in colorectal cancer incidence rates. Overall, colorectal cancer mortality rates (the number of people who died from colorectal cancer out of every 100,000 people) have dropped by 2.3 percent per year for men and by 2.2 percent per year for women in California.

5. Why are rates going down for some groups and not others?
The exact reasons are not known, but these differences most likely reflect differences in the use of colorectal cancer screening.

6. Who has the highest colorectal cancer rates in California? Who has the lowest?
African Americans have higher rates of colorectal cancer than any other racial/ethnic group in California. On average, over the five-year period 2003-2007 the African-American colorectal cancer incidence rate was 57.5 (per 100,000), about 25 percent higher than the rates for non-Hispanic whites at 45.2. While rates among Asian/Pacific Islanders overall are about 13 percent lower than non-Hispanic whites, there is much variability among the major Asian subgroups (Chinese, Japanese, Filipino, Korean, Vietnamese, and South Asian). Japanese have the highest rate - 52.5 per 100,000, while rates among South Asians are the lowest of any group in the state (21.3 per 100,000).

7. How does California compare with the rest of the United States with regard to colorectal cancer rates?
Colorectal cancer rates in California are among the lowest in the nation. Most likely this is related to the higher proportion of Hispanics and Asian/Pacific Islanders in the California population compared to other states, two groups who have lower rates of colorectal cancer than non-Hispanic whites and African Americans.

8. How many Californians are being diagnosed with late-stage colorectal cancer?
Despite the availability of colorectal cancer screening, too many Californians are being diagnosed with colorectal cancer at late stage. Over half of California adults age 50 years and older who are diagnosed with colorectal cancer are diagnosed at late stage, after it has already spread beyond the colon or rectum and treatments are much less effective.

9. What are the five-year survival rates for patients diagnosed with colorectal cancer?
Survival rates for colorectal cancer depend upon the stage at diagnosis. Ninety percent of those diagnosed with colorectal cancer at local stage (the cancer is confined to the colon or rectum) survive at least five years after diagnosis. If the cancer has metastasized to distant organs only 10 percent of patients are still alive after five years after diagnosis.

10. Where can I get information on cancer rates in California counties?
The CCR website (www.ccrcal.org) has detailed information on cancer statistics in California by cancer type, year, sex, race/ethnicity, and county.