根治性放射治疗后远处转移鼻咽癌的预后研究

目的分析鼻咽癌根治性放疗后发生远处转移患者的生存预后因素,为临床治疗方案的选择提供依据。方法回顾性分析根治性放疗后发生远处转移的鼻咽癌83例,Kaplan-Meier法计算生存率;Log-ranktest对生存率差异进行显著性检验。采用Cox风险比模型进行单因素及多因素分析。结果全组中位生存12个月,1、2、3年生存率分别为51.3%、33.0%和23.8%。单因素分析发现,根治性放疗后远处转移患者的生存时间与初诊时N分期、放疗结束到发生远处转移的时间间隔、转移部位、转移后所行化疗的周期数相关。多因素分析显示初诊时N分期、转移后所行化疗的周期数具有独立的预后意义。结论初诊时N分期对鼻咽癌的总生存有决定性作用,足够有效的化疗有望延长放疗后远处转移患者的生存时间。     

N2~3期局部晚期鼻咽癌不同新辅助化疗疗程预后分析

 目的 探讨不同新辅助化疗（NCT）疗程对N2~3期局部晚期鼻咽癌的预后影响。方法 回顾性分析2012—2013年收治的270例N2~3期局部晚期鼻咽癌行新辅助化疗+同步放化疗或单纯同步放化疗患者的一般临床资料,全组NCT≥3程、NCT=1~2程、NCT=0程患者分别为84例、106例和80例。Kaplan-Meier法计算生存率并行Log rank法检验,Cox单、多因素分析无远处转移生存影响因素。 结果 全组中位随访时间63月（6~75月）。全组5年总生存（5-OS）、无瘤生存（5-DFS）、无局部复发生存（5-LRFS）和无远处转移生存率（5-DMFS）分别为78.4%、77.8%、97.7%和79.5%。三组5-OS分别为88.1%、78.8%和73.5%（P=0.03）;三组5-DFS分别为89.3%、74.0%和72.3%（P=0.021）,三组5-DMFS分别为89.3%、76.6%和74.5%（P=0.031）,三组5-LRFS差异无统计学意义（P=0.535）;单、多因素分析提示新辅助化疗疗程、N分期、年龄均是治疗后有无转移的独立预后因素。结论 N2~3期局部晚期鼻咽癌患者行NCT≥3程诱导化疗+同步放化疗可明显提高总生存期、降低远处转移率。     

结直肠癌肺转移手术治疗疗效及预后影响因素的回顾性分析

目的:探讨结直肠癌肺转移患者手术切除肺转移灶的疗效及术后生存的影响因素。方法:回顾性分析79例结直肠癌肺转移灶切除患者的临床资料,统计分析其生存期及预后影响因素。结果:全组患者中位随访时间52.0个月。中位生存时间36.0个月,5年生存率为35.1%。29例患者死于肿瘤进展;27例生存患者中,18例带瘤生存,9例无瘤生存,其中1例至今已无瘤生存159个月。单因素分析结果显示,无瘤间期(DFI)时间的长短对肺转移瘤切除术后的生存有影响(P=0.036);而患者的性别、年龄、原发肿瘤部位、肺转移瘤大小和位置、手术方式、肺转移瘤手术前CEA水平及复发后再次行肺转移瘤切除均与其术后生存时间无关。结论:对于结直肠癌肺转移患者,手术是有潜在治愈可能的治疗方法。DFI可能与肺转移瘤切除术后生存有关。     

非高发地区初诊远处转移鼻咽癌患者生存及预后的单中心分析

  目的  分析非高发地区初治远处转移鼻咽癌患者的生存情况及预后因素。  方法  回顾性分析2008年6月至2015年12月四川省肿瘤医院收治的91例初诊远处转移鼻咽癌患者,所有患者均接受原发灶的根治性放疗,放疗剂量为66.0~76.6 Gy（中位剂量71.0 Gy）。87例患者采用以铂类为基础的化疗方案（1~7个周期）,未行化疗4例,放疗期间同步靶向治疗17例（尼妥珠单抗或西妥昔单抗）。初治时完成转移灶的局部治疗49例（放疗48例,孤立肺转移手术1例）。患者治疗结束后每3个月随访1次。采用KaplanMeier法计算生存率,采用Cox回归模型进行多因素分析。  结果  中位随访时间41个月。患者1、2、3年生存率分别为83.4%、58.6%、43.3%,中位生存期为32（6~87）个月。转移灶数目>3个（P=0.020）及转移灶无局部治疗（P=0.034）是患者总生存预后不良的独立影响因素。  结论  对于初诊远处转移鼻咽癌,予原发灶根治性放疗（≥66.0 Gy）剂量联合转移灶局部治疗可以改善患者生存率。      

