Rectal neuroendocrine tumors in a Latin American population: Insights from a Peruvian national cancer institute

Table 1 Demographic, clinical, and symptomatic variables, n (%)

Variables	n = 52
Age in years
Mean (minimum-maximum)	51.9 (27-74)
Sex
Female	34 (65.4)
Male	18 (34.6)
Region of birth
Lima	14 (26.9)
Ancash	6 (11.5)
Junín	5 (9.6)
Cajamarca	4 (7.7)
Piura	4 (7.7)
La Libertad	3 (5.8)
Arequipa	2 (3.8)
Cusco	2 (3.8)
Huánuco	2 (3.8)
Loreto	2 (3.8)
San Martin	2 (3.8)
Apurímac	1 (1.9)
Ayacucho	1 (1.9)
Ica	1 (1.9)
Lambayeque	1 (1.9)
Pasco	1 (1.9)
Puno	1 (1.9)
ECOG scale
0	25 (48.1)
1	23 (44.2)
2	3 (5.8)
3	1 (1.9)
Symptoms
Rectal bleeding	19 (36.5)
Abdominal pain	13 (25.0)
Anorectal pain	10 (19.2)
Constipation	10 (19.2)
Weight loss	8 (15.4)
Diarrhea	3 (5.8)
Anorectal tumor	1 (1.9)

ECOG: Eastern Cooperative Oncology Group.

Table 2 Tumor-nodes-metastasis classification, n (%)

Variables	n = 52
Classification T
T1	29 (55.7)
T2	8 (15.4)
T3	11 (21.2)
T4	4 (7.7)
Classification N
N0	31 (59.6)
N1	21 (40.4)
Classification M
M0	33 (63.5)
M1	19 (36.5)
Stage
I	25 (48.1)
II	3 (5.8)
III	5 (9.6)
IV	19 (36.5)
Disease stage
Localized	29 (55.8)
Advanced	23 (44.2)
Status of advanced disease, n = 23
Metastatic	19 (82.6)
Recurrent	3 (13.0)
Unresectable	1 (4.3)

T: Tumor; N: Node; M: Metastasis.

Table 3 Tumor grade by disease stage, tumor size, and node classification, n (%)

Variables	Grade 1, 27 (51.9)	Grade 2, 25 (48.1)	P value
Disease stage
Localized	25 (92.6)	4 (16.0)
Advanced	2 (7.4)	21 (84.0)	< 0.001
Tumor size in cm
≤ 2	25 (92.6)	6 (24.0)
> 2	2 (7.4)	19 (76.0)	< 0.001
Classification N
N1	3 (11.1)	18 (72.0)
N0	24 (88.9)	7 (28.0)	< 0.001

N: Node.

Table 4 Location of the metastasis, n (%)

Variables	n = 52
Organ
Liver	22 (42.3)
Bone	9 (17.3)
Non-regional lymph node	4 (7.7)
Pancreas	3 (5.8)
Lung	3 (5.8)
Prostate	2 (3.8)
Soft tissue	1 (1.9)
Ovary	1 (1.9)
Cervix	1 (1.9)
Bladder	1 (1.9)
Vagina	1 (1.9)
Adrenal	1 (1.9)
Number of metastatic organs
0	29 (55.8)
1	10 (19.2)
2	6 (11.5)
3	3 (5.8)
4	2 (3.8)
5	2 (3.8)
Liver lesions, n = 22
Single	1 (4.5)
Multiples	21 (95.5)
Bulky liver tumor, as volume involvement > 25%, n = 22
Yes	13 (59.1)
No	9 (40.9)

Table 5 Systemic treatment, n (%)

