Cancer treatment-related declines in CD4 count may increase mortality risk in people with HIV
medwireNews: Treatment with chemotherapy and/or radiotherapy is associated with a reduction in CD4 count in adults with HIV and cancer, relative to surgery or other therapy, and this in turn is associated with an increased risk for death, US study findings indicate.
Keri Calkins and colleagues from Johns Hopkins University in Baltimore, Maryland, say their data support “the hypothesis that immune status in persons with HIV can influence mortality after cancer diagnosis.”
The cohort study included 196 adults (69% men; median age 50 years) with HIV who were treated for cancer between 1997 and 2016. The participants had a median baseline CD4 count of 297 cells/μL, and the majority (60.2%) received chemotherapy and/or radiotherapy.
Among patients with a baseline CD4 count of greater than 500 cells/μL, there was an initial reduction in CD4 count regardless of treatment type, but the researchers found that the fall was 203 cells/µL greater with chemotherapy and/or radiotherapy than with surgery or other treatment.
Furthermore, the difference between the two groups then persisted during 5 years of follow-up.
By contrast, among the patients with a baseline CD4 count of 350 cells/μL or lower, the initial reduction was on average 45 cells/μL greater with chemotherapy and/or radiotherapy than with surgery or other treatment, and reduced during follow-up such that there was no difference between the two groups by 5 years.
Contrary to expectations, the researchers also found that treatment with chemotherapy and/or radiotherapy was not associated with an increase in HIV RNA levels.
Indeed, among the patients who were virally suppressed (HIV RNA ≤400 copies/mL), there was no change in their HIV RNA level compared with surgery or other treatment, while those who were virally unsuppressed at baseline experienced a decline in HIV viral load from a mean of 3311 copies/mL to a mean 1698 copies/mL.
“This finding suggests that perhaps the monitoring and engagement in health care associated with ongoing chemotherapy and/or radiotherapy may improve ART [antiretroviral therapy] uptake or ART adherence and rejects the concern that more intensive cancer treatment regimens may negatively affect ART adherence,” Calkins and co-authors write in JAMA Oncology.
The researchers report that the 5-year cumulative mortality rate was 45.1%. However, after adjustment for potential confounders, including longitudinal log10 HIV RNA level and cancer severity, they found that each 100 cells/μL decrease in CD4 count after initial cancer treatment resulted in a 27% increased risk for death.
They therefore conclude: “The results of this cohort study suggest that maintaining a high CD4 count after cancer diagnosis has clinically meaningful implications for survival.”
In an accompanying comment, Thomas Uldrick, from Fred Hutchinson Cancer Research Institute in Seattle, Washington, USA, and co-authors say that the findings “reflect the feasibility of treating HIV and cancer concurrently.”
However, they add that “[i]mproved methods to evaluate immune function in people with HIV and cancer are also needed.”
Uldrick et al conclude: “Future research should focus on further optimization of ART initiation and reducing ART interruption during cancer therapy and build on the success story of ART through development of additional highly effective immunotherapeutic approaches for a range of HIV-associated cancers.”
By Laura Cowen
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