Phenomenome Discoveries, Inc, Saskatoon, SK, Canada.
Int J Cancer. 2013 Jan 15;132(2):355-62. doi: 10.1002/ijc.27673. Epub 2012 Jun 26.
Gastrointestinal tract acid-446 (GTA-446) is a long-chain polyunsaturated fatty acid present in the serum. A reduction of GTA-446 levels in colorectal cancer (CRC) patients has been reported previously. Our study compared GTA-446 levels in subjects diagnosed with CRC at the time of colonoscopy to the general population. Serum samples and pathology data were collected from 4,923 representative subjects undergoing colonoscopy and from 964 subjects from the general population. Serum GTA-446 levels were determined using a triple-quadrupole tandem mass spectrometry method. A low-serum GTA-446 level was based on the bottom tenth percentile of subjects with low risk based on age (40-49 years old) in the general population. Eighty-six percent of newly diagnosed CRC subjects (87% for stages 0-II and 85% for stages III-IV) showed low-serum GTA-446 levels. A significant increase in the CRC incidence rate with age was observed in subjects with low GTA-446 levels (p = 0.019), but not in subjects with normal levels (p = 0.86). The relative risk of CRC given a low GTA-446 level was the highest for subjects under age 50 (10.1, 95% confidence interval [C.I.] = 6.4-16.4 in the reference population, and 7.7, 95% C.I. = 4.4-14.1 in the colonoscopy population, both p < 0.0001), and declined with age thereafter. The CRC incidence rate in subjects undergoing colonoscopy with low GTA-446 levels was over six times higher than for subjects with normal GTA-446 levels and twice that of subjects with gastrointestinal symptoms. The results show that a low-serum GTA-446 level is a significant risk factor for CRC, and a sensitive predictor of early-stage disease.
胃肠道酸 446（GTA-446）是一种存在于血清中的长链多不饱和脂肪酸。先前有报道称，结直肠癌（CRC）患者的 GTA-446 水平降低。我们的研究比较了结肠镜检查时诊断为 CRC 的患者与一般人群的 GTA-446 水平。从接受结肠镜检查的 4923 名代表性受试者和普通人群中的 964 名受试者中收集了血清样本和病理数据。使用三重四极杆串联质谱法测定血清 GTA-446 水平。低血清 GTA-446 水平基于普通人群中低危人群（年龄 40-49 岁）的底部十分位数。86%的新诊断 CRC 患者（0-II 期为 87%，III-IV 期为 85%）表现出低血清 GTA-446 水平。在低 GTA-446 水平的受试者中，CRC 发病率随年龄显著增加（p=0.019），而在正常水平的受试者中则没有（p=0.86）。低 GTA-446 水平下 CRC 的相对风险对于年龄在 50 岁以下的患者最高（参考人群中为 10.1，95%置信区间[CI]为 6.4-16.4，结肠镜人群中为 7.7，95%CI 为 4.4-14.1，两者均<0.0001），此后随年龄下降。低 GTA-446 水平的结肠镜检查患者的 CRC 发病率是 GTA-446 水平正常患者的 6 倍以上，是胃肠道症状患者的 2 倍。结果表明，低血清 GTA-446 水平是 CRC 的一个显著危险因素，也是早期疾病的敏感预测指标。
