Introduction

Kaposi's Sarcoma (KS) is a vascular tumor that can affect any part of the body. Though called a sarcoma, some schools do not consider it a neoplastic tumor for the following reasons: It has a multifocal origin, runs a low indolent course with few mitotic features and does not spread by metastases, instead it does by extension. It was first described in 1872 by Moriez Kaposi, a Hungarian Dermatologist (₁). The first case of KS in Cameroon was described in 1922(₂). Before this time the tumor was thought to be absent in Africans. In classic and endemic KS, more males are affected. (₂,₃,₄) Immune suppression associated or iatrogenic KS is seen in organ recipients and patients on immune suppressive therapy for a variety of medical conditions. KS associated with HIV infection is the last to be described. This tumor was first described in patients, who were later found to be HIV positive in 1981 in New York (₅). HIV associated KS is a major cause of morbidity and mortality in HIV/AIDS patients. The characteristic clinical presentation are flat topped nodular-macular lesions with dark brown to purple color, involving lymph nodes, viscera, skin and mucosa. There are macules and nodules of different sizes, infiltrative plaques, florid ulcerated lesions, fungating lesions and lymphadenopathic types with lymphedema and lymph node involvement. KS is an AIDS defining cancer. The prevalence in western countries varies from 0-30%(₆). In certain tropical countries the prevalence of HIV associated KS has been found to be below 10% (₆, ₇, ₈, ₉) However, there are strong regional variations. Viroj et al found no case of KS in their Thai series; while Nnoruka et al in Nigeria and Stebbing et al in the UK found 3.3 % and 6% respectively (₇,₈,₉,₁₀). In Cameroon, neither the prevalence nor the characteristics of the tumor have been documented.

The purpose of this cohort study was to evaluate and describe the clinical characteristics of and the prevalence of HIV/AIDS associated KS in Cameroon. This study was carried out at the University Teaching Hospital Yaoundé between January and December 2005.

Material And Methods

All case notes of patients with HIV/AIDS associated KS in the Department Of Medicine of the University Hospital were studied. We collected 1700 HIV positive patient records seen by the Dermatology Department at the University Teaching Hospital between January and December 2005. Of these 1,700 patients, 165 patients with confirmed Kaposi's Sarcoma were included in the study. Data collected included, demographic information, site of lesions, duration of lesions, and delay in presentation. Treatment received and outcome were also documented. Patients were monitored for durations ranging from four weeks to four years.

Results

Among the 1700 HIV/AIDS patients who were seen during this period, 165 (9.7%) had HIV associated KS. KS was the presenting problem in 123/165 of HIV positive patients (75%). The delay before presentation was three to six months.

There were 75 males and 90 females. Their ages ranged from 20 to 65 years (Table 1). The age group most affected was 25 to 44 years (n =115) representing 69.7 % of all cases.

Figure 1

Table 1: Age Distribution

Ninety patients (55%) had generalized disease. Forty-eight had lesions on the limbs, 5 had pulmonary lesions, and 5 had lesions in the gastrointestinal tract (GIT). Other sites included the eyes, genitalia, palate and tongue (Table 2). Twelve and 6 cases had GIT and lung involvement respectively. Two patients developed gastrointestinal bleeding due to visceral KS.

Figure 2

Table 2: Site of lesions

Only 123 had a CD₄ cell count done. Among those with CD₄ cell count 65/123 (52.8%) had CD₄ cell count below 50 cells/mm3 (Table 3). Only 14 patients had done a viral load and the values ranged between 1,368 copies/ml to 2,638,456 copies/ml.

Figure 3

Table 3: CD4 Cell Count Distribution in 123 patients

Only 71 (42.6%) had a platelet count done (Table 4). A majority of the patients had platelets above 100,000/mm3, all nine patients with platelets below 50,000/mm3 died.

