Background The aims of this study were to investigate the cancer incidence and risk in HIV/AIDS patients relative to the general population in Taiwan. Methods Using Taiwan’s National Health Insurance Research Database, 15,269 HIV/AIDS patients were identified between 1998 and 2009. Gender-specific incidence densities (IDs) of both AIDS-defining cancers (ADC) and non-AIDS-defining cancers (NADC) after HIV infection were calculated. Age-, sex- and period-adjusted standardized incidence rates (SIRs) were obtained using 1.8 million people from the general population as controls. Results A total of 1,117 male and 165 female HIV/AIDS patients were diagnosed with cancer. Non-Hodgkin lymphoma (n=196; ID=328.79/100,000 person-years) and cervical cancer (n = 50; ID = 712.08/100,000 person-years) were the most common ADCs, while liver cancer (n=125; ID=184.52/100,000 person-years) and colon cancer (n=11; ID=156.66/100,000 person-years) were the most common NADCs in males and females, respectively. Period-adjusted gender-specific ADC and NADC rates decreased from more than 1,500 cases/100,000 person-years to less than 500 cases/100,000 person-years (p <0.001 for trend). SIRs of ADCs and NADCs also decreased. However, relative to the general population, increased SIRs were still seen for most cancers, many of which had an infectious etiology. The highest SIRs in ADCs and NADCs were seen in Kaposi's sarcoma (SIR=298.0, 95%CI=258.16, 343.85) and anal cancer (SIR=19.10, 95%CI=12.80, 27.50). Conclusion This study showed that although the cancer incidence rates have significantly decreased in the HAART era, HIV/AIDS patients were still at increased risk of ADCs and most NADCs. Cancer screening, especially for infection-related NADCs, should therefore be promoted.

The number of men who have sex with men (MSM) infected with HIV-1 in Taiwan has increased rapidly in the past few years. The goal of this study was to conduct a molecular epidemiological study of HIV-1 infection among MSM in Taiwan to identify risk factors for intervention. Voluntary counseling program and anonymous testing were provided to patrons at 1 gay bar, 7 night clubs and 3 gay saunas in Taipei and New Taipei Cities in 2012. HIV-1 subtypes were determined using gag subtype-specific PCR and phylogenetic analysis by env sequences. Recent HIV-1 infection was determined using LAg-Avidity EIA. In-depth interviews and questionnaires were used to identify risk factors. The prevalence and incidence of HIV-1 among MSM in Taiwan were 4.38% (53/1,208) and 3.29 per 100 person-years, respectively. Of 49 cases genotyped, 48 (97.9%) were infected with subtype B and 1 with CRF01_AE (2%). Phylogenetic analysis of 46 HIV-1 strains showed that 25 (54.4%) subtype B strains formed 9 clusters with each other or with other local strains. The CRF01_AE case clustered with a reference strain from a Thai blood donor with bootstrap value of 99. Multivariate logistic regression analysis showed that risk factors associated with HIV-1 infection included use of oil-based solution as lubricant (vs. saliva or water-based lubricants, OR= 4.23; p <0.001); exclusively receptive role (vs. insertive role, OR= 9.69; p <0.001); versatile role (vs. insertive role, OR= 6.45; p= 0.003); oral sex (vs. insertive role, OR= 11.93; p= 0.044); times of sexual contact per week (2-3 vs. zero per week, OR= 3.41; p= 0.021); illegal drug use (OR= 4.12; p <0.001); and history of sexually transmitted diseases (OR= 3.65; p= 0.002). In conclusion, there was no new HIV-1 subtype or circulating recombinant form responsible for the increase of HIV-1 among MSM in Taiwan in 2012. Misuse of oil-based solution as lubricant is a new risk factor identified among MSM in Taiwan. The Taiwan’s Centers for Disease Control has created a video (www.youtube.com/watch?v=BinExvvOTMM&feature=iv&src_vid=BW81-PfmY3E&annotation_id=annotation_2436493705) to correct such misconception in its AIDS prevention campaign.