Neuroendocrine differentiation: The mysterious fellow of colorectal cancer

Table 1 Relationship between neuroendocrine differentiation and clinico-pathological parameters

Clinical parameter	Link to neuroendocrine differentiation	Ref.
Age	No	[39, 55, 63]
Gender	No	[39, 55, 63]
Preoperative conditions	Association with lower CEA levels	[63]
Tumor markers
DNA ploidy	No	[50]
TP53 expression	No	[50, 67]
	Similar abnormal expression as in conventional adenocarcinomas	[25]
BCL-2 expression	Yes	[68]
Ki-67 labeling index	Very low (< 5%)	[25]
	No	[24]
Tumor localization	No	[24, 25, 39, 45, 48-50, 53, 55, 63, 66]
	Yes	[38, 59]
Tumor morphology
Polypoid vs ulceration	No	[55, 63]
Tumor differentiation	No	[24, 39, 45, 48-50, 52, 53, 63, 66]
	Yes	[38, 56, 57, 60, 69]
Tumor size	No	[55, 63]
Tumor stage	No	[24, 39, 45, 48-50, 53, 55, 66]
	Yes	[56]
Lymphatic and venous invasion	No	[55, 63]
Perineural invasion	No	[63]
Lymph node metastases	No	[55]
	Yes	[57, 58]
Distant metastases	Yes	[47, 51]
Clinical stage	No	[53, 55]
	Yes	[36]
Therapy response	Associated with better response to radiochemotherapy	[25]
Prognosis	No	[38, 44, 50, 53, 55, 62, 63]
	Better prognosis	[60]
	Shorter survival from time of metastasis	[24]
	More aggressive behavior	[48]
	Poor prognosis	[36, 39, 45, 46, 54, 56, 57, 59, 61 (stage II), 66 (stage III and IV), 70, 71]