Ovarian cancer not only is a serious threat to the health and life of women but also has the highest mortality rate of all gynecological cancers. Because there is no exact method of screening, 70% of patients have reached the advanced stage by the time of presentation and often have abdominal metastasis, organ metastasis, ascites and pleural effusion. At present, the treatment of newly diagnosed patients with advanced epithelial ovarian cancer (EOC) is divided into two types: neoadjuvant chemotherapy combined with interval debulking surgery (NACT + IDS) and primary debulking surgery (PDS). NACT, also known as primary chemotherapy, refers to systemic chemotherapy that is administered before local treatment (such as radiotherapy or surgery). This treatment is primarily administered when PDS cannot achieve ideal tumor cytoreduction and/or patients are in poor condition and cannot tolerate tumor cytoreductive surgery. The ideal tumor cytoreductive rate can be improved by NACT [
6]. Ovarian cancer is very sensitive to chemotherapy drugs. About 70 to 80% of patients with ovarian cancer have a complete response after chemotherapy [
7]. Studies have shown that NACT has the following advantages: it kills metastastic cells surrounding the lesion, loosens the adhesion of the tumor and surrounding tissue, reduces tumor volume, improves the ideal tumor cytoreductive rate, and reduces the difficulty and complications of surgery [
8]; it controls ascites and pleural effusion to improve the overall condition of patients and improve their surgical tolerance; it shortens the operation time, reduces intraoperative blood loss, and improves patient quality of life [
9]; and it puts the tumor cells into a “dormant state”, reducing tumor spread and tumor cell seeding by surgery due to intraoperative squeezing and mechanical trauma stimulation, thereby reducing recurrence. However, the use of NACT for the treatment of patients with advanced ovarian cancer has been continuously controversial. For patients with advanced ovarian cancer who remain in good condition, studies have shown that PDS can achieve better tumor reduction and prognosis than NACT.
Based on the CT evaluation model of ovarian cancer patients that was established by Bristow et al. in 2000, patients with a cumulative score ≥ 4 (score ≥ 4) are not suitable for PDS. They noted that such patients should undergo NACT until the condition is under control prior to surgery. In addition, a large number of studies have shown that more than 85% of patients with ovarian cancer have a serum CA125 level higher than 35 U/mL, and serum CA125 levels are closely related to disease status in 93% of patients. Therefore, the level of serum CA125 is considered strong evidence in the evaluation of the ability of patients to achieve ideal tumor cytoreduction [
10]. Vorgias et al. found that when serum CA125 levels were higher than 500 U/ml, the accuracy of its predictive ability was highest for patients undergoing tumor cytoreductive surgery to achieve the ideal standard, accounting for 84.2% in all observed ideal tumor cytoreductive surgeries. Obeidat et al. [
11] supported this view and reported that a preoperative serum CA125 level of 500 U/ml was the most valuable indicator of whether ideal tumor cytoreductive surgery could be achieved. This indicator’s sensitivity and specificity were 72 and 73%, respectively. The positive predictive value was 68%. However, some investigators believed that the negative predictive value of CA125 is poor and that this measure cannot be used independently as an index to predict surgery. Therefore, in order to predict more suitable treatment for patients, we have assessed patients with newly diagnosed advanced EOC by taking advantage of an ovarian cancer CT evaluation model established by Bristow et al. combined with serum CA125 levels.
