Second primary malignancy (SPM) is the major long-term cause of patient mortality with head and neck squamous cell carcinoma (HNSCC). As the incidence of high-risk human papillomavirus (HPV)-related HNSCC is increasing globally, we analyzed the patterns of SPM occurrence, the effect of the index tumor site along with attributes to HPV, and the effect of SPM on survival in South Korean patients with head and neck cancer (HNC). Data were retrieved from the Korea Central Cancer Registry, a nationwide population-based cancer registry, from 1993 to 2010. Standardized incidence ratios were analyzed and compared between index tumor sites, particularly oropharyngeal vs. non-oropharyngeal sites. After adjustment for competing risks, 3- and 5-year SPM rates were calculated using the cumulative incidence function. The effects of SPM occurrence on overall survival (OS) were then analyzed. SPM rates were significantly lower for HPV-attributable oropharyngeal sites than for non-oropharyngeal sites, such as the larynx and hypopharynx (p<0.001). SPM rates were also lower for oral cavity first primary sites than for non-oropharyngeal first primary sites (p<0.001). SPMs typically occurred in the esophagus, lungs and the head and neck. Uterine cervical cancers occurred significantly more frequently after index oropharyngeal cancer in women. The 5-year and 10-year OS rates were 57.8 and 45.7% in all HNC patients, respectively. The OS after SPM occurrence was poor (5-year, 31.8%; 10-year, 20.8%) compared to after index HNC occurrence (5-year, 68.4%; 10-year, 41.2%). SPM occurrence in the esophagus and lung/bronchus showed a worse OS than SPM localized to the head and neck. South Korean HNC patient, the first primary cancer site affected SPM risk and distribution. The 5- and 10-year OS rates deteriorated after SPM occurrence, particularly in the esophagus and lungs. Further optimization of follow-up strategies for effective surveillance of SPM, particularly in the esophagus and lungs, is warranted.

Background: Active surveillance (AS) is an alternative to thyroidectomy for the management of low-risk papillary thyroid microcarcinoma (PTMC). However, prospective AS data collected from diverse populations are needed. Methods: This multicenter prospective cohort study enrolled patients from three referral hospitals in Korea. The participants were self-assigned into two groups, AS or immediate surgery. All patients underwent neck ultrasound every 6–12 months to monitor for disease progression. Progression under AS was evaluated by a criterion of tumor size increment by 3 mm in one dimension (3 mm), 2 mm in two dimensions (2 × 2 mm), new extrathyroidal extension (ETE), or new lymph node metastasis (LNM), and a composite outcome was defined using all four criteria. Results: A total of 1177 eligible patients with PTMC (919 female, 78.1%) with a median age of 48 years (range 19–87) were enrolled; 755 (64.1%) patients chose AS and 422 (35.9%) underwent surgery. Among 755 patients under AS, 706 (female 537, 76.1%) underwent at least two ultrasound examinations and were analyzed. Over a follow-up period of 41.4 months (standard deviation, 16.0), 163 AS patients (23.1%) underwent surgery. Progression defined by the composite outcome was observed in 9.6% (68/706) of patients, and the 2- and 5-year progression estimates were 5.3% and 14.2%, respectively. The observed progression rates were 5.8% (41/706) and 5.4% (38/706) as defined by tumor size enlargement by 3 mm and 2 × 2 mm, respectively, and 1.3% (9/706) and 0.4% (3/706) for new LNM and ETE, respectively. No distant metastases developed during AS. In multivariate logistic regression analysis examining variables associated with progression under AS, age at diagnosis <30 years (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.10 − 7.45), male sex (OR, 2.48; 95% CI, 1.47 − 4.20), and tumor size ≥6 mm (OR, 1.89; 95% CI, 1.09 − 3.27) were independently significant. Conclusions: The progression of low-risk PTMC during AS in the Korean population was low, but slightly higher than previously reported in other populations. Risk factors for disease progression under AS include younger age, male sex, and larger tumor size. Clinical trial registration: NCT02938702.

We undertook this study to estimate an accurate incidence and spread patterns of occult papillary thyroid carcinoma (PTC) in patients with a preoperative diagnosis of solitary PTC by using whole-specimen mapping of all specimens after a total thyroidectomy. Enrolled prospectively in this whole-thyroid mapping study are 82 consecutive patients who underwent a total thyroidectomy under a preoperative diagnosis of solitary PTC. All thyroidectomy specimens were serially sectioned in 2 mm thickness and whole-thyroid mapping was carried out for additional foci of occult PTC. The frequencies of occult lesions detected in the whole and contralateral lobe were determined, and clinicopathologic factors associated with multifocality were assessed. Whole-thyroid mapping revealed 66 occult PTC lesions missed by preoperative ultrasound in 37 (45.1%) of the 82 patients. The great majority (92.5%) of the occult PTC was smaller than 3 mm in size and 25 patients (30.5%) had contralateral lesions. We found that the male sex was an independent predictor of multifocality (odds ratio (OR), 3.00; 95% CI, 1.11-8.14), adjusting for preoperative findings. Analysis with pathologic parameters showed that the male sex (OR, 5.03; 95% CI, 1.68-15.08) and extrathyroidal extensions (OR, 3.03; 95% CI,) were associated with multifocal PTC. However, none of the clinicopathologic factors evaluated predicted contralateral PTC. Our study demonstrates the diagnostic limitations of ultrasound for the detection of multifocal PTC and the need to consider the possibility of occult lesions in the management of solitary PTC, especially in male patients.

Postoperative SIB-IMRT is feasible and effective in improving locoregional control in patients with locally advanced PTC. Large-scale randomized studies are warranted.

The purpose of this study was to evaluate the impact of radioactive iodine therapy (RIT) on vocal function during the early follow-up period after total thyroidectomy (TT) using perceptive and objective measurements, questionnaires regarding subjective symptoms, and data on vocal function in a prospectively enrolled and serially followed thyroid cancer cohort. Methods: Of 212 patients who underwent TT and were screened between January and December 2010 at our hospital, 160 were included in the final analysis. Patients with the following histories were excluded: lateral neck dissection, organic vocal fold disease, external radiotherapy, and voice evaluation during thyroxine withdrawal. Patients were stratified into 3 groups: TT, TT with low-dose RIT (1.1-2.2 GBq), and TT with high-dose RIT ($3.7 GBq). Voice evaluations were performed before surgery and at 1, 6, and 12 mo after TT. Results: Vocal characteristics were altered after TT, including changes on the grade, roughness, and strain scale; increased amplitude perturbation; decreased fundamental frequency; narrowed pitch range; and global disturbances in subjective functional parameters on the voice handicap index. However, the degree of vocal changes among the 3 groups did not significantly differ within the 1-y postoperative follow-up period. According to the results of subgroup analyses of patients who demonstrated good voice outcomes after TT, there were no significant functional differences among the 3 groups. Conclusion: RIT at any dose does not affect vocal function within 1 y of TT.