2012年1月3日,，據(jù)《每日科學(xué)》報(bào)道，多年以來，醫(yī)生們已經(jīng)知道致命性肝癌的發(fā)病率正在逐年上升,，但是究竟什么原因造成這種趨勢(shì)仍然是個(gè)謎,。最近發(fā)表于1月份Mayo Clinic Proceeding期刊上的2篇Mayo臨床研究為肝癌（HCC）的上升趨勢(shì)提供了一副較為清晰的圖像。在美國(guó),，肝癌患者在過去的三十年中增加了3倍，在晚期階段診斷的患者其5年生存率僅為10％至12％,。
"這些研究闡明了在特定群體中鑒定出具有肝癌風(fēng)險(xiǎn)因素的個(gè)體的重要性,，以在其早期可治療階段制伏疾病，"W. Ray Kim說,，醫(yī)師,、胃腸病學(xué)和肝病專家及一項(xiàng)研究的首席研究員。
Kim博士的研究小組,，調(diào)查了數(shù)十年來來羅切斯特流行病學(xué)項(xiàng)目的記錄（一個(gè)數(shù)據(jù)庫,，涵括了整個(gè)國(guó)家的住院和門診護(hù)理記錄）。研究發(fā)現(xiàn),，肝癌的群體發(fā)病率（每10萬人中有6.9個(gè)人）比基于國(guó)家癌癥研究所數(shù)據(jù)（每10萬人中有5.1個(gè)人）所預(yù)計(jì)的群體發(fā)病率要高,。該研究還發(fā)現(xiàn)，肝癌,，這個(gè)二十年前傾向于由肝臟疤痕的疾病如酒精所致肝硬化引起,，現(xiàn)在則由丙型肝炎病毒感染所致。
"丙型肝炎所致的肝臟疤痕經(jīng)過20至30年后發(fā)展成癌癥,，"Kim博士說,。"我們現(xiàn)在看到的50歲和60歲患者，在30年前就感染了丙型肝炎,，而他們甚至不知道自己已經(jīng)被感染了,。"
11％ 的肝癌與肥胖有關(guān)，尤其是與脂肪肝,。
"總體而言,，這是一個(gè)很小的比例，"Kim博士說,。 "但隨著全國(guó)性肥胖的流行,，我們相信肝癌的發(fā)病率在可預(yù)見的將來可能會(huì)顯著地增加。"
另一項(xiàng)研究主要側(cè)重于索馬里群體,，這個(gè)群體數(shù)量在美國(guó)不斷增長(zhǎng),，尤其是在明尼蘇達(dá)州，在過去二十年中多達(dá)50,000名索馬里人定居此地,。東非國(guó)家乙型肝炎的患病率較高,，而乙型肝炎是肝癌的危險(xiǎn)因素。
研究人員調(diào)查了在Mayo臨床生命科學(xué)系統(tǒng)的記錄證實(shí)，乙肝仍然是一個(gè)危險(xiǎn)因素,，但他們同時(shí)驚奇地發(fā)現(xiàn),，在人群中相當(dāng)比例的肝癌病例歸因于丙型肝炎，這在之前未被認(rèn)為有顯著的普遍性,。
"這項(xiàng)研究表明,，丙型肝炎篩檢將有助于索馬里人群體，同時(shí)能夠密切監(jiān)測(cè)這些患者的肝癌風(fēng)險(xiǎn),。 " Mayo診所的研究員,、文章的第一作者Abdirashid Shire博士說，"這將大大改善這些索馬里肝癌患者的治療和生存,。"
該研究是由美國(guó)國(guó)立衛(wèi)生研究院和（NIH）Mayo診所中心轉(zhuǎn)化科學(xué)活動(dòng)組支持,。（生物谷bioon.com）
Risk Factors in Rising Trend of Liver Cancer Identified
ScienceDaily (Jan. 3, 2012) - Doctors have known for years that the incidence of deadly liver cancer is on the rise, but what is causing that trend has remained a mystery. Two recent Mayo Clinic studies published in the January issue of Mayo Clinic Proceedings offer a clearer picture of the rise of hepatocellar carcinoma (HCC), or liver cancer, which has tripled in the U.S. in the last three decades and has a 10 to 12 percent five-year survival rate when detected in later stages.
"The studies illuminate the importance of identifying people with risk factors in certain populations to help catch the disease in its early, treatable stages," said W. Ray Kim, M.D., a specialist in Gastroenterology and Hepatology and principal investigator of one study.
Dr. Kim's research group looked at several decades of records in the Rochester Epidemiology Project, a database that accounts for an entire county's inpatient and outpatient care. The study found the overall incidence of HCC in the population (6.9 per 100,000) is higher than has been estimated for the nation based on data from the National Cancer Institute (5.1 per 100,000). The study also found that HCC, which two decades ago tended to be caused by liver-scarring diseases such as cirrhosis from alcohol consumption, is now occurring as a consequence of hepatitis C infection.
"The liver scarring from hepatitis C can take 20 to 30 years to develop into cancer," Dr. Kim says. "We're now seeing cancer patients in their 50s and 60s who contracted hepatitis C 30 years ago and didn't even know they were infected."
Eleven percent of cases were linked to obesity, in particular fatty liver disease.
"It's a small percentage of cases overall," Dr. Kim says. "But with the nationwide obesity epidemic, we believe the rates of liver cancer may dramatically increase in the foreseeable future."
Another study looked exclusively at the Somali population, which is growing in the U.S., particularly in Minnesota, where as many as 50,000 Somalis have settled in the last two decades. The East African country is known to have a high prevalence of hepatitis B, a risk factor for HCC.
Researchers investigating records in the Mayo Clinic Life Sciences System confirmed that hepatitis B remains a risk factor, but they were surprised to find that a significant percentage of liver cancer cases in the population are attributable to hepatitis C, which had not been known to be significantly prevalent.
"The study suggests that screening for hepatitis C would be helpful for the Somali population and would enable close surveillance of liver cancer among those at risk," says lead author Abdirashid Shire, Ph.D., a Mayo Clinic researcher. "That would greatly improve treatment and survival of Somalis with this type of cancer."
The studies were funded by the National Institute of Health and the Mayo Clinic Center for Translational Science Activities.
