• Genomics & Informatics
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• v.16 no.2
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• pp.30-35
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• 2018

Patient-derived xenograft (PDX) models are useful tools for tumor biology research and testing the efficacy of candidate anticancer drugs targeting the druggable mutations identified in tumor tissue. However, it is still unknown how much of the genetic alterations identified in primary tumors are consistently detected in tumor tissues in the PDX model. In this study, we analyzed the genetic alterations of three primary colorectal cancers (CRCs) and matched xenograft tissues in PDX models using a next-generation sequencing cancer panel. Of the 17 somatic mutations identified from the three CRCs, 14 (82.4%) were consistently identified in both primary and xenograft tumors. The other three mutations identified in the primary tumor were not detected in the xenograft tumor tissue. There was no newly identified mutation in the xenograft tumor tissues. In addition to the somatic mutations, the copy number alteration profiles were also largely consistent between the primary tumor and xenograft tissue. All of these data suggest that the PDX tumor model preserves the majority of the key mutations detected in the primary tumor site. This study provides evidence that the PDX model is useful for testing targeted therapies in the clinical field and research on precision medicine.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.164-168
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• 1997

Multiple primary tumors in the head and neck are not uncommon, however those in the thyroid and the larynx are known to be very rare. In most cases of multiple primary tumors involving the thyroid and the larynx, lesions are observed usually simultaneously and thyroid tumors are found incidentally during the laryngeal tumor surgery. In rare cases, thyroid tumors are found metachronously after radiation therapy of laryngeal cancer. The authors recently experienced a case of multiple primary tumor involving the thyroid and the larynx, in which thyroid papillary carcinoma was the index tumor and the laryngeal squamous carcinoma was the meatachronous second tumor. Both tumors showed aggressive local extension and regional nodal meatastasis with tumor collision in the same node. The patient died of recurrent or of residual squamous carcinoma shortly after main surgical treatment index thyroid cancer.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.61-70
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• 2020

Background: Circulating tumor cells (CTCs) are frequently detected in patients with advanced-stage malignant tumors and could act as a predictor of poor prognosis. However, there is a paucity of data on the relationship between CTC number and primary tumor volume in patients with lung cancer. Therefore, our study aimed to evaluate the relationship between CTC number and primary tumor volume in patients with lung adenocarcinoma. Methods: We collected blood samples from 21 patients with treatment-naive lung adenocarcinoma and 73 healthy individuals. To count CTCs, we used a CTC enrichment method based on fluid-assisted separation technology. We compared CTC numbers between lung adenocarcinoma patients and healthy individuals using propensity score matching, and performed linear regression analysis to analyze the relationship between CTC number and primary tumor volume in lung adenocarcinoma patients. Results: CTC positivity was significantly more common in lung adenocarcinoma patients than in healthy individuals (p<0.001). The median primary tumor volume in CTC-negative and CTC-positive patients was 10.0 ㎤ and 64.8 ㎤, respectively. Multiple linear regression analysis showed that the number of CTCs correlated with primary tumor volume in lung adenocarcinoma patients (β=0.903, p=0.002). Further subgroup analysis showed a correlation between CTC number and primary tumor volume in patients with distant (p=0.024) and extra-thoracic (p=0.033) metastasis (not in patients with distant metastasis). Conclusion: Our study showed that CTC numbers may be associated with primary tumor volume in lung adenocarcinomas patients, especially in those with distant metastasis.

• Journal of Digestive Cancer Research
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• v.5 no.1
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• pp.32-36
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• 2017

In unresectable stage IV colorectal cancer, the role of palliative surgery is not defined clearly. The palliative surgery can be categorized into two surgeries; first, palliative primary tumor resection; second, palliative metastatectomy. Several retrospective studies reported initial palliative systemic chemotherapy in unresectable stage IV colorectal cancer did not increase primary tumor related complications such as obstruction, perforation and hemorrhage, so they insisted that primary tumor resection in asymptomatic stage IV colorectal cancer should be preserved. However, in terms of overall survival and cancer-specific or progression-free survival, several retrospective studies, especially using population-based big data, reported favored survivals in palliative primary tumor resection group. And also several studies reported that palliative metastatectomy such as liver resection without resection of lung metastasis showed better overall survivals. But those results from those studies came from retrospective studies and are likely to be affected by selection bias. Prospective randomized studies are needed to define the benefit of palliative primary tumor resection and metastatectomy in unresectable stage IV colorectal cancer. However, based on the updated evidences, the dogma that palliative primary tumor resection should be preserved in asymptomatic unresectable stage IV colorectal cancer should be questioned.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.145-152
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• 2010

