Sun protection messages, vitamin D and skin cancer: out of the frying pan and into the fire?
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Australia↗
Biomedical subjects
Rachel E Neale
Publications and source records attributed to Rachel E Neale.
Basal cell carcinoma on the trunk is associated with excessive sun exposure.
BACKGROUND AND OBJECTIVE: Basal cell carcinoma (BCC) is the most common of all cancers. Ultraviolet radiation is the major etiologic agent in the pathogenesis of BCC, but there is not a straightforward relationship between cumulative exposure and risk. A high proportion of lesions arise on the trunk, which is generally much less exposed to the sun than the head, the major site affected. We tested the hypothesis that the phenotypic determinants and patterns of sun exposure that give rise to BCC on the head and trunk vary in a way that explains the anomalous site distribution. METHODS: The study was set in the context of the Nambour Skin Cancer Study, a community-based follow-up study among 1621 participants with virtually complete ascertainment of BCCs between 1992 and 2004. We compared phenotypic and sun exposure characteristics of participants who developed a first BCC of the head or trunk with those of participants who had no diagnosis of BCC. RESULTS: BCCs of the trunk were more likely to occur in men; they also occurred at a younger age than BCCs of the head. There was a positive association between sun sensitivity and BCC of the head that was absent for BCC of the trunk. A high number of solar keratoses conferred a greater than 3-fold risk for BCCs of both the head and the trunk. BCCs of the trunk had a particularly strong association with the number of reported sunburns and solar lentigines on the trunk, whereas many lentigines conferred a greater than 3-fold risk of truncal BCC compared with a 50% increased risk of BCC of the head. LIMITATIONS: The relatively small numbers of tumors may have limited our ability to detect statistically significant differences. CONCLUSIONS: BCCs of the trunk are the result of overexposure of the sensitive basal cells of the epidermis to ultraviolet radiation. This may result from acute intense exposures sufficient to cause sunburn among people whose ability to tan makes the skin of their face generally less susceptible to the carcinogenic effects of ultraviolet radiation.
Age Distribution↗
Re: Human papillomavirus infection and incidence of squamous cell and basal cell carcinomas of the skin.
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Basal Cell Carcinoma↗
Pregnancy outcome among twins conceived after subfertility treatment compared with natural twins: A population-based study.
Pregnancy outcome and characteristics of women who conceive following subfertility treatment remains a subject of great interest. We analyzed these variables among 199 women who delivered a registerable twin birth compared with 1773 women who delivered a naturally conceived twin birth in a population-based obstetric cohort drawn from around Oxford, England. Treatment was restricted to conceptions involving simple ovulation induction only. Treated mothers were of significantly higher social class and older, more likely to deliver girls and to be delivered by cesarean section, and significantly less likely to be smokers at the time of antenatal booking and to have delivered previous pregnancies. Pregnancy outcome was similar between the two groups for most measures, with the exception of birthweight which was lower in treated twins, though not significantly so. Overall the results are reassuring with respect to outcome in twin pregnancies following simple ovulation induction.
Adult↗
Long-term increase in sunscreen use in an Australian community after a skin cancer prevention trial.
BACKGROUND: Given the public health burden of skin cancer in white populations, an increase in sun protective behavior is needed. In a high-risk community, we assessed long-term sunscreen use among people who had participated in a randomized trial of daily sunscreen application for prevention of skin cancer. METHODS: In 1992, 1621 residents of the subtropical Australian township of Nambour were randomly allocated to either daily or discretionary sunscreen use until 1996. From 1997 to 2002, we monitored by questionnaires their ongoing sunscreen use. RESULTS: People who had never or irregularly used sunscreen when in summer sun before the trial were more likely (P < 0.0001) to be sustaining regular application especially to their face (20% vs. 11%) and forearms (14% vs. 5%) if they had been allocated to daily, not discretionary, use of sunscreen for 5 years. CONCLUSIONS: Regular voluntary sunscreen use for skin cancer prevention can be sustained by sun-sensitive people in the long term. Habit formation appears to be an important goal for sun protection programs among those living, or on vacation, in sunny places.
Adult↗
Longitudinal analysis of the effect of prenatal nicotine exposure on subsequent smoking behavior of offspring.
We explored the influence of maternal smoking during pregnancy on the likelihood of smoking among offspring in adolescence and adulthood using data from two similar British birth cohort surveys, the 1958 National Child Development Study and the 1970 British Birth Survey. Similar information was available in each cohort on maternal age at delivery, offspring sex, maternal smoking during pregnancy, parental and offspring socioeconomic status, and parental smoking at the time offspring smoking was assessed at age 16 years. Offspring smoking at 16 years and at 30/33 years were the primary outcomes of interest. Our data support an association between maternal smoking during pregnancy and an increased risk of offspring smoking later in life among female offspring but not among male offspring. Female offspring of mothers who smoked during pregnancy were more likely to smoke at 16 years than were their male counterparts. Moreover, in this same subgroup, female offspring smoking at 16 years was associated with an increased likelihood of smoking at 30/33 years. Further investigation in larger studies with greater detail of factors shaping smoking in childhood and adulthood and biochemically verified outcome measures would be desirable to clarify the relationship.
Adolescent↗
Childhood and adult cancer in twins: evidence from the Utah genealogy.
