For a lot of baby boomers, the death of former teen idol David Cassidy this week brought a rush of nostalgia.
But The Partridge Family TV star's passing at the not-so-old-age of 67 was also part of a surge in deaths from liver disease among his generation.
The root of Cassidy's own liver failure was no mystery. He had spoken publicly in recent years about his alcoholism, and went to rehab in 2014 after a series of DUI arrests.
However, many who are at risk of liver disease don't drink. They may not realize that the liver also can be destroyed by infection with hepatitis C or B, as well as by a buildup of fat in the liver that is linked to the modern epidemics of obesity and diabetes.
Physicians and public health organizations are trying to raise awareness because liver disease often has no symptoms until advanced stages, yet it is entirely reversible if caught in time. Symptoms may include fatigue, abdominal pain and swelling, yellowing of the skin and eyes (jaundice), nausea, itchy skin, bruising.
"Even losing 10 percent of body weight can reverse fatty liver disease" in obese patients, said gastroenterologist Dina Halegoua-DeMarzio, director of Thomas Jefferson University's fatty liver center. "The liver has an amazing ability to regenerate."
Hepatologist David S. Goldberg, director of the living donor liver transplant program at the University of Pennsylvania, added that even patients with cirrhosis — in which normal liver tissue is replaced by scarring, usually after years of damage — may be able to heal with lifestyle changes such as alcohol abstinence and weight loss.
"We all have stories of people who were almost at the point of needing a transplant," Goldberg said. "They got rid of the insult to the liver and then recovered. We don't know what the point of no return is."
Cassidy apparently had passed that point when he stopped drinking after a 2014 DUI arrest led to 90 days of court-ordered rehab. After he fell on stage and couldn't remember lyrics earlier this year, he said he had not started drinking again. Rather, he said, he had been diagnosed with dementia, which also affected his mother and grandfather.
Though dementia may involve genetic factors, it also can be related to brain damage caused by heavy drinking.
The liver is vital to many processes in the body, including filtering toxins from the blood, making proteins for blood clotting, and digesting fats to produce energy. The wedge-shaped organ may keep functioning through decades of bad habits or hepatitis, but as damaged cells try to heal by creating scar tissue, the toughening can lead to cirrhosis. That, in turn, increases the risk of liver cancer.
From 2000 to 2015, U.S. death rates for chronic liver disease and cirrhosis increased 30 percent (from 20 to 26 deaths per 100,000 people) among those aged 45 to 64, according to the Centers for Disease Control and Prevention (CDC).
Between 1990 and 2015, cases of liver cancer rose more than 20 percent in the U.S. — and 75 percent worldwide, according to an international liver disease study group. The group concluded "most cases of liver cancer can be prevented through vaccination, antiviral treatment, safe blood transfusion, and injection practices, as well as interventions to reduce excessive alcohol use." More recently, obesity also is being linked with liver cancer.
Hepatitis B vaccination is standard. Although there is no vaccine against hepatitis C, infection can now be treated with new antiviral drugs that have cure rates of 95 percent or better.
Hep C, a blood-borne virus, is a big reason for the rise in liver disease among boomers. An estimated 1 in 30 were unwittingly infected in their youths, before safe blood transfusion procedures were adopted. Intravenous drug use, contaminated tattoo tools, and changing sexual practices also contributed to boomers' increased risk.
Recognizing that hep C is now readily curable, the CDC in 2012 recommended that adults born between 1945 and 1965 get a one-time hep C antibody test — but fewer than 30 percent have done so.
Goldberg believes doctors are partly to blame.
"My own mother had to remind her doctor a couple of times," he said. "She said to her doctor, 'My son is a liver doctor and he said you should test me.' "
Screening for liver disease raises another set of challenges, said University of Toronto hepatologist Jordan Feld.
For one thing, routine liver function tests, which check the blood for enzymes released by the liver in response to damage, can be unreliable, even in late stages of disease. For another thing, screening strategies are varied and complicated. If the hep C antibody test is positive, for example, that is followed by a test for the actual virus, then a test to genotype the virus, then imaging to evaluate the liver for scarring, Feld said.
The most reliable test, a liver biopsy, is expensive, invasive, and comes with a small chance of excessive bleeding.
"There's a real need for us is to streamline our testing strategies," Feld said.
He believes newer ultrasound technology that enables specialists to assess the extent of scarring with a three-minute scan of the liver could improve diagnosis — and help motivate patients to make lifestyle changes.