By comparing two groups (NACT + IDS and PDS), we found that there was no significant difference in the operation time, intraoperative blood loss, the ideal tumor cytoreductive rate or postoperative complications between the two groups of patients with a score < 5 (
p = 0.764,
p = 0.504,
p = 0.906,
p = 0.705). However, the overall survival rate was significantly different between the two groups (
p = 0.029), with the PDS group having superior survival to the NACT + IDS group. This finding suggests that PDS did not show any advantage in terms of intraoperative and postoperative complications compared with the NACT + IDS group for patients with newly diagnosed advanced EOC when the score was < 5, but the postoperative quality of life and long-term prognosis of these patients were significantly better than those of the NACT + IDS group. For scores < 5, there was no significant difference between the NACT + IDS and PDS groups in terms of operation time, intraoperative blood loss and ideal tumor cytoreduction. Therefore, in order to avoid side effects and adverse reactions brought on by unnecessary chemotherapy, as well as excessive treatment costs and lengths of treatment that may delay the optimal operation time, we support the notion that advanced EOC patients should undergo PDS. In the two groups of patients with a score ≥ 5, the operation time of the NACT + IDS group was significantly shorter than that of the PDS group (
p = 0.002). The amount of blood loss during operation in the former was less than that in the latter, and the ideal cytoreductive rate was higher (
p = 0.040,
p = 0.014). This finding showed that for scores ≥5, patients undergoing NACT could significantly improve their condition prior to surgery to reduce surgical difficulty and risks. In addition, the incidence of postoperative complications in the NACT + IDS group was significantly lower than that in the PDS group (
p = 0.021). This result suggested that NACT could significantly reduce the incidence of complications and improve the quality of life of patients who were newly diagnosed with severe illness. None of these patients could undergo PDS immediately. In terms of overall survival rate, we found no significant difference between the two groups of patients (
p = 0.383). NACT + IDS did not appear to improve prognosis. This result was in line with that of many published reports. Lozzi et al. [
12] conducted a paired study of neoadjuvant chemotherapy with patients treated with standard treatment over the same period and showed no significant differences between the neoadjuvant chemotherapy group and the standard treatment group in terms of median survival time, median progression-free survival time and 3-year survival rate. Wright et al. [
13] compared the efficacy of PDS and NACT + IDS in elderly patients with ovarian cancer using SEER data. They noted that the average survival of patients in the NACT + IDS and PDS groups was 15.8 months and 28.8 months, respectively, with 2-year survival rates of 36 and 56%, respectively. Fago-Olsen et al. [
14] reported that the average overall survival of patients without residual tumor in the PDS group was better than that of those in the NACT + IDS group, at 55.5 and 36.7 months, respectively (
p = 0.002). Simultaneously, patients in the NACT + IDS group had an increased risk of death after 2 years. We speculated that the reason for this analysis may be as follows: although NACT can reduce the difficulty and risk of surgery, the criterion for satisfactory tumor shrinkage in these studies was the same for patients with intermittent cytoreductive surgery following neoadjuvant chemotherapy as for direct cytoreductive surgery, namely, residual lesions less than 1 cm. The number of chemotherapy regimens after intermittent neoplastic cytoreductive surgery following neoadjuvant chemotherapy is fewer than the number after direct surgery, because neoadjuvant chemotherapy may increase the chemoresistance potential of ovarian cancer cells. However, NACT + IDS did not improve patient prognosis. By analyzing the ideal tumor cytoreductive rates of two PDS groups of patients who scored < 5 and ≥ 5, the difference in the ideal tumor cytoreductive rate of the two groups was approximately 10%, and the ideal surgical cytoreductive rate in patients in the PDS group and with a score < 5 was significantly higher than that of patients with a score ≥ 5. Although there was no statistically significant difference between the two groups (
p = 0.296), we cannot conclude that there was no difference in the rate of reduction between the two groups. We believe the reason may stem from limitations in the collection of cases. For the treatment of patients with newly diagnosed advanced EOC, the choice of the re-established New Scoring System score cut-off point has substantial guiding significance. Whether there is a score < 5 or ≥ 5, patients with ovarian cancer can choose a relatively more favorable treatment. Therefore, we believe the choice of the cut-off point was reasonable. Taken together, we hypothesize that patients with newly diagnosed advanced EOC and score < 5 who can tolerate PDS at presentation may be better able to manage the optimal surgical treatment time, shorten the duration of patient treatment, reduce pain, reduce treatment costs and improve long-term outcomes. However, patients with a score ≥ 5 who were treated with NACT + IDS were more conducive to reducing the difficulty and risk of surgery, improving the reduction rate of tumor cells and improving the quality of life.