在7月出版的愛思唯爾期刊《美國外科醫(yī)師學(xué)會雜志》（Journal of The American College of Surgeons）上,，一項新研究的結(jié)果證實血漿DNA濃度的上升是食道癌復(fù)發(fā)的可靠標(biāo)志。研究同時還指出,，對于大多數(shù)患者而言,，其血漿中DNA濃度的增加先于其它臨床證據(jù)發(fā)生,。
食道癌是引起世界范圍內(nèi)患者死亡的主要癌癥之一，它一般在晚期階段才能得到診斷,。因此,，一種準(zhǔn)確的檢測食道癌轉(zhuǎn)移的標(biāo)志物能幫助醫(yī)生更好的選擇接受治療的患者，預(yù)測患者接受治療之后的反應(yīng),，以及在癌癥復(fù)發(fā)時采取必要的措施,。盡管科學(xué)家已經(jīng)知道癌胚抗原（carcinoembryonic antigen CEA）和血漿DNA濃度會在食道癌患者體內(nèi)增加，并且濃度在發(fā)生轉(zhuǎn)移情況下變得更高,，但是這些標(biāo)志物在復(fù)發(fā)診斷過程中的靈敏性和特異性并未得到確定,。
加州大學(xué)洛杉磯分校醫(yī)學(xué)院外科系助理教授Farzaneh Banki表示：“不通過手術(shù)診斷食道癌轉(zhuǎn)移以及在術(shù)后診斷癌癥的復(fù)發(fā)一直是我們面臨的一個挑戰(zhàn)，這是由于食道癌的臨床分期很困難,，而目前的掃描技術(shù)有限,。我們的研究結(jié)果表明，測量DNA含量能有助于診斷和預(yù)測食道癌的復(fù)發(fā),。”
研究分析了血漿DNA作為食道癌術(shù)前轉(zhuǎn)移和術(shù)后殘留/復(fù)發(fā)的標(biāo)志物的靈敏性和特異性,。科學(xué)家測量了45位食道癌病人和44位健康志愿者體內(nèi)血漿DNA的含量,，此外,，研究小組還測量了31位患者的血清CEA濃度。
結(jié)果發(fā)現(xiàn),，相比CEA,，血漿DNA在檢測那些無法被外科手術(shù)去除的癌癥方面靈敏度更好，血漿DNA的靈敏度為100%，CEA為40%,。并且血漿DNA在檢測食道癌復(fù)發(fā)方面也比CEA靈敏度高（分別為100%和33%）,。所有癌癥復(fù)發(fā)的患者血漿DNA濃度都有所上升，而且血漿DNA正常的患者全都沒有復(fù)發(fā),。對于67%的復(fù)發(fā)患者而言,，其血漿DNA濃度上升早于臨床證據(jù)出現(xiàn)，而對于CEA而言,，這一數(shù)字僅有17%,。
科學(xué)家因此建議，血漿DNA對于診斷復(fù)發(fā)病人有重要價值,，而正常的CEA值則需要小心對待,，因為它并未完全排除疾病復(fù)發(fā)的可能。最后研究人員表示,，還需要更多患者和更長的追蹤研究來確認(rèn)以上發(fā)現(xiàn),。（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of The American College of Surgeons，doi:10.1016/j.jamcollsurg.2008.01.004,，F(xiàn)arzaneh Banki, Tom R. DeMeester
Plasma DNA Is More Reliable than Carcinoembryonic Antigen for Diagnosis of Recurrent Esophageal Cancer
Farzaneh Banki MDa, , Wael N. Yacoub MDa, Jeffrey A. Hagen MD, FACSa, Rodney J. Mason MD, PhD, FACSa, Shahin Ayazi MDa, Steven R. DeMeester MD, FACSa, John C. Lipham MD, FACSa, Kathleen Danenberg BScb, Peter Danenberg PhDb and Tom R. DeMeester MD, FACSa
Background
Carcinoembryonic antigen (CEA) and plasma DNA are known to be elevated in patients with esophageal cancer and are higher in patients with disseminated disease. The sensitivity and specificity of these markers in the diagnosis of recurrent esophageal cancer have not been compared.
Study Design
Plasma DNA was measured using polymerase chain reaction in 45 patients with esophageal cancer and 44 asymptomatic volunteers. The 95th percentile (19 ng /mL) in the volunteers was used to define normal. Thirty-nine patients had localized cancer and underwent resection, and six had disseminated disease at operation. Plasma DNA was measured preoperatively in all patients, with serum CEA measured in 31. Plasma DNA was measured sequentially during followup in 21 patients, including 7 who developed recurrence. CEA was measured in 14 of 21 patients who had sequential plasma DNA measured and in 6 of 7 patients with recurrence. CEA levels greater than 5.0 ng/mL were used as cut-off.
Results
Plasma DNA was more sensitive than CEA for detecting unresectable esophageal cancer (100% versus 40%), but it had a lower specificity (22% versus 89%).The positive predictive value (19% versus 40%) and negative predictive value (100% versus 89%) were similar for plasma DNA and serum CEA, respectively.
Plasma DNA was also more sensitive than CEA in detecting recurrent esophageal cancer (100% versus 33%). The specificity and positive predictive values were 100% for both tests, but the negative predictive values were higher for plasma DNA. Plasma DNA rose before there was clinical evidence of recurrence in 67% compared with only 17% for CEA.
Conclusions
Elevated plasma DNA is an extremely reliable indicator of the presence of recurrent disease, and, in the majority of patients, it rises before clinical evidence of recurrence. In contrast, a normal CEA should be interpreted cautiously, because it does not exclude recurrent disease.
