Purpose: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

The selected treatment for a nodule that is diagnosed as thyroid cancer is surgery. Imaging and blood tests are performed prior to surgery to determine the extent of the surgery. An Ultrasound (US) of the thyroid and neck should be performed to evaluate the size of the cancer, whether it is multifocal and has invaded surrounding tissues, and the status of the cervical lymph nodes (LNs). In addition to US, contrast-enhanced computed tomography may help detect cervical LN metastasis and evaluate patients suspected with invasive thyroid cancer.Generally, routine preoperative measurement of serum thyroglobulin and thyroglobulin antibody concentrations is not recommended. Integrated 18F-fluorodeoxyglucose positron-emission/computed tomography may be helpful either in patients with suspected lateral cervical LNs or distant metastasis or in patients with aggressive histology.

The initial treatment for differentiated thyroid cancer includes appropriate surgery and radioactive iodine (RAI) therapy, followed by thyroid-stimulating hormone (TSH) suppression therapy as long-term management to prevent recurrence. RAI therapy following thyroidectomy has the three main purposes: remnant ablation, adjuvant therapy, and therapy for known disease. To optimize the goals and targets of RAI therapy, postoperative disease assessment, determination of recurrence risk, and consideration of various individual factors are necessary. The objectives of RAI therapy are determined based on the individual’s recurrence risk, and the administered activity of RAI is then determined according to these treatment objectives. Adequate stimulation of serum TSH is necessary before RAI therapy, and recombinant human TSH is widely used because of its advantage in reducing the risk of exacerbation of comorbidities associated with levothyroxine discontinuation and improving patients’ quality of life. Additionally, reducing iodine intake through appropriate low-iodine diet is necessary. Whole-body scans are conducted to assess the disease status after RAI therapy. If planar whole-body scans are inconclusive, additional single-photon emission computed tomography (SPECT)/CT imaging is recommended. Over the past decade, prospective randomized or retrospective clinical studies on the selection of candidates for RAI therapy, administered activity, methods of TSH stimulation, and advantages of SPECT/CT have been published. Based on these latest clinical research findings and recommendations from relevant overseas medical societies, this clinical practice guideline presents the indications and methods for administering RAI therapy after thyroidectomy.

Based on the clinical, histopathological, and perioperative data of a patient with differentiated thyroid cancer (DTC), risk stratification based on their initial recurrence risk is a crucial follow-up (FU) strategy during the first 1–2 years after initial therapy. However, restratifiying the recurrence risk on the basis of current clinical data that becomes available after considering the response to treatment (ongoing risk stratification, ORS) provides a more accurate prediction of the status at the final FU and a more tailored management approach. Since the 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and DTC, the latest guidelines that include the National Comprehensive Cancer Network clinical practice and European Association for Medical Oncology guidelines have been updated to reflect several recent evidence in ORS and thyroid-stimulating hormone (TSH) suppression of DTC. The current clinical practice guideline was developed by extracting FU surveillance after the initial treatment section from the previous version of guidelines and updating it to reflect recent evidence. The current revised guideline includes recommendations for recent ORS, TSH target level based on risk stratification, FU tools for detection of recurrence and assessment of disease status, and long-term FU strategy for consideration of the disease status. These evidence-based recommendations are expected to avoid overtreatment and intensive FU of the majority of patients who will have a very good prognosis after the initial treatment of DTC patients, thereby ensuring that patients receive the most appropriate and effective treatment and FU options.

Radioactive iodine (RAI) therapy can effectively eliminate persistent or recurrent disease in patients with advanced differentiated thyroid cancer (DTC), potentially improving progression-free, disease-specific, and overall survival rates. Repeated administration of RAI along with thyroid-stimulating hormone (TSH) suppression is the mainstay of treatment for patients with distant metastases. Remarkably, one in three patients with distant metastases can be cured using RAI therapy and experience a near-normal life expectancy. Patients with elevated serum thyroglobulin and a negative post-RAI scan may be considered for empiric RAI therapy in the absence of structurally evident disease. However, in some patients, the iodine uptake capacity of advanced lesions decreases over time, potentially resulting in RAI-refractory disease. RAI-administered dose can be either empirically fixed high activities or dosimetry-based individualized activities for treatment of known diseases. The preparation method (levothyroxine withdrawal vs. recombinant human TSH administration) should be individualized for each patient.RAI therapy is a reasonable and safe treatment for patients with advanced DTC. Despite the risk of radiation exposure, administration of low-activity RAI has not been associated with an increased risk of a secondary primary cancer (SPM), leukemia, infertility, adverse pregnancy outcomes, etc. However, depending on the cumulative dose, there is a risk of acute or delayed-onset adverse effects including salivary gland damage, dental caries, nasolacrimal duct obstruction, and SPM. Therefore, as with any treatment, the expected benefit must justify the use of RAI in patients with advanced DTC.

Pediatric differentiated thyroid cancers (DTCs), mostly papillary thyroid cancer (PTC, 80-90%), are diagnosed at more advanced stages with larger tumor sizes and higher rates of locoregional and/or lung metastasis. Despite the higher recurrence rates of pediatric cancers than of adult thyroid cancers, pediatric patients demonstrate a lower mortality rate and more favorable prognosis. Considering the more advanced stage at diagnosis in pediatric patients, preoperative evaluation is crucial to determine the extent of surgery required. Furthermore, if hereditary tumor syndrome is suspected, genetic testing is required. Recommendations for pediatric DTCs focus on the surgical principles, radioiodine therapy according to the postoperative risk level, treatment and follow-up of recurrent or persistent diseases, and treatment of patients with radioiodine-refractory PTCs on the basis of genetic drivers that are unique to pediatric patients.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.