Birth Order and Family Size's Impact on Cancer Risk
Author Information
Author(s): Hemminki K, Mutanen P
Primary Institution: Department of Biosciences at Novum, Karolinska Institute
Hypothesis
How do birth order and family size affect the risk of cancer in young and middle-aged adults?
Conclusion
The study found that higher birth order is associated with an increased risk of breast cancer and a decreased risk of melanoma.
Supporting Evidence
- The study included 1.38 million offspring with 50.6 million person-years of data.
- Breast cancer risk increased with higher birth order.
- Melanoma risk decreased with higher birth order and family size.
- Birth orders 5–17 showed a relative risk of 1.41 for breast cancer.
- Socio-economic factors may influence melanoma risk.
Takeaway
Having more siblings can change your chances of getting certain types of cancer, like breast cancer and melanoma.
Methodology
The study used the Swedish Family-Cancer Database and Poisson regression analysis to assess cancer risk factors.
Potential Biases
Potential socio-economic biases may affect the results, particularly regarding melanoma risk.
Limitations
Prostate cancer was excluded due to a small number of cases, and the study may not account for all socio-economic factors.
Participant Demographics
Offspring born between 1958 and 1996, up to age 55.
Statistical Information
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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