A dose‐response curve for sun exposure and basal cell carcinoma

Abstract

A population-based case-control study of sun exposure and basal cell carcinoma (BCC) was conducted in Western Australia in 1988. Its aim was to examine the relationship between risk of BCC and the amount and pattern of sun exposure. This report deals with amount of exposure. The odds ratios (ORs) for BCC on the head and neck and limbs decreased with increasing total exposure, whereas the opposite was observed for BCC on the less heavily exposed trunk, with the highest OR in those with the greatest exposure. In an analysis of all body sites together in which the total hours of exposure to the specific site was treated as a continuous variable, an initial rise in risk of BCC was seen with a peak OR of 1.4 at about 35,000 hr of exposure, followed by a fall. In contrast to these site-specific patterns, lifetime accumulated sun exposure of the whole body showed no appreciable association with BCC either in total or for working days only. Risk of BCC was positively associated with lifetime exposure on non-working days, however, with an OR for higher than baseline categories of around 1.7. There was a significant interaction between ability to tan and total and occupational sun exposure. Risk increased with increasing exposure in those who tanned well but not in those who tanned poorly. This pattern is consistent with other observations which indicate that beyond a certain level of sun exposure risk of BCC does not increase further.

Sun exposure may protect against non‐Hodgkin lymphoma: A case‐control study

“…Variables for personal sun exposure and ambient solar irradiance were categorised into approximate quarters or thirds of the exposure distribution in controls. It was known a priori 22,33 that men at all ages have higher outdoor hours than women, so separate models of personal sun exposure were constructed for men and women together, men only and women only.…”

“…They were an estimated 93.4% of patients diagnosed in the study period and registered as NHL by the Cancer Registry; 18,19 those registered but not ascertained for the study were probably mainly cases registered after ascertainment ended or not diagnosed pathologically. Of those ascertained and initially confirmed as eligible, 197 were subsequently found to be ineligible because of prior immunosuppression or immune deficiency (28), poor English (73), illness (74) or disability preventing interview (22). A further 178 were excluded from the possibility of interview because they had died (144) or could not be contacted (34).…”

“…A computer-assisted telephone interview was the main source of information on sun exposure. Participants were asked to complete a residence and occupation calendar for each year of their life 22 and a brief paper questionnaire before the interview; the calendar information was used to customise the interview and assist recall. All interviews were conducted between March 2000 and May 2002 by 4 trained and experienced female interviewers.…”

“…We constructed separate variables for working and nonworking days sun exposure by summing the reported hours outdoors across the decade years, and a combined working and nonworking days variable as an indicator of total outdoor exposure. We have previously demonstrated the utility of this method for measuring sun exposure [22][23][24][25][26][27] and hereafter refer to outdoor exposure simply as sun exposure.…”

Known and potential new risk factors for skin cancer in European populations: a multicentre case-control study

“…Questions from questionnaires already successfully used in other parts of the world 14,25,26 were also included (http://www.epiderm-network.eu). A dermatological assessment was part of the data collection.…”