Patient characteristics
A total of 410 advanced ovarian tumor patients were analyzed in this study, 170 cases in Group A and 240 in Group B, and the characteristics of the two groups are listed in Table 1.
Table 1 Patient characteristics
|
No
|
GroupA
|
GroupB
|
P-value
|
Total
|
410
|
170
|
240
|
|
Age (years)
|
|
|
|
0.257
|
Median
|
|
54
|
51
|
|
Range
|
|
29-72
|
28-71
|
|
Serum CA-125 level (U/mL)
|
|
|
|
0.532
|
Median
|
|
606.8
|
455.1
|
|
Range
|
|
13-6743
|
6-10000
|
|
Intraoperative blood loss (ml)
|
|
|
|
0.889
|
Mean
|
|
537.7±335.3
|
542.5±352.4
|
|
Range
|
|
100-1500
|
100-2200
|
|
Histology
|
|
|
|
0.475
|
Serous
|
320
|
136(80%)
|
184(76.7%)
|
|
Clear cell
|
6
|
4(2.4%)
|
2(0.8%)
|
|
Endometrioid
|
46
|
16(9.4%)
|
30(12.5%)
|
|
Mucinous
|
24
|
10(5.9%)
|
14(5.8%)
|
|
Others
|
14
|
4(2.4%)
|
10(4.2%)
|
|
FIGO stage
|
|
|
|
0.686
|
III
|
342
|
140(82.4%)
|
202(84.2%)
|
|
IV
|
68
|
30(17.6%)
|
38(15.8%)
|
|
The median age of patients in Groups A and B was 54 (29-72) and 51 (28-71) years old, respectively. The median serum CA-125 level was 606.8 U/mL (13-6743 U/ mL) in Group A and 455.1 U/mL (6-10000 U/mL) in Group B. The majority of patients in Groups A and B were at FIGO stage III (82.4% of Group A and 84.2% of Group B), and a few cases were at stage IV (17.6% of Group A and 15.8% of Group B). Out of 410 total patients, serous tumors were the most common pathological subtype (n=320; 78%), followed by endometrioid (n=46; 11.2%), mucinous (n=24; 5.9%), clear cell (n=6; 1.5%) and 14 patients (3.4%) had others histological types. In addition, the mean intraoperative blood loss in Group B was slightly higher than that in Group A (542.5±352.4 vs 537.7±335.3 ml). There was no significant difference in the patients’ clinical characteristics between the two groups, including the age (P = 0.257), median serum CA-125 level (P = 0.532), intraoperative blood loss (P = 0.889), FIGO stage (P = 0.686), or pathological type (P = 0.475).
The postoperative complications and primary systemic treatment in Groups A and B are summarized in Table 2.
Table 2 Postoperative Complications and Primary Systemic Treatment
Complication or Treatment
|
Group A
|
Group B
|
P-value
|
|
(N=170)
|
(N=240)
|
|
Complication
|
|
|
|
Infection treated with antibiotics
|
22(12.9%)
|
52(21.7%)
|
0.027
|
Thrombosis
|
4(2.4%)
|
6(2.5%)
|
0.924
|
Lymph cysts
|
4(2.4%)
|
50(20.8%)
|
<0.001
|
Intestinal fistula
|
2(1.2%)
|
4(1.7%)
|
0.684
|
Repeat laparotomy for complications
|
2(1.2%)
|
6(2.5%)
|
0.340
|
Postoperative bleeding
|
0(0)
|
2(0.8%)
|
0.233
|
Primary systemic therapy
|
|
|
0.100
|
Paclitaxel and platinum
|
98(57.6%)
|
160(66.7%)
|
|
Docetaxel and platinum
|
68(40%)
|
76(31.7%)
|
|
Other systemic treatment
|
2(1.2%)
|
4(1.7%)
|
|
No systemic treatment
|
2(1.2%)
|
0(0)
|
|
It was found that the patients in lymphadenectomy group had a higher incidence of postoperative complications than those in no-lymphadenectomy group. Especially for the incidence of infection treated with antibiotics (21.7% [52 of 240 patients] vs. 12.9% [22 of 170 patients], P=0.027) and the incidence of lymph cysts (20.8% [50 of 240] vs. 2.4% [4 of 170], P<0.001). In addition, the main reason for repeat laparotomy of complications in Group B (2.5% [6 of 240 patients]) was postoperative bleeding, intestinal fistula or lymph cysts, and the main reason in Group A (1.2% [2 of 170 patients]) was fistula.
With respect to primary systemic treatment after cytoreductive surgery, the majority of patients received adjuvant chemotherapy, 98.4% of the patients in Group B and 97.6% of those in Group A were treated with paclitaxel or docetaxel and platinum. No significant difference was found between the two groups (P = 0.100) as well.
Survival
The 5-year OS and 2-year PFS rates were 78% and 24% in no-lymphadenectomy group and 76% and 26% in lymphadenectomy group (P=0.385 and 0.214, respectively). The survival curves of these two groups were examined by Kaplan–Meier analysis, as shown in Fig.1.
Without residual tumor
When patients without residual tumor were analyzed, the 5-year OS and 2-year PFS rates were 73% and 31% in no-lymphadenectomy group and 69% and 26% in lymphadenectomy group, the difference was not statistically significant (P=0.392 and 0.397, respectively). The survival curves are displayed in Fig.2.
Histological type (serous or non-serous type)
Similarly, when confining analysis to patients with serous type or non-serous type, the difference in 5-year OS and 2-year PFS between the two groups was no significant (serous: P=0.601 and 0.603, non-serous: P=0.310 and 0.051). The survival curves are illustrated in Fig.3.
Clinical evaluation for lymph nodes (negative)
In subgroup analysis of patients with negative lymph nodes (including evaluation of preoperative imaging and intraoperative exploration), the difference in the 5-year OS and 2-year PFS was also not statistically significant (P=0.077 and 0.128, respectively). The survival curves are shown in Fig.4.
FIGO stage IIIB-IV
In the separate analysis of patients with macroscopic peritoneal metastasis beyond pelvic (FIGO stage IIIB-IV), there was no significant difference in 5-year OS and 2-year PFS between the two groups (P=0.440 and 0.331, respectively). The survival curves are presented in Fig.5.
Multivariate analysis of clinicopathologic factors in relation to PFS and OS of patients (Table 3)
A multivariate Cox regression model was established in this study, FIGO stage (III/IV), histological types (serous/non-serous), and lymphadenectomy (no/yes) were imported into this model. The results showed that, systematic retroperitoneal lymphadenectomy was not a significant factor influencing the patients’ survival.
Table 3 Multivariate analysis of clinicopathologic factors in relation to PFS and OS of patients
|
No
|
Progression-free survival (PFS)
|
Overall survival (OS)
|
|
|
Hazard ratio (95% CI)
|
P-value
|
Hazard ratio (95% CI)
|
P-value
|
Total
|
410
|
|
|
|
|
FIGO stage
|
|
|
|
|
|
III
|
342
|
1
|
0.006
|
1
|
0.403
|
IV
|
68
|
0.694(0.534-0.902)
|
|
0.804(0.483-1.340)
|
|
Histology
|
|
|
|
|
|
Serous type
|
320
|
1
|
0.521
|
1
|
0.725
|
Non-serous type
|
90
|
0.926(0.731-1.172)
|
|
1.082(0.697-1.680)
|
|
Lymphadenectomy
|
|
|
|
|
|
No
|
170
|
1
|
0.237
|
1
|
0.389
|
Yes
|
240
|
1.127(0.924-1.374)
|
|
0.846(0.578-1.238)
|
|
|
|
|
|
|
|
|