Survival Prediction and Feature Selection in Patients with Breast Cancer Using Support Vector Regression

Table 1

Comparison of characteristics of dead and alive patients in the BC dataset, and the relation between the features and the estimated prognostic based on standard linear SVR.

Independent variables	Category	Characteristics of patients in dataset				⁢Estimated prognostic index in SVR model
		Alive		Dead				value
		Count	Mean (SD)	Count	Mean (SD)		Pearson correlation (with prognostic index)
Age of diagnosis		341	45.33 (10.26)	201	47.30 (11.64)	−0.22		0.001
		Count	Percent	Count	Percent	Mean prognostic index	SD prognostic index
Tumor size (cm)	2	230	70.12	98	29.88	−15.98	12.18	0.313
	2–5	103	56.28	80	43.72	−16.47	12.59
	>5	8	25.80	23	74.2	−23.18	8.12
Involved lymph nodes ()	<4	198	69.72	86	30.28	−13.44	11.87	<0.001
	4	103	62.05	63	37.95	−21.14	11.32
	Unknown	40	43.48	52	56.52
Marital status	Married	326	62.69	194	37.31	−16.20	12.21	0.354
	Single	15	68.18	7	31.82	−20.29	12.93
Family history	Yes	300	62.11	183	37.89	−16.46	7.12	0.418
	No	41	69.49	18	30.51	−14.94	12.58
Type of surgery	Lumpectomy	18	64.24	10	35.76	−13.34	9.19	0.031
	Radical mastectomy	250	61.27	158	38.73	−15.47	12.13
	Segmental mastectomy	26	63.41	15	36.59	−18.64	15.79
	simple mastectomy	47	72.30	18	27.70	−22.62	9.75
Histological type	Ductal	301	62.57	180	37.43	−17.18	12.26	0.022
	Lobular	21	61.76	13	38.24	−10.63	10.69
	Medullar	19	70.37	8	29.63	−10.76	10.81
Metastases status	Present	51	36.42	89	63.58	−34.32	10.82	<0.001
	Absent	290	72.13	112	27.87	−12.83	8.99
HER2	Positive	110	65.47	58	34.53	−20.89	11.62	<0.001
	Negative	84	60.00	56	40.00	−10.02	10.09
	Unknown	147	62.82	87	37.18
ER status	Positive	106	63.85	60	36.15	−17.54	12.35	0.148
	Negative	126	68.10	59	31.90	−15.24	12.06
	Unknown	109	57.06	82	42.94
PR status	Positive	85	59.44	58	40.56	−20.39	11.57	<0.001
	Negative	142	71.71	56	28.29	−13.37	11.88
	Unknown	114	56.71	87	43.29

value < 0.05, value < 0.01, value < 0.001.