Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
World J Gastroenterol. 2012 Oct 14;18(38):5397-403. doi: 10.3748/wjg.v18.i38.5397.
To improve the interpretation of fecal immunochemical test (FIT) results in colorectal cancer (CRC) cases from screening and referral cohorts.
In this comparative observational study, two prospective cohorts of CRC cases were compared. The first cohort was obtained from 10 322 average risk subjects invited for CRC screening with FIT, of which, only subjects with a positive FIT were referred for colonoscopy. The second cohort was obtained from 3637 subjects scheduled for elective colonoscopy with a positive FIT result. The same FIT and positivity threshold (OC sensor; ≥ 50 ng/mL) was used in both cohorts. Colonoscopy was performed in all referral subjects and in FIT positive screening subjects. All CRC cases were selected from both cohorts. Outcome measurements were mean FIT results and FIT scores per tissue tumor stage (T stage).
One hundred and eighteen patients with CRC were included in the present study: 28 cases obtained from the screening cohort (64% male; mean age 65 years, SD 6.5) and 90 cases obtained from the referral cohort (58% male; mean age 69 years, SD 9.8). The mean FIT results found were higher in the referral cohort (829 ± 302 ng/mL vs 613 ± 368 ng/mL, P = 0.02). Tissue tumor stage (T stage) distribution was different between both populations [screening population: 13 (46%) T1, eight (29%) T2, six (21%) T3, one (4%) T4 carcinoma; referral population: 12 (13%) T1, 22 (24%) T2, 52 (58%) T3, four (4%) T4 carcinoma], and higher T stage was significantly associated with higher FIT results (P < 0.001). Per tumor stage, no significant difference in mean FIT results was observed (screening vs referral: T1 498 ± 382 ng/mL vs 725 ± 374 ng/mL, P = 0.22; T2 787 ± 303 ng/mL vs 794 ± 341 ng/mL, P = 0.79; T3 563 ± 368 ng/mL vs 870 ± 258 ng/mL, P = 0.13; T4 not available). After correction for T stage in logistic regression analysis, no significant differences in mean FIT results were observed between both types of cohorts (P = 0.10).
Differences in T stage distribution largely explain differences in FIT results between screening and referral cohorts. Therefore, FIT results should be reported according to T stage.
提高筛查和转诊队列中结直肠癌（CRC）病例粪便免疫化学检测（FIT）结果的解读能力。
在这项比较观察性研究中，比较了两个 CRC 病例的前瞻性队列。第一队列来自 10322 名接受 CRC 筛查的普通风险受试者，其中仅对 FIT 阳性的受试者进行了结肠镜检查转诊。第二队列来自 3637 名接受 FIT 阳性结果的选择性结肠镜检查的受试者。两个队列均使用相同的 FIT 和阳性阈值（OC 传感器；≥50ng/mL）。所有转诊受试者和 FIT 阳性筛查受试者均进行结肠镜检查。从两个队列中均选择所有 CRC 病例。主要结局测量指标为每个组织肿瘤分期（T 分期）的平均 FIT 结果和 FIT 评分。
本研究共纳入 118 例 CRC 患者：28 例来自筛查队列（64%为男性；平均年龄 65 岁，标准差 6.5），90 例来自转诊队列（58%为男性；平均年龄 69 岁，标准差 9.8）。转诊队列的平均 FIT 结果更高（829±302ng/mL 比 613±368ng/mL，P=0.02）。两组人群的组织肿瘤分期（T 分期）分布不同[筛查人群：13 例（46%）T1 期、8 例（29%）T2 期、6 例（21%）T3 期、1 例（4%）T4 期癌；转诊人群：12 例（13%）T1 期、22 例（24%）T2 期、52 例（58%）T3 期、4 例（4%）T4 期癌]，更高的 T 分期与更高的 FIT 结果显著相关（P＜0.001）。按肿瘤分期分析，两组之间的平均 FIT 结果无显著差异（筛查 vs 转诊：T1 期 498±382ng/mL 比 725±374ng/mL，P=0.22；T2 期 787±303ng/mL 比 794±341ng/mL，P=0.79；T3 期 563±368ng/mL 比 870±258ng/mL，P=0.13；T4 期未评估）。在逻辑回归分析中校正 T 分期后，两组之间的平均 FIT 结果无显著差异（P=0.10）。
T 分期分布的差异在很大程度上解释了筛查和转诊队列中 FIT 结果的差异。因此，应根据 T 分期报告 FIT 结果。
