Liver cancer, one of the more preventable diseases,
rises for non-Asians living in Los Angeles County.The Los Angeles Cancer Surveillance Program
(CSP), a state-mandated database managed by the Keck School and the USC Norris
Comprehensive Cancer Center, provides scientists everywhere with essential
statistics on cancer
.
Newswise, August 22, 2016In the past four decades, liver
cancer rates have more than doubled among non-Asians living in Los Angeles
County, according to a recently released report card administered by USC.
The increase is also reflected among the county’s
Asian-Americans.
For some perspective, in the seven years between 2005 and
2012, liver cancer rates increased by 33 percent among white men and by 21
percent among Latino men. The increase was more modest with women in these
groups — partially because liver cancer is more common in men.
While Vietnamese are the most likely ethnic group to be
diagnosed with the disease, between 2005 and 2012, liver cancer rates actually
dropped. The decrease was 1.3 percent among Vietnamese men and 8.7 percent for
Vietnamese women.
The data comes from “Cancer in Los Angeles County: Trends by
Race/Ethnicity 1976-2012.” Released on Aug. 15, the book is based on all cancers
diagnosed among Los Angeles County residents over the past 37 years — more than
1.3 million cases.
Each year about 16,000 men and 8,000 women die from liver
cancer in the United States, according to the Centers for Disease Control and
Prevention.
V. Wendy Setiawan, assistant professor of preventive medicine
at the Keck School of Medicine of USC, is an expert in cancer epidemiology. She
shares her thoughts on the deadly but often preventable malady.
Q: Why is
liver cancer on the rise among whites in L.A. County?
VWS: We know that chronic hepatitis C is a major risk factor
for liver cancer in whites. We are seeing the rise because of the elevated
prevalence of hepatitis C infection among white baby boomers who used illicit
drugs in the ’60s and ’70s. The increasing number of people who are
overweight/obese and/or diabetics have also contributed to this trend.
Q: Why is
liver cancer becoming more prevalent among Latinos?
VWS: Liver cancer is becoming more common in Latinos because
obesity and metabolic syndrome [diabetes] — important risk factors for liver
cancer — have become a big problem in this population. Public health efforts to
prevent and control diabetes and obesity in this population may reduce the
liver cancer burden. Lifestyle changes are advisable.
Q: Why
are immigrants from East Asia and Southeast Asia at higher risk of liver
cancer?
VWS: In most Asian countries and for immigrants from these
countries, liver cancer is mainly due to chronic hepatitis B infection.
Vietnamese, for example, have the highest liver cancer rates in L.A. County.
Studies have shown that the prevalence of hepatitis B virus carriers is quite
high among Vietnamese.
Fortunately, hepatitis B infection can be prevented; the
hepatitis B vaccine is safe and highly effective. With the implementation of
this vaccination program in newborns, the rate of liver cancer has been
declining in high-risk Asian countries. We expect the rate of hepatitis
B-related liver cancer will continue to decline.
Q: How is
coffee a protective agent against liver cancer? How much coffee should someone
drink for this protective effect?
VWS: There are thousands of compounds in coffee. The most
studied compounds in relation to liver function and disease are caffeine,
diterpenes and chlorogenic acids, but the exact constituents that protect
against liver cancer are still unknown. A recent World Health Organization
report showed that coffee drinkers’ risk of liver cancer decreases 15 percent
for each cup they drink per day.
In my study, we compared coffee drinkers to non-coffee
drinkers. People who reported drinking two to three cups of coffee per day had
a 38 percent drop in liver cancer risk. For those who drank four or more cups
daily, their risk of developing liver cancer dropped by 41 percent. We mainly observed
the beneficial association with caffeinated coffee, not with decaf tea, tea
[green/black] or soda.
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Anthony El-Khoueiry, chair of the Clinical Investigations
Support Office at the USC Norris Comprehensive Cancer Center and an associate
professor of clinical medicine at the Keck School, is known nationwide for his
clinical research on liver cancer. He answers some important questions about
the disease.
Q: Why do
men tend to have higher liver cancer rates than women?
