• 대한두경부종양학회지
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• 제33권1호
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• pp.15-19
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• 2017

Background/Objective: The survival and recurrence pattern of the patients with primary cancer of the external auditory canal was evaluated. Materials & Methods: Seventeen patients with primary cancer of the external auditory canal from 2002 to 2013 was analyzed retrospectively. Overall survival, recurrence free survival, local recurrence free survival and distant metastasis free survival was calculated by Kaplan-Meyer's method. Results: Five year overall survival rate, 5 year recurrence free survival rate, 5 year local recurrence free survival rate and 5 year distant metastasis free survival rate were 49.3% 54.9%, 64.7% and 69.6% respectively. The recurrence pattern is different to the pathologic type, squamous cell carcinoma or adenoid cystic carcinoma. The patients with squamous cell carcinoma showed local recurrence and the patients with adenoid cystic carcinoma showed distant metastasis mainly. Conclusion: Primary cancer of external auditory canal showed different clinical course depend on the pathologic diagnosis.

• Journal of Gastric Cancer
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• 제12권2호
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• pp.88-98
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• 2012

Purpose: Local recurrence, due to residual tumor, may occur after endoscopic resection for early gastric cancer. The aims of this study are to evaluate the predictive factors for local recurrence, and suggest an appropriate follow-up biopsy strategy. Materials and Methods: We retrospectively reviewed 396 early gastric cancers from 372 consecutive patients, who underwent endoscopic resection between January 2002 and April 2008. Cumulative recurrence rates were determined by the Kaplan-Meier method, and Cox proportional hazard analysis was used to determine the risk factors for local recurrence. Results: Local recurrence at the endoscopic resection site was found in 17 cases, among the total 396 lesions, during a median follow-up period of 48 months. The 5-year cumulative local recurrence rate was 4.8%. Multivariate analyses determined that tumor involvement at the lateral resection margin [hazard ratio: 35.9; P<0.001], uncheckable lateral resection margin [hazard ratio: 16.8; P<0.001], uncheckable or involved deep resection margin [hazard ratio: 3.76; P=0.047], and piecemeal resection [hazard ratio: 3.95; P=0.007] were associated with local recurrence. If a lesion was positive for any of these risk factors, the 5-year cumulative recurrence rate was 27.0%, while local recurrence was not found in any lesion that lacked these risk factors. Most episodes of recurrence were found during the first or second follow-up endoscopic biopsy at the ulcer scar. Conclusions: Routine follow-up biopsies at the endoscopic resection site might be unnecessary in cases where an early gastric cancer lesion was endoscopically resected en bloc with tumor-free lateral and deep margins.

• Journal of Korean Neurosurgical Society
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• 제53권4호
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• pp.228-234
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• 2013

Objective : We have limited understanding on the presentation and survival of primary spinal sarcomas. The survival, recurrence rate, and related prognostic factors were investigated after treatment for primary sarcomas of the spine. Methods : Retrospective analysis of medical records and radiological data was done for 29 patients in whom treatment was performed due to primary sarcoma of the spine from 2000 to 2010. As for treatment method, non-radical operation, radiation therapy, and chemotherapy were simultaneously or sequentially combined. Overall survival (OS), progression free survival (PFS), ambulatory function, and pain status were analyzed. In addition, factors affecting survival and recurrence were analyzed : age (${\leq}42$ or ${\geq}43$), gender, tumor histologic type, lesion location (mobile spine or rigid spine), weakness at diagnosis, pain at diagnosis, ambulation at diagnosis, initial treatment, radiation therapy, kind of irradiation, surgery, chemotherapy and distant metastasis. Results : Median OS was 60 months, the recurrence rate was 79.3% and median PFS was 26 months. Patients with distant metastasis showed significantly shorter survival than those without metastasis. No factors were found to be significant relating to recurrence. Prognostic factor associated with walking ability was the presence of weakness at diagnosis. Conclusion : Primary spinal sarcomas are difficult to cure and show high recurrence rate. However, the development of new treatment methods is improving survival.

• 대한두개안면성형외과학회지
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• 제22권3호
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• pp.135-140
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• 2021

Background: Wide surgical excision is the gold standard for basal cell carcinoma (BCC) treatment. Typically, resection requires a safety margin ≥ 4 mm. We aimed to confirm BCC excisions' cancer recurrence rate and safety on the facial region with new safety margins. Methods: We included patients with primary BCC on the facial region who underwent wide excision with 2- or 3-mm safety margins at our institution between January 2010 and December 2018. Medical records were reviewed to confirm the epidemiology and surgical information. Recurrence was confirmed by physical examination through regular 6-month follow-up. Results: We included 184 out of 233 patients in this study after applying the exclusion criteria. The mean age and follow-up period were 71.2±10.2 years and 29.3±13.5 months, respectively. The predominantly affected area was the nose (95 cases); a V-Y advancement flap was the most commonly used surgical method. There were two cases of recurrence in the 2 mm margin group and one recurrence in the group resected with 3 mm margins. Conclusion: In this large cohort study, we found 2-3 mm excision margins can yield enough safety in facial BCCs. The recurrence rates were found to be comparable with those reported after wider margins.

