Table 3. Relationships between ATM protein expression and various clinicopathologic factors in colorectal neuroendocrine tumors.

		ATM expression
Characteristics	n	Negative	Positive	P value
Tumor site
Colon	4	4	0	0.101
Rectum	27	12	15
Grade
G1	27	12	15	0.101
G2	4	4	0
Sex
Female	8	6	2	0.22
Male	23	10	13
Age
<60	18	9	9	0.833
≥60	13	7	6
Tumor behavior
Metastatic tumor	14	12	2	0.001
Non-metastatic tumor	17	4	13