The Prevalence of Human Papillomavirus–Positive Oropharyngeal Squamous Cell Carcinoma at One of the Largest Tertiary Care Centers in Sub-Saharan Africa

Abstract

Context.— Limited data exist on the prevalence of human papillomavirus (HPV)–positive oropharyngeal squamous cell carcinoma in sub-Saharan Africa. Objective.— To determine the prevalence of HPV-positive oropharyngeal squamous cell carcinoma at a large tertiary care center in South Africa. Design.— A total of 266 oropharyngeal squamous cell carcinomas diagnosed during an 11-year period (2007–2017) were selected for evaluation. Cases staining positive for p16 immunohistochemistry were evaluated for high-risk HPV using the BD Onclarity assay (BD Diagnostics, Sparks, Maryland). Results.— Of 266 oropharyngeal squamous cell carcinomas, 14% (n = 36) were positive for p16. Polymerase chain reaction for high-risk HPV performed on the p16-positive cases was negative in 23 cases and positive in 13 cases (13 of 266; 5%). p16 showed a positive predictive value of 36.1%. The HPV subtypes were HPV-16 (n = 10), HPV-18 (n = 1), HPV-52 (n = 1), and HPV-31 (n = 1). Human papillomavirus–positive cases occurred in 10 men and 3 women (mean age, 51 years) and arose from the tonsil (n = 10) or base of the tongue (n = 3). The HPV-positive cases were non-keratinizing (n = 10) or partially keratinizing (n = 1). Partially/nonkeratinizing cases revealed a modest improvement in p16 positive predictive value (11 of 21; 52.4%). Conclusions.— The presence of high-risk HPV in 5% of cases suggests that high-risk HPV is a minor etiologic agent in oropharyngeal squamous cell carcinoma in this region. Given its suboptimal positive predictive value, p16 is not a reliable marker for high-risk HPV infection in this region. When p16 is positive, HPV-specific testing is necessary. The identification of less common high-risk HPV types, HPV-52 and HPV-31, may influence current local vaccination strategies.

Human Papillomavirus–Associated Head and Neck Malignancies in Sub-Saharan Africa: A Systematic Review

“…Among those seven samples, none were positive on HPV ISH (Table 2 ). When the 20 studies that only include head and neck squamous cell carcinomas of the upper aerodigestive tract were assessed, 8 , 13 , 15 - 19 , 40 - 44 , 46 , 52 - 58 the proportion of specimens that were positive for HPV (Data Supplement) was similar to that when assessing all the studies (Table 1 ).…”

“…The highest proportion was noted in oropharyngeal (20.3%, 78 of 384 patients), hypopharyngeal (16.7%, 3 of 18 patients), and oral cavity cancers (11.7%, 18 of 154 patients). When we assessed the 20 studies that only include head and neck squamous cell carcinomas of the upper aerodigestive tract, 8 , 13 , 15 - 19 , 40 - 44 , 46 , 52 - 58 the proportion of specimens that were positive for p16 IHC (Data Supplement) was similar to that when assessing all the studies (Table 1 ).…”

“…Of the 31 studies included (Table 1 ), seven tested by both p16 IHC and HPV PCR, 8 , 13 - 15 , 17 , 43 one study used HPV PCR and HPV ISH, 44 four studies used p16 IHC only, 18 , 19 , 40 , 45 and the remaining 19 studies used HPV PCR only. Among the seven studies that tested by both p16 IHC and PCR, four studies tested the whole patient population, 13 , 15 , 17 , 46 one study tested p16 only on the samples that were reported as HPV-positive by PCR, 8 and two studies tested by HPV only on the samples that tested positive by p16 IHC. 14 , 43 For the study that used both HPV PCR and HPV ISH, the ISH was only tested on the samples that were positive by HPV PCR.…”

“…The most commonly reported was HPV 16 (226, 59.2%), HPV 18 (78, 20.4%), and HPV 56 (19, 5.0%). Among the three papers that reported on patients with oropharyngeal cancer and HPV genotypes, 13 , 46 , 59 the most common were HPV 16 (17 of 27, 63.0%) and HPV 6, 13, and 52 (2 of 27, 7.4% each).…”

“…Seven studies reported tobacco use in patients, which ranged from 20.0% to 66.8%. 18 , 19 , 40 , 41 , 46 , 48 , 57 Alcohol use was reported by five studies, ranging from 8.0% to 85.0%. 19 , 40 , 41 , 46 , 48 Sexual history was reported in two studies.…”