CANCERS associated with AIDS are not new diseases. They occur with low frequency in the ordinary population. Their frequency has, however, markedly increased in HIV/AIDS patients. These cancers are not only associated with HIV/AIDS but studies now show that the natural history of these cancers is altered in HIV-infected patients.
Patients tend to present more advanced disease that is more rapidly progressive and respond less well to therapy/treatment than in HIV-negative people.
Cancers develop in approximately 40 percent of AIDS patients. Cancers arise from cells that have lost control of their division process. Of the 10 or so types of cancer survivors and patients associated with AIDS , the first three are the most common and these will be discussed further in this article.
1. Kaposi's sarcoma
2. B-cell lymphoma
3. Invasive cervical carcinoma
4. Hodgkin's disease
5. Carcinoma of the orophanynx
6. Hepatocellular carcinoma
7. Carcinoma of the lung
8. Testicular tumor
9. Melanoma
Kaposi's sarcoma
Kaposi's sarcoma (KS), once a rarely reported cancer worldwide before the HIV epidemic, is the most commonly reported cancer affecting HIV-infected individuals.
The exact cause of Kaposi's sarcoma is still unknown. Some studies have implicated a sexually transmitted agent. Evidence continues to accumulate implicating the Human Herpes Virus (HHV-8).
Others have implicated certain chemicals found in the body while others doubt whether Kaposi's sarcoma is really a cancer because unlike other cancers which arise from a single cell type, Kaposi's sarcoma arises from several cell types.
Kaposi's sarcoma lesions are made up of an overgrowth of blood vessels. The highest prevalence in HIV patients occurs in homosexual men, followed by heterosexual men and lastly women.
Moritz Kaposi first described Kaposi's sarcomain the 1800s, prior to the AIDS epidemic, as a cancer of muscle and skin. Kaposi's sarcoma was relatively uncommon and three forms of the disease were recognized.
- Classic KS a chronic skin disease affecting the legs of elderly men of Mediterranean, Eastern European or Jewish descent.
- Kaposi's sarcoma that occurred endemically in parts of Central Africa and consists of benign nodular lesions.
- Iatrogenic KS (that is, caused by medical treatment) occurring in a wide spectrum of patients receiving immune suppressive agents for organ transplants, etc.
A fourth form of Kaposi's sarcoma, epidemic KS, which is AIDS-related, was recognized in 1981. The incidence of Kaposi's sarcoma continues to rise in patients with HIV infection. In AIDS patients Kaposi's sarcoma is more virulent and progressive. The exact cause of KS is not known.
Clinical presentation
Lesions of KS vary with the colour of the patient. They start off small, painless and flat. They become enlarged, raised, pink to purplish plagues on the skin and mucous surfaces, especially in the mouth.
Spread occurs to the lungs, liver, spleen, lymph nodes, digestive tract and other internal organs. In its advanced stage it may affect any area from the skull to the feet. In the mouth, the hard palate is the most common site of the KS but it may also occur on the gum line, tongue and tonsils.
KS does not usually cause death directly in HIV patients. However, bulky coetaneous lesions may become painful and can restrict movement. Lymphatic obstruction is common and can result in severe edema of the legs and face.
Rare cases of obstruction, perforation and GI bleeding have been reported. Pulmonary KS results in cough and other respiratory symptoms, including death from respiratory failure.
Finally, Kaposi's sarcoma can have enormous psychological problems due to disfiguring, particularly swelling of the face and lower limbs. Diagnosis
Careful examination of the skin and mouth at each clinic visit is the key to early diagnosis. Once lesions are identified, a biopsy for histological confirmation should be taken.
Therapy for KS is palliative, particularly because most patients do not die as a direct result of KS. Specific therapeutic goals include cosmetic improvement, relief of local symptoms — for example pain and edema — or relief of systemic complications of visceral KS.
Lymphoma
Lymphoma, a cancer of lymphoid immune cells, is the second most common cancer in HIV/AIDS and is now the seventh most common cause of death in people with AIDS. It is common in patients with swollen lymph nodes. Some cancers arise from T-cells of the immune system but the majority 95 percent originates from B-cells (B-lymphocytes).
The cause of lymphoma in patients with HIV is not know for sure but scientists link it to the presence of both Epstein-Barr virus (EBV) and Human herpes virus 8 (HHV8). This does not, however, exclude other viruses as causative agents.
Clinical presentation
The commonest sites of cancer growth are the heart and rectal area but particularly the brain, resulting in symptoms such as memory loss and confusion, fits, lethargy, headache and weakness of one side of the face. Lymphomas have however been reported in almost all other parts of the body in HIV/AIDS patients.
Approximately 75 percent of patients with AIDS-related lymphomas also present non-specific symptoms of unexplained fever, weight loss and drenching night sweats.
Diagnosis
Procedures that assist in the diagnosis of lymphomas are CT scan of the brain and abdomen, surgical biopsy and needle aspiration of tissues and fluids from suspected organs of the body. The diagnosis is then reached when the typical histologic picture is detected on examination of the specimen.
Treatment of brain lymphoma is with radiotherapy. Cancers often respond but survival is very poor beyond three months. Slight improvement has been reported with combined radiotherapy and chemotherapy.
Disease outside the brain is generally treated with chemotherapy, which again gives limited success. In fact, chemotherapy has been found to be detrimental to the immune system, resulting incidentally in accelerated progression of the HIV disease. There was a progressive decline in CD4 cell and a two-fold increase in opportunistic infections during chemotherapy. Invasive cancer of the cervix
Cervical intraepithelial neoplasia (CIN), also referred to as cervical dysplasia, are pre-cancerous lesions that lead to cancer of the cervix in females.
In normal people, the progression of CIN to invasive cancer is a slow process taking many years, affecting women between the ages of 45 and50 years. Treatment outcome in normal female patients is very favorable once detected.
However in HIV/AIDS female patients, CIN progresses more rapidly and occurs early between the ages of 16 and 40 years. It is also less responsive to treatment and has a poor prognosis (forecast). The risk of developing cancer of the cervix is greatly increased by:
- Early age at first sexual intercourse.
- History of sexually transmitted diseases.
- Multiple sexual partners.
- Immuno suppression especially infection with Human papilloma virus (HPV).
- Use of oral contraceptives.
- Cigarette smoking.
- Dietary deficiencies.
- Low socio-economic status.
- A lack of access to health care.
HPV is detected in 95 percent of all cancers of the cervix. Cancer of the cervix is considered a preventable disease; it is therefore recommend that women with HIV infection have a Pap smear more frequently than HIV-negative women.
Clinical presentation
Vaginal bleeding, especially during and after sexual intercourse, is the most common symptom of cancer of the cervix. Other symptoms include heavy bleeding, blood-stained discharge, abdominal pain, pelvic, back and leg pain, anorexia, weight loss and anemia.
A complete diagnostic study should be performed by a gynecologist. Treatment depends on the stage of the disease and includes single or combination strategies of radiotherapy and chemotherapy.
Summary
Patients with HIV infection are at a higher risk of developing many cancers such as Kaposis sarcoma (KS), lymphomas and invasive cervical cancer. Many of the cancers that occur in HIV-infected patients have a more aggressive course resulting in a shorter survival time.