Variables	n = 52
First-line chemotherapy
Yes	20 (38.5)
No	32 (61.5)
First chemotherapy scheme, n = 20
TEMCAP	16 (80.0)
Cisplatin/etoposide	3 (15.0)
Octreotide	1 (5.0)
Cycles of the 1st chemotherapy, n = 20
Median (IQR)	9.5 (5.5-20)
Duration of the 1st chemotherapy, n = 20
Median (IQR)	11 (6-18)
Unregistered	1
Response to the 1st chemotherapy, n = 20
CR	1 (5.0)
SD	6 (30.0)
PD	10 (50.0)
Not evaluated	3 (15.0)
Second-line chemotherapy, n = 20
Yes	9 (45.0)
No	11 (55.0)
2nd Chemotherapy scheme, n = 9
CAPOX	2 (22.2)
Dacarbazine	2 (22.2)
TEMCAP	2 (22.2)
Carboplatin/etoposide	1 (11.1)
FOLFOX	1 (11.1)
Interferon alpha	1 (11.1)
2nd chemotherapy cycles, n = 9
Median (IQR)	3 (2-5)
Duration of the 2nd chemotherapy, n = 9
Median (IQR)	1 (0-5)
Response to 2nd chemotherapy, n = 9
CR	1 (11.1)
PR	1 (11.1)
SD	1 (11.1)
PD	4 (44.4)
Not evaluated	2 (22.2)

TEMCAP: Capecitabine plus temozolomide; IQR: Interquartile range; CR: Complete response; SD: Stable disease; PD: Progressive disease; CAPOX: Capecitabine plus oxaliplatin; FOLFOX: Fluorouracil, oxaliplatin, and leucovorin; PR: Partial response.

Table 6 Overall survival estimates according to clinical and pathological characteristics

Variables	n (events)	1-year	3-year	5-year	P value
All patients	52 (15)	92.9%	73.4%	60.6%	N/A
Age in years					0.86
< 65	44 (13)	93.9%	71.1%	61.6%
≥ 65	8 (2)	87.5%	87.5%	43.8%
Sex					0.34
Female	34 (9)	100%	71.2%	64.7%
Male	18 (6)	78.0%	78.0%	52.0%
Grade					0.00032
G1	27 (3)	100%	92.9%	92.9%
G2	25 (12)	87.1%	57.0%	32.6%
Ki-67 (%)					0.00032
< 3	27 (3)	100%	92.9%	92.9%
3-20	25 (12)	87.1%	57.0%	32.6%
Tumor size (cm)					0.048
≤ 1	24 (3)	100%	91.7%	91.7%
> 1	28 (12)	87.6%	62.8%	43.9%
Tumor size (cm)					0.0056
≤ 2	31 (4)	95.8%	89.4%	89.4%
> 2	21 (11)	89.9%	59.1%	37.0%
Classification N					0.0063
N0	31 (4)	100%	94.1%	84.7%
N1	21 (11)	83.9%	51.9%	37.1%
Disease stage					0.00049
Advanced	23 (13)	86.5%	58.8%	39.2%
Localized	29 (2)	100%	92.9%	92.9%
First-line chemotherapy					0.086
No	32 (5)	92.0%	76.7%	76.7%
Yes	20 (10)	94.4%	69.6%	46.4%

G: Grade; N: Node; N/A: Not applicable.

Table 7 Cox regression analysis of the effect of clinical and pathological characteristics on overall survival

Variables	Univariate			Multivariate
	HR	95%CI	P value	HR	95%CI	P value
Grade
G1	1.01			1.01
G2	19.42	2.34-161.2	0.006	21.89	1.01-472.41	0.049
Ki-67 as%
< 3	1.01
3-20	19.42	2.34-161.2	0.006
Tumor size in cm
≤ 1	1.01
> 1	3.39	0.94-12.16	0.062
Tumor size in cm
≤ 2	1.01			1.01
> 2	5.34	1.44-19.73	0.012	0.53	0.05-5.51	0.598
Classification N
N0	1.01			1.01
N1	4.39	1.38-13.95	0.012	1.34	0.18-9.92	0.774
Classification M
M0	1.01			1.01
M1	5.08	1.59-16.23	0.006	0.65	0.09-4.65	0.67
Disease stage
Localized	1.01
Advanced	16.22	2.07-127	0.008
Number of metastatic sites
None	1.01
≥ 1	16.22	2.07-127	0.008

¹1.0 was used as the reference group, indicates the reference category.

N: Node; M: Metastasis; HR: Hazard ratio; CI: Confidence interval.