Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Cancer. 2012 May 1;118(9):2532-40. doi: 10.1002/cncr.26516. Epub 2011 Sep 1.
There are differences in outcomes in blacks compared with whites with lymph node-negative (pN0) colorectal cancer. Recurrence in pN0 patients suggests the presence of occult metastases undetected by conventional approaches. This study explores the association of racial differences in outcomes with occult tumor burden in regional lymph nodes.
Lymph nodes (range, 2-159) from 282 prospectively enrolled pN0 colorectal cancer patients followed for a median of 24 months (range, 2-63 months) were subjected to molecular analysis. Occult tumor burden was estimated by quantifying the expression of GUCY2C, a biomarker for metastatic colorectal cancer cells. Risk categories defined using occult tumor burden was the primary outcome measure. Association of prognostic variables and risk were defined by multivariate polytomous logistic regression.
Occult tumor burden stratified this cohort of 259 whites and 23 blacks into categories with low (60%; recurrence rate [RR] = 2.3%; 95% confidence interval [CI], 0.1%-4.5%), intermediate (31%; RR = 33.3%; 95% CI, 23.7%-44.1%), and high (9%; RR = 68.0%; 95% CI, 46.5%-85.1%; P < .001) risk. Blacks compared with whites exhibited 4-fold greater occult metastases in individual lymph nodes (P < .001). Multivariate analysis revealed that race (P = .02), T stage (P = .02), and number of lymph nodes collected (P = .003) were independent prognostic markers of risk category. Blacks compared with whites were more likely to harbor levels of occult tumor burden, associated with the highest recurrence risk (adjusted odds ratio = 5.08; 95% CI, 1.69-21.39; P = .007).
Racial disparities in stage-specific outcomes in colorectal cancer are associated with differences in occult tumor burden in regional lymph nodes.
与淋巴结阴性（pN0）结直肠癌的白人相比，黑人的结局存在差异。pN0 患者的复发提示存在常规方法无法检测到的隐匿性转移。本研究探讨了种族差异与区域淋巴结隐匿性肿瘤负担之间的关联。
对 282 例前瞻性入组的 pN0 结直肠癌患者的淋巴结（范围 2-159 个）进行了分子分析。通过定量检测转移性结直肠癌细胞的生物标志物 GUCY2C 的表达来估计隐匿性肿瘤负担。使用隐匿性肿瘤负担定义的风险类别是主要的观察终点。通过多元多变量逻辑回归定义预后变量和风险的相关性。
隐匿性肿瘤负担将这组 259 名白人患者和 23 名黑人患者分为低危（60%；复发率[RR] = 2.3%；95%置信区间[CI]，0.1%-4.5%）、中危（31%；RR = 33.3%；95% CI，23.7%-44.1%）和高危（9%；RR = 68.0%；95% CI，46.5%-85.1%；P<.001）风险类别。与白人相比，黑人患者单个淋巴结隐匿性转移的可能性高出 4 倍（P<.001）。多变量分析显示，种族（P=.02）、T 分期（P=.02）和收集的淋巴结数量（P=.003）是风险类别的独立预后标志物。与白人相比，黑人更有可能存在隐匿性肿瘤负担水平，与最高的复发风险相关（调整后的优势比=5.08；95% CI，1.69-21.39；P=.007）。
结直肠癌特定分期结局的种族差异与区域淋巴结隐匿性肿瘤负担的差异有关。
