Darron R. Brown

Bio: Darron R. Brown is an academic researcher from Indiana University. The author has contributed to research in topics: Cervical cancer & HPV infection. The author has an hindex of 37, co-authored 123 publications receiving 9849 citations.

A controlled trial of a human papillomavirus type 16 vaccine.

Abstract: Background Approximately 20 percent of adults become infected with human papillomavirus type 16 (HPV-16). Although most infections are benign, some progress to anogenital cancer. A vaccine that reduces the incidence of HPV-16 infection may provide important public health benefits. Methods In this double-blind study, we randomly assigned 2392 young women (defined as females 16 to 23 years of age) to receive three doses of placebo or HPV-16 virus-like–particle vaccine (40 μg per dose), given at day 0, month 2, and month 6. Genital samples to test for HPV-16 DNA were obtained at enrollment, one month after the third vaccination, and every six months thereafter. Women were referred for colposcopy according to a protocol. Biopsy tissue was evaluated for cervical intraepithelial neoplasia and analyzed for HPV-16 DNA with use of the polymerase chain reaction. The primary end point was persistent HPV-16 infection, defined as the detection of HPV-16 DNA in samples obtained at two or more visits. The primary analys...

Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in young women: a randomised double-blind placebo-controlled multicentre phase II efficacy trial

Abstract: Summary Background A randomised double-blind placebo-controlled phase II study was done to assess the efficacy of a prophylactic quadrivalent vaccine targeting the human papillomavirus (HPV) types associated with 70% of cervical cancers (types 16 and 18) and with 90% of genital warts (types 6 and 11). Methods 277 young women (mean age 20·2 years [SD 1·7]) were randomly assigned to quadrivalent HPV (20 μg type 6, 40 μg type 11, 40 μg type 16, and 20 μg type 18) L1 virus-like-particle (VLP) vaccine and 275 (mean age 20·0 years [1·7]) to one of two placebo preparations at day 1, month 2, and month 6. For 36 months, participants underwent regular gynaecological examinations, cervicovaginal sampling for HPV DNA, testing for serum antibodies to HPV, and Pap testing. The primary endpoint was the combined incidence of infection with HPV 6, 11, 16, or 18, or cervical or external genital disease (ie, persistent HPV infection, HPV detection at the last recorded visit, cervical intraepithelial neoplasia, cervical cancer, or external genital lesions caused by the HPV types in the vaccine). Main analyses were done per protocol. Findings Combined incidence of persistent infection or disease with HPV 6, 11, 16, or 18 fell by 90% (95% CI 71–97, p Interpretation A vaccine targeting HPV types 6, 11, 16, 18 could substantially reduce the acquisition of infection and clinical disease caused by common HPV types. Published online April 7, 2005 DOI 10.1016/S1470-2045(05)70101-7

The Impact of Quadrivalent Human Papillomavirus (HPV; Types 6, 11, 16, and 18) L1 Virus-Like Particle Vaccine on Infection and Disease Due to Oncogenic Nonvaccine HPV Types in Generally HPV-Naive Women Aged 16–26 Years

Abstract: Background. Human papillomavirus (HPV)-6/11/16/18 vaccine reduces the risk of HPV-6/11/16/18-related cervical intraepithelial neoplasia (CIN) 1-3 or adenocarcinoma in situ (AIS). Here, its impact on CIN1-3/AIS associated with nonvaccine oncogenic HPV types was evaluated. Methods. We enrolled 17,622 women aged 16-26 years. All underwent cervicovaginal sampling and Pap testing at regular intervals for up to 4 years. HPV genotying was performed for biopsy samples, and histological diagnoses were determined by a pathology panel. Analyses were conducted among subjects who were negative for 14 HPV types on day 1. Prespecified analyses included infection of >= 6 months' duration and CIN1-3/AIS due to the 2 and 5 most common HPV types in cervical cancer after HPV types 16 and 18, as well as all tested nonvaccine types. Results. Vaccination reduced the incidence of HPV-31/45 infection by 40.3% (95% confidence interval [CI], 13.9% to 59.0%) and of CIN1-3/AIS by 43.6% (95% CI, 12.9% to 64.1%), respectively. The reduction in HPV-31/33/45/52/58 infection and CIN1-3/AIS was 25.0% (95% CI, 5.0% to 40.9%) and 29.2% (95% CI, 8.3% to 45.5%), respectively. Efficacy for CIN2-3/AIS associated with the 10 nonvaccine HPV types was 32.5% (95% CI, 6.0% to 51.9%). Reductions were most notable for HPV-31. Conclusions. HPV-6/11/16/18 vaccine reduced the risk of CIN2-3/AIS associated with nonvaccine types responsible for similar to 20% of cervical cancers. The clinical benefit of cross-protection is not expected to be fully additive to the efficacy already observed against HPV-6/11/16/18-related disease, because women may have >1 CIN lesion, each associated with a different HPV type. (Less)

Impact of Human Papillomavirus (HPV)-6/11/16/18 Vaccine on All HPV-Associated Genital Diseases in Young Women