AEK: There is no clear answer. Scientists are looking at the
role of hormones. One hypothesis is that estrogen has a protective effect on
women, especially in the premenopausal years, but that alone cannot explain
everything. Some studies in laboratory animals also suggest that androgen male
hormones may contribute to the risk of liver cancer.
Q:
Long-term alcohol abuse increases the risk of liver cancer. At what consumption
level does alcohol become a serious risk factor?
AEK: Hepatologists usually say an average of three alcoholic
drinks a day or higher puts people at high risk for cirrhosis, where healthy
liver tissue is replaced with scar tissue. Cirrhosis could lead to liver
cancer.
Q: Should
people who have liver cancer abstain from alcoholic beverages?
AEK: This is a poorly studied area. Continuing alcohol
consumption may not impact the behavior of the cancer itself; however, it could
negatively impact underlying liver function, which could in turn prevent
oncologists from being able to treat tumors properly. It would be best to
discontinue alcohol consumption if one has liver cancer in order to minimize
the ongoing insult to the liver and prevent added pressure on the already
compromised liver function.
Q: What
is causing the drastic increase of liver cancer cases?
AEK: Scientists believe hepatitis C and obesity, along with
diabetes, are the main causes for the increasing rates of liver cancer. Obesity
and metabolic syndrome — characterized by abdominal obesity, diabetes, high
blood pressure or high cholesterol — are established risk factors of liver
cancer. Metabolic syndrome could lead to non-alcoholic steatohepatitis
(inflammation in the liver along with fat deposition), which can lead to
cirrhosis and liver cancer.
These are relatively recent observations, so therapeutic
interventions to lower liver cancer risk have not been fully established. One
could, of course, follow common sense: lower weight, have a healthy diet,
exercise regularly to prevent metabolic syndrome.
Q: What
preventive measures can be taken?
AEK: The risk factors for liver cancer are alcohol, hepatitis
B and C, autoimmune hepatitis or any continuous inflammation of the liver that
leads to cirrhosis.
• Avoid excessive intake of alcohol.
• Get the hepatitis B vaccination.
• Avoid dangerous behavior that increases the risk of hepatitis C: sharing needles or syringes, multiple sex partners, unsafe sex with infected individuals.
• Get FDA-approved treatments for hepatitis C.
• If you know that you have any form of chronic liver disease, it is important to see a liver specialist [hepatologist] and have routine surveillance to catch cancer early. Surveillance includes liver ultrasound and a blood test for a tumor marker known as alpha fetoprotein.
• Get the hepatitis B vaccination.
• Avoid dangerous behavior that increases the risk of hepatitis C: sharing needles or syringes, multiple sex partners, unsafe sex with infected individuals.
• Get FDA-approved treatments for hepatitis C.
• If you know that you have any form of chronic liver disease, it is important to see a liver specialist [hepatologist] and have routine surveillance to catch cancer early. Surveillance includes liver ultrasound and a blood test for a tumor marker known as alpha fetoprotein.
Q: How
important is early diagnosis?
AEK: If the disease is caught early, then you can cure it.
Surveillance for people who have chronic liver disease is helpful to catch
small tumors early. The chances of cure are much higher when the cancer is
early (no more than 3 tumors and less than 3 centimeters in maximum size). The
two main treatments that provide a cure include liver transplant and surgery to
remove the tumor.
Q: Have
there been any breakthroughs in treatment?
AEK: The challenge in the treatment of liver cancer is that
doctors have to balance the cancer and the underlying liver disease and
cirrhosis. Patients do better with liver cancer when they are treated by a
multidisciplinary team of doctors that includes different specialties. At USC,
any patient with liver cancer is reviewed at a multidisciplinary tumor board to
make a joint and comprehensive plan that maximizes the patient’s chances.
Historically, we have had limited treatment options for
patients with advanced liver cancer who are not candidates for surgery or liver
transplant. Things are changing rapidly in this area thanks to new research and
clinical trials. One of the exciting areas that is showing promise is using
drugs that stimulate the patient’s own immune system to recognize and fight the
cancer. USC has played a leading role in the early studies to evaluate this
approach, which is now showing good promise and is being studied in large,
international clinical trials.