Significance of monitoring imatinib plasma concentration in second-line treatment decisions for c-kit 11 gene-mutated gastrointestinal stromal tumors

Table 1 Baseline characteristics of the two groups of patients, n (%)

Characteristics	Group A (n = 32)	Group B (n = 43)	P value
Age	51 ± 16	53 ± 12	0.608
Sex			0.888
Male	25 (78)	33 (77)
Female	7 (22)	10 (23)
Primary tumor site			0.275
Stomach	12 (38)	10 (23)
Small intestine	14 (44)	19 (44)
Other	6 (19)	14 (33)
Mitotic count (/50 HPF)			0.142
≤ 5	13 (41)	27 (63)
5 to ≤ 10	10 (31)	7 (16)
> 10	9 (28)	9 (21)
Ki 67			0.189
≤ 10	16 (50)	28 (65)
> 10	16 (50)	15 (35)
Risk classification			> 0.9991
Medium	1 (3)	1 (2)
High	31 (97)	42 (98)
Mutation type			0.5181
Point mutation	6 (19)	13 (30)
Delete mutation	25 (78)	29 (67)
Other	1 (3)	1 (2)
Sum of largest diameter (cm)			0.317
≤ 5	10 (31)	12 (28)
5-10	10 (31)	8 (19)
> 10	12 (38)	23 (53)
Lesions > 3			0.435
Yes	18 (56)	28 (65)
No	14 (44)	15 (35)
R0 resection			0.350
Yes	13 (41)	13 (30)
No	19 (59)	30 (70)

¹Using the Fisher’s exact test.

HPF: High-power field.