Season, Sun, Sex, and Cervical Cancer

Abstract

Introduction: Sunlight's UV B component, a known cellular immunosupressant, carcinogen, and activator of viral infections, is generally seasonally available. Venereal human papillomavirus (HPV) transmission, at least in part, causes cervical cancer. We have previously inspected the monthly rates of venereal HPV infection and sunlight fluency in Southern Holland over 16 consecutive years. Both peak in August with at least 2-fold seasonality. The amount of available sunlight and the rate of Papanicolaou (Pap) smear screen -detected HPV are positively correlated. We now investigate whether premalignant and malignant cervical epithelial changes are also seasonal and related to seasonal sunlight fluency. Methods: We have studied >900,000 consecutive, serially independent, interpretable screening Pap smears obtained by a single cervical cancer screening laboratory in Leiden, Holland, during a continuous 16-year span from 1983 through 1998. The average monthly rates of premalignant and malignant epithelial change were inspected and the annual patterns contrasted to the annual pattern of sunlight fluency at this global location and to monthly average HPV infection rate. Because HPV is venereally transmitted, Dutch seasonal sexual behavior was evaluated by assessment of the

There is a high prevalence of human papillomavirus infection in American Indian women of the Northern Plains

“…2a). Previous studies have indicated a seasonal correlation of HPV infection [23,24]; however, in our study there was no correlation (p=0.33) between HPV infection and seasonal variation (Fig. 2b).…”

Sunspot Dynamics Are Reflected in Human Physiology and Pathophysiology

“…Multi-year rhythms in the waxing and waning of infectious epidemics are the rule rather than the exception (Davis and Lowell, 2006). These are usually explained by pathogen/population feedback interactions and have generally not been adequately examined for possible links to Sun-based nonphotic geomagnetic perturbations (Hrushesky et al, 2005(Hrushesky et al, , 2006. Peaks in solar radiation associated with the 10-11 year solar cycle have been implicated as a possible cause for genetic disruption of all life by means of direct mutation and immunologic stress, since even the resultant 1-2% increase in UV radiation at ground level during sunspot cycle peaks is a significant stress to an organism's DNA repair mechanisms and can, thereby, be a modulator of disease (Davis and Lowell, 2006).…”

“…Many physiologic functions, as well as Pap smear-defined histopathologic signs of cervical epithelial human papillomavirus (HPV) infection and resultant cervical cancer, occur with strong seasonal patterns (Rietveld et al, 1997;Hrushesky et al, 2005Hrushesky et al, , 2006. Peak incidences (rates/1000) of HPV, premalignant and malignant cervical changes in Pap smears occur during the summer months (Rietveld et al, 1997).…”

“…Ultraviolet B not only activates many viruses, both in vitro and in vivo, including HPV (Taylor et al, 2003), which causes human cervical cancer, but also suppresses cellular immune defenses against cancer and bacterial, fungal, parasitic, and viral infections, both locally and systemically (Goettsch et al, 1993;Bos, 1997;Selgrade et al, 1997). Annual rhythms in physiologic function have also been tied to regular seasonal daylight length changes in temperate latitudes (Farner, 1985;Sposito et al, 2000;Halberg et al, 2004;Hrushesky et al, 2005;Al-Tamer et al, 2008). In addition, a wide variety of circannual rhythms in clinical symptoms and diseases, including cardiovascular morbidity and mortality, respiratory illness, sexually transmitted diseases, depressive disorders, and cancer, have been reported (cf., Sothern, 2006a), For example, breast cancer has been shown to be a seasonal disease (Cohen et al, 1983;Ross et al, 1997), and the amplitude of this annual rhythmicity increases exponentially as the population residence diverges from the equator (Oh et al, 2010).…”

All sites but skin cancer incidences analyzed worldwide by sex, age, and skin type over time (1955-2007), advancing age, and UVB dose reveals important carcinogenic drivers

“…The incidence of female breast cancer is in excellent agreement with their incidences of all sites but skin cancer. Moreover, the observed seasonality of many cancers [62][63][64][65][66][67] might reflect the hormonal seasonal fluctuations of estrogen. [68,69] Thus, our findings add epidemiological support to the already existing biochemical evidence obtained from birth control pills and hormonal replacement therapy in females suggesting a carcinogenic role for estrogen [20] in many cancers of both sexes.…”