The Bay Area is the epicenter of a liver cancer epidemic. there are more cases of liver cancer in Santa Clara and San Francisco counties than anywhere in the United States.

Largely caused by hepatitis B viral infection (HBV), liver cancer is lethal. According to the World Health Organization, it kills nearly 750,000 people each year. The five-year survival rate after diagnosis is just 15 percent.

The good news is that most cases of liver cancer can be prevented. there is an effective and safe vaccine for HBV that the Centers for Disease Control and Prevention and WHO call the first “anti-cancer” vaccine. HBV is also easily diagnosed with a simple blood test. The challenge is to educate, test and vaccinate as many people as possible, especially those at greatest risk.

HBV, which can appear in either chronic or acute form, is responsible for 80 percent of liver cancers. HBV is called a “silent killer” because most people with chronic infection often have no symptoms. By the time they realize they have the disease, it is too late for effective treatment. sometimes people only find out about the disease when they are diagnosed with liver cancer. Untreated, HBV can also lead to cirrhosis and liver failure.

HBV is transmitted much the same way as HIV/AIDS. it is only transmitted through blood or semen, but it is 100 times more infectious than HIV. it cannot be transmitted through casual contact.

No one is immune, but liver cancer is especially prevalent in people from Asia and the Pacific Islands. The statistics are staggering. Asians and Pacific Islanders make up 4.5 percent of the U.S. population but account for more than 50 percent of chronic hepatitis B cases. recent immigrants are at greater risk. Two-thirds of those infected are unaware that they have HBV. Many acquired the virus at birth from mothers who were unaware they were carriers.

In Santa Clara County, where an estimated one-third of the population is of Asian descent, approximately 35,000 live with chronic HBV. A quarter of those with chronic HBV will die from liver cancer.

The Stanford Asian Liver Center and Stanford Health Library have scheduled “Understanding Hepatitis B and Liver Cancer,” a program featuring Stanford physician Stephanie Chao, M.D., 10 a.m. Nov. 5 at the Clark Center auditorium on the Stanford Medical School campus. Admission is free and open to the public. to register, call 498-7826.

Interested in learning more? Visit Stanford Health Library for books and additional resources, in both English and Chinese.

A good place to begin is “The Liver Disorders and Hepatitis Sourcebook” (McGraw Hill, 2006). Author Howard J. Worman, M.D., professor at Columbia University, covers the broad topic of liver disorders, so there is much more in the book than the focused discussion of HBV and liver cancer.

The value of this book is in Worman’s clear, reader-friendly explanation of liver function and things that can go wrong with the liver. An excellent chapter on viral hepatitis begins with an explanation of viruses in general before he delves into the specific types of hepatitis, including hepatitis B. A similar book is the “Cleveland Clinic Guide to Liver Disorders” (Cleveland Clinic, 2009).

A new book, “Hepatitis Essentials” (Jones & Bartlett, 2011), provides a concise overview of viral hepatitis. it is written for clinicians but is of interest to many consumers. with contributions from some of the world’s leading hepatitis experts, this book covers all aspects of prevention and management of the disease.

An action plan that both describes the problem and prescribes a solution, the National Academy of Sciences Institute of Medicine published a report in 2010, “Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C” (Institute of Medicine for the National Academies of Science). The report makes a strong case for stepped-up vaccination efforts, a public education campaign and increased resources for prevention and treatment, as HBV infection is increasing nationwide. it explains that few among the populations most at risk seek testing or information on how to protect themselves from infection. it is valuable reading for those who want to understand the issues better.

Stanford Health Library has a large collection of books on HBV and liver cancer written in simplified Chinese. The library also carries DVDs.

Stanford Health Library is free and open to the public in five locations: Stanford Shopping Center, Stanford Hospital, Stanford’s Cancer Center, the Taube Koret Center for Jewish Life and the Ravenswood Family Health Center. For more information, call 725-8400, email This e-mail address is being protected from spam bots, you need JavaScript enabled to view it or visit healthlibrary.stanford.edu.

Nancy Dickenson is head librarian at Stanford Health Library.