OBJECTIVE: Evidence suggests that the in utero environment may contribute to subsequent development of cancers in childhood and adulthood. Raised levels of estrogen during pregnancy may be the primary in utero etiologic factor. Mothers of twins have higher estrogen levels during pregnancy than mothers of singletons, therefore, assessment of cancer risk in twins may be informative. METHOD: We conducted a retrospective cohort study of cancer among twin and singleton newborns selected from the Utah Population Database, matched on birth year and sex. Cancer diagnoses were determined by linkage with the Utah state cancer register. Relative rates of all cancers in childhood and in adulthood in twins compared with singletons, and for specific cancers including testicular, breast and melanoma, were calculated using Poisson regression. RESULTS: Twin (35,271) and singleton (74,199) births were identified, among whom there were 336 and 691 cancer diagnoses, respectively. The relative risk (RR) of childhood cancer in twins compared with singletons was 0.82 [95% confidence interval (CI) 0.55-1.24] and of adult cancer was 1.06 (0.92-1.22). We found nonsignificant increases in risk among adult twins for cancers of the breast, prostate, testis, lymphatic system, thyroid, and large bowel. The largest departures from unity were for testicular cancer (RR 1.47; 95% CI, 0.73-2.95) and melanoma (RR 0.67; 95% CI, 0.42-1.06). CONCLUSIONS: These results are consistent with the body of evidence suggesting that twins have a reduced risk of cancer in childhood. Although there is no overall differential in adult cancer risk, these data support the hypothesis that the in utero environment may play an important role in specific cancers.
Adolescent↗
The effects of twins, parity and age at first birth on cancer risk in Swedish women.
The effect of reproductive history on the risk of cervical, colorectal and thyroid cancers and melanoma has been explored but the results to date are inconsistent. We aimed to examine in a record-linkage cohort study the risk of developing these cancers, as well as breast, ovarian and endometrial cancers, among mothers who had given birth to twins compared with those who had only singleton pregnancies. Women who delivered a baby in Sweden between 1961 and 1996 and who were 15 years or younger in 1961 were selected from the Swedish civil birth register and linked with the Swedish cancer registry. We used Poisson regression to assess associations between reproductive factors and cancer. Twinning was associated with reduced risks of breast, colorectal, ovarian and uterine cancers, although no relative risks were statistically significant. The delivery of twins did not increase the risk of any cancers studied. Increasing numbers of maternities were associated with significantly reduced risks of all tumors except thyroid cancer. We found positive associations between a later age at first birth and breast cancer and melanoma, while there were inverse associations with cervix, ovarian, uterine and colorectal cancers. These findings lend weight to the hypothesis that hormonal factors influence the etiology of colorectal cancer in women, but argue against any strong effect of hormones on the development of melanoma or tumors of the thyroid.
Adult↗
Twinning and the incidence of breast and gynecological cancers (United States).
Increasing epidemiological and experimental evidence indicates that the carcinogenic pathway in the breast and female reproductive organs is driven, at least in part, by factors associated with reproduction. We conducted a retrospective cohort study, comparing the risk of ovarian, breast, endometrial, and cervical cancers among women who had records of at least one twin pregnancy, compared with women who had given birth to only single children. Subjects were selected from the Utah Population Database, which consists of multiple linked datasets including genealogy, births and deaths and cancer registries. We used Poisson regression to calculate relative risks, adjusted for the number of pregnancies and the age of the mother at the birth of first and last children, with singleton mothers as the reference group in each case. The risks of breast and ovarian cancers did not differ between mothers of twins and mothers of single children. The risk of endometrial cancer was slightly lower in mothers of twins than in mothers of singleton children (RR = 0.90, 95% CI 0.67-1.21). Conversely the risk of cervical cancer was higher among twin mothers (RR = 1.78, 95% CI 0.88-3.52). This latter finding supports previous data suggesting that reproductive hormones act as cofactors in the etiology of cervical cancer.
Adolescent↗
Sun exposure as a risk factor for nuclear cataract.
BACKGROUND: Cataracts are the leading cause of blindness and visual impairment throughout the world. An association of sun exposure with cortical cataract has been well established, but the association with nuclear cataract remains unclear. METHODS: This case-control study was nested within the Nambour (Australia) Trial of Skin Cancer Prevention conducted between 1992 and 1996. We compared 195 cases who had a nuclear opacity of grade 2.0 or greater with 159 controls. Structured questionnaires were used to ascertain lifetime sun exposure history, eyeglasses and sunglasses use, and potentially confounding variables such as education and smoking. RESULTS: There was a strong positive association of occupational sun exposure between the ages of 20 and 29 years with nuclear cataract (odds ratio = 5.9; 95% confidence interval = 2.1-17.1). Exposure later in life resulted in weaker associations. Wearing sunglasses, particularly during these early years, afforded some protective effect. CONCLUSIONS: This study provides new evidence to support a link between sun exposure and nuclear cataract. Risk was highest among those with high sun exposure at younger ages.
Adolescent↗
Measuring behavioral interventions by questionnaires and prospective diaries: an example of sunscreen use.
BACKGROUND: Diaries are used to measure behavior in intervention trials, despite the tendency of diaries to overestimate adherence. METHODS: We estimated the frequency of sunscreen application using prospective diaries and a questionnaire in a trial evaluating sunscreen use. RESULTS: Sunscreen application was reported more frequently in the diaries than in the questionnaire by the intervention group. This was supported by an increase in the weight of sunscreen used during the times participants were keeping diaries. CONCLUSIONS: Diaries may be better as an aid to increase adherence than as a tool for its estimation. Use of diaries did not overestimate the frequency of application in the control group.
Australia↗