Efficacy and safety of intraperitoneal bevacizumab combined with hyperthermic intraperitoneal chemotherapy in the treatment of patients with ovarian cancer and peritoneal effusion and the effect on serum lncRNA H19 and VEGF levels

Abstract

Peritoneal effusion is a common event in ovarian cancer (OC) patients. LncRNA H19 and vascular endothelial growth factor (VEGF) are implicated in cancer progression. The study evaluated the curative effect and safety of bevacizumab combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in OC patients with peritoneal effusion and the effect on serum lncRNA H19/VEGF levels. Totally 248 OC patients with peritoneal effusion were treated with intraperitoneal bevacizumab + HIPEC (observation group) or abdominal paracentesis without HIPEC (control group). The clinical efficacy, quality of life, and adverse reactions were evaluated after two treatment cycles. The serum lncRNA H19 and VEGF levels pre-/post-treatment were determined by RT-qPCR and ELISA. The observation group exhibited better clinical efficacy than the control group, evidenced by a higher partial response rate, response rate, and disease control rate. The observation group exhibited reduced physical/cognitive/role/social/emotional function scores and total adverse reactions. LncRNA H19/VEGF levels showed no significant difference between the two groups before treatment but were significantly downregulated in the observation group after treatment. Summarily, intraperitoneal bevacizumab + HIPEC has significant efficacy in treating peritoneal effusion, improves the quality of life, and reduces serum lncRNA H19 and VEGF levels in OC patients, with fewer adverse reactions and higher safety.

Impact statement

• What is already known on this subject? The utilization of hyperthermic intraperitoneal chemotherapy (HIPEC) as an emerging treatment option for abdominal malignancies has garnered the attention of numerous researchers over the years, which has significant clinical effects on peritoneal effusion in ovarian cancer and can control patients’ conditions and improve their signs and symptoms to a certain extent.

• What do the results of this study add? In this paper, we investigated the efficacy and safety of intraperitoneal bevacizumab combined with hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal effusion in ovarian cancer. Meanwhile, we compared serum lncRNA H19 and VEGF levels before and after treatment.

• What are the implications of these findings for clinical practice and/or further research? Our findings may provide a clinically worthy method for the treatment of peritoneal effusion in ovarian cancer. The treatment method reduces serum lncRNA H19 and VEGF levels in patients, which provides a theoretical basis for further research.

Keywords:

• Ovarian cancer
• peritoneal effusion
• hyperthermic intraperitoneal chemotherapy
• Bevacizumab
• curative effect
• safety
• LncRNA H19
• vascular endothelial growth factor

Introduction

Ovarian cancer (OC) is regarded as the deadliest gynaecologic malignancy and has a 5-year survival of approximately 47%, which has remained constant for the past 20 years (Moufarrij et al. 2019). In 2020, OC is responsible for 313,959 new cases and 207,252 deaths, accounting for 1.6% of cancer occurrences and 2.1% of cancer-related deaths (Sung et al. 2021). Recent investigations have come to light indicating that approximately more than 70% of women have progressed to a late stage (stage III or IV) at diagnosis due to the vague presenting symptoms and insidious onset; and worse, the 1-year survival has dropped from 93.5% in stage II to 71% in stage III, thus leading to a high mortality rate (Gupta et al. 2019). Peritoneal effusion (or ascites) refers to the pathological and aberrant accumulation of fluid in the peritoneal cavity and occurs in over one-third of OC patients at initial diagnosis, which is extensively associated with a poor prognosis and also a strong contributor to metastasis, chemoresistance, and decreased resectability, making it detrimental to clinical treatment (Ford et al. 2020). Ascites is comprised of acellular and cellular components, such as inflammatory factors, various metabolites, and tumour cells, thus providing an immune-evading and growth-promoting microenvironment for tumour cells to enable phenotypic changes and facilitating chemoresistance (Rickard et al. 2021). In addition to increasing the difficulty of surgery during treatment, ascites also reduce the curative effect of conventional postoperative chemotherapy. There is an urgent need to actively alleviate the symptoms of ascites in OC and improve the patient’s condition in the clinic.

