Demographic and clinical characteristics
From 2000 to 2018, our study cohort included a total of 250 cases. Among them, 150 patients with SCC, 27 with LCC and 73 with other types of cancer. The demographic and clinical characteristics of cervical neuroendocrine carcinoma patients are shown in Table 1. In this cohort, 143(57%) of patients are dead of the disease, 99(40%) are alive or dead of other causes, and 8(3%) remained unknown. Moreover, there were 71(28%) patients with FIGO stage I~IIA, 80(32%) with stage IIB~IVA, and 99(40%) with FIGO stage IVB. Chi-square test showed no significant differences in some variables and treatment patterns, including diagnosis age, race, marital status, primary sites, number of regional lymph nodes, primary lesions, and FIGO stage.
Table 1 The demographic and clinical characteristics of cervical neuroendocrine carcinoma patients
Variables
|
Total (n = 250)
|
SCC (n = 150)
|
LCC (n = 27)
|
Others (n = 73)
|
p
|
Outcome, n (%)
|
|
|
|
|
0.781
|
Dead
|
161 (64)
|
95 (63)
|
19 (70)
|
47 (64)
|
|
Live
|
89 (36)
|
55 (37)
|
8 (30)
|
26 (36)
|
|
Outcome2, n (%)
|
|
|
|
|
0.655
|
Dead
|
143 (57)
|
81 (54)
|
17 (63)
|
45 (62)
|
|
Live. or Died other causes
|
99 (40)
|
63 (42)
|
9 (33)
|
27 (37)
|
|
Unknown
|
8 (3)
|
6 (4)
|
1 (4)
|
1 (1)
|
|
Outcome3, n (%)
|
|
|
|
|
0.664
|
Died of cervical cancer
|
143 (57)
|
81 (54)
|
17 (63)
|
45 (62)
|
|
Died other causes
|
10 (4)
|
8 (5)
|
1 (4)
|
1 (1)
|
|
Live
|
89 (36)
|
55 (37)
|
8 (30)
|
26 (36)
|
|
Unknown
|
8 (3)
|
6 (4)
|
1 (4)
|
1 (1)
|
|
Age, Median (IQR)
|
46.0 (36.0, 57.0)
|
46.0 (35.0, 56.8)
|
45.0 (38.0, 63.0)
|
43.0 (36.0, 53.0)
|
0.368
|
Race, n (%)
|
|
|
|
|
0.103
|
Black
|
46 (18)
|
34 (23)
|
1 (4)
|
11 (15)
|
|
Others
|
32 (13)
|
16 (11)
|
5 (19)
|
11 (15)
|
|
White
|
172 (69)
|
100 (67)
|
21 (78)
|
51 (70)
|
|
Primary.site, n (%)
|
|
|
|
|
0.672
|
Cervix uteri
|
213 (85)
|
125 (83)
|
24 (89)
|
64 (88)
|
|
Others
|
37 (15)
|
25 (17)
|
3 (11)
|
9 (12)
|
|
Surgery, n (%)
|
|
|
|
|
0.696
|
NO
|
130 (52)
|
80 (53)
|
12 (44)
|
38 (52)
|
|
YES
|
120 (48)
|
70 (47)
|
15 (56)
|
35 (48)
|
|
Radiation, n (%)
|
|
|
|
|
0.491
|
NO
|
182 (73)
|
106 (71)
|
22 (81)
|
54 (74)
|
|
YES
|
68 (27)
|
44 (29)
|
5 (19)
|
19 (26)
|
|
Chemotherapy, n (%)
|
|
|
|
|
0.277
|
NO
|
37 (15)
|
27 (18)
|
3 (11)
|
7 (10)
|
|
YES
|
213 (85)
|
123 (82)
|
24 (89)
|
66 (90)
|
|
Marital, n (%)
|
|
|
|
|
0.661
|
Divorced
|
57 (23)
|
37 (25)
|
6 (22)
|
14 (19)
|
|
Married
|
100 (40)
|
55 (37)
|
14 (52)
|
31 (42)
|
|
Single/UnMarried
|
83 (33)
|
53 (35)
|
6 (22)
|
24 (33)
|
|
Unknown
|
10 (4)
|
5 (3)
|
1 (4)
|
4 (5)
|
|
Regional.nodes, n (%)
|
|
|
|
|
0.209
|
0
|
156 (62)
|
99 (66)
|
12 (44)
|
45 (62)
|
|
0~12
|
38 (15)
|
23 (15)
|
5 (19)
|
10 (14)
|
|
13~
|
56 (22)
|
28 (19)
|
10 (37)
|
18 (25)
|
|
Nodes.positive, n (%)
|
|
|
|
|
0.832
|
0
|
215 (86)
|
127 (85)
|
23 (85)
|
65 (89)
|
|
0~3
|
28 (11)
|
19 (13)
|
3 (11)
|
6 (8)
|
|
4~
|
7 (3)
|
4 (3)
|
1 (4)
|
2 (3)
|
|
FIGO, n (%)
|
|
|
|
|
0.136
|
I~IIA
|
71 (28)
|
38 (25)
|
10 (37)
|
23 (32)
|
|
IIB~IVA
|
80 (32)
|
53 (35)
|
3 (11)
|
24 (33)
|
|
IVB
|
99 (40)
|
59 (39)
|
14 (52)
|
26 (36)
|
|
Age.cat, n (%)
|
|
|
|
|
0.066
|
~39
|
90 (36)
|
55 (37)
|
8 (30)
|
27 (37)
|
|
40~44
|
30 (12)
|
15 (10)
|
5 (19)
|
10 (14)
|
|
45~59
|
73 (29)
|
45 (30)
|
3 (11)
|
25 (34)
|
|
60~
|
57 (23)
|
35 (23)
|
11 (41)
|
11 (15)
|
|
Survival analysis and prognostic factors for NECCs
Kaplan-Meier analysis determined the impact of variables on survival. As expected, there were significantly lower rates of death in patients with lower FIGO staging (I-IIA vs. IIB~IVA vs. IVB; P < 0.001) (Figure 1A). We also found that patients with less regional lymph nodes had poorer survival outcomes in cervical neuroendocrine carcinoma (0 vs. 0-12 vs. 13 and above; P < 0.001) (Figure 1B). But the number of positive lymph nodes showed no significant effect on survival (P=0.403) (Figure 1C). Among all age groups, young age (0-39 vs. 40-44 vs. 45-59 vs. >60 years; P < 0.001) was associated with better prognosis (Figure 1D). More interestingly, married people showed better outcomes than the other groups (single/unmarried vs. married vs. divorced vs. other status; P < 0.001) (Figure 1E). Among all tumor subtypes, SCC had the most favorable survival, whereas LCC was associated with the worst prognosis (Figure 1F). With respect to the factors associated with treatments, we found that patients who underwent surgery (yes vs. no), or chemotherapy (yes vs. no), or radiation (yes vs. no) all experienced a significantly prolonged survival (Figure 2A-C) (All P ≤0.01).
