Medical student at Stanford University School of Medicine, Stanford, California, now with Department of Dermatology, University of California, San Francisco.
Department of Dermatology, University of California, San Francisco.
JAMA Dermatol. 2015 Apr;151(4):382-8. doi: 10.1001/jamadermatol.2014.3307.
Patients with basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) (often termed nonmelanoma skin cancer or keratinocyte carcinoma [KC]) often develop new KCs, but information is limited on the frequency and timing of these subsequent tumors. This information is crucial to guide follow-up care.
To determine the timing of subsequent new KCs in patients who present with KC.
DESIGN, SETTING, AND PARTICIPANTS: We enrolled a consecutive cohort of 1426 patients diagnosed as having biopsy-proven KC from January 1, 1999, through December 31, 2000, in a university dermatology practice and its affiliated Department of Veterans Affairs dermatology service. After exclusion of patients with basal cell nevus syndrome and immunocompromise, 1284 patients (90.0%) were followed up prospectively for a mean of 5.7 (range, 0-12.3) years.
We assessed the risks for subsequent KCs over time using single-failure and multiple-failure models. We separately assessed outcomes after first lifetime KCs and after nonfirst lifetime KCs. We also performed secondary analyses of the risk for a subsequent BCC after a prior BCC diagnosis and the risk for a subsequent SCC after a prior SCC diagnosis.
The risk for a subsequent KC was substantially lower after the first lifetime KC diagnosis: 14.5% (95% CI, 11.9%-17.7%) at 1 year, 31.1% (95% CI, 27.3%-35.3%) at 3 years, and 40.7% (95% CI, 36.5%-45.2%) at 5 years, than after a nonfirst KC: 43.9% (95% CI, 42.0%-45.9%) at 1 year, 71.1% (95% CI, 69.1%-73.0%) at 3 years, and 82.0% (95% CI, 80.2%-83.7%) at 5 years. Secondary analyses of the risks for a subsequent BCC after a prior BCC diagnosis and of a subsequent SCC after a prior SCC diagnosis yielded results consistent with the analyses for the pooled KC sample.
Although all patients with KC are assumed to be at high risk for subsequent tumors, a subset may not develop another KC after their first tumor. Whether these findings are related to biological or behavioral differences or to differences in health care services should be investigated further to inform and improve care. Ongoing routine screening for subsequent KC may not be indicated for all patients with KC. Skin cancer screening can be improved with a better understanding of the course and frequency of subsequent KC diagnoses.
患有基底细胞癌（BCC）和皮肤鳞状细胞癌（SCC）（通常称为非黑色素瘤皮肤癌或角质形成细胞癌[KC]）的患者经常会出现新的 KC，但关于这些后续肿瘤的频率和时间的信息有限。这些信息对于指导后续护理至关重要。
确定出现 KC 的患者后续出现新 KC 的时间。
设计、地点和参与者：我们招募了 1999 年 1 月 1 日至 2000 年 12 月 31 日期间在一所大学皮肤科诊所及其附属退伍军人事务部皮肤科服务中通过活检证实患有 KC 的 1426 例连续队列患者。排除基底细胞痣综合征和免疫功能低下的患者后，1284 例（90.0%）患者进行了平均 5.7（范围，0-12.3）年的前瞻性随访。
我们使用单失效和多失效模型评估了随时间推移出现后续 KC 的风险。我们分别评估了首次终生 KC 和非首次终生 KC 后的结果。我们还对先前诊断为 BCC 后的后续 BCC 风险和先前诊断为 SCC 后的后续 SCC 风险进行了二次分析。
首次终生 KC 诊断后，出现后续 KC 的风险显著降低：1 年内为 14.5%（95%CI，11.9%-17.7%），3 年内为 31.1%（95%CI，27.3%-35.3%），5 年内为 40.7%（95%CI，36.5%-45.2%），而非首次 KC 为：1 年内为 43.9%（95%CI，42.0%-45.9%），3 年内为 71.1%（95%CI，69.1%-73.0%），5 年内为 82.0%（95%CI，80.2%-83.7%）。先前诊断为 BCC 后的后续 BCC 风险和先前诊断为 SCC 后的后续 SCC 风险的二次分析结果与对汇总 KC 样本的分析结果一致。
尽管所有患有 KC 的患者都被认为存在发生后续肿瘤的高风险，但有一部分患者在首次肿瘤后可能不会再出现另一个 KC。这些发现是否与生物学或行为差异或医疗保健服务差异有关，或者与这些差异有关，应进一步调查，以为提供信息和改善护理提供依据。并非所有患有 KC 的患者都需要进行后续 KC 的常规筛查。通过更好地了解后续 KC 诊断的过程和频率，可以提高皮肤癌筛查的效果。