同期化疗对Ⅲ期鼻咽癌放疗患者预后影响的回顾性分析

目的:分析并评价同期化疗对提高Ⅲ期鼻咽癌患者放疗后远期生存率的影响和价值。方法:收集首程治疗Ⅲ期鼻咽癌患者507例,其中178例放疗同期联合含顺铂方案的化疗。Kap-lan-meier法计算生存率,Log-rank检验并行预后的单因素分析,Cox比例风险模型进行多因素预后分析。结果:中位随访时间53个月。Ⅲ期鼻咽癌患者的5年总生存率、局部区域无复发生存率、无远处转移生存率和无瘤生存率分别为65.8%、81.4%、75.0%和62.5%。放化组总生存率为71.6%,单放组为62.7%,χ2=4.830,P=0.028;局部区域无复发生存率放化组为90.5%,单放组为76.3%,χ2=11.464,P=0.001;无远处转移生存率放化组为77.4%,单放组为73.6%,χ2=1.092,P=0.296;无瘤生存率放化组为70.6%,单放组为58.1%,χ2=8.078,P=0.004。单因素分析结果表明,同期化疗是影响鼻咽癌治疗总生存率、局部区域无复发生存率和无瘤生存率的预后有利因素。多因素分析结果显示,同期化疗是影响局部区域无复发生存率和无瘤生存率的独立预后因素。结论:同期化疗有助于提高Ⅲ期鼻咽癌放疗后的局部区域无复发生存率和无瘤生存率。     

905例鼻咽癌远期疗效及失败模式的探讨

摘 要：［目的］ 分析905例鼻咽癌患者的远期生存情况及治疗失败模式并探讨其预后因素。［方法］ 回顾性分析2004年10月至2005年12月中山大学肿瘤防治中心收治的905例经病理证实的初治无转移鼻咽癌患者的临床资料。采用 Kaplan-Meier 法进行生存分析,Cox 回归模型进行多因素预后分析。［结果］ 全组中位随访时间为118.6个月（1.6～152.4个月）,5年及10年总生存率（OS）、无局部区域复发率(LRFS)、无远处转移生存率（DMFS）、无病生存率（DFS）分别为77%、91%、86%、79%和67%、88%、85%、75%。211例（23.3%）患者治疗失败,出现远处转移、局部复发、区域复发的患者分别为126例、82例、14例。远处转移（13.9%）最常见,其次是鼻咽局部复发（9.1%）,颈部淋巴结复发（1.5%）较少。多因素分析显示T、N分期是影响总生存、无远处转移生存及无病生存的独立因素,年龄是影响总生存的独立因素。［结论］ 早期鼻咽癌治疗效果良好,但局部晚期患者治疗效果较差,远处转移是鼻咽癌治疗失败的首要原因。     

伽玛刀治疗40例骨肉瘤肺转移患者的生存分析

目的探讨伽马刀治疗骨肉瘤肺转移患者的生存情况,并分析影响其预后的相关因素。方法回顾性分析上海交通大学附属第六人民医院2008-01-01-2012-12-31共40例骨肉瘤肺转移患者接受伽马刀治疗的临床资料,使用Kaplan-Meier法绘制生存曲线,并采用Log-rank进行单因素检验,并通过Cox回归模型分析与患者生存有关的独立影响因素。结果 40例骨肉瘤肺转移患者2年生存率为42.5%,中位生存时间为27个月,95%CI为19.4~34.6个月。Log-rank单因素分析结果显示,伽玛刀治疗骨肉瘤肺转移患者的预后与性别(P=0.901)、年龄(P=0.903)、KPS评分(P=0.936)、单/双肺转移(P=0.522)、有无肿瘤原发部位的复发(P=0.985)、有无除肺以外的远处转移(P=0.333)、原发部位的手术方式(P=0.359)及有无行新辅助化疗(P=0.415)均无关,而与肺转移瘤数目有关,P=0.032。Cox模型多因素回归分析结果显示,肺转移瘤数目是影响预后的独立相关因素,P=0.039。结论伽玛刀治疗骨肉瘤肺转移患者预后较好,值得做进一步临床研究。肺转移瘤数目对接受伽玛刀治疗的肺转移患者的生存时间有影响。     