Bevacizumab is a recombinant humanised monoclonal antibody that has been approved for first-line maintenance therapy in advanced OC (Mao et al. 2022). The application of bevacizumab in standard front-line cytotoxic chemotherapy leads to an approximately 3-4-month elevation in progression-free survival (Haunschild and Tewari 2020). Bevacizumab possesses the ability to improve the survival of OC patients (Li et al. 2021) and reduces the expression levels of cancer-related markers more than chemotherapy alone (Ma 2022). The hard-done work of our peers has highlighted the curative effect of IV bevacizumab combined with various chemotherapeutic agents for the treatment of ovarian peritoneal malignancy/ascites (Lemoine et al. 2017). Hyperthermic intraperitoneal chemotherapy (HIPEC), comprising induction of hyperthermia as well as delivery of chemotherapeutic drugs into the peritoneal cavity, is an emerging treatment for patients with peritoneal cancer, including epithelial OC (Gadducci et al. 2022). There is evidence to indicate that hyperthermia can enhance the penetration of chemotherapeutic agents at the peritoneal surface and elevate the chemosensitivity of cancer cells by impairing DNA repair, which is also shown to activate the heat-shock proteins that act as vital receptors for natural killer cells, trigger apoptosis, suppress angiogenesis, and confer direct cytotoxic effects through promotion of protein denaturation (van Driel et al. 2018). Therefore, we analysed the efficacy of intraperitoneal bevacizumab combined with HIPEC in treating peritoneal effusion in OC patients.

Vascular endothelial growth factor (VEGF) emerges as a kind of pro-angiogenic growth factor that is capable of stimulating the division and migration of tumour cells and accelerating the growth and invasion of tumours by increasing the permeability of vascular endothelial cells (Geindreau et al. 2021, Zhang and Brekken, 2022). Interestingly, reducing copper levels in ascites may help to downregulate VEGF expression, thereby improving the prognosis of OC (Onuma et al. 2021). Inherently, bevacizumab can bind to circulating VEGF and repress its binding to receptors, thereby impeding tumour development (Mao et al. 2022), which also significantly improves the prognosis of advanced OC patients with downregulated VEGF-A165b (an antiangiogenic VEGF-A splice variant) (Wimberger et al. 2022). Additionally, long non-coding RNAs (lncRNAs) are considered key regulators of cancer progression, and their dysregulation contributes to malignant phenotypical changes in OC (Wang et al. 2019). In particular, lncRNA H19 is associated with poor prognosis in OC and promotes cell migration, proliferation, and invasion (Wang and Gao 2021, Ma et al. 2022). Compelling evidence reveals that overexpression of lncRNA H19 activates the PI3K/AKT pathway and promotes OC cell growth and epithelial-mesenchymal transition (Xu et al. 2021). The above evidence implies the involvement of VEGF and lncRNA H19 in OC. In light of the aforementioned research, the current study set out to investigate the efficacy and safety of intraperitoneal bevacizumab combined with HIPEC in the treatment of peritoneal effusion and the effect on serum lncRNA H19 and VEGF levels in OC patients.

Materials and methods

Ethics statement

This current study was conducted with the approval of the Ethics Committee of Anhui No.2 People’s Hospital and conformed to the Enhancing the Quality and Transparency Of health Research (EQUATOR) network guidelines (Approval number: (R)2020-005-02). All participants and their families had voluntarily signed the informed consent.

Study subjects

A total of 248 OC patients with peritoneal effusion admitted at the Huoshan County Hospital, Huoshan County, The People's Hospital of Chizhou, Anhui No.2 People's Hospital, Taihe County Hospital of Traditional Chinese Medicine, Fuyang Cancer Hospital from January 2019 to April 2022 were enrolled as the study subjects and allocated into the observation group (N = 124) and the control group (N = 124) by the random number table. Patients in the observation group were treated with intraperitoneal bevacizumab combined with HIPEC, and patients in the control group underwent abdominal paracentesis without HIPEC.

Inclusion and exclusion criteria

Patients met the following inclusion criteria were included: (1) ≥18 years old; (2) with OC and peritoneal effusion confirmed by pathological or cytological examination as well as B-ultrasound; (3) without a history of chemotherapy or radiotherapy; (4) at stage III-IV; (5) with an expected survival of more than 1 year; (6) without major organ dysfunction; (7) acceptable to treatment with intraperitoneal bevacizumab and HIPEC.

We excluded the patients with: (1) severe heart, lung, liver, and kidney dysfunction; (2) chemotherapy contraindications; (3) intestinal obstruction, peritoneal adhesion, and abdominal infection that affects intraperitoneal chemotherapy; (4) bone marrow function and circulatory system dysfunction; (5) haemorrhagic disorders; (6) failure to complete the treatment, voluntary interruption of treatment, intolerance of adverse reactions during treatment.

