Cancer diagnoses which are not confirmed by pathology are often under-registered in cancer registries compared to pathology-confirmed diagnoses. It is unknown how many patients have a non pathology-confirmed cancer diagnosis, and whether their characteristics and survival differ from patients with a pathology-confirmed diagnosis. Participants from the prospective population-based Rotterdam Study were followed between 1989 and 2013 for the diagnosis of cancer. Cancer diagnoses were classified into pathology-confirmed versus non pathology-confirmed (i.e., based on imaging or tumour markers). We compared participant characteristics and the distribution of cancers at different sites. Furthermore, we investigated differences in overall survival using survival curves adjusted for age and sex. During a median (interquartile range) follow-up of 10.7 (6.3–15.9) years, 2698 out of 14,024 participants were diagnosed with cancer, of which 316 diagnoses (11.7%) were non pathology-confirmed. Participants with non pathology-confirmed diagnoses were older, more often women, and had a lower education. Most frequently non pathology-confirmed cancer sites included central nervous system (66.7%), hepato-pancreato-biliary (44.5%), and unknown primary origin (31.2%). Survival of participants with non pathology-confirmed diagnoses after 1 year was lower compared to survival of participants with pathology-confirmed diagnoses (32.6% vs. 63.4%; risk difference of 30.8% [95% CI 25.2%; 36.2%]). Pathological confirmation of cancer is related to participant characteristics and cancer site. Furthermore, participants with non pathology-confirmed diagnoses have worse survival than participants with pathology-confirmed diagnoses. Missing data on non pathology-confirmed diagnoses may result in underestimation of cancer incidence and in an overestimation of survival in cancer registries, and may introduce bias in aetiological research.

与病理证实的诊断相比，未经病理证实的癌症诊断通常在癌症登记册中注册不足。尚不清楚有多少患者具有未经病理学证实的癌症诊断，以及其特征和生存率是否与经过病理学确诊的患者不同。在1989年至2013年期间，追踪了基于前瞻性人群的鹿特丹研究的参与者，以诊断癌症。癌症诊断分为病理确认和非病理确认（即，基于影像学或肿瘤标志物）。我们比较了参与者的特征和不同部位癌症的分布。此外，我们使用针对年龄和性别调整的生存曲线调查了总体生存率的差异。在中位（四分位间距）期间随访10.7（6。在3–15.9年内，在14,024名参与者中，有2698名被诊断出患有癌症，其中316名（11.7％）的诊断未经病理证实。未进行病理学确诊的参与者年龄较大，女性较多，学历较低。最常见的未经病理证实的癌症部位包括中枢神经系统（66.7％），肝胰胆管癌（44.5％）和主要来源不明（31.2％）。1年后未经病理学确诊的受试者的存活率低于经病理学确诊的受试者的存活率（32.6％vs. 63.4％；风险差异为30.8％[95％CI 25.2％; 36.2％]）。癌症的病理确认与参与者特征和癌症部位有关。此外，未进行病理学确诊的患者比未进行病理学确诊的患者生存率低。缺少未经病理证实的诊断的数据可能会导致癌症发病率被低估并且癌症登记处的生存率被高估，并且可能在病因学研究中引入偏见。