Impact of Head and Neck Cancer Treatment on CD4 T Cell Decline and Recovery in People with HIV.

PURPOSE/OBJECTIVE(S): The effect of cancer treatment on immunologic decline and recovery in people with HIV (PWH) is not well-described. This study aims to describe the trajectory of treatment-related immunosuppression in PWH treated for HNC predominantly with radiotherapy with or without chemotherapy and/or surgery.

MATERIALS/METHODS: We performed a retrospective chart review of 23 PWH diagnosed with nonmetastatic HNC at our institution between 2002 and 2020. Baseline and longitudinal changes in CD4 count from the time of cancer treatment initiation were investigated. Patients were followed for 3 years after treatment completion. Nonparametric Mann-Whitney tests were used to compare median baseline CD4 count, post-treatment nadir CD4 count within 1 year after start of treatment, and peak recovery CD4 count within 3 years. Nonparametric Kruskal-Wallis and Mann-Whitney tests were used to compare median baseline, nadir, and peak recovery CD4 counts stratified by treatment.

RESULTS: The majority of patients were male (20 [87%]), were white (13 [57%]), had a smoking history (21 [91%]), and had stage III-IV disease (17 [74%]). The median age was 58 (IQR 55-62). Primary subsites included oropharynx (11 [48%]), larynx (5 [22%]), oral cavity (4 [17%]), hypopharynx (2 [9%]) and nasal sinus (1 [4%]). Treatment comprised of surgery alone (S, n = 2), radiotherapy +/- surgery (RT, n = 6), and chemoradiotherapy +/- surgery (CRT, n = 15), thereby involving radiotherapy in 21 (91%) patients. All patients were on antiretroviral therapy at the time of diagnosis, and baseline HIV load was <200 copies/ml in 20 (87%) patients. Median baseline CD4 count prior to diagnosis was 592 cells/mm3 (IQR 329 to 834). The median nadir CD4 count was 201 cells/mm3 (IQR 104-282) or 34% of baseline (IQR 23-52%) (p<0.0001 compared to baseline), occurring at a median of 3.8 months (IQR 2.5-6.0). The median CD4 counts at 6 months and 1-year post-treatment were 236 cells/mm3 (IQR 135-337) and 274 cells/mm3 (IQR 150-334), respectively, representing 39% (IQR 31-58%) and 50% (IQR 40-63%) of baseline, respectively. The median peak recovery CD4 count was 431 cells/mm3 (IQR 371-561), or 68% of baseline (IQR 59-102%) (p<0.0001 compared to nadir), occurring at a median of 31 months (IQR 22-34). Stratified by treatment, the median nadir CD4 count as a percentage of baseline was 53% (S), 41% (RT), and 34% (CRT) (p = 0.32) and the peak recovery CD4 count as a percentage of baseline was 82% (S), 88% (RT), and 63% (CRT) (p = 0.45).

CONCLUSION: Among PWH with HNC, CD4 count nadirs to a 1/3 of baseline but gradually rebounds to 2/3 of baseline over the subsequent 2-3 years. While this data supports continuing to treat HNC in PWH with standard-of-care management, CD4 count should be monitored closely for several years following HNC radiotherapy.