Background & Aims

Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening. FITs detect most CRCs. Although detection of CRC at early stages is most relevant for reducing CRC mortality, there is limited evidence for the stage-specific sensitivity of the FIT in CRC detection. We estimated stage- and location-specific sensitivities of a quantitative FIT in a large cohort of patients with CRC.

Methods

Fecal samples were collected before treatment from 435 patients with newly diagnosed CRC. Sensitivities of a quantitative FIT (FOB Gold, Sentinel Diagnostics; Milano, Italy) for tumors of different T stages and overall TNM stages (according to Union for International Cancer Control) were calculated at the cutoff recommended by the manufacturer (17 μg/g feces) and at alternative cutoffs, ranging from 10 to 40 μg/g feces, overall and stratified by tumor location.

Results

At the cutoff recommended by the manufacturer, the FIT detected T1 tumors with 52% sensitivity (95% CI, 37%–67%), T2 tumors with 79% sensitivity (95% CI, 68%–88%), T3 tumors with 93% sensitivity (95% CI, 89%–95%), and T4 tumors with 84% sensitivity (95% CI, 72%–92%) (P_trend < .0001). The FIT detected stage I cancers with 68% sensitivity (95% CI, 57%–78%), stage II cancers with 92% sensitivity (95% CI, 87%–96%), stage III cancers with 82% sensitivity (95% CI, 73%–89%), and stage IV cancers with 89% sensitivity (95% CI, 80%–95%) (P_trend 0.01). The FIT detected T1 colorectal tumors with sensitivity values that were 22%–52% lower than for tumors of other T stages and stage I CRC with sensitivity values that were 11%–33% lower than for later-stage CRCs, at any of the evaluated cutoff values. The FIT detected T1 and stage I CRCs in the distal colon with sensitivity values of 32% and 52%, respectively.

Conclusions

Although the FIT identifies patients with CRC with overall high sensitivity, it can miss approximately one-third of stage I CRCs. Studies are needed to increase noninvasive detection of early-stage CRC.

中文翻译：

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粪便免疫化学试验检测大肠癌的敏感性因分期和部位而异。

背景与目标

粪便免疫化学测试 (FIT) 广泛用于结直肠癌 (CRC) 筛查。FIT 检测大多数 CRC。尽管早期检测 CRC 与降低 CRC 死亡率最相关，但 FIT 在 CRC 检测中的阶段特异性敏感性的证据有限。我们在一大群 CRC 患者中估计了定量 FIT 的分期和位置特异性敏感性。

方法

在治疗前收集了 435 名新诊断的 CRC 患者的粪便样本。以制造商推荐的临界值（17 μg/g 粪便）计算定量 FIT（FOB Gold，Sentinel Diagnostics；Milano，Italy）对不同 T 分期和总体 TNM 分期（根据国际癌症控制联盟）的肿瘤的敏感性) 和替代截止值，范围从 10 到 40 μg/g 粪便，总体上和按肿瘤位置分层。

结果

在制造商推荐的临界值下，FIT 检测 T1 肿瘤的敏感性为 52%（95% CI，37%–67%），T2 肿瘤的敏感性为 79%（95% CI，68%–88%），T3 肿瘤的敏感性为93% 的敏感性（95% CI，89%–95%），T4 肿瘤的敏感性为 84%（95% CI，72%–92%）（P_趋势< .0001）。FIT 检测 I 期癌症的敏感性为 68%（95% CI，57%–78%），II 期癌症的敏感性为 92%（95% CI，87%–96%），III 期癌症的敏感性为 82%（95 % CI, 73%–89%) 和敏感性为 89% (95% CI, 80%–95%) 的 IV 期癌症（P_趋势0.01）。FIT 检测到 T1 结直肠肿瘤的敏感性值比其他 T 分期和 I 期 CRC 的肿瘤低 22%–52%，其敏感性值比晚期 CRC 低 11%–33%，在任何评估的截止值。FIT 在远端结肠中检测到 T1 和 I 期 CRC，灵敏度分别为 32% 和 52%。

结论

尽管 FIT 对 CRC 患者的识别总体敏感性很高，但它可能会遗漏大约三分之一的 I 期 CRC。需要进行研究以增加对早期 CRC 的无创检测。