Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Background/Aims: Epidermal growth factor receptor (EGFR) mutation is important in determining the treatment strategy for advanced lung cancer patients with malignant pleural effusion (MPE). Contrary to serum carcinoembryonic antigen (S-CEA) levels, the associations between pleural fluid CEA (PF-CEA) levels and EGFR mutation status as well as between PF-CEA levels and treatment efficacy have rarely been investigated in lung adenocarcinoma patients with MPE. Methods: This retrospective study enrolled lung adenocarcinoma patients with MPE and available PF-CEA levels and EGFR mutation results. The patients were categorized based on PF-CEA levels: < 10 ng/mL, 10–100 ng/mL, 100–500 ng/mL, and ≥ 500 ng/mL. The association between PF-CEA levels and EGFR mutation status as well as their therapeutic impact on overall survival was compared among the four groups. Results: This study included 188 patients. PF-CEA level was found to be an independent predictor of EGFR mutation but not S-CEA level. The EGFR mutation rates were higher as the PF-CEA levels increased, regardless of cytology results or sample types. Among EGFR-mutant lung adenocarcinoma patients receiving EGFR-tyrosine kinase inhibitor (TKI) treatment, those with high PF-CEA levels had significantly better survival outcomes than those with low PF-CEA levels. Conclusion High PF-CEA levels were associated with high EGFR mutation rate and may lead to a favorable clinical outcome of EGFR-TKI treatment in EGFR-mutant lung adenocarcinoma patients with MPE. These findings highlight the importance of actively investigating EGFR mutation detection in patients with suspected MPE and elevated PF-CEA levels despite negative cytology results.

Background: The quality-of-life of patients with irritable bowel syndrome is low; incorrect diagnosis/treatment causes economic burden and inappropriate consumption of medical resources. This survey-based study aimed to analyze the current status of irritable bowel syndrome treatment to examine differences in doctors’ perceptions of the disease, and treatment patterns. Methods: From October 2019 to February 2020, the irritable bowel syndrome and Intestinal Function Research Study Group of the Korean Society of Neurogastroenterology and Motility conducted a survey on doctors working in primary, secondary, and tertiary healthcare institutions. The questionnaire included 37 items and was completed anonymously using the NAVER platform (a web-based platform), e-mails, and written forms. Results: A total of 272 doctors responded; respondents reported using the Rome IV diagnostic criteria (amended in 2016) for diagnosing and treating irritable bowel syndrome.Several differences were noted between the primary, secondary, and tertiary physicians’ groups. The rate of colonoscopy was high in tertiary healthcare institutions. During a colonoscopy, the necessity of random biopsy was higher among physicians who worked at tertiary institutions. ‘The patient did not adhere to the diet’ as a reason for ineffectiveness using low-fermentable oligo-, di-, and mono-saccharides, and polyols diet treatment was higher among physicians in primary/secondary institutions, and ‘There are individual differences in terms of effectiveness’ was higher among physicians in tertiary institutions. In irritable bowel syndrome constipation predominant subtype, the use of serotonin type 3 receptor antagonist (ramosetron) and probiotics was higher in primary/secondary institutions, while serotonin type 4 receptor agonist was used more in tertiary institutions. In irritable bowel syndrome diarrhea predominant subtype, the use of antispasmodics was higher in primary/secondary institutions, while the use of serotonin type 3 receptor antagonist (ramosetron) was higher in tertiary institutions. Conclusion Notable differences were observed between physicians in primary/secondary and tertiary institiutions regarding the rate of colonoscopy, necessity of random biopsy, the reason for the ineffectiveness of low-fermentable oligo-, di-, and mono-saccharides, and polyols diet, and use of drug therapy in irritable bowel syndrome. In South Korea, irritable bowel syndrome is diagnosed and treated according to the Rome IV diagnostic criteria, revised in 2016.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Background: Skin aging can be divided into intrinsic and extrinsic processes, and occur due to several factors. Although the interest in skin youthfulness is increasing globally, research on facial skin youthfulness and lifestyle is limited. Objective: This study aimed to evaluate the association between facial skin youthfulness and biophysical facial skin parameters in Korean women over 50 years of age. We further investigated lifestyle factors that make people appear younger than their chronological age. Methods: We surveyed the essential information and lifestyle of subjects by questionnaires, and measured the biophysical parameters of the facial skin. We then performed clinical facial assessments, and the values were compared with the chronologic age. The associations between age differences, biophysical parameters, and living habits were evaluated. Results: We identified a positive correlation between age and melanin index (r=0.245, p＜0.001) and erythema index (r=0.119, p=0.002). The melanin index was statistically significantly lower in the group without regular outdoor activities (144.66±43.24 vs. 137.00±55.48, p=0.043). The melanin index and erythema index were the significant differences that defined younger perceived age than chronological age. The perceived age was younger in the group who wore a hat when performing outdoor activities than the group who did not (3.70±1.84 vs. 3.40±1.94, p=0.034). Conclusion To retain youthful skin, it is essential to reduce sun exposure, as this factor can affect the melanin and erythema indices by inducing photoaging. Therefore, avoiding the sun bia proper methods, such as wearing a hat and sunscreen during outdoor activities, is recommended to maintain skin youthfulness.