Ⅲ期、ⅣA期鼻咽癌患者椎前肌及颅底枕骨侵犯的预后分析

目的 探讨鼻咽癌椎前肌及颅底枕骨侵犯对Ⅲ期和ⅣA期鼻咽癌患者预后的影响。方法 收集2010年12月至2017年12月新发Ⅲ期和ⅣA期鼻咽癌患者141例,分为鼻咽癌椎前肌侵犯组89例,鼻咽癌不伴椎前肌侵犯组52例,鼻咽癌椎前肌侵犯但不伴颅底骨质侵犯组36例,鼻咽癌颅底枕骨侵犯组55例(53例合并椎前肌侵犯)。计算各组病例的1、3、5年局部无复发生存率、无远处转移生存率和生存率。影响预后的多因素分析采用Cox比例风险回归模型。结果 Cox多因素分析显示,性别、椎前肌侵犯、V区淋巴结转移和淋巴结最大径是影响鼻咽癌患者无远处转移生存时间的独立因素(P<0.05);而各纳入因素均与局部无复发生存时间和总生存时间无关(P>0.05)。鼻咽癌不伴椎前肌侵犯组与鼻咽癌椎前肌侵犯组1、3、5年局部无复发生存率分别为100.0%、98.0%、98.0%和98.0%、91.0%、86.0%(P=0.071); 1、3、5年无远处转移生存率分别为100.0%、98.0%、91.0%和91.0%、81.0%、77.0%(P=0.008),1、3、5年生存率分别为100.0%、98.0%、98.0%和...     

内皮素受体A表达与鼻咽癌预后的关系

背景与目的:内皮素受体A(endothelin A receptor,ETAR)激活参与肿瘤的生长及转移,包括细胞增殖、细胞凋亡、血管生成与肿瘤转移等作用。本研究探讨鼻咽癌组织中ETAR的表达与临床特征及预后的关系。方法:采用ETAR单克隆抗体对153例鼻咽癌组织中ETAR的表达进行免疫组化SABC技术检测。结果:鼻咽癌ETAR的阳性率为73.9%。ETAR的表达与性别、年龄、T分期、N分期及临床TNM分期无明显相关性(P>0.05)。ETAR阴性组和阳性组的3年总生存率分别为87.5%和73.2%(P=0.029),3年无瘤生存率分别为80.0%和57.3%(P=0.009),3年无局部区域复发生存率分别为86.9%和80.2%(P=0.228),3年无远处转移生存率分别为89.9%和70.4%(P=0.012)。Cox模型多因素分析显示ETAR表达、性别、年龄、T分期和N分期是影响总生存、无瘤生存及远处转移的独立预后因素。结论:ETAR的表达与鼻咽癌患者的远处转移风险有关,其高表达提示患者预后不良。     

ⅣA期鼻咽癌常规放疗448例预后因素分析

目的:探讨首程接受常规放射治疗的448例ⅣA期鼻咽癌患者的预后因素。方法:2000-01-01-2004-12-31,首程常规放射治疗ⅣA期(92分期)鼻咽癌448例,其中252例放疗同期联合含顺铂方案的化疗。Kaplan-Meier方法进行单因素分析,Cox比例风险模型进行多因素预后分析。结果:ⅣA期鼻咽癌患者的5年总生存率、局部区域无复发生存率、无远处转移生存率和无瘤生存率分别为52.5%、82.4%、61.9%和51.1%。单因素和多因素分析结果表明,N3是影响总生存率、无远处转移生存率和无瘤生存率的共同预后不良因素。与单纯放疗比较,同期化疗提高了T4N0-2组患者的5年总生存率(66.6%:51.6%;χ2=3.917,P=0.048),但T1-4N3组患者未能从同期化疗中获益。结论:N3分期是影响ⅣA期鼻咽癌总生存率,无远处转移生存率和无瘤生存率的主要不良因素。建议将N3分期患者从ⅣA期中分出另设亚组并在治疗上区别对待。     

