Risk factors and predictive model construction of brain metastases in patients with limited-stage SCLC undergoing preventive brain radiotherapy after remission

doi:10.3760/cma.j.cn371439-20230715-00074

Abstract

Abstract:

Objective To investigate the risk factors of brain metastases in patients with limited-stage small cell lung cancer （SCLC） undergoing preventive brain radiotherapy after remission and to construct prediction model. Methods A total of 231 patients with limited-stage SCLC who received chemoradiotherapy and achieved remission in 3201 Hospital from January 2015 to January 2023 were selected as the study objects. Logistic regression was used to analyze the influencing factors on the occurrence of brain metastases after remission in patients with limited-stage SCLC who received preventive brain radiotherapy. Binary logistic regression was used to construct a prediction model. Receiver operator characteristic （ROC） curve was used to evaluate the diagnostic efficacy of each indicator and the prediction model on the occurrence of brain metastases in patients. Results The median follow-up time of the whole group was 73 months， and 42 cases of brain metastases occurred， with an incidence rate of 18.18%. There were statistically significant differences in the incidence of brain metastases among patients with different T stage （Z=-4.97， P<0.001）， clinical stage （Z=-8.17， P<0.001）， and time from initial treatment to thoracic radiotherapy （χ²=21.38， P<0.001）. Multivariate analysis showed that T stage （stage T₃： OR=6.29， 95%CI： 1.58-25.06， P=0.009； stage T₄： OR=12.91， 95%CI： 3.74-44.57， P<0.001）， clinical stage （stageⅡ， OR=8.75， 95%CI： 2.89-26.51， P<0.001； stage Ⅲ， OR=18.43， 95%CI： 7.24-46.92， P<0.001）， and time from initial treatment to thoracic radiotherapy （OR=0.25， 95%CI： 0.11-0.56， P=0.001） were independent influencing factors on the occurrence of brain metastases after remission in patients with limited-stage SCLC who received preventive brain radiotherapy. The diagnostic prediction model based on the above indicators was logit（P）=-19.91+1.84× stage T₃ +2.56× stage T₄+2.17× stage Ⅱ+2.91× stage Ⅲ-1.38× time from initial treatment to thoracic radiotherapy. ROC curve analysis showed that the area under the curve of T stage， clinical stage， time from initial treatment to thoracic radiotherapy， and the diagnostic prediction model for predicting the occurrence of brain metastasis after remission in patients with limited-stage SCLC who received preventive brain radiotherapy were 0.728， 0.660， 0.687， and 0.846， respectively， and the area under the curve of the diagnostic prediction model was significantly larger than those of the other indicators （all P<0.05）. Conclusion T stage， clinical stage and the time from initial treatment to thoracic radiotherapy are all influential factors for the occurrence of brain metastases after remission in patients with limited-stage SCLC who received preventive brain radiotherapy. The diagnostic prediction model based on the above indicators can help to guide clinicians to accurately screen patients at high risk of brain metastases in the early stage.

Key words: Small cell lung carcinoma, Radiotherapy, Brain metastasis, Models

Yu Hongxin, Bai Yan, Gong Yuan, Wang Jianzhuang, Fan Zhigang. Risk factors and predictive model construction of brain metastases in patients with limited-stage SCLC undergoing preventive brain radiotherapy after remission[J]. Journal of International Oncology, 2024, 51(7): 453-457.

Figures/Tables 4

References 20

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临床病理特征	例数	脑转移发生	χ²/Z值	P值
性别
男	186	37（19.89）	1.88	0.171
女	45	5（11.11）	1.88	0.171
年龄（岁）
<60	91	13（14.29）	1.53	0.216
≥60	140	29（20.71）	1.53	0.216
T分期
T₁期	65	5（7.69）	-4.97	<0.001
T₂期	109	13（11.93）
T₃期	24	7（29.17）
T₄期	33	17（51.52）
N分期
N₀期	25	5（20.00）	-1.72	0.085
N₁期	21	5（23.81）
N₂期	111	24（21.62）
N₃期	74	8（10.81）
临床分期
Ⅰ期	22	1（4.55）	-8.17	<0.001
Ⅱ期	27	9（33.33）
Ⅲ期	182	32（17.58）
放化疗缓解情况
完全缓解	47	8（17.02）	0.05	0.817
部分缓解	184	34（18.48）	0.05	0.817
放疗分割方式
常规分割	93	17（18.28）	0.01	0.975
超分割	138	25（18.12）	0.01	0.975
放化疗方式
同步	97	22（22.68）	2.28	0.131
序贯	134	20（14.93）	2.28	0.131
化疗周期数（个）
<4	51	13（25.49）	2.35	0.125
≥4	180	29（16.11）	2.35	0.125
初始治疗至胸部放疗时间（月）
>2	78	27（34.62）	21.38	<0.001
≤2	153	15（9.80）	21.38	<0.001
初始治疗至预防性脑部放疗时间（月）
>4	135	23（17.04）	0.29	0.593
≤4	96	19（19.79）	0.29	0.593

变量	β值	SE值	Wald χ²值	OR值	95%CI	P值
T分期			22.69			<0.001
T₂期	0.55	0.58	0.92	1.74	0.56~5.38	0.339
T₃期	1.84	0.71	6.80	6.29	1.58~25.06	0.009
T₄期	2.56	0.63	16.36	12.91	3.74~44.57	<0.001
临床分期			46.65			<0.001
Ⅱ期	2.17	0.57	14.70	8.75	2.89~26.51	<0.001
Ⅲ期	2.91	0.48	37.36	18.43	7.24~46.92	<0.001
初始治疗至胸部放疗时间	-1.38	0.41	11.44	0.25	0.11~0.56	0.001
常量	-19.91	7 167.94	<0.01	0.00		0.998

项目	曲线下面积	敏感性（%）	特异性（%）	约登指数（%）
T分期	0.728^a	57.14	82.54	39.68
临床分期	0.660^b	92.86	38.10	30.95
初始治疗至胸部放疗时间	0.687^c	64.29	73.02	37.30
诊断预测模型	0.846	80.95	81.48	62.43