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Multiple primary tumours: incidence estimation in the presence of competing risks.

Rosso S, Terracini L, Ricceri F, Zanetti R - Popul Health Metr (2009)

Bottom Line: In a simulation study we applied the proposed method in different settings with constant or varying underlying intensities and applying age standardisation.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.Finally, the proposed approach has been shown to be reliable and informative under several aspects.

View Article: PubMed Central - HTML - PubMed

Affiliation: Piedmont Cancer Registry - CPO, Turin, Italy. stefano.rosso@cpo.it.

ABSTRACT

Background: Estimating the risk of developing subsequent primary tumours in a population is difficult since the occurrence probability is conditioned to the survival probability.

Methods: 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.

Results: 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.

Conclusion: 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.

No MeSH data available.


Related in: MedlinePlus

The multi-state model.
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Related In: Results  -  Collection

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Figure 1: The multi-state model.

Mentions: The tumours occurrence in a general population can be depicted as in Figure 1. From demographic sources we know the amount of deaths (me) and the general mortality rate (μe). From cancer registries we measure the number of first primary tumours (n1) the incidence rate (λ1), the number and rates of these patients deceased for other causes (m1e;μe) and for the specific cause of death (m1;μ1). After this first process has taken place we can observe (n2) second primaries with a rate (λ2) to be estimated conditioned to the quantities and parameters previously seen.


Multiple primary tumours: incidence estimation in the presence of competing risks.

Rosso S, Terracini L, Ricceri F, Zanetti R - Popul Health Metr (2009)

The multi-state model.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2682788&req=5

Figure 1: The multi-state model.
Mentions: The tumours occurrence in a general population can be depicted as in Figure 1. From demographic sources we know the amount of deaths (me) and the general mortality rate (μe). From cancer registries we measure the number of first primary tumours (n1) the incidence rate (λ1), the number and rates of these patients deceased for other causes (m1e;μe) and for the specific cause of death (m1;μ1). After this first process has taken place we can observe (n2) second primaries with a rate (λ2) to be estimated conditioned to the quantities and parameters previously seen.

Bottom Line: In a simulation study we applied the proposed method in different settings with constant or varying underlying intensities and applying age standardisation.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.Finally, the proposed approach has been shown to be reliable and informative under several aspects.

View Article: PubMed Central - HTML - PubMed

Affiliation: Piedmont Cancer Registry - CPO, Turin, Italy. stefano.rosso@cpo.it.

ABSTRACT

Background: Estimating the risk of developing subsequent primary tumours in a population is difficult since the occurrence probability is conditioned to the survival probability.

Methods: 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.

Results: 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.

Conclusion: 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.

No MeSH data available.


Related in: MedlinePlus