Background: Descriptive epidemiologists have repeatedly reported that males are more susceptible to head and neck cancers. However, most published data are those of cross-sectional studies, and no population-based cohort study has yet been published. The aim of this study was to compare the prevalence of head and neck cancers in healthy males with females. Methods: A retrospective cohort study using the Korean National Health Insurance Service database on 9,598,085 individuals who underwent regular health checkups from 1 January to 31 December 2009. We sought head and neck cancers developed during the 10-year follow-up. Results: A total of 10,732 (incidence rate (IR) per 1000 person-years 0.25) individuals were newly diagnosed with head and neck cancer among the 9,598,085 individuals during the 10-year follow-up. The IR was 0.19 in males (8500 affected) and 0.06 in females (2232 affected). Notably, the male–female ratio increased with age below 70 years but decreased thereafter. The male–female difference was most apparent for laryngeal cancer; the male IR was 11-fold higher in the 40 s and 20-fold higher in the 60 s, followed by hypopharyngeal cancer (6.8- and 24.2-fold). Males smoked more and drank more alcohol than females (p < 0.0001 *, p < 0.0001 *). When never-smokers/-drinkers (only) were compared, males remained at a 2.9-fold higher risk of head and neck cancer than females. The hazard ratios for head and neck cancers in males tended to increase in the lower part of the upper aerodigestive tract: larynx (13.9) > hypopharynx (10.9) > oropharynx (4.4) > nasopharynx (2.9) > sinonasal region (1.8) > oral (1.6). Only the salivary gland cancer incidence did not differ between the sexes; the gland is not in the upper aerodigestive tract. Conclusion: Males are much more susceptible to head and neck cancers than females regardless of whether they drink alcohol or smoke tobacco. Sex differences in the incidence of head and neck cancer are most evident in the 60 s in the lower part of the upper aerodigestive tract, such as the larynx and hypopharynx.

Background: The carboxy-terminal 42 kDa region ofPlasmodium vivaxmerozoite surface protein-1 (PvMSP-1₄₂) is a leading candidate antigen for blood stage vaccine development. However, this region has been observed to be highly polymorphic among filed isolates ofP. vivax. Therefore it is important to analyse the existing diversity of this antigen in the field isolates ofP. vivax. In this study, the genetic diversity and natural selection in PvMSP-1₄₂amongP. vivaxKorean isolates were analysed.Methods: A total of 149P. vivax-infected blood samples collected from patients in Korea were used. The region flanking PvMSP-1₄₂was amplified by PCR, cloned intoEscherichia coli, and then sequenced. The polymorphic characteristic and natural selection of PvMSP-1₄₂were analysed using the DNASTAR, MEGA4 and DnaSP programs.Results: A total of 11 distinct haplotypes of PvMSP-1₄₂with 40 amino acid changes, as compared to the reference Sal I sequence, were identified in the KoreanP. vivaxisolates. Most of the mutations were concentrated in the 33 kDa fragment (PvMSP-1₃₃), but a novel mutation was found in the 19 kDa fragment (PvMSP-1₁₉). PvMSP-1₄₂of Korean isolates appeared to be under balancing selection. Recombination may also play a role in the resulting genetic diversity of PvMSP-1₄₂.Conclusions: PvMSP-1₄₂of KoreanP. vivaxisolates displayed allelic polymorphisms caused by mutation, recombination and balancing selection. These results will be useful for understanding the nature of theP. vivaxpopulation in Korea and for development of a PvMSP-1₄₂based vaccine againstP. vivax.

Introduction. Mucosal margins exhibit a mean shrinkage of 30–40% after resection of oral and oropharyngeal cancers, and an adequate in situ surgical margin frequently results in a pathological close margin. However, the impact on prognosis remains unclear. We investigated the impact of a pathological close margin on disease-free survival (DFS) and overall survival (OS). Methods. We retrospectively reviewed the clinicopathological data of 418 patients diagnosed with squamous cell carcinomas of the oral cavity or oropharynx who underwent initial surgery (with curative intent) at our institute between 2010 and 2016. Results. Of the total population, the pathological marginal status of 290 (69.4%) patients was reported as clear (>5 mm), 61 (14.6%) as close (>1 mm, ≤5 mm), and 67 (16.0%) as positive (≤1 mm). The 5-year DFSs were 79.3%, 65.1%, and 52% in patients in the negative margin (group 1), close margin (group 2), and positive margin (group 3) groups, respectively. The difference between groups 1 and 2 was not significant (p = 0.213) but the difference between groups 2 and 3 was (p = 0.034). The 5-year OSs were 79.4%, 84%, and 52.3% in groups 1, 2, and 3, respectively. The difference between groups 1 and 2 was not significant (p = 0.824) but the difference between groups 2 and 3 was (p = 0.001). In multivariate analysis, older age, advanced T stage, and a positive margin were independently prognostic of the 5-year DFS and OS. Conclusion. In conclusion, the OS of patients with close margins was no different than that of others when appropriate postoperative adjuvant and/or salvage treatment were/was prescribed. However, we could not determine the impact of close margins on locoregional recurrence given various biases in our study setting. A future prospective study is needed.