Favourable long-term results after surgical removal of lung metastases of breast cancer

We retrospectively evaluated whether a surgical strategy benefits patients with operable lung metastasis of breast cancer. Between 1960 and 2000, 90 patients (mean age 55.1; range 32-77) with lung metastasis (79 solitary, 11 multiple) underwent surgery as follows: wedge resection (n = 10), segmental resection (n = 11), lobectomy (n = 68) and pneumonectomy (n = 1). The metastases were completely resected in 89% of them. One patient died due to surgical complications. The overall 5- and 10-year cumulative overall survival rates were 54% and 40%, respectively (median, 6.3 years). Fifteen patients survived without relapse for over 10 years. They were 24% of those who progressed for 10 years or more after lung surgery. The most significant prognostic factor was disease-free interval (DFI) and stage at breast surgery. The 10-year survival rates of those with >==3 and <3 years of DFI were 47% and 26%, respectively (P = 0.014). Survival times were significantly longer for patients with clinical stage I at breast surgery than those with stage II-IV (P = 0.013). Our data, although limited and highly selective, suggest that surgical approach to lung metastasis from breast cancer may prolong survival in certain subgroups of patients to a greater extent than systemic chemotherapy alone. Surgical approach to lung metastasis of breast cancer, if possible, should be a treatment of choice to a great extent.     

Uncertain benefit from surgery in patients with lung metastases from breast carcinoma

BACKGROUND: Isolated lung metastases have been reported to occur in 10-20% of all women with breast carcinoma. The authors described a series of patients who underwent surgery for lung metastases from breast carcinoma. METHODS: They reviewed the files of 125 consecutive patients who underwent surgery with a curative intent for lung metastases from breast carcinoma between 1972 an 1998 at a single institution. Survival curves were plotted by the Kaplan-Meier method. Prognostic factors were identified using the log-rank test and a Cox proportional hazards model for univariate and multivariate analyses, respectively. RESULTS: The median age at surgery was 53 years. There was a median of 1 resected metastasis (range, 1-16 resected metastases). The median size of the largest metastasis was 19 mm (range, 5-70 mm). The median disease-free interval (DFI) was 3 years. The median follow-up time after surgery was 8.5 years (range, 25 days to 22 years). The 3-year, 5-year, and 10-year probabilities of survival were 58% (95% confidence interval [95% CI], 49-67%), 45% (95% CI, 36-55%), and 30% (95% CI, 21-41%), respectively. The median survival time after surgery was 4.2 years. Complete resection was achieved in 96 patients. The quality of the resection (complete vs. incomplete) was not a statistically significant prognostic factor by univariate analysis and there was no significant difference between these two groups in terms of adjuvant postoperative therapy. The characteristics of the primary tumor and the number of metastases (one vs. two or more) had no detectable influence on survival. The size of the largest metastasis (> 20 mm or < or = 20 mm) and the DFI (< or = 3 years vs. > 3 years) were highly significant prognostic factors (P = 0.006 and P = 0.003, respectively). This was confirmed by multivariate analysis. Patients with a DFI < or = 3 years and/or the largest metastasis > 20 mm reportedly had a poor outcome (median survival, 2.6 years vs. 8.5 years for patients with none of these poor prognostic factors). CONCLUSIONS: Resection of lung metastases from breast carcinoma was associated with a significant 5-year survival rate of 45%. Whether these encouraging findings resulted from the surgical procedure itself or the preoperative selection of patients remained uncertain. When surgery is considered in this setting, the size of the largest metastasis and the DFI should be taken into account.     

Surgical resection of pulmonary metastases from colorectal cancer: Four favourable prognostic factors

BACKGROUND: Surgical resection has been the first choice for treatment of pulmonary metastases from colorectal cancer; however, indications for surgery have yet to be adequately clarified. In considering strategies for the treatment of pulmonary metastases from colorectal carcinoma, determination of disease status as either systemic or pre-systemic is of primary importance. The aim of this study is to define the characteristics of those patients who are most likely to benefit from surgical resection. METHODS: Fifty-eight patients who underwent pulmonary resection for colorectal metastases were retrospectively reviewed and examined for clinicopathological factors. RESULTS: Overall, 5-year survival rates were 29%, with a median survival time (MST) of 27 months. Multivariate analysis identified four factors that indicate independent and favourable prognostic impact: three or less tumours, metachronous metastasis, negative hilar and/or mediastinal lymph node metastasis and normal prethoracotomy serum carcinoembryonic antigen level. The 5-year survival rate for 16 patients who satisfied all of these favourable characteristics was 62% (MST = 86 months), which was significantly better than those patients lacking these characteristics. The 5-year survival rate for 13 patients who underwent repeated metastasectomy was 37% (MST = 32 months). CONCLUSIONS: The four factors selected in our multivariate analysis appear to be favourable factors for the practical identification of those patients who are most likely to benefit from surgical resection. Repeated pulmonary resection for lung-only recurrence may benefit carefully selected patients.     

