Treating HIV early, before CD4s drop significantly, lowers the risk of infection-related cancers such as Kaposi’s sarcoma (KS) and non–Hodgkin lymphoma and possibly non-infection-related cancers as well.

The global START trial, published in 2015, included 4,685 people with HIV who started the study with more than 500 CD4 cells. They were randomized either to receive antiretroviral (ARV) treatment immediately or after their CD4s dropped below 350 or they experienced an AIDS-defining illness.

The landmark study, which helped prompt the World Health Organization (WHO) to recommend treatment for all people with HIV regardless of CD4 count, found that immediate versus delayed HIV treatment lowered the risk of cancer in particular by 64 percent.

In a more recent analysis, researchers sought to parse this beneficial effect according to different types of cancers.

The infection-related cancers analyzed included KS (related to herpes), non–Hodgkin and Hodgkin lymphomas (related to Epstein-Barr virus) and anal and cervical cancers (related to human papillomavirus, or HPV). The numerous non-infection-related cancers included, among others, prostate, lung, testicular and breast cancers.

Those in the immediate treatment group experienced 14 cancers during the study’s follow-up period, including six infection-related and eight non-infection-related cancers. The members of the delayed treatment group experienced 39 cancers, including 23 infection-related and 16 non-infection-related cancers.

The researchers calculated that immediate HIV treatment reduced the risk of infection-related cancer by 74 percent, mostly on account of lower rates of KS and non–Hodgkin lymphoma. Immediate treatment also reduced the risk of non-infection-related cancer by 51 percent. However, this latter finding was not statistically significant, meaning it may have been driven by chance.

“There is now compelling evidence from [multiple] trials that the risk-benefit ratio of early [HIV treatment] initiation is favorable for the individual and the community,” said Álvaro Borges, MD, MSc, PhD, a clinical associate professor at Rigshospitalet at the University of Copenhagen and the new study’s lead author. “Having said this, the decision to initiate [treatment] in symptomless [people] with early HIV infection is nuanced and each case has to be evaluated on an individual basis. Sound clinical judgment, in conjunction with patient willingness and commitment to initiate a lifelong therapy, will remain a crucial step in this shared decision-making process.”