Objective : The aim of this report is to provide accurate nationwide epidemiologic data on primary central nervous system (CNS) tumors in Korea. Despite its importance, there are no accurate statistics on primary CNS tumors in Korea. We analyzed primary CNS tumors diagnosed in 2005 from the nationwide registry. Methods : Data on primary CNS tumors diagnosed in 2005 were collected from the Korean Central Cancer Registry and the Korean Brain Tumor Society. Crude and age-standardized rates were calculated in terms of gender, age, and histological type. Tumors of uncertain histology were investigated individually at the corresponding hospitals and had their diagnoses confirmed. Results : A total of 5,692 patients diagnosed with primary CNS tumors in 2005 were included in this study. CNS tumors occurred in females more often than in males (female to male, 1.43 : 1). The most common tumor was meningioma (31.2%). Glioblastoma accounted for 30.7% of all gliomas, and 19.3% of all malignant primary CNS tumors. In children under 19 years of age, both germ cell tumor and embryonal/primitive/medulloblastoma were the most common tumors. Conclusion : This article is the first nationwide primary CNS tumor epidemiology report in Korea. Data from this study should provide valuable information regarding the understanding of primary CNS tumors epidemiology in Korea.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.195-204
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• 2017

Objective : This 2009-2011 nation-wide study of adult Koreans was aimed to provide characteristics, medical utilization states, and survival rates for newly diagnosed patients with primary nonmalignant and malignant spine tumors. Methods : Data for patients with primary spine tumors were selected from the Korean Health Insurance Review and Assessment Service database. The data included their age, sex, health insurance type, co-morbidities, medical cost, and hospital stay duration. Hospital stay duration and medical costs per person occurring in one calendar year were used. In addition, survival rates of patients with primary malignant spine tumors were evaluated. Results : The incidence rate of a primary spine tumor increased with age, and the year of diagnosis ($p{\leq}0.0001$). Average annual medical costs ranged from 1627 USD (pelvis & sacrum & coccyx tumors) to 6601 USD (spinal cord tumor) for primary nonmalignant spine tumor and from 12137 USD (spinal meningomas) to 20825 USD (pelvis & sacrum & coccyx tumors) for a primary malignant spine tumor. Overall survival rates for those with a primary malignant spine tumor were 87.0%, 75.3%, and 70.6% at 3, 12, and 24 months, respectively. The Cox regression model results showed that male sex, medicare insurance were significantly positive factors affecting survival after a diagnosis of primary malignant spine tumor. Conclusion : Our study provides a detailed view of the characteristics, medical utilization states, and survival rates of patients newly diagnosed with primary spine tumors in Korea.

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1265-1268
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• 1992

Primary tumors of the heart are extremely rare, and about 25 per cent of all primary cardiac tumors are malignant. Recently We experinced three cases of primary malignant tumor; malignant fibrous histiwytoma, carcinosarcoma, and synovial sarcoma, These three cases involved 2 men and 1 woman. There was one operative death, and two operative survivors died of metastatic disease at 12 months postoperatively in spite of chemotherapy and radiotherapy. We report these three cases of primary malignant cardiac tumors with review of the literatures.

• Journal of Breast Disease
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• v.6 no.2
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• pp.73-78
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• 2018

Primary angiosarcoma of the breast is extremely rare and is observed in 0.0005% to 0.05% of primary breast tumor cases. The diagnosis of this tumor is difficult due to its undefined characteristics. Radiologic findings are often nonspecific and appear completely normal in one-third of patients with primary angiosarcomas. The prognosis is usually poor, and the treatment choices include mastectomy or wide excision. Radiotherapy and chemotherapy produce varying results. We report a patient with primary angiosarcoma of the breast to further our understanding of the characteristics of this tumor and facilitate the correct diagnosis of breast angiosarcoma.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.186-189
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• 2007

Metastasizing mixed tumors [MMT] of salivary glands are inexplicably metastasize maintaining benign histology. There is no pathologic and flow cytometric analysis criteria to predict the metastasis. MMT is known to metastasize by local implantation, vascular and lymphatic embolization after multiple surgery to local recurrences of primary tumor. However, multiple metastasis including cranium and spine occurred even without surgery to the primary tumor in this case. No pathological evidence of malignancy could be found in both primary and metastatic tumor. MMT is considered as an low grade malignancy based on clinical behavior rather than histologic evidence, such as low mortality rate, long delay of metastasis after primary lesion. Cranial metastasis is also extremely rare and only two cases have been reported. We report this unusual case with a literature review.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.4
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• pp.221-226
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• 2016

Spindle cell carcinoma (SpCC) is referred to as a variant of oral squamous cell carcinoma. It is also known as "sarcomatoid squamous cell carcinoma" because it consists of normal squamous carcinoma cells with spindle-shaped cells that appear similar to a sarcoma. The term, "second primary tumor" (SPT) or "double primary tumor", is proposed for a second tumor that develops independently from the first. SPTs can present as either synchronous or metachronous lesions. Synchronous SPTs are defined as tumors occurring simultaneously or within 6 months after the first tumor. The patient in this case, whose primary tumor was in the tongue, was diagnosed with SpCC with metastases to both neck lymph nodes. This case also exhibited a second primary cancer as a synchronous lesion in the thyroid gland, which is uncommon. All carcinomas, both in the tongue and thyroid gland, were removed surgically, and especially in the tongue, an anterolateral thigh free flap was performed successfully to replace the defect.