孤立性肺转移瘤的诊断与外科治疗(附156例报告)

背景与目的近年来手术治疗孤立性肺转移瘤取得了满意的疗效,为提高患者的生存率,本研究对其诊断、外科治疗的适应证、手术方式及影响预后的因素进行分析讨论。方法对156例接受手术治疗的孤立性肺转移瘤患者的临床资料进行回顾性分析。结果原发肿瘤为癌者134例,肉瘤21例,不明组织类型1例。全组无围手术期死亡,随访153例,随访时间1年-10年。术后5生存率为31.2%,中位生存期为35.8个月。113例行淋巴结系统性清扫,淋巴结转移阴性和阳性患者5年生存率分别为37.3%、12.5%。行肺叶切除术患者5年生存率为38.5%。结论手术治疗孤立性肺转移瘤可取得满意的疗效,电视胸腔镜手术是有效的手术方式,有无淋巴结转移和肺叶切除方式是影响预后的重要因素。     

Disease-free survival after resection of lung metastases in patients with breast cancer.

AIMS: Metastatic breast cancer is a systemic disease. The discussion concerning the resection of lung metastases in patients with breast cancer is controversial. METHODS: Retrospective analysis of 25 patients with suspected pulmonary metastases operated between March 1989 and September 1998. Survival probabilities and disease-free survival was analysed using the Kaplan-Meier method and the log-rank test. RESULTS: The median survival rate after resection of lung metastases for the 21 patients was 96.9 months. The disease-free survival (DFS) after resection of lung metastases was 27.6 months. Survival was not influenced by the receptor status, lymph node involvement, number of lung metastases (p=0.8) or the disease-free interval (DFI) (0.59). DFS was, however, influenced by the DFI. With a DFI of <2 years survival was 8.5 months, whereas with a DFI >2 years it was 36.1 months (p=0.012). The DFS was influenced, but not statistically significant, by the number of lung metastases (n=1/n>1). The median DFS was 28.8 months with one metastasis and 13.1 months with multiple metastases (p=0.29). CONCLUSIONS: The indication to remove solitary lung metastases in patients with previous breast cancer is supported by these findings. Especially when the disease-free interval is greater than two years.     

Role of major resection in pulmonary metastasectomy for colorectal cancer in the Spanish prospective multicenter study (GECMP-CCR)

BackgroundPatients with pulmonary metastases from colorectal cancer (CRC) may benefit from aggressive surgical therapy. The objective of this study was to determine the role of major anatomic resection for pulmonary metastasectomy to improve survival when compared with limited pulmonary resection.Patients and methodsData of 522 patients (64.2% men, mean age 64.5 years) who underwent pulmonary resections with curative intent for CRC metastases over a 2-year period were reviewed. All patients were followed for a minimum of 3 years. Disease-specific survival (DSS) and disease-free survival (DFS) were assessed with the Kaplan–Meier method. Factors associated with DSS and DFS were analyzed using a Cox proportional hazards regression model.ResultsA total of 394 (75.6%) patients underwent wedge resection, 19 (3.6%) anatomic segmentectomy, 5 (0.9%) lesser resections not described, 100 (19.3%) lobectomy, and 4 (0.8%) pneumonectomy. Accordingly, 104 (19.9%) patients were treated with major anatomic resection and 418 (80.1%) with lesser resection. Operations were carried out with video-assisted thoracoscopic surgery (VATS) in 93 patients. The overall DSS and DFS were 55 and 28.3 months, respectively. Significant differences in DSS and DFS in favor of major resection versus lesser resection (DSS median not reached versus 52.2 months, P = 0.03; DFS median not reached versus 23.9 months, P < 0.001) were found. In the multivariate analysis, major resection appeared to be a protective factor in DSS [hazard ratio (HR) 0.6, 95% confidence interval (CI) 0.41–0.96, P = 0.031] and DFS (HR 0.5, 95% CI 0.36–0.75, P < 0.001). The surgical approach (VATS versus open surgical resection) had no effect on outcome.ConclusionMajor anatomic resection with lymphadenectomy for pulmonary metastasectomy can be considered in selected CRC patient with sufficient functional reserve to improve the DSS and DFS. Further prospective randomized studies are needed to confirm the present results.     

