Objectives: We introduced the cohort studies included in the Korean Cohort Consortium (KCC), focusing on large-scale cohort studies established in Korea with a prolonged follow-up period. Moreover, we also provided projections of the follow-up and estimates of the sample size that would be necessary for big-data analyses based on pooling established cohort studies, including population-based genomic studies. Methods: We mainly focused on the characteristics of individual cohort studies from the KCC. We developed “PROFAN”, a Shiny application for projecting the follow-up period to achieve a certain number of cases when pooling established cohort studies. As examples, we projected the follow-up periods for 5000 cases of gastric cancer, 2500 cases of prostate and breast cancer, and 500 cases of non-Hodgkin lymphoma. The sample sizes for sequencing-based analyses based on a 1:1 case-control study were also calculated. Results: The KCC consisted of 8 individual cohort studies, of which 3 were community-based and 5 were health screening-based cohorts. The population-based cohort studies were mainly organized by Korean government agencies and research institutes. The projected follow-up period was at least 10 years to achieve 5000 cases based on a cohort of 0.5 million participants. The mean of the minimum to maximum sample sizes for performing sequencing analyses was 5917-72 102. Conclusions We propose an approach to establish a large-scale consortium based on the standardization and harmonization of existing cohort studies to obtain adequate statistical power with a sufficient sample size to analyze high-risk groups or rare cancer subtypes.

BACKGROUND/AIMS: Since patients with human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) have favorable outcomes after treatment, treatment de-escalation for these patients is being actively investigated. However, not all HPV-positive HNSCCs are curable, and some patients have a poor prognosis. The purpose of this study was to identify poor prognostic factors in patients with HPV-positive HNSCC. METHODS: Patients who received a diagnosis of HNSCC and tested positive for HPV from 2000 to 2015 at a single hospital site (n = 152) were included in this retrospective analysis. HPV typing was conducted using the HPV DNA chip assay or liquid bead microarray system. Expression of p16 in the tumors was assessed by immunohistochemistry. To determine candidate factors associated with overall survival (OS), univariate and multivariable Cox regression analyses were performed. RESULTS: A total of 152 patients with HPV-positive HNSCC were included in this study; 82.2% were male, 43.4% were current or former smokers, and 84.2% had oropharyngeal cancer. By univariate analysis, old age, performance status ≥ 1, non-oropharyngeal location, advanced T classification (T3–4), and HPV genotype 18 were significantly associated with poor OS. By multivariable analysis, performance status ≥ 1 and non-oropharyngeal location were independently associated with shorter OS (hazard ratio [HR], 4.36, p = 0.015; HR, 11.83, p = 0.002, respectively). Furthermore, HPV genotype 18 positivity was also an independent poor prognostic factor of OS (HR, 10.87, p < 0.001). CONCLUSIONS Non-oropharyngeal cancer, poor performance status, and HPV genotype 18 were independent poor prognostic factors in patients with HPV-positive HNSCC. Patients with these risk factors might not be candidates for de-escalation treatment.

BACKGROUND: Epidural steroid injection (ESI) is one of the most common procedures for patients presenting low back pain and radiculopathy. However, there is no clear consensus on what constitutes appropriate steroid use for ESIs. To investigate optimal steroid injection methods for ESIs, surveys were sent to all academic pain centers and selected private practices in Korea via e-mail. METHODS: Among 173 pain centers which requested the public health insurance reimbursements for their ESIs and were enrolled in the Korean Pain Society, 122 completed questionnaires were returned, for a rate of 70.5%; also returned were surveys from 39 academic programs and 85 private practices with response rates of 83.0% and 65.9%, respectively. RESULTS: More than half (55%) of Korean pain physicians used dexamethasone for ESIs. The minimum interval of subsequent ESIs at the academic institutions (3.1 weeks) and the private practices (2.1 weeks) were statistically different (P = 0.01). CONCLUSIONS: Although there was a wide range of variation, there were no significant differences between the academic institutions and the private practices in terms of the types and single doses of steroids for ESIs, the annual dose of steroids, or the limitations of doses in the event of diabetes, with the exception of the minimum interval before the subsequent ESI.
Consensus ; Dexamethasone ; Electronic Mail ; Humans ; Insurance ; Korea ; Low Back Pain ; Pain Clinics ; Private Practice ; Public Health ; Surveys and Questionnaires ; Radiculopathy ; Steroids ; Triamcinolone