Figure 4

Table 4: Platelet levels in patients (n = 71)

Figure 5

Table 5: Hemoglobin levels in patients (n = 89)

Sixty-four patients died without receiving antiretroviral (ARV) drugs. Sixty patients received ARV drugs, 9 had chemotherapy and ARV and 3 had radiotherapy and ARV (Table 6). Most deaths occurred less than 6 months from the first visit to the hospital. Others died from the recrudescence of KS after the introduction of Highly Active Antiretroviral Therapy (HAART), following Immune Reconstitution Inflammatory Syndrome (IRIS). Forty were alive at the end of the study, while 30 were lost to follow-up. The patients who survived were those who had localized disease.

Figure 6

Table 6: Treatment Regimens Received (n=72)

Discussion

The prevalence of HIV associated KS in our study is 9.7%. The prevalence of HIV associated KS varies from one geographical region to the other and also from one cultural group to the other. This variation may range from 0% to 30% (₆, ₇, ₈, ₁₀, ₁₁, ₁₂, ₁₃, ₁₄). A high prevalence is usually associated with homosexual practices (₁₃, ₁₄). HIV associated KS was first described in homosexual men. There was only one homosexual man in our series. Infection was mainly by heterosexual contact.

In this study of 165 patients with HIV associated KS, the male:female ratio is 1:1.2 (45 males and 55% females). Other authors have reported an increase in the number of females with HIV associated KS. (₁₅, ₁₆) This increase is not consistent with our findings, as the ratio is similar to the normal sex distribution in Cameroon.

The mode of infection in our patients is almost 100% heterosexual. There may be a different route of infection for Human Herpes Virus type 8 (HHV8), the oncogenic virus for Kaposi's sarcoma. This concurs with the findings of Gessain et al (₁₇) that HHV8 infection is acquired during childhood in Cameroon. Therefore, aside from sexual transmission of HHV8, vertical transmission is possible (₁₈) and may be oro-fecal transmission in low resource settings where clean water is a luxury. One of the characteristics of HIV associated KS in our study is younger age group. Of the 165 patients, 115 (69.1%) were between the age of 25 and 44 years, as compared to endemic KS which is more common in men and with a higher incidence in older age groups. (₄)

Ninety patients, (55%) had generalized disease with multiple nodules and plaques, scattered all over their bodies. Generalized KS was associated with high mortality in this study. The mucosa were also involved in those with generalized lesions. Forty-eight patients, (29%) had lesions involving only upper and lower limbs.

The patients with visceral lesions presented with vague abdominal pain and pains mimicking peptic ulcer disease. These cases of abdominal KS were confirmed by endoscopy. Three of the GIT lesions were complicated by fatal GIT hemorrhages. Of the 123 patients who had their CD4 T-cell count done, 65(52.8%) had a CD4 T-cell count less than 50, which is indicative of severe immune depression.

Treatment opportunities were limited by the cost of cytotoxic drugs. Mortality was associated with hemoglobin level below 6 grams, low CD4 count, severe immune depression and a heavy tumor burden.

Conclusion

The prevalence of HIV associated KS in this study was.9.7%, with KS heralding a diagnosis of HIV infection in 75% of patients. The site of the lesions was related to prognosis. Prognosis is better in those with localized lesions. Patients with generalized lesions, mouth lesions, low CD4 cell count and anemia had a very poor prognosis. ARV drugs improved the outcome when started early. A combination of chemotherapy and ARV is the best modality for treatment. Unfortunately radiotherapy and chemotherapy are very expensive. This is the major limitation to treatment in a resource limited setting.

We recommend that more studies be carried out to evaluate the factors that adversely affect the prognosis of HIV associated KS. Building awareness on the recognition of early KS lesions especially in young people along with HIV testing may make treatment more effective and improve outcome.

Correspondence to

Mbuagbaw Lawrence C. E. Bafut HIV/AIDS Treatment Centre, PO Box 2085, Bafut, North West Province, Cameroon Email: mbuagbawl@yahoo.com