Cancer survival improving in HAART era

Survival rates in AIDS patients with cancer have increased following the introduction of highly active antiretroviral therapy (HAART), according to the results of a 20-year study published in the 1^st July edition of The Journal of Acquired Immune Deficiency Syndromes. However, survival rates still lag behind those of patients without AIDS for some types of cancer.

Cancer remains a serious concern for many patients with HIV or AIDS. While the introduction of HAART in 1996 reduced the incidence of some types of cancer, it is becoming clear that other types are becoming more common as HIV-positive people are living longer. Furthermore, patients with HIV or AIDS can now be treated with more aggressively, as the risks of immunosuppression from chemotherapy and other cancer treatments become less problematic.

To assess the change in cancer prognosis, investigators compared the two-year survival rates of patients with and without AIDS in New York City between 1980 and 2000. They linked data from the New York State Cancer Registry and the New York City HIV/AIDS Registry, including data from a total of almost 114,000 patients with AIDS and 755,000 with cancer (Biggar 2005).

“Recent improvements in AIDS and cancer care have greatly narrowed the gap in survival between cancer patients with and without AIDS,” they conclude. “Clinicians should be encouraged by the improving diagnosis”.

The researchers chose to analyse three types of AIDS-related cancer – Kaposi’s sarcoma, non-Hodgkin’s lymphoma and cervical cancer - as well as eight types of cancer that are not listed as being AIDS-defining conditions. These were cancers of the lung, larynx, colorectum, anus, breast, prostate gland and testis, as well as Hodgkin’s lymphoma.

After adjustment for the patients’ age, sex and race, and the time when cancer was diagnosed, the investigators found that the survival rates increased over time for most cancer types. These included non-Hodgkin’s lymphoma affecting the central nervous system (CNS; p

Of the non-AIDS-related cancers, cancer of the colorectum (p

In the final four years of their analysis, when HAART was available, two-year survival rates for people with AIDS were comparable to those in patients without AIDS for most types of cancer. Survival was reported as 58% for Kaposi’s sarcoma and 64% for cervical cancer, which were not significantly different from patients without AIDS.

Non-Hodgkin’s lymphoma that did not affect the CNS had survival rates of 43% between 1996 and 2000 in AIDS patients. However, the death rate from this disease remained higher than in people without AIDS (hazard ratio = 1.9; 95% confidence interval [CI]: 1.6 – 2.2).

There were also significantly lower survival rates for Hodgkin’s lymphoma and lung, larynx, and prostate cancers between 1996 and 2000 in patients with AIDS. Survival for lung cancer was poorest at 10% in 1996 to 2000, 2.5 times lower than in people without AIDS. In contrast, other non-AIDS-related cancers had higher survival rates, such as anal cancer (76%), Hodgkin’s lymphoma (55%) and breast cancer (87%).

“For many cancers there remained increases in the risk of dying within 24 months in people with AIDS compared with persons without AIDS who had the same cancers,” the researchers write. “These survival gaps can focus attention on opportunities to improve cancer care in people with AIDS.”

The researchers also reported survival rates for the various types of non-CNS non-Hodgkin’s lymphoma, including immunoblastic, Burkitt’s and large cell diffuse lymphoma. They found that survival increased over time for all of the categories of non-Hodgkin’s lymphoma (p

The investigators did not have any information on the anti-HIV or cancer treatments taken by the patients. Consequently, it was not possible to conclude whether improvements in the diagnosis and treatment of HIV infection, cancers or both are responsible for the improvements in prognosis.

The researchers also stress that their analysis includes people with and without an AIDS diagnosis, and that people without AIDS could include those with HIV infection. “Because our linkage was between the AIDS and cancer registries, we could not identify HIV-infected persons who never developed AIDS, and they were included with the non-AIDS group,” they explain.

Other recently published studies support the findings of the New York study, showing links between the use of HAART and lymphoma survival. A French study, looking at 28 AIDS patients with the rare non-Hodgkin’s primary effusion lymphoma found two factors that were linked to poorer outcome: poor performance status (a measure of the ability to carry out normal daily activities) and the absence of effective HAART (Boulanger 2005).

Similarly, a larger study of 363 patients with AIDS-related lymphoma found that survival of patients with diffuse large cell lymphoma increased in the HAART era. In contrast, however, survival of Burkitt’s lymphoma patients with AIDS remains poor, and poor survival is related to low CD4 cell counts (Lim 2005). This was in agreement with a sub-study of the PETHEMA-LAL3/97 study, showing significantly better two-year survival in Burkitt’s lymphoma patients with a successful virological response to HAART, compared with those who did not reach viral loads below 80 copies/ml (Oriol 2005).