Multiple primary tumours: incidence estimation in the presence of competing risks.
Multiple primary tumours: incidence estimation in the presence of competing risks.
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DOI：
10.1186/1478-7954-7-5
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发表时间：
2009-04-01
影响因子：
3.3
通讯作者：
Zanetti R
中科院分区：
文献类型：
--
作者：
Rosso S;Terracini L;Ricceri F;Zanetti R
由于发生概率取决于生存概率，因此很难估计人群中发生后续原发肿瘤的风险。我们建议应用马尔可夫模型研究从第一个肿瘤到第二个肿瘤的转移强度，并使用Aalen-Johansen(AJ)估计器，就像在竞争风险模型中通常所做的那样。在一项模拟研究中，我们在不同的背景强度恒定或变化的情况下应用了所提出的方法，并应用了年龄标准化。此外，我们用皮德蒙特癌症登记处的乳腺癌数据说明了这种方法。模拟研究表明，人年法比AJ估计法产生的偏差要大得多。最大的偏差是在假设发病率不断增加的情况下观察到的。然而，这种情况在随后的肿瘤发病率中是相当罕见的。在1985年至1998年期间发生在意大利都灵的9233例乳腺癌患者中，我们观察到，根据年龄标准化的Aalen-Johansen发病率(AJ-IR)估计，继发子宫癌的风险显著增加1.91，而可能与乳腺癌放射治疗有关的癌症的风险显著增加1.29。这些癌症的发生高峰是在8年后观察到的。在其他研究中也观察到子宫癌风险的增加，通常被解释为共同的风险因素，如低产次、月经初潮早和更年期晚。我们还将那些可能与既往局部放射治疗相关的癌症分组在一起：14年的累积风险仍然不显著，但AJ估计人员显示在第8年至第9年之间有一个显著的风险峰值。最后，在几个方面证明了所提出的方法是可靠和信息丰富的。它允许正确估计风险，并调查随后癌症发生的时间趋势。
Estimating the risk of developing subsequent primary tumours in a population is difficult since the occurrence probability is conditioned to the survival probability. We proposed to apply Markov models studying the transition intensities from first to second tumour with the Aalen-Johansen (AJ) estimators, as usually done in competing risk models. In a simulation study we applied the proposed method in different settings with constant or varying underlying intensities and applying age standardisation. In addition, we illustrated the method with data on breast cancer from the Piedmont Cancer Registry. The simulation study showed that the person-years approach led to a sensibly wider bias than the AJ estimators. The largest bias was observed assuming constantly increasing incidence rates. However, this situation is rather uncommon dealing with subsequent tumours incidence. In 9233 cases with breast cancer occurred in women resident in Turin, Italy, between 1985 and 1998 we observed a significant increased risk of 1.91 for subsequent cancer of corpus uteri, estimated with the age-standardised Aalen-Johansen incidence ratio (AJ-IRstand), and a significant increased risk of 1.29 for cancer possibly related to the radiotherapy of breast cancer. The peak of occurrence of those cancers was observed after 8 years of follow-up. The increased risk of a cancer of the corpus uteri, also observed in other studies, is usually interpreted as the common shared risk factors such as low parity, early menarche and late onset of menopause. We also grouped together those cancers possibly associated to a previous local radiotherapy: the cumulative risk at 14 years is still not significant, however the AJ estimators showed a significant risk peak between the eighth and the ninth year. Finally, the proposed approach has been shown to be reliable and informative under several aspects. It allowed for a correct estimation of the risk, and for investigating the time trend of the subsequent cancer occurrence.