Kaposi Sarcoma

Kaposi sarcoma (KS) is a cancer affecting the lining of blood and lymph vessels. It causes unusual growths, called lesions, to appear on the skin. These lesions can be various colors – pink, red, purple, or brown – and are often found on the face, arms, and legs. In more advanced stages, lesions can also develop on the genitals, inside the mouth, and even spread to internal organs like the lungs and digestive system.

KS is primarily caused by a virus called human herpesvirus 8 (HHV-8). A healthy immune system usually keeps this virus under control. However, when the immune system is weakened, HHV-8 can trigger the development of KS. There are several types of KS, each linked to different factors that weaken the immune system:

• AIDS-related Kaposi Sarcoma: This is the most common type, occurring in people with HIV/AIDS. The weakened immune system due to HIV allows HHV-8 to thrive and cause cancer.

• Transplant-Associated Kaposi Sarcoma: Individuals who have received organ transplants often take immunosuppressant drugs to prevent organ rejection. This weakens their immune system, making them susceptible to HHV-8 and KS.

• Classic Kaposi Sarcoma: This type typically affects older adults of Mediterranean, Eastern European, or Middle Eastern descent. It develops slowly and often involves swelling, especially in the legs.

• Endemic Kaposi Sarcoma: More common in young people in parts of Africa, this type can grow slowly on the skin or more rapidly within the body.

In essence, KS is a viral-induced cancer that primarily affects people with compromised immune systems. The specific type of KS depends on the underlying cause of the immune deficiency.

KS initially presents as skin growths (lesions). These can be flat or raised and are usually red, purple, or brown. While often painless initially, they can grow larger over time if left untreated. This can lead to complications such as swelling in the lower legs (due to impaired blood flow), enlarged lymph nodes, and painful or itchy skin.

KS isn't confined to the skin. Internal organ involvement, especially in the digestive system and lungs, can lead to additional symptoms. Digestive tract involvement might manifest as diarrhea, nausea, stomach pain, vomiting, and unexplained weight loss. Lung involvement may cause breathing difficulties or coughing.

If you notice any unusual skin growths, particularly if they are discolored, raised, or changing in size or number, consult your doctor immediately. Don't hesitate to seek medical attention if you experience any of the symptoms mentioned above, especially if they are persistent or worsening. Early diagnosis is crucial for effective management.

The primary cause of KS is infection with human herpesvirus 8 (HHV-8). This virus is believed to spread through saliva and blood contact. Most people's immune systems successfully control HHV-8, preventing any disease. However, in individuals with weakened immune systems (due to HIV, immunosuppressant medications, or other conditions), the virus can reactivate and lead to the development of KS.

While anyone can develop KS, certain factors significantly increase the risk:

• HIV Infection: A weakened immune system due to HIV dramatically increases the risk of developing KS.

• Age: The risk of KS tends to increase with age, particularly in the 50-70 age range, reflecting the natural decline in immune function.

• Geographic Location: KS is more prevalent in certain regions, including the Mediterranean, Eastern Europe, and sub-Saharan Africa. This may be related to genetic factors, environmental exposures, or variations in diagnostic practices.

• Immunosuppressive Medications: Medications used to prevent organ rejection after transplantation significantly weaken the immune system, increasing vulnerability to KS.

Diagnosis often begins with a physical examination. If a suspicious lesion is present, a skin biopsy is performed. A small tissue sample is taken and sent to a laboratory for microscopic examination to confirm the presence of KS cells.

If KS is suspected, further investigations may be necessary to determine if the cancer has spread to other organs. This might involve:

• Digestive System: Tests such as fecal occult blood tests, endoscopy, colonoscopy, and abdominal CT scans can help detect KS in the digestive tract.

• Lungs: Chest X-rays, CT scans of the chest, and bronchoscopy can be used to evaluate lung involvement.

There's currently no cure for KS, but various treatments effectively manage the disease. Treatment decisions are individualized and depend on several factors: the type of KS, the number and location of lesions, the impact on daily life, and the patient's overall health.

In some cases, particularly with localized and slow-growing KS, observation may be the initial approach. However, active treatment is often needed. Treatments include:

• Localized Treatments (for small lesions): Surgery, cryotherapy (freezing), radiation therapy, injection of chemotherapy drugs (like vinblastine), and topical creams or gels.

• Systemic Treatments (for widespread or rapidly growing KS): Radiation therapy and chemotherapy.

Importantly, even with successful treatment, lesions may recur. Therefore, ongoing monitoring and potential re-treatment are essential. Advances in HIV/AIDS treatment have significantly improved the prognosis for AIDS-related KS.