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Kaposi's sarcoma (see Cancers of the Skin: Kaposi Sarcoma), non-Hodgkin lymphoma (see Lymphomas: Non-Hodgkin Lymphomas), and cervical cancer are AIDS-defining cancers in HIV-infected patients. Other cancers that appear to be increased in incidence or severity include Hodgkin lymphoma (especially the mixed cellularity and lymphocyte-depleted subtypes), primary CNS lymphoma, anal cancer, testicular cancer, melanoma and other skin cancers, and lung cancer. Leiomyosarcoma is a rare complication of HIV infection in children.
Non-Hodgkin lymphoma
Incidence 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, GI tract, and other sites that are unusual in non–HIV-associated non-Hodgkin lymphoma, such as the CNS and body cavities (eg, pleural, pericardial, peritoneal).
Common presentations include rapidly enlarging lymph nodes or extranodal masses or systemic symptoms (eg, weight loss, night sweats, fevers).
Diagnosis 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 CSF examination and CT or MRI of the chest, abdomen, and other areas where tumors are suspected.
Poor prognosis is predicted by the following:
Non-Hodgkin lymphoma is treated with systemic, multidrug chemotherapy (eg, cyclophosphamide, doxorubicin, and vincristine plus prednisone), usually combined with antiretrovirals, 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. Another possible treatment is IV anti-CD20 monoclonal antibody (rituximab), which is effective for non-Hodgkin lymphoma in patients without HIV. Radiation therapy may debulk large tumors and control pain or bleeding.
Primary CNS lymphoma
Incidence is markedly increased in HIV-infected patients with very low CD4 counts (see also Intracranial and Spinal Tumors: Primary Brain Lymphomas). These lymphomas consist of intermediate- or high-grade malignant B cells, originating in CNS tissue, and do not spread systemically.
Presenting symptoms include headache, seizures, neurologic deficits (eg, cranial nerve palsies), and mental status change.
Acute treatment requires control of cerebral edema and whole-brain radiation therapy. Radiographic response is common, but median survival is < 6 mo. The role of antitumor chemotherapy is unclear, but highly active antiretroviral therapy (HAART) improves survival.
Cervical cancer
In HIV-infected women, incidence 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 cancer include the following:
HIV infection does not change the management of CIN or cervical cancer. Frequent Papanicolaou tests are important to monitor for progression. HAART 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 vulva
Squamous cell cancers of the anus (see also Tumors of the GI Tract: Anorectal Cancer) and vulva (see also Gynecologic Tumors: Vulvar Cancer) are caused by the same oncogenic types of HPV as cervical cancers and occur more commonly in HIV-infected patients. The reason for the increased incidence in these patients appears to be the increased rate of high-risk behaviors (eg, anal-receptive intercourse) rather than HIV itself. 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.
Last full review/revision January 2009 by J. Allen McCutchan, MD, MSc
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