Are HIV-Infected Persons at a Higher Risk for Certain Types of Cancer Comparative to the General Population - Article Example

Are HIV-Infected Persons at a Higher Risk for Certain Types of Cancer Comparative to the General Population?Health Outcome of Interest: The research interest is comparing health outcomes in cancer incidences among HIV infected individuals and those who are not HIV infected. The research identifies a group of subjects with HIV and variant Cancer types and an unaffected group who constitute the control group then compares their past exposure to the factors of interest. Exposure(s) of Interest: The research interests cover a number of exposures aimed at relating HIV/Aids with different cancer types inclusive of anal, vaginal, liver, leukemia, colorectal, renal, Hodgkin lymphoma, melanoma, oropharyngeal and liver.

Type of Study: The study type is prospective observational cohort study undertaken between 1992 and 2003. Description/Ascertainment of Cohort: Subjects included in the study were 54, 780 HIV- infected persons in the Adult and Adolescent HIV disease project and 6948 HIV positive outpatients. The subjects were subjected to 2 large prospective cohort studies; the Adult and Adolescent Spectrum of HIV Disease (ASD) project and the HIV Outpatient Study (HOPS). Data Collection at Baseline: 12 month initial medical review was conducted by the researchers to establish the characteristics of the subjects of study.

During this period a total of 60,000 HIV infected persons were observed with over 180,000 persons-years of observation. The HOPS study was conducted at 9 HIV specialty clinics in 8 US cities with the data being gathered electronically from physician-patient interactions. Of interest to the researchers included; symptoms, diagnoses, CD4 lymphocyte counts, laboratory test results and socio-demographic characteristics. Type, Frequency and Duration of Follow-Up:For the HOPS project, investigators conducted follow-up medical reviews after a six month period.

With the total study population of 54, 780 HIV-infected persons, median follow-up times were 2.0 and 2.6 years in the ASD and the HOPS projects respectively. Type of Data Analysis: Standardized Rate Ratios (SRRs) was used during data analysis to compare cancer incidences within the HIV infected population together with standardized cancer incidence within the general population. Multivariable Poisson regression was used to evaluate the trends of specific cancer types in HIV infected population.

Results/Main Findings of Study:  The study found that the incidence of a number of non-Aids defining cancer was higher within the HIV infected population comparative to the general population. The combined HOPS and ASD project identified 3550 cancer incidents of which 80% (2842) of the cases were Aids defining and the remaining 20% non-Aids defining cancer types. Subjecting specific cancer cases to Standardized rate ration (SRR), the results were; 42.9, 21.0, 14.7, 7.7, 3.3, 2.6, 2.5, 2.3, and 1.

8 for anal, vaginal, Hodgkin lymphoma, liver, lung, melanoma, oropharyn- geal, leukemia, colorectal and renal cancer types respectively. Standardized rate ratio for prostrate cancer was found to be relatively lower at 0.6. Assessment of Bias : Based on the methods used, there existed potential bias in underestimating the standardized rate ratio hence rate disparities. This is because there were generally reduced chances of ascertaining cancer within the study population.Assessment of Confounders: A number of confounders were identified during the study.

Case ascertainment standard for SEER, ASD and HOPS were 98%, 75% and 85% respectively, hence had the potential of underestimating standardized rate ratio. Multivariate analysis served to control confounding.Comments:  The study concludes that the study revealed that the incidence of a number of non-Aids defining cancer was found to be higher within the HIV-infected persons comparative to the general population. Article Citation: Patel, P., Hanson, D. L., Sullivan, P. S., Novak, R. M., Moorman, A. C., Tong, C. T., Holmberg, S. D., & Brooks, J. T. (2008) ‘Incidence of Types of Cancer Among HIV-Infected Persons Compared with the General Population in the United States, 1992-2003.

’ Annals of Internal Medicine, 148: 728-736