OBJECTIVES: This study was performed to evaluate the pregnancy rate following the transfers of frozen- thawed embryos which was derived from intracytoplasmic sperm injection (ICSI) using sperm obtained by ejaculated, testicular sperm extraction (TESE), and frozen-thawed testicular sperm extraction (t-TESE). METHODS: Frozen-thawed embryos were successfully transferred to the patients in 664 cycles among 695 cycles from January 1998 to December 2002, where ICSI was done with various origins of sperm. Subjects were divided into three groups according to the origin of sperm; ejaculated sperm group as a control (n=535), TESE group (n=98) and t-TESE group (n=62). After conventional ICSI, the supernumerary PN stage or developing embryos were cryopreserved by slow freezing protocol with 1, 2-propanediol as cryoprotectant. RESULTS: The survival rate of frozen-thawed embryos was 77.7% (2515/3236) in ejaculated sperm group, 76.6% (441/576) in TESE group and 83.9% (292/348) in frozen-thawed TESE group, respectively. The difference of survival rate of between t-TESE group and other two groups was statistically significant (p<0.01). The good embryo formation rate and positive beta-hCG rate was 46.3% (1164/2515), 28.8% (148/513) in ejaculated sperm group, 49.2% (217/441), 36.6% (34/93) in TESE group and 46.2% (135/292), 34.9% (22/63) in frozen-thawed TESE group, respectively. CONCLUSION: This study demonstrates that comparable pregnancy rate and implantation rate could be achieved after the transfer of frozen-thawed embryos following ICSI using various sources of sperm. As there was no statistically significant difference in pregnacy rate between ICSI with fresh testicular sperm and with frozen-thawed testicular sperm, the sequential cryopreservation of supernumerary testicular sperm and embryos may be a useful method for increasing pregnancy outcome in infertile couples with male factor.
Cryopreservation ; Embryonic Structures* ; Family Characteristics ; Female ; Freezing ; Humans ; Male ; Pregnancy ; Pregnancy Outcome* ; Pregnancy Rate ; Pregnancy* ; Sperm Injections, Intracytoplasmic* ; Spermatozoa* ; Survival Rate

OBJECTIVE: To compare the pregnancy outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) between obstrucvtive and non-obstrucvtive azoospermia. METHODS: From January 1994 to December 2002, 524 patients with obstructive azoospermia (886 cycles) and 163 patients with non-obstructive azoospermia (277 cycles) were included in this study. Microsurgical epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) in obstructive azoospermia and TESE in non-obstructive azoospermia were perfomed to retrieve sperm, which was used for ICSI and then fertilized embryos were transferred. The results of ICSI-fertlization rate (FR), clinical pregnancy rate (CPR), clinical abortion rate (CAR) and delivery rate (DR)- were statistically analysed in obstructive versus non-obstructive azoospermia. RESULTS: There were no differences in the number of retrieved oocytes, injected oocytes for ICSI and oocyte maturation rate. FR was significantly higher in obstructive than non-obstructive azoospermia (71.7% vs. 61.1%, p<0.001). There was no difference in CPR per embryo transfer cycle. After pregnancy was established, however, CAR was significantly higher in non-obstructive than obstructive azoospermia (25.6% vs. 12.5%, p=0.004). DR per clinical pregnancy cycle was significantly higher in obstructive than non-obstructive azoospermia (78.0% vs. 64.4%, p=0.012). In the karyotype ananlysis of abortus, abnormal karyotypes were found in 75.0% (6/8) of obstructive and 55.6% (5/9) of non-obstructive azoospermia. CONCLUSION: Our data show significantly higher FR in obstructive than non-obstructive azoospermia. Though there was no differrence in CPR, CAR was significantly higher in non-obstructive than obstructive azoospermia. The abortion may be related to the abnormal karyotype of embryo, but further investigations are necessary to elucidate the cause of clinical abortion in azoospermia.
Abnormal Karyotype ; Abortion, Induced ; Azoospermia* ; Cardiopulmonary Resuscitation ; Embryo Transfer ; Embryonic Structures ; Female ; Fertilization in Vitro* ; Humans ; Karyotype ; Oocytes ; Pregnancy ; Pregnancy Outcome* ; Pregnancy Rate ; Pregnancy* ; Sperm Injections, Intracytoplasmic* ; Sperm Retrieval ; Spermatozoa

