Organ transplant recipients (OTRs) have a 100‐fold increased risk of cutaneous
squamous cell carcinoma (cSCC). We prospectively evaluated the association
between β genus human papillomaviruses (βPV) and keratinocyte carcinoma in
OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted
in 2003‐2006 (n = 274) and cohort 2 was transplanted in 1986‐2002 (n = 352).
Participants were followed until death or cessation of follow‐up in 2016. βPV
infection was assessed in eyebrow hair by using polymerase chain
reaction–based methods. βPV IgG seroresponses were determined with multiplex
serology. A competing risk model with delayed entry was used to estimate
cumulative incidence of histologically proven cSCC and the effect of βPV by
using a multivariable Cox regression model. Results are reported as adjusted
hazard ratios (HRs). OTRs with 5 or more different βPV types in eyebrow hair
had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7,
95% confidence interval 1.1‐2.6). A similar risk was seen with high βPV loads
(HR 1.8, 95% confidence interval 1.2‐2.8). No significant associations were
seen between serum antibodies and cSCC or between βPV and basal cell
carcinoma. The diversity and load of βPV types in eyebrow hair are associated
with cSCC risk in OTRs, providing evidence that βPV is associated with cSCC
carcinogenesis and may present a target for future preventive strategies