Patterns of malignancies in patients with HIV-AIDS: a single institution observational study

Discussion

In 2015, a report from the Indian government estimated the prevalence of HIV in the country as 0.26% (0.22%-0.32%).⁵ The report also noted a decreasing trend in the number of new cases of HIV diagnosed and a decrease in the number of AIDS-related deaths.⁵ The decrease in deaths from AIDS is primarily attributed to the widespread use of HAART. With the introduction of HAART therapy, the survival of patients diagnosed with HIV-AIDS has increased markedly.⁶ However, newer challenges have emerged with improved survival, such as an increasing number of patients being diagnosed with malignancies. In the current HAART era, the pattern of malignancies in people living with HIV-AIDS has changed compared with the pre-HAART era.⁷ The literature suggests that worldwide, malignancies are encountered in about 30% patients with HIV-AIDS, but that percentage differs sharply from that encountered in India, where it is less than 5%.⁸ This may partly be explained by opportunistic infections such as tuberculosis in Indian patients, which remains the leading cause of death in the HIV-AIDS population. In our study, we retrospectively analyzed the pattern of malignancies in patients with HIV-AIDS.

Although few studies have quoted NHL as the predominant malignancy in their patients with HIV-AIDS, the predominant malignancy was cervical cancer in our patient population, as seen in few other studies.^8-10 Head and neck malignancies also continue to be common malignancies in men with HIV-AIDS.¹⁰ Thus, an increase in malignancies induced by the human papillomavirus (HPV) can be seen in this group of patients. Only a few pediatric malignancies were noted in our study, and all of those patients had a vertical transmission of HIV.

Kaposi sarcoma is quite rare in the Indian population, and no case of Kaposi sarcoma was diagnosed in our study population. A similar finding was seen in several earlier publications from India. In the largest published series from India by Dhir and colleagues, evaluating 251 patients with HIV-AIDS and malignancy, no case of Kaposi sarcoma was reported.¹⁰ The authors mentioned that this finding might be because of the low seroprevalence of Kaposi sarcoma-associated herpesvirus in the Asian population.¹⁰ Three different studies from southern India have also not reported the incidence of Kaposi Sarcoma in their series of HIV-AIDS patients with malignancies,^11-13 and similar findings were also reported in a study from northern India.⁹ The incidence of other immunodeficiency-related malignancies was identical to those reported in other studies in the literature.^10,14

As seen in other studies, the CD4 counts in patients with ADM were significantly lower compared with those of patients with NADM, and that difference was not seen when CD4 counts of patients with cervical cancer were compared with patients in the NADM subgroup. The risk of NHL increases proportionally to the degree of immune suppression. The increased susceptibility to various infections in patients with low CD4 counts may also contribute to the occurrence of NHL in patients with low CD4 counts. The occurrence of various other rare cancers in patients with HIV-AIDS may be because of confounding rather than a direct HIV or immunosuppression effect.

An increasing incidence of NADMs has been noted in the Western literature.^7,14 ADMs remain the most common malignancies in the HIV-AIDS population, accounting for about 48% of all malignancies.⁸ This is in concordance with previous publications from India.^8,10 With the widespread availability of generic HAART, the incidence of ADMs may decrease even more in the future. In developing countries where the screening procedures for malignancies in both the general population and patients with HIV-AIDS have not yet been implemented at a national level, premalignant lesions of the cervix are not detected.¹⁰ Cervical cancer is the most common malignancy in our study population, which underscores the importance of cervical cancer screening in patients with HIV-AIDS.

In the developed countries, following the introduction of HAART in HIV-AIDS management, the incidence of Kaposi sarcoma decreased by 60% to 70%, and the incidence of NHL decreased by 30% to 50%, whereas the rates of cervical cancer remained either stable or declined.^15,16 Despite the declining trend, the incidence of these malignancies continues to be high among patients with HIV-AIDS compared with the general population.¹⁷ A study from the United States showed increasing trends in various NADMs (such as anal, lung, and liver cancers and Hodgkin lymphoma) from 2006 to 2010.¹⁷ In 2003, the number of patients with NADM were higher than the number of patients with ADM in the United States.¹⁴ In a population-based study from Brazil, ADMs were the most common malignancies diagnosed in patients with HIV-AIDS. A declining trend was noted in the incidence of ADMs in the population and an increasing trend in the incidence of NADMs. This increase in NADM incidence was contributed by anal and lung cancers.¹⁸ Studies from developing countries such as Uganda and Botswana have also shown a decrease in the incidence of Kaposi sarcoma after the introduction of HAART.^19-21

Kaposi sarcoma, cervical cancer, NHL (including Burkitt lymphoma, immunoblastic lymphoma, and primary CNS lymphoma [PCNSL]) comprise ADMs. All 3 ADMs have an underlying viral infection as the causative agent.²² Kaposi sarcoma is caused by the Kaposi sarcoma herpes virus, for which seroprevalence varies worldwide.²³ As already noted in this article, the incidence of Kaposi sarcoma among the HIV-AIDS population has decreased worldwide since the introduction of HAART. The preinvasive uterine cervix lesions and carcinoma cervix are caused by HPV. NHL in patients with HIV-AIDS is a predominantly aggressive B-cell neoplasm. Epstein-Barr virus is implicated for most of the ADM NHLs.²⁴ PCNSL occurs in patients with low CD4 counts and poses a diagnostic challenge. The treatment outcomes for patients with PCNSL before the HAART era were dismal. With the widespread use of HAART, the treatment outcomes of patients with HIV-AIDS and NHL improved, and, currently, these patients are managed the same way as other patients with NHL.²²

The increasing incidence of the NADM is partly attributed to the increasing incidence of these malignancies in the general population. An elevated risk of certain NADMs is also attributable to viral infections. The common NADMs in the United States are lung, anal, oropharyngeal, and hepatocellular cancers and Hodgkin lymphoma.¹⁴ The common NADMs in our study population were oral, oropharyngeal, colon, and breast cancers and Hodgkin lymphoma. One-third of head and neck cancers, including most oropharyngeal cancers, and cervical and anal cancers in patients with HIV-AIDS are related to HPV.²⁵ Patients with HIV-AIDS are at increased risk for chronic HPV infection from immunosuppression. Chronic HPV infections and prolonged immunosuppression cause premalignant high-grade squamous intraepithelial lesions and invasive cancers.²² The initiation of and adherence to HAART leads to immune recovery and reduces high-risk HPV-associated morbidity.²⁶ Findings from previous studies have demonstrated the benefits of screening for cervical cancer in patients with HIV-AIDS.²⁷ The HPV vaccine is immunogenic in patients with HIV-AIDS and might help prevent HPV-associated malignancies.²⁸