• Journal of Korean Neurosurgical Society
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• 제30권11호
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• pp.1278-1283
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• 2001

Objective : Transsphenoidal approach(TSA) has been used as useful operative method for pituitary tumor but is still controversal in case of cavernous sinus invasion or severe suprasellar extension. This study was performed to evaluate the surgical result, recurrence, effect of adjuvant treatment, especially in cases of suprasellar extension or cavernous sinus invasion. Material and Methods : We studied 56 cases of surgically treated pituitary adenoma that we were able to follow up, treated by TSA from 1993 to 1998. There were 24 cases of suprasellar extension and 11 cases of cavernous sinus invasion. The medical records and radiological findings were reviewed. Surgical results including hormonal function and recurrence rates were analyzed according to extent of tumor invasion. Mean follow-up period was 19.1 months. Results : Tumors with suprasellar extension were removed totally in 54%, whereas total tumor removal was possible only in 38% with cavernous sinus invasion. Overall of recurrence rate was 14% and recurrence rate was 25% in suprasellar extension and 9% in cavernous sinus invasion. In cases of both suprasellar extension and cavernous sinus invasion, tumors that were treated by TSA and radiation showed recurrence rate of 7%, whereas those treated by surgery alone showed 28% of recurrence. Conclusion : Transsphenoidal approach is safe and useful operative method for pituitary adenoma and adjuvant therapy including radiation therapy is effective means to decrease the recurrence in cases of suprasellar extension or cavernous sinus invasion.

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.116-120
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• 2005

Objective : The aim of this study is to analyze the clinical symptoms, radiological changes, interval from first operation to symptom recurrence and to propose the proper treatment method for re-operated patients following chronic subdural hematoma surgery. Methods : Between January 1992 and April 2003, 18 of 138patients of chronic subdural hematoma repeatedly underwent surgical treatment. The symptoms, mental status by Bender grade, radiological hematoma size and midline shifting, interval from symptom onset to diagnosis, surgical method and prognosis by Glasgow outcome scale[GOS] between the first attack and the recurrence were compared. Results : The symptoms at the time of recurrence were nearly the same as with the first attack, but two patients[2/18, 11.1%] showed a more declined mentality. In addition, the recurred hematoma sizes were the same or large than those previously found. Many patients were recurred within two weeks[13/18, 72.2%]. Most patients were operated on using the previous burr hole, with the exception of one patient who recurred at a different site. All patients had a good prognosis more than GOS 4 [GOS 4:4, GOS 5:12], but two died due to extracranial complication and infection. Conclusion : These results suggest that the early diagnosis and treatment are important, mostly recurred same symptoms within two weeks. Re-operation using the previous burr hole site is a good method.

• Journal of the Korean Data and Information Science Society
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• 제14권2호
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• pp.385-391
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• 2003

A sequence of n Bernoulli trials which violates the constant success probability assumption is termed as "Poisson trials". In this paper, the recurrence formula for the r-th central moment of number of successes with n Poisson trials is derived. Romanovsky's method, based on the differentiation of characteristic function, is used in the derivation of recurrence formula for the central moments of conventional binomial distribution. Romanovsky's method is applied to that of Poisson trials in this paper. Some central moment calculation results are given to compare the central moments of Poisson trials with those of conventional binomial distribution.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.58-65
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• 1998

A purpose of this research is to develope the calculation methods of design input seismic loads, Where, calculation methods are ; (1) Considering different recurrence period of earthquakes which was proposed by ATC 14. (2) Using earthquake records which was modified Korean codes. Responce spectra that was adopted by codes has an estimated recurrence interval of 500 years, with approximately a 90 percent probability of not being exceeded in 50 years. But If we considered the life-time of existing buildings in some cases, response spectra be modified with return period of earthquakes. If we be design highrise and irregular buildings, dynamic analysis method that use time history records should be used. But in Korea, time history records of earthquakes was very few. Therefore to use foreign countries's earthquake record, it is need to select of records considered Korean coeds. As a results, this study propose a calculation method of seismic design input loads that considered return period of earthquakes and also propose using method of earthquakes.

• 호남수학학술지
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• 제46권1호
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• pp.136-145
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• 2024

In this paper we obtained several properties that the characteristic polynomial of the unit-primitive matrix satisfies. In addition, using these properties we have shown that the recurrence relation given as in the formula (1) is true. In fact, Xin and Zhong ([4]) showed it earlier. However, we provide a simpler method here.

• Journal of Chest Surgery
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• 제33권7호
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• pp.570-575
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• 2000

Background; Surgical resection remains the mainstay of treatment for esophageal cancer. Despite recent advances in surgical therapy, i.e. en bloc resection and extended lymphadenectomy, the overall long-term prognosis of patients with esophageal carcinoma has not, however, improved during the last decades. One of the major reasons in its relatively high recurrence rate. Material and Method; A retrospective review of recurrent patte군 of cancer in 42 patients who underwent curative surgery for primary esophageal cancer was performed clinically and histo-phthologically. Result; Nineteen patients had developed recurrece during the 18 to 52 months(mean 34.2 nonths), 8 had local recurrences, 1 had both, and 11 had systemic recurrences. Twelve patients(63%) had developed recurrence within 1 year, 5 patients(26%) between 1 year to 2 patients(11%) after 2 years. The recurrence rate according to growth pattern of tumor or presence of microinvasive findings was not statistically significant, but it increased significantly in clinical tumor stage III than stage IIA, B and in patients with the number of metastatic lymph node over ten. Conclusion; Post-operative recurrences of esophageal cancer appear as a high rate even though curative wide resection was done. Several clinical and histo-pathological factors correlate with the recurrence.