Greater family size is associated with less cancer risk: an ecological analysis of 178 countries.

BACKGROUND: Greater family size measured with total fertility rate (TFR) and with household size, may offer more life satisfaction to the family members. Positive psychological well-being has been postulated to decrease cancer initiation risk. This ecological study aims to examine the worldwide correlation between family size, used as the measure of positive psychological well-being, and total cancer incidence rates. METHODS: Country specific estimates obtained from United Nations agencies on total cancer incidence rates (total, female and male rates in age range 0-49 years and all ages respectively), all ages site cancer incidence (bladder, breast, cervix uteri, colorectum, corpus uteri, lung, ovary and stomach), TFR, household size, life expectancy, urbanization, per capita GDP PPP and self-calculated Biological State Index (Ibs) were matched for data analysis. Pearson's, non-parametric Spearman's, partial correlations, independent T-test and multivariate regressions were conducted in SPSS. RESULTS: Worldwide, TFR and household size were significantly and negatively correlated to all the cancer incidence variables. These correlations remained significant in partial correlation analysis when GDP, life expectancy, Ibs and urbanization were controlled for. TFR correlated to male cancer incidence rate (all ages) significantly stronger than it did to female cancer incidence rate (all ages) in both Pearson's and partial correlations. Multivariate stepwise regression analysis indicated that TFR and household size were consistently significant predictors of all cancer incidence variables. CONCLUSIONS: Countries with greater family size have lower cancer risk in both females, and especially males. Our results seem to suggest that it may be worthwhile further examining correlations between family size and cancer risk in males and females through the cohort and case-control studies based on large samples.

Diagnosing congenital syphilis using Hutchinson's method: Differentiating between syphilitic, mercurial, and syphilitic-mercurial dental defects.

OBJECTIVES: This study focuses on the dental abnormalities observed by Sir Jonathan Hutchinson, Henry Moon and Alfred Fournier in patients with congenital syphilis and in those treated with mercury, in order to define alterations in dental morphology attributable to each of these causes. These definitions are applied to reported paleopathological cases, exploring various etiologies behind the defects, in order to aid in the diagnosis of congenital syphilis. METHODS: Original works were examined for descriptions of dental abnormalities in congenital syphilis and in mercurial treatments. These descriptions were compared with dentitions of paleopathological cases (n = 4) demonstrating abnormalities attributed to congenital syphilis. RESULTS: Distinct morphological differences were recognized between congenital syphilitic teeth and teeth affected by mercury. Mercury produces a pronounced deficiency in enamel of incisors, canines and first permanent molars that become rugged and pitted, and of dirty grey honeycombed appearance. Mercury-induced dental changes are evident in three out of four cases studied here. In one case, only syphilitic changes were present. DISCUSSION: Dental changes in congenital syphilis range from no visible signs to those beyond the classical models of Hutchinson, Moon and Fournier. Treatment of neonates and infants with mercury produces additional changes. Signs of disease and treatment with mercury on teeth may occur together; permanent incisors, first molars and canines, are typically affected, premolars and second/third molars are usually spared. Signs of treatment with mercury might be the only evidence of the occurrence of the disease as mercury was rarely used to treat other diseases.

Presence of dental signs of congenital syphilis in pre-modern specimens.

OBJECTIVE: Tooth morphology can vary due to genetic factors, infectious diseases and other environmental stresses. Congenital syphilis is known to interrupt tooth formation i.e. odontogenesis and amelogenesis, producing specific dental characteristics. Variation of those characteristics can occur, resulting in dental signs "not typical" of the disease, however, they are described in the 19th century literature. Past treatments of congenital syphilis with mercury also interrupted dental processes resulting in significantly different dental signs. The aim of this study is to examine the dentition of the oldest (pre 15th century) cases attributed to congenital syphilis to determine whether their dental processes have been affected by either congenital syphilis itself, its treatments (mercury) or a combination of both (syphilitic-mercurial). DESIGN: Comparisons of dental signs of congenital syphilis and its mercuric treatments as described by Hutchinson, Moon and Fournier in the 1800s and in standardised methods as established by modern studies, are made with the dentition of specimens found in archaeological sites in Mexico, Italy, Turkey and Austria dating back to the Terminal Formative Period, Classical Antiquity, Byzantine times and Middle Ages. RESULTS: The dentitions of a child from Oaxaca, Mexico, St. Pölten, Austria, and two juveniles from Classical Antiquity site Metaponto, Italy, show signs attributed to syphilis only. One adolescent from Byzantine site Nicaea, Turkey, shows dental signs characterised as syphilitic-mercurial. CONCLUSIONS: Dental abnormalities observed in Mediterranean individuals match a range of signs attributable to congenital syphilis and its treatments, more so than the New World case. Therefore, it is likely that these individuals suffered from congenital syphilis.