Nordén T, Thurfjell E, Hasselgren M, Lindgren A, Norgren A, Bergström R, Holmberg L
Department of Surgery, University Hospital, Uppsala, Sweden.
Eur J Cancer. 1997 Apr;33(4):624-8. doi: 10.1016/s0959-8049(96)00482-0.
The aim of this study was to compare lymph node involvement of breast cancer cases detected at mammography screening with clinically-detected cases. During a 3-year period, 273 primary breast cancers were detected in a population-based screening programme, and 149 primary breast cancers were diagnosed clinically. Lymph node involvement was evaluated in univariate and multivariate logistic regression models correcting for tumour size, histological grade, steroid receptor status and DNA-ploidy. Patients with screen-detected cancers had a low relative risk of having lymph node metastases (univariate, OR = 0.31; 95% confidence interval = 0.19-0.52). In the multivariate logistic regression model, the relative risk was halved (OR = 0.47; 0.28-0.78). The reduced risk was more pronounced for women younger than 50 years of age compared to older women. The risk for screen-detected cases of having lymph node metastases at diagnosis was statistically significantly lower than for clinically-detected cases. The marked reduction, even when correcting for tumour size, makes it less likely that factors such as detection of clinically innocent tumours, length bias sampling or clinical symptoms related to axillary metastases can explain the whole difference. The results indicate at least part of the effect may be explained by tumour progression in the late preclinical detectable phase.
本研究的目的是比较在乳腺钼靶筛查中检测出的乳腺癌病例与临床检测出的病例的淋巴结受累情况。在3年期间，在一项基于人群的筛查计划中检测出273例原发性乳腺癌，149例原发性乳腺癌经临床诊断。在单变量和多变量逻辑回归模型中评估淋巴结受累情况，对肿瘤大小、组织学分级、类固醇受体状态和DNA倍性进行校正。筛查发现癌症的患者发生淋巴结转移的相对风险较低（单变量，OR = 0.31；95%置信区间 = 0.19 - 0.52）。在多变量逻辑回归模型中，相对风险减半（OR = 0.47；0.28 - 0.78）。与老年女性相比，50岁以下女性风险降低更为明显。筛查发现的病例在诊断时发生淋巴结转移的风险在统计学上显著低于临床检测出的病例。即使校正肿瘤大小后仍有显著降低，这使得诸如检测到临床无害肿瘤、长度偏倚抽样或与腋窝转移相关的临床症状等因素不太可能解释全部差异。结果表明，至少部分效应可能由临床前可检测晚期的肿瘤进展来解释。