Background: Alopecia areata (AA) is an autoimmune disease characterized by chronic inflammation, the pathogenesis of which is unknown. Stress is believed to play a role; however, evidence remains insufficient. A recent study showed that substance P (SP) damaged hair follicles by causing neurogenic inflammation, activating perifollicular mast cells, and inducing keratinocyte apoptosis. Objective: We aimed at studying the role of SP in AA pathogenesis. We investigated the SP levels in the lesional scalp tissues and serum. We also studied the effect of SP on the inflammatory response and hair growth in the outer root sheath (ORS) cells. Methods: We compared the serum levels of SP in 58 AA patients and 28 healthy subjects.Then, we checked the expression of SP and SP receptor, neurokinin-1 receptor (NK-1R) in the scalps of AA patients and healthy controls using immunohistochemical staining.Finally, we analyzed the mRNA expression of inflammatory cytokines and hair growthrelated factors in ORS cells. Results: SP and NK-1R expression were markedly higher in the hair follicles and interfollicular epidermis of the scalp lesions of AA patients. However, there was no statistically significant difference in serum SP levels between controls and patients, regardless of the type of alopecia. SP significantly increased the mRNA expression of inflammatory cytokines and decreased hair growth-related growth factors in ORS cells, but the results were not dramatic. Conclusion SP triggered a localized micro-inflammation in lesional hair follicles, provoked an inf lammatory response, and inhibited hair growth, thereby confirming the pathogenic role of SP in AA.

Background: Acral melanoma is the most common subtype of melanoma among Koreans, and regional or distant metastasis is an indicator of poor prognosis. Yes-associated protein (YAP), a key effector of the Hippo pathway, is known to induce tumor progression and metastasis in various cancers. Objective: We aimed to analyze the clinical and histopathological characteristics of acral melanoma among Koreans and to evaluate their association with YAP expression. Methods: This retrospective review included 27 patients with acral melanoma. Clinical features including age, sex, lesion site, and stage were obtained from the medical records and images. Biopsy slides of patients with acral melanoma were reviewed, and immunohistochemical staining for YAP was performed. Results: The rate of YAP expression was significantly higher in patients having acral melanoma with regional or distant lymph node (LN) metastasis than in those without metastasis (n=4/5, 80.0% vs. n=2/22, 9.1%; p=0.004). Histopathologically, the rate of YAP expression was higher in patients having acral melanoma with lymphovascular invasion than in those without lymphovascular invasion (n=4/8, 50.0% vs. n=2/19, 10.5%; p=0.044). Among the 27 lesions, 14 (51.9%) were on stress-bearing sites such as the forefoot and heel. However, the rate of YAP expression did not differ significantly between weight-bearing and non-weight-bearing locations (p=0.834). Conclusion YAP expression is significantly associated with metastasis, especially LN metastasis, in patients with acral melanoma. Therefore, YAP expression may be used as a prognostic factor for LN metastasis and a target for novel treatments in patients with melanoma.

