Dermatology Service, Memorial Sloan-Kettering Cancer Center, New York, NY 10022, USA.
Cancer Epidemiol. 2013 Feb;37(1):64-70. doi: 10.1016/j.canep.2012.08.010. Epub 2012 Sep 18.
In the United States, the Surveillance, Epidemiology, and End Results (SEER) Program is the authoritative source for population-based data on melanoma incidence and mortality. However, missing data on tumor thickness may lead to biased analyses in this frequently used database. We sought to characterize invasive melanomas with unknown thickness with emphasis on their association with melanoma survival, and to employ techniques to overcome the limitations of missing data on tumor thickness.
We conducted a retrospective cohort analysis of non-occult invasive melanomas in the SEER database from 1989 to 2008.
Of 182184 cases, 24329 (13%) had unknown thickness. From 1989-1993 to 2004-2008, the proportion of unknown thickness cases decreased from 22% to 9% (P(trend) < 0.001). Unknown thickness cases had a significantly increased risk of death due to melanoma (hazard ratio [HR] 3.09, 95% confidence interval [CI]: 2.99, 3.19) than known thickness cases with an increasing trend over time (P(trend) < 0.001). In multivariate analysis, unknown thickness was found to be independently associated with poorer prognostic factors and lack of cancer-directed surgical treatment. Melanoma survival of cases with unknown thickness appeared most similar to 2.01-4.00 mm thickness cases. Multiple imputation demonstrated that imputed tumor thickness was significantly associated with melanoma survival (HR 1.31, 95% CI: 1.30, 1.32) and Clark level (odds ratio [OR] 1.85, 95% CI: 1.82, 1.89) though the strength of associations were not as strong as the associations of original SEER-coded known tumor thickness with melanoma survival (HR 1.46, 95% CI: 1.45, 1.47) and Clark level (OR 2.92, 95% CI 2.89, 2.95), respectively.
Exclusion of missing data on melanoma thickness from SEER introduces a selection bias that leads to an underestimation in the prevalence of fatal and likely thicker melanomas. Multiple imputation appears to be an effective tool to predict missing tumor thickness data.
在美国，监测、流行病学和最终结果（SEER）计划是黑色素瘤发病率和死亡率的人群数据的权威来源。然而，肿瘤厚度的缺失数据可能会导致在这个经常使用的数据库中进行有偏差的分析。我们旨在描述厚度未知的浸润性黑色素瘤，重点研究它们与黑色素瘤生存的关系，并采用技术来克服肿瘤厚度缺失数据的局限性。
我们对 1989 年至 2008 年 SEER 数据库中的非隐匿性浸润性黑色素瘤进行了回顾性队列分析。
在 182184 例病例中，24329 例（13%）的肿瘤厚度未知。从 1989-1993 年到 2004-2008 年，厚度未知病例的比例从 22%下降到 9%（趋势 P<0.001）。与已知厚度病例相比，厚度未知病例死于黑色素瘤的风险显著增加（危险比[HR]3.09，95%置信区间[CI]：2.99，3.19），且随着时间的推移呈上升趋势（趋势 P<0.001）。在多变量分析中，厚度未知与预后不良因素独立相关，且缺乏癌症导向的手术治疗。厚度未知病例的黑色素瘤生存率似乎与 2.01-4.00mm 厚度病例最相似。多项插补表明，插补的肿瘤厚度与黑色素瘤生存率（HR1.31，95%CI：1.30，1.32）和 Clark 水平（OR1.85，95%CI：1.82，1.89）显著相关，尽管关联的强度不如 SEER 原始编码的已知肿瘤厚度与黑色素瘤生存率（HR1.46，95%CI：1.45，1.47）和 Clark 水平（OR2.92，95%CI 2.89，2.95）的关联强。
从 SEER 中排除黑色素瘤厚度缺失数据会引入选择偏倚，导致致命和可能更厚的黑色素瘤的患病率被低估。多项插补似乎是预测缺失肿瘤厚度数据的有效工具。