MRSA strains cause serious nosocomial infections. The rate of MRSA among Staphylococcus aureus isolated in Korea is about 70 - 80%. The treatment for MRSA infection is vancomycin. But vancomycin has several side effects and its therapeutic rate is 60 - 75%. Therefore the disinfectants play an important role in preventing and treating MRSA infection. In this study, 44 MRSA isolates were obtained from Wonkwang University Hospital, and examined for the efficacy of disinfectants commonly used in hospital. The tested disinfectants were chlorohexidine (Hibitan(R)), H2O2, tego, Gentian Violet, potadine, chlorohexidine gluconate (Microshield(R)), boric acid, alcohol, zepanon, acetic acid, and combinations of these disinfectants. MRSA studied were killed after exposure to chlorohexidine gluconate (Microshield (R)), alcohol, zepanon, alcohol+potadine, and alcohol+Gentian Violet within 30 seconds. But, tego, boric acid, and Gentian Violet+acetic acid could not kill MRSA after 30 minutes. Agar dilution minimal inhibitory concentration test was done with cephalothin, ciprofloxacin, clindamycin, erythromycin, fusidic acid, gentamicin, mupirocin, oxacillin, penicillin G, rifampin, tetracycline, and vancomycin. We found that bactericidal activity of vancomycin, fusidic acid, and mupirocin were good. In conclusion, this study provided useful information: 75% alcohol is the best disinfectant for wound dressing, 4% chlorohexidine gluconate(Microshield(R)) is useful for hand washing, and zepanon is useful for ward cleansing. Vancomycin-resistant Staphylococcus aureus was not found in our study.
Acetic Acid ; Agar ; Anti-Bacterial Agents* ; Bandages ; Cephalothin ; Ciprofloxacin ; Clindamycin ; Cross Infection ; Disinfectants* ; Erythromycin ; Fusidic Acid ; Gentamicins ; Gentian Violet ; Gentiana ; Hand Disinfection ; Korea ; Methicillin-Resistant Staphylococcus aureus* ; Mupirocin ; Oxacillin ; Penicillin G ; Rifampin ; Staphylococcus aureus ; Tetracycline ; Vancomycin ; Viola ; Wounds and Injuries

For the diagnosis of nasal bone fracture and medial orbital wall fracture, plain radiography and computerized tomography(CT) have been utilized. But plain radiography is less reliable due to its low specificity. So CT has been given a preference to plain radiography in examining both fractures. However, CT has some disadventages; high expense, heavy radiation hazard, and coexistent injuries may restricted a patient,s positioning and so thus preventing or delaying the diagnosis. By comparison, ultrasonography(US) represents a safe, inexpensive, noninvasive, portable, and wide availability. This paper compares the relative values of CT and US in the diagnosis of both fractures. In nasal bone fracture, US proved to be more accurate than CT. Thirty-seven nasal bone fractures were diagnosed by US; whereas only thirty-two of these were revealed on CT. Compared with US, CT demonstrated 87% sensitivity. In examining medial orbital wall fracture, eight cases were diagnosed by CT; whereas seven of these were revealed on US. Compared with CT, US demonstrated 88% sensitivity. In medial orbital wall fracture, US was almost as accurate as CT. In this research, it is concluded that in the investigation of nasal bone fracture and medial orbital wall fracture, US is an accurate diagnostic modality and correlates well with CT.
Diagnosis* ; Nasal Bone* ; Orbit* ; Radiography ; Sensitivity and Specificity

