Anti-HIV treatment has brought longer and healthier lives for many people with HIV. Indeed, side-effects of treatment are the most likely cause of ill-health in HIV-positive people now. In many cases these either lessen (or even go away) with time or can be controlled.

However, around 500 people a year in the UK develop an AIDS-defining illness, and around 400 HIV-positive people die every year .  Many of these people only have their HIV diagnosed when they are already very ill with a serious HIV-related illness.

Although illnesses such as PCP and TB still cause illness and even death in people with HIV, it seems that cancers and coinfection with hepatitis B and/or hepatitis C are becoming more common as causes of illness and death in people with HIV.

Kaposi’s sarcoma and non-Hodgkin’s lymphoma have become rarer since the introduction of effective anti-HIV treatment, but still occasionally cause illness and death in people with HIV. Often, these people have very weak immune systems, but there have been cases of these cancers developing in people who are taking HIV treatments and have good CD4 cell counts.

Other cancers that are not regarded as AIDS-defining conditions appear to have become more common in HIV-positive people since effective anti-HIV treatment became available. Some of these are linked to other infections, particularly some strains of the virus that causes genital and anal warts, human papilloma virus (HPV).

It should be stressed that there is no evidence at all that anti-HIV drugs cause these cancers. The increased rates of some cancers seen in people with HIV since the introduction of anti-HIV treatment are often due to infections other than HIV or other long-term health risks.

Anal cancer

Anal cancer is emerging as a health concern, particularly for HIV-positive gay men. Human papilloma virus (HPV), the cause of genital and anal warts, is the underlying cause of anal cancer, and anti-HIV drugs are not effective against HPV. There has been a very slight increase in the amount of anal cancer seen in people with HIV since the introduction of anti-HIV treatments. Doctors think that this could be because HIV-positive people are living longer and HPV takes years, even decades, to cause cancer.

Before cancer develops, pre-cancerous lesions, called AIN (anal intraepithelial neoplasia), form. These are graded AIN I, AIN II, and AIN III according to severity. It takes a long time for AIN to progress to anal cancer. In some cases, AIN may be removed surgically.

Anal cancer is treated aggressively, with a combination of chemotherapy and radiotherapy. Sometimes, surgery is also needed, and the overall cure rate is about 60%.

Some HIV clinics are looking at the value of screening people with HPV in their anus or rectum for AIN. This involves using a test very similar to the PAP smear used to detect pre-cancerous cervical cells in women. Although these tests aren’t 100% accurate, the earlier AIN is detected, the greater the chance of effective treatment. DNA testing is also showing promise as a way of detecting potentially cancer-causing strains of HPV.

Vaccines against the strains of HPV particularly associted with anal and cervical cancer has been developed.

However, studies into the vaccines' safety and effectiveness did not involve people with HIV.  Nor did they involve men. So it is not known how effective it will be at preventing anal cancer in people with HIV. It's also important to note that the vaccine was shown to be most effective in young women who were not yet sexually active. Most people in this country acquired HIV through sex and there's good evidence to show that many people with HIV are infected with multiple strains of HPV, so the value of the vaccine in people with HIV is far from certain.

Lung cancer

People with HIV seem to be at increased risk of developing lung cancer. It’s very rare, however, and the outcome is no worse in people with HIV than it is in those without HIV. In one study, all the HIV-positive people who developed lung cancer were smokers. Another risk factor identified in a further study was long-term lung inflammation from illnesses such as asthma.

Testicular cancer

There’s some evidence to suggest that testicular cancer is more common in HIV-positive men. The reason for this isn’t known. If you notice a lump in your testicles you should see a doctor as soon as possible. Treatment works just as well in HIV-positive men as in HIV-negative men. The sooner treatment is provided the better.

Cervical cancer

Since the mid-1990s, cervical cancer has been an AIDS-defining condition. Doctors have noticed an increase in the incidence of cervical cancer since effective HIV treatment became available, probably because women with pre-cancerous changes in their cervix are now living long enough for this to become a problem. It’s important for HIV-positive women to have regular PAP smears.

Vaccines against the strains of human pailloma virus (HPV) associted with cervical (and anal) cancer has been developed.

However, studies into the vaccines' safety and effectiveness did not involve women with HIV.  It's also important to note that the vaccine was shown to be most effective in young women who were not yet sexually active. Most people in this country acquired HIV through sex and there's good evidence to show that many people with HIV are infected with multiple strains of HPV, so the value of the vaccine in people with HIV is far from certain.

Liver cancer

For information on liver cancer, see the section on Illnesses in the age of anti-HIV treatment - hepatitis.