Table 2 shows univariate and multivariate analyses of potential predictors for the OS. Higher FIGO staging, more regional lymph nodes, age above 60, no radiation, no chemotherapy, and no surgery were significantly associated as risk factors for the OS in the univariate analysis. Therefore, these significant risk factors were included in the multivariate analysis. Multivariate analysis identified that higher FIGO staging (IIB~IVA [hazard ratio (HR), 1.934; 95% CI, 1.02–3.668], IVB [HR, 4.465; 95% CI, 2.349–8.487]), no chemotherapy treatment (HR, 0.356; 95% CI, 0.224–0.568), were independent indicators of poor prognosis.
Table 2 Univariate and multivariate analyses of potential predictors
Subgroup analysis and sensitive analysis for risk factors
Subgroup analysis and sensitive analysis were then performed. Table 3 shows the P value for interaction for those variables, and multivariate analysis identified that patients, who had radiation therapy (HR, 0.886; 95% CI, 0.338-2.32), may contribute to better survival outcomes than those who did not have that (HR, 0.468; 95% CI, 0.317-0.692), the P value for interaction is 0.019. The situation for those who had surgery (HR, 0.831; 95% CI, 0.473-1.464) is the similar, compared with those who didn’t (HR, 0.381; 95% CI, 0.24-0.603), the P value for interaction is 0.004. All E-value for sensitivity analysis with the aforementioned data set was performed in Figure 3. The primary finding was robust between the groups who underwent surgery (YES vs. NO, Unknown vs. NO); later FIGO staging (IVB vs. I-IIA, IIB~IVA vs. I~IIA); older aging (60~ vs. ~39); a larger number of regional positive lymph nodes (0~3 vs. 0).
Table 3 P value for interaction of potential predictors
Survival analysis for risk factors
Then we calculated the median survival time and overall survival rate of all variables in the sensitivity analysis data, and plotted the KM curve. The survival curve was grouped for five: 0-, 120-, 240-, 360-, 480-. We found that patients with the tumor subtype of LCC had poorer survival than patients whose tumor subtype was SCC (median OS, 15 vs. 21 months; P = 0.022) (Figure 4A). Among all age groups, young age was associated with better prognosis (P < 0.001) (Figure 4B). And interestingly, the median OS of patients who were married was 23 months (95% CI, 20-26), while the median OS of patients who were single /unmarried was 18 months (95% CI, 16-25) and 14 (95% CI, 11-16) for those who were divorced (P < 0.001) (Figure 4C). Among all races, subtype of other races had the most favorable survival, whereas black was associated with the worst prognosis (P = 0.001) (Figure 4D). Patients, whose FIGO staging is IVB or regional lymph nodes were more than 13, had worst survival than other groups (Figure 4E, 4F). With respect to the factors associated with treatments, we found that patients who underwent surgery (yes vs. no vs. unknown) or radiation (yes vs. no) experienced prolonged survival, both P < 0.001 (Figure 4G, 4H). However, there was no statistical significance between patients who underwent chemotherapy (yes vs. no) (P = 0.843).
We then again performed univariate and multivariate analyses of Cox regression analysis based on the sensitivity analysis data set, the results were shown in Table 3. Higher FIGO staging, more regional lymph nodes, older age, no radiation, and no surgery were significantly associated as risk factors for the OS. And multivariate analysis identified that higher FIGO staging (IVB vs. IA~IIA [HR, 2.4; 95% CI, 1.505-3.828], P < 0.001), no surgery treatment (Unknown vs. NO [HR, 0.569; 95% CI, 0.443-0.731], YES vs. NO [HR, 0.467; 95% CI, 0.358-0.609], both P < 0.001), were independent indicators of poor prognosis.