INVASIVE CERVICAL CANCER AMONG HIGH-RISK WOMEN: SPATIAL EPIDEMIOLOGY, SCREENING AND ORAL INFECTION
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Background: In spite of the general decline in cervical cancer incidence and the highly preventable nature of this cancer, new cases and deaths are recorded annually in Maryland and in other parts of the United States. Using the cancer care continuum and the Human Papillomavirus (HPV) carcinogenesis process as guiding frameworks, this research evaluated the prevention and control of invasive cervical cancer (ICC) among the subgroups at highest risk for disease. Methods: In Aim 1 using registry data we evaluated space-time variation in ICC incidence over a 10-year period at the county level within the state of Maryland. For Aim 2 we longitudinally assessed utilization and determinants of Pap testing among women living with HIV (WLWH) seen at Johns Hopkins Hospital over a 10-year period. Finally, in Aim 3 using data from HIV positive and high-risk HIV negative women enrolled in the Women’s Interagency Health Study (WIHS) cohort, we examined the determinants and risk conferred by prevalent type-specific cervical HPV infections on the acquisition of oral HPV infections. Results: Aim 1- The overall average annual crude and adjusted state ICC rate between 2003-2012 for Maryland was 7.3 per 100,000. Upon adjusting for contextual differences including median income, age and Pap testing rates at the county level, the average annual adjusted ICC incidence rate in Maryland for this period was 9.2 per 100,000. Within this period, 2003-2012, we identified some clusters with significantly different ICC incidence rates than rates observed in the rest of the state. These included both clusters of significantly lower and higher than expected incidence rates (p-value ≤0.05). Two of the 3 significant clusters of higher than expected ICC incidence rates identified occurred in a more recent time period, 2009-2012. The third significant cluster of high rates was observed in an earlier period, 2005-2008. Aim 2- Our findings showed that although most WLWH (79%) in clinical care receive Pap testing, some women (21%) are not screened and others (5%) consistently receive Pap testing at intervals longer than recommended. WLWH with a decreased likelihood of screening included older women, injection drug users, white women and those who had lived for a longer time with HIV. Aim 3- Factors associated with an increased risk of incident oral HPV infection included a recent history of sexual activity with either a male (adjusted hazard (aHR)=2.47, 95%CI: 1.02-6.01) or female partner (aHR=2.79, 95%CI: 1.14, 6.79) as well as a recent history of performing oral sex (aHR=1.75, 95%CI: 1.16, 2.62). No association was observed with type-specific cervical HPV infection, age, alcohol or condom use during oral sex. Conclusions: Although ICC rates have declined over time, there are still some counties experiencing an anomalously high ICC incidence rate. The recent clusters of high ICC incidence rates identified need to be prioritized and investigated further, while the clusters of low incidence rates identified may represent areas of successful prevention and control within the state of Maryland. The determinants of Pap testing identified in Aim 2 present potential targets in an urban HIV care setting for closer monitoring and directed interventions to improve Pap test adherence among WLWH. Findings for Aim3 suggest that having a prevalent cervical HPV infection does not increase the risk of an incident type-specific oral HPV infection; however, sexual activity remains a significant risk factor for acquiring oral HPV infections.