Background: Pathogenesis of psoriasis is related to dysregulated keratinocyte function and immune responses. Genetic background is one of the most important factors in disease pathogenesis. However, psoriasis-associated genes have not yet been fully identified. Activating transcription factor 3 (ATF3) is a member of the cyclic adenosine monophosphate responsive element-binding protein family of transcription factors, which may regulate epidermal keratinocytes. Objective: We aimed to evaluate the effects of ATF3 on inflammation and differentiation of keratinocytes. Methods: We evaluated the expression of ATF3 in polyinosinic:polycytidylic acid (poly[I:C])-treated keratinocytes. Subsequently, we compared ATF3 levels in psoriatic and normal skin using immunohistochemical staining. To illustrate the role of ATF3, we generated ATF3-overexpressing keratinocytes and ATF3-knockdown keratinocytes using a recombinant adenovirus. We investigated inflammation and differentiation of keratinocytes by measuring the mRNA levels of inflammatory cytokines and differentiation markers. Results: Treatment of keratinocytes with poly(I:C) increased ATF3 expression in a time-dependent manner. Immunohistochemical staining showed that ATF3 expression was increased in the epidermis of psoriatic tissues. When ATF3 was overexpressed in keratinocytes using a recombinant adenovirus, poly(I:C)-induced inflammation was reduced. Conversely, ATF3 knockdown increased poly(I:C)-induced inflammation. Thus, ATF3 overexpression inhibited keratinocyte differentiation, while ATF3 knockdown promoted it. Conclusion ATF3 may be involved in the pathogenesis of psoriasis by influencing the inflammatory response and differentiation of keratinocytes.

Background: Increased sebum secretion is considered the main causative factor in the pathogenesis of acne. There is an unmet pharmacological need for a novel drug that can control sebum production with a favorable adverse effect profile. Objective: To investigate the effect of azidothymidine on lipid synthesis in sebocytes and to identify the underlying mechanism of the inhibitory effect of azidothymidine on insulin-like growth factor (IGF)-1-induced lipid synthesis in sebocytes. Methods: Immortalized human sebocytes were used for the analysis. Thin-layer chromatography (TLC) and Oil Red O staining were performed to evaluate lipid synthesis in the sebocytes. The differentiation, lipid synthesis, mitochondrial biogenesis, and mitophagy in sebocytes were investigated. Results: TLC and Oil Red O staining revealed that azidothymidine reduced IGF-1 induced lipid synthesis in the immortalized human sebocytes. Azidothymidine also reduced IGF-1-induced expression of transcriptional factors and enzymes involved in sebocyte differentiation and lipid synthesis, respectively. Moreover, we found that IGF-1 upregulated the levels of peroxisome proliferator-activated receptor-gamma coactivator-1α, LC-3B, p62, and Parkin, major regulators of mitochondrial biogenesis and mitophagy in immortalized human sebocytes. In contrast, azidothymidine inhibited IGF-1 induced mitochondrial biogenesis and mitophagy in the sebocytes. Conclusion These results suggest that azidothymidine downregulates IGF-1-induced lipogenesis by dysregulating the quality of mitochondria through suppression of mitochondrial biogenesis and mitophagy in immortalized human sebocytes. Our study provides early evidence that azidothymidine may be an effective candidate for a new pharmacological agent for controlling lipogenesis in sebocytes.

Background: Hormone therapy, which includes tamoxifen and aromatase inhibitors, is the most common adjuvant therapy used for breast cancer. However, only a few studies have reported endocrine therapy induced alopecia. Objective: We investigated the effects of long-term adjuvant hormone therapy on hair in patients with breast cancer, in addition to patients’ concerns and current treatment for hair loss. Methods: Patients completed a questionnaire that included information on self-perceived hair changes after each adjuvant therapy session, distress, and current treatment for hair loss. Using a folliscope, we measured hair density and thickness in each patient and in healthy controls. Results: The study included 93 patients with breast cancer (mean age 51.9±9.8 years). The density and hair thickness were 106.36±21.85 hairs/cm2 and 0.07±0.01 mm in the patient group and 147.86±30.67 hairs/cm2 and 0.07±0.01 mm in the control group (n=98, mean age 52.10±8.40 years), respectively. The mean hair density was significantly lower in the patient group than in the control group; however, no statistically significant intergroup difference was observed in hair thickness. Among 76 patients who perceived hair changes after adjuvant therapy, 71.1% (n=54) were distressed with regard to hair changes. However, only 7.8% of the patients, including two who were treated by dermatologists, currently received treatment for hair changes. Conclusion Dermatologists should be familiar with hair changes in patients with breast cancer and provide appropriate education to encourage patients to consult dermatologists for hair loss and thinning after breast cancer treatment.