| Literature DB >> 17535973 |
David Dynnes Ørsted1, Stig Egil Bojesen, Anne Tybjaerg-Hansen, Børge Grønne Nordestgaard.
Abstract
p53 is an important tumor suppressor, normally preventing cancer development via apoptosis. A genomic Arg72Pro substitution in the p53 protein has important influence on cell death via apoptosis, which could be beneficial. We therefore tested the hypotheses that this polymorphism influences longevity, survival after a cancer diagnosis, and risk of cancer in the general population. We examined a cohort of 9,219 participants ages 20-95 from the Danish general population with 100% follow-up. The overall 12-yr survival was increased in p53 Arg/Pro heterozygotes with 3% (P = 0.003) and in Pro/Pro homozygotes with 6% (P = 0.002) versus Arg/Arg homozygotes, corresponding to an increase in median survival of 3 yr for Pro/Pro versus Arg/Arg homozygotes. We also demonstrated an increased survival after the development of cancer, or even after the development of other life-threatening diseases, for Pro/Pro versus Arg/Arg homozygotes. The Arg72Pro substitution did not associate with decreased risk of cancer. In conclusion, in this large cohort from the general population, we show that a well-known functional single nucleotide polymorphism in the tumor suppressor p53 protein leads to increased longevity, but not to decreased risk of cancer. The increased longevity may be due to increased survival after a diagnosis of cancer or other life-threatening diseases.Entities:
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Year: 2007 PMID: 17535973 PMCID: PMC2118619 DOI: 10.1084/jem.20062476
Source DB: PubMed Journal: J Exp Med ISSN: 0022-1007 Impact factor: 14.307
Basic characteristics according to p53 Arg72Pro genotype in individuals in the general population
| Characteristic | Arg/Arg | Arg/Pro | Pro/Pro |
|---|---|---|---|
| Number (%) | 4,934 (54) | 3,623 (39) | 662 (7) |
| Women (%) | 55 | 55 | 56 |
| Age (yr) | 58 ± 15 | 58 ± 15 | 57 ± 15 |
| Total tobacco consumption (pack-years | 23 ± 24 | 22 ± 24 | 23 ± 23 |
| Current or former smoker (%) | 78 | 76 | 78 |
| Body mass index (kg/m2) | 25 ± 4 | 25 ± 4 | 25 ± 4 |
| Alcohol (g/wk) | 112 ± 147 | 113 ± 151 | 106 ± 133 |
| Plasma cholesterol (mmol/liter) | 6.2 ± 1.3 | 6.1 ± 1.3 | 6.1 ± 1.3 |
| Systolic blood pressure (mmHg) | 139 ± 23 | 138 ± 22 | 137 ± 22 |
| Physically inactive (%) | 12 | 12 | 14 |
Variables expressed as mean ± standard deviation or proportion were collected at the 1991–1994 examination of the Copenhagen City Heart Study. Statistical comparisons between the three genotype groups were made using two-sided Mann-Whitney U test, Pearson's χ2 test, or Student's t test on untransformed or log-transformed parameters as appropriate. No parameter had differences that were statistically significant among the three genotype groups.
Pack-years indicates the average number of packs of cigarettes smoked daily by a person multiplied by the number of years that person has been a smoker.
Figure 1.12-yr survival and longevity of the general population by p53 Arg72Pro genotype. Death endpoints were collected from the Danish Civil Registration System, which is 100% complete. (A) For 12-yr survival, follow-up started at blood sampling and ended at death, emigration, or March 11, 2004, whichever came first. (B) For longevity using left-truncated age, follow-up started at blood sampling and ended at death, emigration, or March 11, 2004, whichever came first. (C) Comparison of the effect of p53 Arg72Pro genotype with that of smoking status on 12-yr survival and median survival in the same population. Arg/Arg homozygotes are in blue, Arg/Pro heterozygotes are in red, and Pro/Pro homozygotes are in green.
