Study Finds Link Between Women's Height, Cancer Risk
July 25, 2013
Women's chances of developing cancer after menopause increase with their height, according to a new study.
Among nearly 145,000 women between the ages of 50 and 79, researchers found that height was more strongly associated with cancer than such established risk factors as obesity.
The association held true for everything from thyroid cancer to melanoma, researchers reported in the latest issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
It's not height itself that's the risk factor, though. The authors of the new study say height “should be thought of as a marker for one or more exposures that influence cancer risk, rather than a risk factor itself.”
“There's an intriguing indication that things going on in early life appear to feed into a process that may increase the risk for various cancers,” said Geoffrey Kabat, lead author of the study and a senior epidemiologist at Albert Einstein College of Medicine of Yeshiva University in New York.
Those things might include diet as well as hormones in the body that contribute to normal growth, although researchers aren't sure yet.
Cancer involves the uncontrolled division of abnormal cells in processes having to do with growth, so it follows that hormones or other growth factors that influence height may also influence cancer risk, Kabat said in a telephone interview with Reuters.
Dr. Walter Willett, chair of the department of nutrition at the Harvard School of Public Health, said the study should not raise alarm for the tall, though it does provide additional evidence that greater height is associated with cancer.
“The increase in risk is modest and is balanced by a lower risk of cardiovascular disease in taller people, so there is no reason for those of us who are tall to panic,” Willett, who was not involved in the study, said in an email. “Most importantly, research to understand the reason for the extra risk in taller people may lead us to new ways to prevent or treat cancer.”
Isolating the link to height
The postmenopausal women in the study were participants in the Women's Health Initiative, a 15-year research program established in 1991 by the National Institutes of Health and other agencies to address the most common causes of death, disability and poor quality of life in postmenopausal women.
Altogether the researchers tracked 144,701 women for an average of 12 years, during which 20,928 of them developed new cancers.
Even after adjusting for such factors as body mass index - a ratio of weight in relation to height - the women's risk of developing any cancer rose by 13 percent for every 10-centimeter increase in height (about 4 inches), the researchers say.
With every extra 10 centimeters, researchers found, women's risk for cancers of the kidney, rectum, thyroid or blood rose by 23 to 29 percent, and their risk of melanoma and cancers of the breast, ovary, endometrium or colon rose by 13 to 17 percent.
According to the American Cancer Society, the average woman's lifetime risk of cancer is 38.2 percent.
Other large studies have identified an association between height and certain cancers, but most of those studies didn't rule out the influence of other factors.
Kabat and his colleagues say they took more than a dozen potential risk factors into account - including age, use of oral contraceptives, smoking history, alcohol intake, age at their first menstrual period, and education - and they still found that women's height was linked to their cancer risk.
“At this point it seems to be a plausible mechanism whereby early nutrition could affect growth and cancer,” Kabat said.
For example, tallness is tied to greater consumption of milk proteins by rapidly growing pre-pubescent girls, and in some studies milk intake has been linked with higher levels of a certain protein that may play a role in some of the abnormal cellular processes seen in cancers.
“It is also possible that the larger organ size and skin surface area associated with greater height may put more cells at risk of being transformed to,” Kabat said.
Two previous studies reported that the correlation between height and any type of cancer was stronger among women who had never smoked, but Kabat and his colleagues found the correlation did not differ by smoking level.
