Immunocompromised patients have a weakened immune system and so a reduced ability to fight infections and other diseases. This state may be caused due to certain diseases or conditions, such as AIDS, cancer, diabetes, malnutrition, and certain genetic disorders. It may also be caused by certain medicines or treatments, such as anticancer drugs, radiation therapy, and stem cell or organ transplant.
Also a large population of women are immunocompromised, approximately 17 million women worldwide are HIV-infected, others are solid organ transplant recipients and patients with conditions such as systemic lupus erythematosus (SLE), inflammatory bowel disease (IBS), and other conditions requiring chronic immunosuppressive therapies. The data also suggest that the immunocompromised populations are at higher risks for HPV-related cancers.
A senior investigator of DCEG Eric A. Engels, M.D., M.P.H. (Infections and Immunoepidemiology Branch) IIB, leads the Transplant Cancer Match (TCM) Study and the HIV/AIDS Cancer Match (HACM) Study, two large and complementary registry linkage studies on cancer among immunosuppressed populations. DCEG is a Division of Cancer Epidemiology and Genetics (DCEG) is a research program of the National Cancer Institute (NCI), one of the National Institutes of Health (NIH).
In 1980, the influence of the HIV epidemic on cancer was first observed. Several studies have examined how oncogenic viruses and other opportunistic infections affect individuals with compromised immune systems. In recent decades the organ transplants have increased for certain organ types and recipients have to take immunosuppressive drugs for whole life lives to prevent organ rejection.
In a study of Journal of the American Medical Association 2011, authors assessed linked registry data from 175,732 solid organ transplant recipients. These recipients represented roughly 40 percent of the U.S. transplant recipient population between 1987 and 2008. The study measured the risk of individual cancer types among recipients of all types of organs. Among transplant recipients a twofold increased risk of cancer was found. This study allowed the investigators to evaluate the risk of rare cancer types. 32 different types of cancer, including some which are not associated with HIV and immunosuppression were noted. The four most common cancers noted were non-Hodgkin lymphoma (NHL) and cancers of the lung, kidney, and liver. NHL also is common among HIV-infected individuals and is associated with immunosuppression and Epstein-Barr virus. Whereas liver cancer is associated with hepatitis B and C. However, researchers do not generally believe that lung and kidney cancers are associated with infection.
DCEG’s HACM Study is an example of a unique resource that has permitted the examination of cancer trends among the HIV and AIDS population over time. James J. Goedert, M.D. (IIB), and Dr. Robert Biggar (formerly of DCEG) initiated the HACM Study in 1990. The study now links data from 14 state and metropolitan HIV/AIDS registries across the United States with corresponding cancer registries. DCEG researchers have been able to show how AIDS-related cancer trends in the United States have changed since the HIV epidemic began, including the impact of the introduction of highly active antiretroviral therapy in 1996, through the mid-2000s.
DCEG work is focusing on the long-term effects of chronic HIV infection and the ways in which cancer affects individuals with HIV as they age. In 2011 Journal of the National Cancer Institute, published a study which showed that the number of AIDS-defining cancers (Kaposi sarcoma, NHL, and cervical cancer) has declined threefold (from 34,580 to 10,320 cases), while the number of other non–AIDS-defining cancers has tripled (from 3,200 to 10,000 cases).
Immunization has also been reported in the protection of immunocompromised patients. Currently, vaccines for 2 carcinogenic viruses oncogenic human papillomavirus (HPV) types and hepatitis B are recommended specifically because they are protective against cancer. Several other vaccines recommended for the general population are particularly important for patients with cancer as well as cancer survivors, because they reduce the probability of complications during and after treatment.
A study recently in the United States estimated that between 2001 and 2005, 28 percent of anal cancer cases in men and 1 percent of cases in women occurred among the HIV-infected population. Anal cancer is rare in the United States, but its rates have been rising steadily for several decades. The large size of the HACM Study benefits by allowing investigators to estimate general population incidence rates with and without HIV-infected cases. Also it showed for the first time that the rates of anal cancer over time in men have been influenced substantially by HIV-infected cases.
Other infections like that of central nervous system (CNS) are infrequently diagnosed in immunocompetent patient. They do occur in patients receiving solid organ transplants (SOT) or with hematological disorders including those with hematopoietic stem cell transplantation (HSCT). CNS infections in immunocompromised patients remains challenge for its diagnosis and management. It also requires constant attention to emerging infections, prophylactic strategies, transfusion safety issues, epidemiologic trends, travel histories, changing microbial susceptibilities, synergistic infections, and evolving cancer regimens or anti-rejection drugs that will continue to impact the nervous system. The possibility of two or more disparate diseases (neoplastic, infectious and autoimmune) may exist concurrently. Despite efforts to stratify patients by risk factors, clinical syndromes, and appropriate diagnostic studies, diagnostic and therapeutic dilemmas are common. Despite the neuroinfectologist’s best efforts outcomes remain frequently disappointing.
Major causes of morbidity and mortality in patients with cancer are infections. Certain cancers are intrinsically associated with immunocompromised state of the patient. Immunosuppressive chemotherapy is principally related to the infection. A patient may have multiple predisposing factors that increase the spectrum of likely pathogens. Diagnostic evaluation and management of infections are very important.
Examining cancer trends in a large registry-based resources will be critical for understanding cancer risk in immunosuppressed populations as evident from earlier studies. Still there is a lot needs to be explored trying to learn about what is driving the increased risk for certain cancers.
References
- UNAIDS Reports on the global AIDS epidemic 2012. Available at: http://www. unaids.org/en/media/unaids/contentassets/documents/epidemiology/2012/gr2012/20121120_UNAIDS_Global_Report_2012_with_annexes_en.pdf. Accessed January 15, 2013.
- HIV among women. Center for Diseases and Prevention-National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention. Available at: http://www.cdc.gov/Features/WomenGirlsHIVAIDS/. Accessed January 15, 2013.
- Meeuwis KA, Melchers WJ, Bouten H, et al. Anogenital malignancies in women after renal transplantation over 40 years in a single center. Transplantation 2012;93(9):914–22.
- Porreco R, Penn I, Droegemueller W, et al. Gynecologic malignancies in immunosuppressed organ homograft recipients. Obstet Gynecol 1975;45(4):359–64.
- Levin SN, Lyons JL. Infections of the Nervous System. Am J Med. 2018; 131 (1): 25-32. PMID: 28889928 DOI: 10.1016/j.amjmed.2017.08.020 3.
- Fishman JA. Infection in Organ Transplantation. Am J Transplant 2017; 17 (4): 856-79. PMID: 28117944 DOI: 10.1111/ajt.14208