Mortality, mortality after disease, and morbidity according to p53 Arg72Pro genotype in the general population
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|
|
| Arg/Arg
| Arg/Pro
| Pro/Pro
| |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Endpoint | Participants | Incidents | Incidence | HR | Incidence | HR | p-value | Incidence | HR | p-value |
| Mortality | 9,219 | 2,264 | 270 | 1.0 | 238 | 0.88 | 0.005 | 210 | 0.82 | 0.02 |
| Mortality after disease | ||||||||||
| Cancer | 2,048 | 1,074 | 680 | 1.0 | 562 | 0.87 | 0.03 | 507 | 0.74 | 0.03 |
| Cardiovascular disease | 2,849 | 1,416 | 560 | 1.0 | 498 | 0.95 | 0.36 | 480 | 0.85 | 0.14 |
| Other | 7,429 | 2,075 | 197 | 1.0 | 173 | 0.88 | 0.007 | 148 | 0.81 | 0.03 |
| Morbidity | ||||||||||
| Cancer | 9,218 | 2,048 | 170 | 1.0 | 178 | 1.10 | 0.03 | 142 | 0.91 | 0.32 |
| Cardiovascular disease | 9,218 | 2,849 | 137 | 1.0 | 132 | 0.96 | 0.31 | 128 | 0.99 | 0.93 |
| Other | 9,214 | 7,429 | 589 | 1.0 | 586 | 0.99 | 0.80 | 607 | 1.03 | 0.55 |
Hazard ratios were adjusted for gender and age in all analyses. Numbers of participants vary slightly because some participants were excluded because of development of disease before follow-up. International Classification of Diseases 8 and 10 codes are as follows: for cardiovascular disease, 390-458, I00-I99; and for cancer, 140-209, C00-C97. HR, hazard ratio; CI, confidence interval.
Person-years indicates the number of collective years that the individuals in a particular group were observed.
bRemained statistically significant (P < 0.05) after Bonferroni correction for multiple comparison for two tests on mortality, six tests on mortality after disease, and six tests on morbidity.
Figure 2.5-yr survival of the general population after a cancer diagnosis by p53 Arg72Pro genotype. Cancer diagnosis and death endpoints were collected from the Danish Cancer Registry and the Danish Civil Registration System, which are 98 and 100% complete. Only cancers diagnosed 1 yr before blood sampling and afterward were included. (A) For 5-yr survival after a cancer diagnosis, follow-up started at cancer diagnosis and ended at death, emigration, or March 11, 2004, whichever came first. (B) Effect of p53 Arg72Pro genotype on 5-yr survival after a cancer diagnosis. Arg/Arg homozygotes are in blue, Arg/Pro heterozygotes are in red, and Pro/Pro homozygotes are in green.
Risk of cancer subgroups according to p53 Arg72Pro genotype in the general population
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| Arg/Arg
| Arg/Pro
| Pro/Pro
| ||
|---|---|---|---|---|---|---|---|
| Endpoint | Participants | Events | HR | HR | p-value | HR | p-value |
| Gastrointestinal cancer | 9,219 | 391 | 1.0 | 1.10 | 0.38 | 0.89 | 0.59 |
| Hematologic cancer | 9,218 | 112 | 1.0 | 2.01 | <0.001 | 1.49 | 0.30 |
| Respiratory cancer | 9,219 | 271 | 1.0 | 0.91 | 0.47 | 0.82 | 0.46 |
| Urologic cancer | 9,217 | 185 | 1.0 | 1.10 | 0.53 | 0.73 | 0.37 |
| Female cancer | 5,155 | 477 | 1.0 | 1.06 | 0.51 | 0.71 | 0.10 |
| Male cancer | 4,114 | 136 | 1.0 | 1.11 | 0.55 | 1.15 | 0.68 |
| Other cancer | 9,219 | 659 | 1.0 | 1.09 | 0.30 | 1.00 | 0.98 |
Hazard ratios were adjusted for gender (when relevant) and age in all analyses. Follow-up started January 1, 1947, at the establishment of the Danish Cancer Registry or at birth, whichever came last, and ended at the date of the first relevant cancer diagnosis, death, emigration, or December 31, 2002, whichever came first. Numbers of participants vary slightly because some participants were excluded as a result of the development of disease before follow-up. HR, hazard ratio; CI, confidence interval.
Remained statistically significant (P < 0.05) after Bonferroni correction for multiple comparison for 14 tests.