 1 Comment 1Commentat Thursday, 20 October 2011 09:12by JP where did you get the statistics for the liver cancer? How do you know it is caused by the virus? What about the radiation coming from Fukushima? Please substantiate. Post Comment

STORY HIGHLIGHTS

• Dr. H. Gilbert Welch: new test is said to detect a single cancer cell in blood
• He says there’s a downside to ever more precise cancer screening
• Tests can detect cancer that may never harm or kill the patient
• Overdiagnosis of cancer leads to pain, side effects, emotional and financial costs, he says

Editor’s note: Dr. H. Gilbert Welch, M.P.H., is a professor of medicine at the Dartmouth Institute of Health Policy & Clinical Practice and the author of "Overdiagnosed: Making People Sick in the Pursuit of Health" (Beacon Press 2011).

(CNN) — A simple blood test. It’s able to detect minute quantities of cancer cells that might be circulating in your bloodstream.

It’s reported to be able to detect a single cell. It’s intended to allow cancer patients to start treatment much earlier.

It’s supposed to save lives. It’s a cancer breakthrough.

But it’s not that simple. The test could just as easily start a cancer epidemic.

We’ve seen it before. twenty years ago another simple blood test was introduced. twenty years later over 1 million Americans had been treated for a cancer that was never going to bother them.

The test was the PSA. It is able to detect minute quantities of prostate specific antigen — minute as in one-billionth of gram. Turned out a lot of men had "abnormal" PSAs. Many were found to have microscopic cancers, far more than would ever suffer from prostate cancer.

They were overdiagnosed.

Does it matter? Absolutely. Most were treated with either radical surgery or radiation. Roughly a third suffered side-effects of treatment — generally related to bowel, bladder or sexual function. and a few have died from it.

Things are rarely simple in modern medicine. and while most think about complexities related to treatment, some of the most challenging relate to diagnosis.

The conventional wisdom is people either have a disease or they do not. but, in fact, there are a lot of people somewhere in between. As we doctors can see more on X-ray images — like shadows as small as the head of a pin — and can measure things that were previously unmeasureable — like a single cancer cell in the blood — we diagnose more of these in-between people as being sick.

You might think we doctors would want to find all the in-between people with any evidence of cancer. That’s probably because you think of cancer as a disease that invariably leads to death if not treated. That’s what we were taught in medical school.

Sensitive blood test detects cancer An increasing number of our early cancer diagnoses … are made in people who are not destined to ever have symptoms or die from their cancer.–Dr. H. Gilbert Welch

But our understanding of cancer is changing. As doctors increasingly try to find cancer early, before it causes symptoms, it has become clear the word "cancer" encompasses a broad array of cellular abnormalities: some grow extremely rapidly, others do so more slowly, others stop growing completely and some even regress.

It also has become clear that an increasing number of our early cancer diagnoses — particularly those involving the breast, prostate, thyroid, kidney and skin — are made in people who are not destined to ever have symptoms or die from their cancer.

They are overdiagnosed.

The problem goes well beyond cancer. The conventional wisdom is that the more diagnoses doctors make, the more healthy we will all be. Not surprisingly, Americans get more diagnoses today than we did in the past. in fact, we are in the midst of an epidemic of diagnosis.

Most assume there are no downsides to looking for things to be wrong. but the truth is that early diagnosis is a double-edged sword. while it has the potential to help some, it always has a hidden side-effect: overdiagnosis, the detection of abnormalities that are not destined to ever bother people in their lifetime.

Becoming a patient unnecessarily has real human costs. There’s the anxiety of being told you are somehow not healthy. There’s the problem that getting a diagnosis may affect your ability to get health insurance. There are the headaches of renewing prescriptions, scheduling appointments and keeping them. Finally, there are the physical harms of treatments that cannot help (because there is nothing to fix): drug side-effects, surgical complications and even death. Not to mention it can bankrupt you.

Americans don’t need more diagnoses, they need the right diagnoses.

I don’t know whether this test will help some patients. It might, but it will take years to figure that out.

But I do know that the test will lead more people to be told they have cancer (or that their cancer has returned). That will lead more people to receive cancer treatment. because these new patients are bound to be less severely ill (if they are ill at all), they will appear to do better. Many will assume that their doing better is because of the new test and early treatment. So the test will be performed more often. and a lot of money will be made along the way.

Ironically, what this test might actually teach us is that it’s not that unusual for healthy people to have an occasional cancer cell in their blood.

The opinions expressed in this commentary are solely those of H. Gilbert Welch.