Abstract: Results The average follow-up was 3.6 years (maximum of 4.9 years). In the population that was negative to 14 HPV types, vaccination was up to 100% effective in reducing the risk of HPV16/18-related high-grade cervical, vulvar, and vaginal lesions and of HPV6/11-related genital warts. In the intention-to-treat group, vaccination also statistically significantly reduced the risk of any high-grade cervical lesions (19.0% reduction; rate vaccine = 1.43, rate placebo = 1.76, difference = 0.33, 95% confidence interval [CI] = 0.13 to 0.54), vulvar and vaginal lesions (50.7% reduction; rate vaccine = 0.10, rate placebo = 0.20, difference = 0.10, 95% CI = 0.04 to 0.16), genital warts (62.0% reduction; rate vaccine = 0.44, rate placebo = 1.17, difference = 0.72, 95% CI = 0.58 to 0.87), Pap abnormalities (11.3% reduction; rate vaccine = 10.36, rate placebo = 11.68, difference = 1.32, 95% CI = 0.74 to 1.90), and cervical definitive therapy (23.0% reduction; rate vaccine = 1.97, rate placebo = 2.56, difference = 0.59, 95% CI = 0.35 to 0.83), irrespective of causal HPV type. Conclusions High-coverage HPV vaccination programs among adolescents and young women may result in a rapid reduction of genital warts, cervical cytological abnormalities, and diagnostic and therapeutic procedures. In the longer term, substantial reductions in the rates of cervical, vulvar, and vaginal cancers may follow.

Global cancer statistics

Abstract: The global burden of cancer continues to increase largely because of the aging and growth of the world population alongside an increasing adoption of cancer-causing behaviors, particularly smoking, in economically developing countries. Based on the GLOBOCAN 2008 estimates, about 12.7 million cancer cases and 7.6 million cancer deaths are estimated to have occurred in 2008; of these, 56% of the cases and 64% of the deaths occurred in the economically developing world. Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among females, accounting for 23% of the total cancer cases and 14% of the cancer deaths. Lung cancer is the leading cancer site in males, comprising 17% of the total new cancer cases and 23% of the total cancer deaths. Breast cancer is now also the leading cause of cancer death among females in economically developing countries, a shift from the previous decade during which the most common cause of cancer death was cervical cancer. Further, the mortality burden for lung cancer among females in developing countries is as high as the burden for cervical cancer, with each accounting for 11% of the total female cancer deaths. Although overall cancer incidence rates in the developing world are half those seen in the developed world in both sexes, the overall cancer mortality rates are generally similar. Cancer survival tends to be poorer in developing countries, most likely because of a combination of a late stage at diagnosis and limited access to timely and standard treatment. A substantial proportion of the worldwide burden of cancer could be prevented through the application of existing cancer control knowledge and by implementing programs for tobacco control, vaccination (for liver and cervical cancers), and early detection and treatment, as well as public health campaigns promoting physical activity and a healthier dietary intake. Clinicians, public health professionals, and policy makers can play an active role in accelerating the application of such interventions globally.

Patterns of Cancer Incidence, Mortality, and Prevalence Across Five Continents: Defining Priorities to Reduce Cancer Disparities in Different Geographic Regions of the World

Abstract: Efforts to reduce global cancer disparities begin with an understanding of geographic patterns in cancer incidence, mortality, and prevalence. Using the GLOBOCAN (2002) and Cancer Incidence in Five Continents databases, we describe overall cancer incidence, mortality, and prevalence, age-adjusted temporal trends, and age-specific incidence patterns in selected geographic regions of the world. For the eight most common malignancies-cancers of lung, breast, colon and rectum, stomach, prostate, liver, cervix, and esophagus-the most important risk factors, cancer prevention and control measures are briefly reviewed. In 2002, an estimated 11 million new cancer cases and 7 million cancer deaths were reported worldwide; nearly 25 million persons were living with cancer. Among the eight most common cancers, global disparities in cancer incidence, mortality, and prevalence are evident, likely due to complex interactions of nonmodifiable (ie, genetic susceptibility and aging) and modifiable risk factors (ie, tobacco, infectious agents, diet, and physical activity). Indeed, when risk factors among populations are intertwined with differences in individual behaviors, cultural beliefs and practices, socioeconomic conditions, and health care systems, global cancer disparities are inevitable. For the eight most common cancers, priorities for reducing cancer disparities are discussed.

The global health burden of infection-associated cancers in the year 2002.

Abstract: Several infectious agents are considered to be causes of cancer in humans. The fraction of the different types of cancer, and of all cancers worldwide and in different regions, has been estimated using several methods; primarily by reviewing the evidence for the strength of the association (relative risk) and the prevalence of infection in different world areas. The estimated total of infection-attributable cancer in the year 2002 is 1.9 million cases, or 17.8% of the global cancer burden. The principal agents are the bacterium Helicobacter pylori (5.5% of all cancer), the human papilloma viruses (5.2%), the hepatitis B and C viruses (4.9%), Epstein-Barr virus (1%), human immunodeficiency virus (HIV) together with the human herpes virus 8 (0.9%). Relatively less important causes of cancer are the schistosomes (0.1%), human T-cell lymphotropic virus type I (0.03%) and the liver flukes (0.02%). There would be 26.3% fewer cancers in developing countries (1.5 million cases per year) and 7.7% in developed countries (390,000 cases) if these infectious diseases were prevented. The attributable fraction at the specific sites varies from 100% of cervix cancers attributable to the papilloma viruses to a tiny proportion (0.4%) of liver cancers (worldwide) caused by liver flukes.