Human papillomavirus genotype contribution to cervical cancer and precancer: Implications for screening and vaccination in Japan

To obtain baseline data for cervical cancer prevention in Japan, we analyzed human papillomavirus (HPV) data from 5045 Japanese women aged less than 40 years and diagnosed with cervical abnormalities at 21 hospitals during 2012‐2017. These included cervical intraepithelial neoplasia grade 1 (CIN1, n = 573), CIN2‐3 (n = 3219), adenocarcinoma in situ (AIS, n = 123), and invasive cervical cancer (ICC, n = 1130). The Roche Linear Array was used for HPV genotyping. The HPV type‐specific relative contributions (RCs) were estimated by adding multiple infections to single types in accordance with proportional weighting attributions. Based on the comparison of type‐specific RCs between CIN1 and CIN2‐3/AIS/ICC (CIN2+), RC ratios were calculated to estimate type‐specific risks for progression to CIN2+. Human papillomavirus DNA was detected in 85.5% of CIN1, 95.7% of CIN2‐3/AIS, and 91.2% of ICC. Multiple infections decreased with disease severity: 42.9% in CIN1, 40.4% in CIN2‐3/AIS, and 23.7% in ICC (P < .0001). The relative risk for progression to CIN2+ was highest for HPV16 (RC ratio 3.78, 95% confidence interval [CI] 3.01‐4.98), followed by HPV31 (2.51, 1.54‐5.24), HPV18 (2.43, 1.59‐4.32), HPV35 (1.56, 0.43‐8.36), HPV33 (1.01, 0.49‐3.31), HPV52 (0.99, 0.76‐1.33), and HPV58 (0.97, 0.75‐1.32). The relative risk of disease progression was 1.87 (95% CI, 1.71‐2.05) for HPV16/18/31/33/35/45/52/58, but only 0.17 (95% CI, 0.14‐0.22) for HPV39/51/56/59/66/68. Human papillomavirus 16/18/31/33/45/52/58/6/11 included in a 9‐valent vaccine contributed to 89.7% (95% CI, 88.7‐90.7) of CIN2‐3/AIS and 93.8% (95% CI, 92.4‐95.3) of ICC. In conclusion, our data support the Japanese guidelines that recommend discriminating HPV16/18/31/33/35/45/52/58 genotypes for CIN management. The 9‐valent vaccine is estimated to provide over 90% protection against ICC in young Japanese women.     

Cutaneous adult xanthogranuloma with a small portion of BRAFV600E mutated Langerhans cell histiocytosis populations: A case report and the review of published work

Histiocytoses, including Langerhans cell histiocytosis (LCH), juvenile or adult xanthogranuloma (AXG) and Rosai–Dorfman disease (RDD), are rare disorders characterized by the proliferation of cells derived from monocyte/macrophage lineages. A few cases of LCH coexisting with xanthogranuloma or RDD have been reported. The etiology of these diseases remains unclear. However, oncogenic BRAF^V600E mutations have been identified in LCH. Here, we report the case of a 26‐year‐old Japanese man with a 3‐month history of a solitary occipital nodule. No abnormality was detected in his other organs, and a total resection of the nodule was performed. Histopathological examination revealed the coexistence of LCH and AXG with prominent emperipolesis characteristic of RDD. Immunohistochemistry showed that most of the large histiocytes were positive for CD68, weakly positive or negative for S100, and negative for CD207 and CD1a, supporting the diagnosis of AXG. The tumor cells with emperipolesis did not show S100‐positive findings characteristic of RDD. The focally aggregated oval histiocytic cells were positive for CD1a, CD207, CD68 and S100, and were compatible with the immunophenotype of LCH cells. In addition, these cells were positive for BRAF^V600E mutation. The tumor cells in our patient exhibited a cellular morphology characteristic of multiple histiocytoses in a solitary cutaneous nodule, which may imply an etiological association among LCH, AXG and RDD. To our knowledge, this is the first report of a BRAF^V600E mutation‐positive case of LCH coexisting with AXG. Because patients with BRAF^V600E mutation have higher risks of multisystemic LCH and recurrence, we should carefully follow up the patient.     

Dental floss use among elementary school children and environmental factors; a cross-sectional study

BackgroundThe onset of carious lesions and periodontal disease originates in plaque formed from dental bacteria. Appropriate plaque control is therefore important. Dental floss is one instrument used to control plaque. The influence of guardians is an important factor in whether children use dental floss regularly. However, the use of dental floss among school-age children and the relationship between use and family background has yet to be examined.AimIn this study, we conducted a questionnaire survey to examine rates of dental floss use and other related factors among elementary school children and their guardians.MethodsSurveys were sent to 298 guardians of children in grades 1–6 at an elementary school in Japan and 283 valid responses were received. Statistical analyses were carried out, with child’s use of dental floss as a dependent variable and grade, sex, guardian assistance with child's tooth brushing, frequency of child’s dental check-ups, and guardian's use of dental floss as independent variables.ResultsThe results revealed that 18.4% of children used dental floss compared with 52.7% of guardians, suggesting that the rate of usage among children is much lower than that among guardians. Logistic regression analysis further revealed that guardian's use of dental floss was significantly related to dental floss use among children.ConclusionThe guardian's use of dental floss was associated with dental floss use among their children in this group of Japanese elementary school.