chance (n) 機會，可能性
menopause (n) 停經 XXXXX *新聞中有另一相關字：postmenopausal，意思是「停經後的」
established (a) 已確立的
hold true (v phr) 適用；有效
melanoma (n) 黑色素瘤XXXXX*注意發音：
marker (n) 標識，標誌
研究發現，停經 (menopause) 後的婦女罹癌的機會與身高有關。研究人員發現，比起像是肥胖 (obesity) 等罹癌的風險因子 (risk factors)，身高與癌症有更高的關聯性 (more strongly associated with . . .)。從甲狀腺癌 (thyroid cancer)到黑色素瘤 (melanoma)，這種關聯性都能被確認為真 (hold true)。但研究人員指出，身高本身並不是罹癌的風險因子，而是可被視為暴露於其它致癌風險的標識 (marker)。
intriguing (a) 令人好奇的、有趣的
division (n) 分裂
Geoffery Kabat 是本研究的主要作者 (lead author)，也是一位資深的流行病學研究人員 (senior epidemiologist)。他認為這份研究報告點出一個有趣的跡象 (intriguing indication)，生命早期的所經歷的變化，如飲食與賀爾蒙 (hormones)，似乎會供給 (feed into) 之後提高癌症風險的過程。癌症是生長過程中不受控制的異常細胞分裂 (division of abnormal cells)，所以自然的推論 (it follows that . . .)，賀爾蒙或其它的成長因子會影響身高，也就影響癌症的風險。另一位學者認為，雖然本報告指出身高與癌症的關聯性，但還不足當成對高個子所發出警報 (raise alarm for . . .)，單就身高所增加的癌症風險並不高 (modest)，而身高較高卻人有較低的心血管疾病 (cardiovascular disease)風險，所以兩相中和後，高個子並沒有理由為此感到驚慌 (panic)。
track (v) 追蹤
rule out (v phr) 排除
take something into account (v phr) 把 . . . 納入考慮
contraceptive (n) 避孕藥
intake (n) 攝取量，吸收
研究人員總共追蹤了144,701位女性平均約12年，他們發現，即使把身體質量指數 (Body Mass Index)納入了調整計算，身高每多十公分，各種癌症的風險仍提高有13%。其它大型研究 (large studies) 都有指出過身高與某些癌症的關聯，但大多這類研究都沒有排除 (rule out) 其它因子的影響。研究人員 Kabat 與他的同事指出，他們把超過12個以上的潛在的風險因子 (potential risk factors) 一併納入考量 (took . . .into account)，包含了年紀，口服避孕藥 (oral contraceptives)的使用紀錄，抽菸史，酒精攝取 (alcohol intake)，初次月經 (menstrual period)的年紀，還有教育等，女性的身高還是直接與罹癌風險有關聯性。
plausible (a) 合理的
pre-pubescent (a) 青春期前的XXXXX* 發音要注意：；本字字首 "pre-" 是「. . . 前的」，把 "pre-" 去掉，pubescent 就是「青春期的」，名詞是 puberty
correlation (n) 相關性
以現在的研究結果來看，Kabat說，早期攝取的養份透過某種可能的運轉機制 (plausible mechanism) 影響了生長與惡性腫瘤增長。青春期前的 (pre-pubescent) 女孩身高上快速發展與攝取較多的牛奶蛋白有關，有些研究發現，攝取牛奶會造成某種蛋白的濃度提高，而此種蛋白與某些惡性腫瘤不正常的細胞發展過程中有一定的作用 (play a role in . . .)。還有另的可能是，較大的器官體積 (organ size) 與皮膚表面積 (skin surface area) 會讓更多的細胞處於轉變成惡性腫瘤 (malignancies) 的風險中 (put . . . at risk of . . .)。之前的 (previous) 兩份研究指出身高與罹癌風險在沒有抽菸的女性上的關聯性 (correlation)，但在 Kabat 的研究中，此關聯性並未因抽菸的程度有差異。
Check your vocabulary!
Fill in the blanks with a word or phrase from the list above. Make necessary changes. After you finish, select the text below to reveal the hidden answers.
1. Police have been tracking the four criminals all over Central America.
2. Pregnant women should reduce their intake of caffeine.
3. The principle still holds true for the present situation.
4. I need to think of a plausible excuse for not going to the meeting.
5. The doctor took X-rays and ruled out the chance of broken bones.
6. Abnormal behavior may be a sign of mental illness.