• Title/Summary/Keyword: Hazard-rate model

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Cause-specific Analysis of Risk Factors in Completely Resected Pathologic Stage Ia Non-small Cell Lung Cancer (병리학적 병기 Ia기 비소세포폐암 환자에서 완전절제술 후 사망의 원인에 따른 위험인자 분석)

  • Park, Seong-Yong;Park, In-Kyu;Byun, Chun-Sung;Lee, Chang-Young;Bae, Mi-Kyung;Kim, Dae-Joon;Chung, Kyung-Young
    • Journal of Chest Surgery
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    • v.42 no.6
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    • pp.725-731
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    • 2009
  • Background: Lobectomy and more extended anatomic resection are regarded as standard treatment for stage Ia non-small cell lung cancer, but approximately 15~40% of patients suffer from treatment failures such as cancer recurrence or death. The authors analyzed types and causes of treatment failures in surgically treated cases of stage Ia non small cell lung cancer. Material and Method: We retrospectively reviewed the medical records of 156 patients who had undergone complete resection for stage Ia NSCLC between Jan 1992 and Aug 2005. Patients were divided into two different treatment failure groups: cancer-related deaths and non-cancer-related deaths. Risk factors were analyzed in each group by the Kaplan-Meyer survival method and the Cox proportional hazard model. Result: Among the 156 patients, 93 were males; the mean age was 61. The median follow-up period was 33.8 months. The 5 year survival rate was 87.6%. Microscopic lympho-vascular permeation was reported in 10 patients. Recurrence was reported in 19 patients and 12 patients died due to recurrent lung cancer. Noncancer related deaths occurred in 16 patients. Risk factors for cancer recurrence and cancer related death were microscopic lympho-vascular permeation (HR=6.81, p=0.007, HR=7.81, p<0.001); for non-cancer related death, risk factors were pneumonectomy (HR=25.92, p=0.001) and postoperative cardiopulmonary complications (HR=29.67, p=0.002). Conclusion: After complete resection of stage Ia non small cell lung cancer patients, mortality includes not only cancer related deaths but also cancer unrelated deaths. Adjuvant chemotherapy is advised for patients who show microscopic lympho-vascular permeation, which is a risk factor for recurrence and for cancer related death. Patients who had pneumonectomy or who suffered from cardiac or respiratory complications need meticulous care in order to reduce comorbidity-induced death.

Research on Earthquake Occurrence Characteristics Through the Comparison of the Yangsan-ulsan Fault System and the Futagawa-Hinagu Fault System (양산-울산 단층계와 후타가와-히나구 단층계의 비교를 통한 지진발생특성 연구)

  • Lee, Jinhyun;Gwon, Sehyeon;Kim, Young-Seog
    • The Journal of the Petrological Society of Korea
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    • v.25 no.3
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    • pp.195-209
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    • 2016
  • The understanding of geometric complexity of strike-slip Fault system can be an important factor to control fault reactivation and surface rupture propagation under the regional stress regime. The Kumamoto earthquake was caused by dextral reactivation of the Futagawa-Hinagu Fault system under the E-W maximum horizontal principal stress. The earthquakes are a set of earthquakes, including a foreshock earthquake with a magnitude 6.2 at the northern tip of the Hinagu Fault on April 14, 2016 and a magnitude 7.0 mainshock which generated at the intersection of the two faults on April 16, 2016. The hypocenters of the main shock and aftershocks have moved toward NE direction along the Futagawa Fault and terminated at Mt. Aso area. The intersection of the two faults has a similar configuration of ${\lambda}$-fault. The geometries and kinematics, of these faults were comparable to the Yansan-Ulsan Fault system in SE Korea. But slip rate is little different. The results of age dating show that the Quaternary faults distributed along the northern segment of the Yangsan Fault and the Ulsan Fault are younger than those along the southern segment of the Yansan Fault. This result is well consistent with the previous study with Column stress model. Thus, the seismic activity along the middle and northern segment of the Yangsan Fault and the Ulsan Fault might be relatively active compared with that of the southern segment of the Yangsan Fault. Therefore, more detailed seismic hazard and paleoseismic studies should be carried out in this area.

Postoperstive Chemoradiotherapy in Locally Advanced Rectal Cancer (국소 진행된 직장암에서 수술 후 화학방사선요법)

  • Chai, Gyu-Young;Kang, Ki-Mun;Choi, Sang-Gyeong
    • Radiation Oncology Journal
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    • v.20 no.3
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    • pp.221-227
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    • 2002
  • Purpose : To evaluate the role of postoperative chemoradiotherapy in locally advanced rectal cancer, we retrospectively analyzed the treatment results of patients treated by curative surgical resection and postoperative chemoradiotherapy. Materials and Methods : From April 1989 through December 1998, 119 patients were treated with curative surgery and postoperative chemoradiotherapy for rectal carcinoma in Gyeongsang National University Hospital. Patient age ranged from 32 to 73 years, with a median age of 56 years. Low anterior resection was peformed in 59 patients, and abdominoperineal resection in 60. Forty-three patients were AJCC stage II and 76 were stage III. Radiation was delivered with 6 MV X rays using either AP-PA two fields, AP-PA both lateral four fields, or PA both lateral three fields. Total radiation dose ranged from 40 Gy to 56 Gy. In 73 patients, bolus infusions of 5-FU $(400\;mg/m^2)$ were given during the first and fourth weeks of radiotherapy. After completion of radiotherapy, an additional four to six cycles of 5-FU were given. Oral 5-FU (Furtulone) was given for nine months in 46 patients. Results : Forty $(33.7\%)$ of the 119 patients showed treatment failure. Local failure occurred in 16 $(13.5\%)$ patients, 1 $(2.3\%)$ of 43 stage II patients and 15 $(19.7\%)$ of 76 stage III patients. Distant failure occurred in 31 $(26.1\%)$ patients, among whom 5 $(11.6\%)$ were stage II and 26 $(34.2\%)$ were stage III. Five-year actuarial survival was $56.2\%$ overall, $71.1\%$ in stage II patients and $49.1\%$ in stage III patients (p=0.0008). Five-year disease free survival was $53.3\%$ overall, $68.1\%$ in stage II and $45.8\%$ in stage III (p=0.0006). Multivariate analysis showed that T stage and N stage were significant prognostic factors for five year survival, and that T stage, N stage, and preoperative CEA value were significant prognostic factors for five year disease free survival. Bowel complication occurred in 22 patients, and was treated surgically in 15 $(12.6\%)$, and conservatively in 7 $(5.9\%)$. Conclusion : Postoperative chemoradiotherapy was confirmed to be an effective modality for local control of rectal cancer, but the distant failure rate remained high. More effective modalities should be investigated to lower the distant failure rate.