Introduction: Transoral endoscopic thyroidectomy vestibular approach (TOETVA) has become increasingly popular. Several reports have emphasized the safety and efficacy of this new approach. However, there is no report on functional voice outcomes, including voice pitch change after TOETVA. Methods: The functional voice outcomes of patients undergoing TOETVA were compared with those of patients undergoing conventional thyroidectomy. A total of 82 consecutive patients were included in the study: 44 underwent thyroid lobectomy via TOETVA (transoral group) and 38 underwent thyroid lobectomy via the classic cervical approach (open group). Thyroidectomy-related voice questionnaire (TVQ), perceptual voice analysis, fiberoptic laryngoscopic and videolaryngostroboscopic examinations, and acoustic analysis were carried out before and one month after surgery. The changes in these values after surgery and the differences between the transoral and open groups were analyzed. Results: We found no significant postoperative change in voice workups in either group. The mean high pitch decreased (from 367.91 ± 120.98 to 325.80 ± 100.86 Hz, p = 0.069) in the transoral group, but statistical significance was not attained. Clinically significant changes in pitch (postoperative change in speaking fundamental frequency, ΔSFF ≥ 12) after surgery were evident in seven (15.91%) patients in the transoral group and eight (21.05%) patients in the open group without significant difference (p = 0.579). Conclusions: This is the first study to assess functional voice outcomes (including pitch) after TOETVA compared with conventional open surgery. TOETVA was associated with good voice outcomes without any significant drop in pitch.

Background: We investigated the association between BMI and HNC subtype incidence in a cohort study of ten million people, adjusting for the effect of smoking and drinking. We also investigated the relationship between waist circumference (WC) and HNC subtype. Methods: All data used in this study originated from the Korean National Health Insurance Service database. We analysed subjects who had undergone health check-ups in 2009 and monitored subjects until 2018 (n = 10,585,852). Finally, 9,598,085 subjects were included after exclusions. We collected variables that could affect the risk of HNC. Cox proportional hazards regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: The overall incidence of HNC was higher in the low BMI category (BMI < 18.5 according to WHO recommendations for Asian people) (HR: 1.322; 95% CI: 1.195–1.464) compared with the normal BMI category. Among the HNC cases, the incidence rates of laryngeal (HR: 1.3; 95% CI: 1.085–1.558), oral cavity (HR: 1.277; 95% CI: 1.011–1.611), and oropharyngeal (HR: 1.584; 95% CI: 1.25–2.008) cancers were higher in the low BMI category compared with the normal BMI category. No significant association was detected between low BMI and sinus cancer, salivary gland cancer, or nasopharyngeal cancer. The low WC category (<80 cm in men and <75 cm in women) was related to a risk of hypopharyngeal (HR: 1.268; 95% CI: 1.061–1.514) and laryngeal (HR: 1.118; 95% CI: 1.007–1.241) cancers. The HR for occurrence of HNC was high in underweight participants according to smoking status (1.219 for never smoker vs. 1.448 for ever smoker, p for interaction = 0.0015) and drinking status (1.193 for never drinker vs. 1.448 for ever drinker, p for interaction = 0.0044). Conclusions: Low BMI was associated with the risk of some types of HNC. The results of this study could assist etiological investigations and prevention strategies.

Objectives: To identify the relationship between pulmonary function and subjective olfactory dysfunction in middle-aged and older adults. Materials and Methods: We used Korea National Health and Nutrition Examination Survey data from 2010 to 2012 to analyze 6191 participants in their 50s or older. Results: The frequency of olfactory dysfunction was 6.8% among the subjects with normal pulmonary function tests, but was significantly more frequent in those diagnosed with restrictive (9.6%) or obstructive (10.1%) pulmonary function. Forced volume vital capacity, forced expiratory volume (FEV)₁, FEV₆, and peak expiratory flow were significantly lower in the olfactory dysfunction group. The risk of olfactory dysfunction was significantly associated with obstructive pulmonary function (odds ratio (OR) [95% confidence interval (CI)]: 1.449 [1.010–2.081]) after adjusting for confounders (sex, rhinitis, chronic rhinosinusitis, hypertension, dyslipidemia, education level, stress, depressed mood, and suicidal ideation). Conclusion: Middle-aged and older adults with obstructive pulmonary function had a higher incidence of subjective olfactory dysfunction than the normal pulmonary function group. Early olfactory testing may improve the quality of life of patients with obstructive pulmonary function.