Data and sample collection

The general clinical baseline data of enrolled subjects were recorded, such as age, Karnofsky performance status (KPS) score, pathological type (serous type and non-serous type) (Dalal et al. 2018), degree of ascites (mild, moderate, and severe), and cancer stage (III and IV). In addition, the serum lncRNA H19 and VEGF levels of OC patients before and after treatment were determined. Early in the morning of the day following the patients’ admission, 2 mL fasting peripheral venous blood samples were drawn from patients and placed in an ethylenediaminetetraacetic acid anticoagulant tube (Shi et al. 2021), followed by centrifugation at 1000×g for 10 min. The collected supernatant was stored at −80 °C for future analysis. After the patients underwent 2 treatment cycles, the serum was collected again.

Treatment modalities

All patients underwent abdominal paracentesis after B ultrasound localisation. The single-lumen central venous catheter was used to drain the peritoneal effusion as much as possible.

The observation group: four HIPEC-specific silicone catheters (5 mm in diameter) were inserted into the peritoneal cavity and externally connected to a hyperthermic perfusion therapy apparatus (HGGZ-1O2, Hanfei Medical Instruments, Shanghai, China). The peritoneal cavity of patients was perfused with 2500–3000 mL distilled water, 40 mg cisplatin (H37021358, Qilu Pharmaceutical, Jinan, Shandong, China), and 5 mg dexamethasone (H44024469, Huanan Pharmaceutical Group, Dongguan, Guangdong, China) at a constant rate each time. The continuous hyperthermic circulation perfusion therapy was performed for 90 min at a constant temperature of 43 ± 0.5 °C. The perfusion fluid was slowly drained, and bevacizumab (300 mg/m², Qilu Pharmaceutical) was administered into the peritoneal cavity. After perfusion, patients were asked to change their body position every 15 min within 6 h to facilitate the complete distribution of the drugs throughout the peritoneal cavity for best efficacy.

The control group: patients underwent an abdominal paracentesis with a peritoneal catheter indwelled to drain ascites. After drainage of ascites, the peritoneal cavity was rapidly injected with 40 mg cisplatin, 5 mg dexamethasone, and the same bevacizumab used in the observation group. The indwelling catheter was clamped for 24 h and then the drugs were administered again. A total of 3 intraperitoneal injections of drugs were carried out. Patients in both groups were subjected to systemic chemotherapy based on TC regimen (paclitaxel + cisplatin), with 3 weeks (21 days) regarded as a cycle. The clinical efficacy was evaluated after 2 cycles of treatment. During treatment, patients received symptomatic therapies, such as conventional antiemetic and hepatoprotective treatments.

Evaluation of indexes

After 2 cycles of treatment, clinical efficacy, quality of life, and adverse reactions were assessed. (1) The clinical efficacy of therapeutic modality in peritoneal effusion was evaluated under the World Health Organisation (WHO) criteria: the patients were categorised into the following 4 grades, complete response (CR): complete disappearance of peritoneal effusion for more than 4 weeks; partial response (PR): a reduction of peritoneal effusion by more than 50% and remission of clinical symptoms and signs for more than 4 weeks; stable disease (SD): reduction of peritoneal effusion by less than 50% or increase by less than 25%; and progressive disease (PD): significantly increased peritoneal effusion as well as persistent or worsening clinical symptoms and signs. Response rate (RR) = (CR + PR)/total cases × 100%, disease control rate (DCR) = (CR + PR + SD)/total cases × 100%. (2) The postoperative quality of life of patients with OC combined with peritoneal effusion was scored by means of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). The EORTC QLQ-C30 scale comprised 30 items and was divided into 5 aspects: physical function, cognitive function, role function, emotional function, and social function. Items 29 and 30 were divided into 7 levels and scored from 1 to 7 points according to the response, and other items were assigned into 4 levels: not at all (1 point), a little (2 points), quite a bit (3 points), and very much (4 points). The higher scores were indicative of a poorer quality of life. (3) The adverse reactions were evaluated in accordance with the WHO grading criteria for common adverse reactions to anticancer drugs.

Reverse transcription-quantitative polymerase chain reaction

The total RNA content was extracted using the TRIzol reagent (Invitrogen, Carlsbad, CA, USA) and then transcribed into cDNA using the PrimeScript RT reagent kit (Takara, Dalian, Liaoning, China). The qPCR was conducted using SYBR^® Premix Ex TaqTM II (Takara) on an ABI7900HT fast PCR real-time system (ABI, Foster city, CA, USA). The reaction conditions were as follows: pre-denaturation at 95 °C for 10 min, and next 40 cycles of denaturation at 95 °C for 10 s, annealing at 60 °C for 20 s, and extension at 72 °C for 34 s. With glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal control, data were analysed using the 2^-ΔΔCt method (Schmittgen and Livak 2008). Primers were synthesised by Sangon Biotech (Shanghai, China) and sequences are exhibited in Supplementary Table 1.