肺楔形切除术及纵隔淋巴结采样治疗早期高龄肺癌患者的体会

背景与目的治疗早期非小细胞肺癌首选手术治疗,但最佳的淋巴结清扫范围仍然不清楚。本研究旨在探讨肺楔形切除+纵隔淋巴结采样治疗在早期高龄肺癌患者中的价值。方法 2004年6月-2008年2月,共有15例70岁以上周围型肺癌患者接受胸腔镜下肺楔形切除术+纵隔淋巴结采样治疗。右侧肺癌行2R、4R、8及9组淋巴结采样,左侧肺癌行5、6、8及9组淋巴结采样。结果早期高龄肺癌患者行胸腔镜下肺楔形切除术+淋巴结采样,手术时间短、创伤小,术后并发症少,恢复快。术后1年生存率和3年生存率分别为100%和86.6%。结论肺楔形切除术+纵隔淋巴结采样治疗早期高龄周围型肺癌患者是一种选择。     

宫颈癌肺转移患者手术治疗效果及预后因素分析

目的:通过对宫颈癌治疗后肺转移患者临床资料进行分析,评价外科手术治疗宫颈癌肺转移的疗效,研究影响患者生存的预后因素.方法:回顾性分析44例宫颈癌治疗后肺转移患者临床资料(手术组23例,对照组21例),采用Kaplan-Meier法进行生存分析,Log-rank检验进行单因素分析,COX风险回归模型进行多因素分析.结果:手术组1、2年生存率分别为78.2%、34.7%.手术组患者的生存曲线高于非手术组患者的生存曲线,差异有统计学意义(P<0.05),单因素分析显示,肿瘤分化程度、肺转移瘤数目、肺转移性肿瘤最大直径与患者生存率有关(P<0.05);COX比例风险回归模型分析显示,肺转移瘤数目及肺转移肿瘤最大直径是宫颈癌肺转移患者预后的独立影响因素(P<0.05).结论:对于肺转移灶数目较少,直径较小的患者,可从肺转移灶切除中获益,积极行肺转移瘤外科治疗有助于改善宫颈癌肺转移患者的长期预后.     

肺转移瘤的外科治疗

目的　探讨肺转移瘤外科治疗的适应证、手术方式以及预后的影响因素。方法　对10 8例接受手术治疗的肺转移瘤患者的临床资料进行回顾性分析。结果　本组患者的 1,3,5 ,7及 10年生存率分别为 87.9%、4 7.3%、31.7%、2 3.7%和 13.9% ,中位生存期为 34.8个月。无瘤间歇期(DFI) >36个月、单个结节、无肺外转移和行开胸手术者预后较好 ,而年龄、性别、症状以及原发病理类型对预后均无影响。结论　对于有适应证的肺转移瘤患者应积极手术治疗 ,并以开胸手术为宜。对于DFI较短、转移灶数目较多的患者 ,手术应慎重。     

31例转移性肺肿瘤的外科治疗分析

目的：分析转移性肺肿瘤的外科治疗效果。方法：本文收集了从1980年至1992年经手术治疗的转移性肺肿瘤共31例，其中男性17例，女性14冽，孤立性转移者22例，多个转移者9例，双侧同时有转移者2例。本组手术以局部及肺叶切除为主，分别为19例及9例，肺叶＋楔形切除2例，全肺切除1例。2例双侧转移者均采取分期开胸手术的方法。结果：本组无手术死亡，手术的1、3、5年生存率分别为67．7％，41．9％，25．8％。结论：通过对肺转移瘤的诊断，手术适应证，手术方式及预后等方面的讨论，作者认为只要诊断准确及时，病例选择得当，肺转移瘤病人是完全可以通过外科手术来提高生存率，甚至可获得长期生存。