Angiosarcoma is a rare malignant vascular tumor featuring endothelial cells. Angiosarcoma have four clinical manifestations that are angiosarcoma in the scalp and face, angiosarcoma in chronic lymphedematous areas, angiosarcoma in previously irradiated sites and malignant angioendothelioma. The most common lesions are those that occur in the scalp and in the face of elderly people. The male to female ratio is 2 : 1. In my case, a 65-years-old male presented progressively growing tumor on the left frontal scalp. The tumor began as an ill-defined bluish macule, which was initially mistaken for an old bruise. The rapidly growing lesion extended to form violaceousm compressible and hemorrhagic plaques. The mass was 6 x 4.5 cm in size. Distinguishing features are the frequent occurrence of a peripheral erythematous ring, satellite nodules, the presence of intratumoral hemorrhage, and the tendency to bleed spontaneously, or after minimal trauma. Histologically the tumor comprised anaplastic pleomorphic endothelial cells with new vascular channels and irregular vascular spaces lined by plump endothelial cell's stroma among them. The lesion was diagnosed as angiosarcoma. No metastasis to other organs were found as evaluated by chest CT, bone and liver scan. We performed wide excision, skin graft, bilateral transposition flap, chemotherapy and radiation. The tumor was recurred at 4 months after surgical excision and with metastasis to the lung. The progress was characterized by an extremely rapid growth accompanied by distant metastasis. Surgery, irradiation and chemotherapy having no effect on the final outcome, the patient died 7 months after diagnosis.
Aged ; Contusions ; Diagnosis ; Drug Therapy ; Endothelial Cells ; Female ; Hemangiosarcoma* ; Hemorrhage ; Humans ; Liver ; Lung ; Male ; Neoplasm Metastasis ; Scalp* ; Skin ; Tomography, X-Ray Computed ; Transplants

Angiosarcoma is a rare malignant vascular tumor featuring endothelial cells. Angiosarcoma have four clinical manifestations that are angiosarcoma in the scalp and face, angiosarcoma in chronic lymphedematous areas, angiosarcoma in previously irradiated sites and malignant angioendothelioma. The most common lesions are those that occur in the scalp and in the face of elderly people. The male to female ratio is 2 : 1. In my case, a 65-years-old male presented progressively growing tumor on the left frontal scalp. The tumor began as an ill-defined bluish macule, which was initially mistaken for an old bruise. The rapidly growing lesion extended to form violaceousm compressible and hemorrhagic plaques. The mass was 6 x 4.5 cm in size. Distinguishing features are the frequent occurrence of a peripheral erythematous ring, satellite nodules, the presence of intratumoral hemorrhage, and the tendency to bleed spontaneously, or after minimal trauma. Histologically the tumor comprised anaplastic pleomorphic endothelial cells with new vascular channels and irregular vascular spaces lined by plump endothelial cell's stroma among them. The lesion was diagnosed as angiosarcoma. No metastasis to other organs were found as evaluated by chest CT, bone and liver scan. We performed wide excision, skin graft, bilateral transposition flap, chemotherapy and radiation. The tumor was recurred at 4 months after surgical excision and with metastasis to the lung. The progress was characterized by an extremely rapid growth accompanied by distant metastasis. Surgery, irradiation and chemotherapy having no effect on the final outcome, the patient died 7 months after diagnosis.
Aged ; Contusions ; Diagnosis ; Drug Therapy ; Endothelial Cells ; Female ; Hemangiosarcoma* ; Hemorrhage ; Humans ; Liver ; Lung ; Male ; Neoplasm Metastasis ; Scalp* ; Skin ; Tomography, X-Ray Computed ; Transplants

The Q-switched lasers which was introduced under the concept of selective photothermolysis. Q-switched Nd:YAG laser, which targets dark pigments in a longer wave length (1064 nm) that has less absorption by melanin, can effectively treat deep tattoos with less pigmentary alterations. We report our experience over the past 3 years in treating 565 patients with tattoos and cutaneous pigmented lesions using the Q-switched Nd:YAG laser. Patients were exposed with a pulse duration of 10 ns and fluences of 6, 7 J/cm2(1064 nm) or 12, 14 J/cm2(532 nm), in exposure spots of 2 mm or 3 mm, at intervals of 4 weeks. Q-switched Nd:YAG laser was effective in removing deep pigmented lesion with 1064 nm, and colored inks with 532 nm. Seventy-three percent of amateur black pigmented lesion were > 75% clear after four to ten treatment. Ninty-eight percent of professional black pigmented lesion were > 75% clear after two on eyebrow, six to eight on extremity and trunk. No significant side effects, including pigmentary changes or scarring, were noted.
Absorption ; Cicatrix ; Extremities ; Eyebrows ; Humans ; Ink ; Melanins