AIDS-defining cancers in HIV-infected patients are
Lymphoma, immunoblastic (or equivalent term)
Lymphoma, primary, of central nervous system
Cervical cancer, invasive
Other cancers that appear to be dramatically increased in incidence or severity include
Hodgkin lymphoma (especially the mixed cellularity and lymphocyte-depleted subtypes)
Other skin and superficial eye cancers
Leiomyosarcoma is a rare complication of HIV infection in children. Also, the rates of other common cancers (eg, lung, head and neck, and cervical carcinomas; hepatomas) are several times higher in HIV-infected patients than in the general population. This finding may reflect, at least in part, greater exposure to the viruses or toxins that cause these cancers: hepatitis B and C for hepatoma, human papillomavirus for cervical, anal, penile, and oropharyngeal carcinoma, and alcohol and tobacco for lung and head and neck carcinomas.
(See also Human Immunodeficiency Virus (HIV) Infection.)
Incidence of non-Hodgkin lymphoma is 50 to 200 times higher in HIV-infected patients. Most cases are B-cell, aggressive, high-grade histologic subtype lymphomas. At diagnosis, extranodal sites are usually involved; they include bone marrow, gastrointestinal tract, and other sites that are unusual in non–HIV-associated non-Hodgkin lymphoma, such as the central nervous system and body cavities (eg, pleural, pericardial, peritoneal).
Common presentations include rapidly enlarging lymph nodes or extranodal masses and systemic symptoms (eg, weight loss, night sweats, fevers).
Diagnosis of non-Hodgkin lymphoma is by biopsy with histopathologic and immunochemical analysis of tumor cells. Abnormal circulating lymphocytes or unexpected cytopenias suggest involvement of the bone marrow, mandating bone marrow biopsy. Tumor staging may require cerebrospinal fluid examination and CT or MRI of the chest, abdomen, and other areas where tumors are suspected.
Poor prognosis is predicted by the following:
Treatment of non-Hodgkin lymphoma is with various regimens of systemic, multidrug chemotherapy that includes cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide. These drugs are combined with IV rituximab and an anti-CD20 monoclonal antibody and supplemented with antiretroviral therapy (ART), prophylactic antibiotics and antifungals, and hematologic growth factors. Therapy may be limited by severe myelosuppression, particularly when combinations of myelosuppressive antitumor or antiretroviral drugs are used. Radiation therapy may debulk large tumors and control pain or bleeding.
Incidence of primary central nervous system lymphoma is markedly increased in HIV-infected patients with very low CD4 counts.
Primary central nervous system lymphomas consist of intermediate- or high-grade malignant B cells, originating in central nervous system tissue. These lymphomas do not spread systemically, but the prognosis is poor; median survival is < 6 months.
Presenting symptoms include headache, seizures, neurologic deficits (eg, cranial nerve palsies), and mental status changes.
Acute treatment of primary central nervous system lymphomas requires control of cerebral edema using corticosteroids. Although whole-brain radiation therapy and antitumor chemotherapy with high-dose methotrexate alone or combined with other chemotherapy drugs or rituximab are commonly used, none of these regimens has been rigorously evaluated. In observational studies of ART and in a single clinical trial of rituximab, survival appeared improved.
In HIV-infected women, prevalence of human papillomavirus (HPV) infection is increased, oncogenic subtypes (types 16, 18, 31, 33, 35, and 39) persist, and the incidence of cervical intraepithelial dysplasia (CIN) is up to 60%, but increased incidence of cervical cancer has not been proved. However, cervical cancers, if they occur, are more extensive, are more difficult to cure, and have higher recurrence rates after treatment.
Confirmed risk factors for cervical cancer in HIV-infected women include the following:
Management of CIN or cervical cancer is not changed by HIV infection. Frequent Papanicolaou tests are important to monitor for progression. ART may result in resolution of HPV infection and regression of CIN but has no clear effects on cancer.
Squamous cell cancer of the anus and squamous cell cancer of the vulva are caused by the same oncogenic types of HPV as cervical cancers and occur more commonly in HIV-infected patients. The increased incidence of anal intraepithelial neoplasia and cancers in these patients appears to be caused by both high-risk behaviors (eg, anal-receptive intercourse) and immunosupression by HIV; ART may decrease risk of progression.
Anal dysplasia is common, and squamous cell cancers can be very aggressive.
Treatments include surgical extirpation, radiation therapy, and combined chemotherapy with mitomycin or cisplatin and 5-fluorouracil.