超重或導致患胰腺癌的風險增加
Pancreatic cancer rates have increased by nearly a fifth since 1999.
自1999年以來，胰腺癌的發病率已增加近五分之一。
Smoking is a known cause of this often-fatal disease yet the number of smokers has reached a record low while pancreatic cancer rates continue to climb. Could the obesity epidemic now be fuelling the increase in pancreatic cancer rates? How does it do this?
衆所周知，吸菸是這種常見致命疾病的誘因之一，但現而今，吸菸人數已達歷史最低，而胰腺癌的發病率仍在繼續攀升。肥胖症是否也在助推胰腺癌發病率的上升？它又是如何做到的？
Obesity causes inflammation, which encourages cell growth and can promote cancer cell mutations. Unsurprisingly, people who have a BMI over 30 before the age of 50 are at a 25% greater risk of dying of pancreatic cancer.
肥胖會引發炎症，從而促進細胞生長、加快癌細胞突變。果不其然，50歲以前身體質量指數超過30的人因胰腺癌而亡的風險會增加25%。
"We've been puzzled by that increase because smoking - a major risk factor for pancreatic cancer - is declining," Dr Eric Jacobs, scientific director at the American Cancer Society, and co-author of the new study has said.
"我們一直對胰腺癌發病率上升一事感到困惑，因爲吸菸--胰腺癌的主要危險因素--正在下降，"美國癌症協會的科學主任兼本項新研究的合著者埃裏克·雅各布（Eric Jacobs）博士說道。
Although pancreatic is one of the more poorly understood forms of cancer, smoking is a major known risk factor - think of Patrick Swayze. Excess body weight is a major risk factor for many forms of cancer - uterine, oesophageal, stomach, kidney, liver, certain brain tumours, plus pancreatic and colorectal cancers and multiple myeloma.
儘管人們對胰腺癌不太瞭解，但大家都知道吸菸是其主要的危險因素--想想帕特里克·斯威茲（Patrick Swayze）吧。超重是多種癌症的主要危險因素--子宮癌、食道癌、胃癌、腎癌、肝癌、腦瘤癌、胰腺癌、結腸直腸癌，以及多發性骨髓瘤。
"Increased weight in the US population is a likely suspect, but previous studies have indicated that excess weight is linked with only a relatively small increase in risk, which doesn't look large enough to fully explain recent increases in pancreatic cancer rates," Dr Jacobs explained.
"美國人口體重增加引起了我們的猜疑，但先前的研究已經表明--超重只與胰腺癌風險相對小幅度增加相關，看起來並不能完全解釋近期胰腺癌患病率增加一事，"雅各布博士解釋道。
But his new study changes that by looking at excess weight gain when people are younger. Dr Jacobs and his team analysed data on 963,317 people without a history of cancer, starting in 1982, to see if those who were overweight before the age of 50 would have higher odds of going on to develop pancreatic cancer.
但他的新研究通過觀察人們年輕時的增重情況改變了這一說法。雅各布博士和他的團隊分析了自1982年以來沒有癌症史的963317人的數據，以查看50歲以前超重是否與後期患胰腺癌風險更高相關。
It turns out people who were overweight earlier in life were more likely to die of pancreatic cancer.
事實表明，年輕時超重的受試者更有可能死於胰腺癌。
For example, a person who had been 32lb overweight between the ages of 30 and 49 was at a 25% greater risk of dying of pancreatic cancer than someone who was a healthy weight at that age.
比如，30至49歲超重32磅的一名受試者死於胰腺癌的風險比這一年齡段體重正常人士高25%。
Based on these results, Dr Jacobs estimates that excess weight will be the driving factor in up to a third of pancreatic cancer deaths for people born between 1970 and 1974.
基於這些結果，雅各布博士估計：三分之一出生於1970至1974年的人羣將受超重驅動患胰腺癌而亡。