Enzyme-linked immunosorbent assay (ELISA)

The levels of VEGF in patients before and after therapy were determined following the provided instructions of the ELISA kit (ml064281, Enzyme-linked Biotechnology, Shanghai, China) (Khaloo et al. 2020).

Statistical analysis

Data were analysed and graphed using SPSS 21.0 (IBM Corp. Armonk, NY, USA) and GraphPad Prism 8 (GraphPad Software Inc., San Diego, CA, USA). Data were checked for consistency with normal distribution by the Shapiro-Wilk test and depicted as mean ± standard deviation (SD). The unpaired t-test was conducted for comparisons between the two groups. Categorical variables were analysed using Fisher’s exact test. A value of p < 0.05 was regarded as statistically significant.

Results

Comparison of clinical baseline data

The enrolled 248 OC patients with peritoneal effusion were allocated into the observation group (N = 124) and the control group (N = 124). The clinical baseline of patients was analysed and compared, the results of which revealed that there were no significant differences in regard to age, KPS score, pathological type, degree of ascites, and cancer stage between the two groups (all p > 0.05) (Supplementary Table 2), with comparability between groups.

Comparison of clinical efficacy

Thereafter, the clinical efficacy of the two groups was assessed. After treatment, the observation group presented an increased CR rate compared with the control group, but the difference showed no statistical significance (p > 0.05). The observation group presented a higher PR rate, RR, and DCR, as well as a lower number of cases of SD and PD than the control group (all p < 0.05) (Table 1). Together, the above results evidenced that a combination of intraperitoneal bevacizumab and HIPEC had better clinical efficacy in the treatment of peritoneal effusion in OC patients.

Table 1. Comparison of clinical efficacy.

	Cases	CR (%)	PR (%)	SD (%)	PD (%)	RR (%)	DCR (%)
Observation group	124	41 (33.06%)	52 (41.94%)	24 (19.35%)	7 (5.65%)	93 (75.00%)	117 (94.35%)
Control group	124	30 (24.19%)	37 (29.84%)	39 (31.45%)	18 (14.52%)	67 (54.03%)	106 (85.48%)
χ^2		2.388	3.943	4.788	5.383	11.910	5.383
p value		0.122	0.047	0.029	0.020	0.001	0.020
95%CI		0.3774-1.126	0.3526-1.000	1.083-3.346	1.196-7.377	0.2256-0.6783	0.1356-0.8364

CR: complete response; PR: partial response; SD: stable disease; PD: progressive disease; RR: response rate; DCR: disease control rate; CI: confidence interval. Enumeration data were expressed as number of cases and percentage and analysed by the χ² test. The p value < 0.05 indicated statistical significance.

Quality of life scores of the two groups

The patients’ quality of life after treatment was assessed using the EORTC QLQ-C30 scale. Subsequent results unravelled that the observation group exhibited lower scores of physical function, cognitive function, role function, social function, and emotional function in QLQ-C30 scale than the control group after treatment (all p < 0.05) (Table 2). Altogether, the above findings indicated that the application of intraperitoneal bevacizumab combined with HIPEC in treating peritoneal effusion can ameliorate the quality of life of OC patients to some extent.

Table 2. Quality of life scores of patients after treatment.

	Cases	Physical function	Cognitive function	Role function	Social function	Emotional function
Observation group	124	62.42 ± 8.73	58.95 ± 6.41	59.36 ± 6.47	56.44 ± 6.04	57.23 ± 6.34
Control group	124	65.34 ± 9.65	62.02 ± 6.28	64.43 ± 5.78	61.42 ± 6.81	67.76 ± 5.96
t		2.499	3.810	6.507	6.092	13.480
p value		0.013	<0.001	<0.001	<0.001	<0.001
95%CI		0.6183–5.222	1.483–4.657	3.535–6.605	3.370–6.590	8.991–12.07

CI: confidence interval. Measurement data were expressed as mean ± standard deviation and analysed using the unpaired t-test. The p value <0.05 indicated statistical significance.

Comparison of adverse reactions during treatment

Furthermore, the adverse reactions of patients during treatment were monitored. Patients in the two groups presented some adverse reactions during therapy, mainly manifested as leukopoenia, thrombocytopenia, haemoglobin reduction, bone marrow suppression, nausea/vomiting, fatigue, fever, diarrhoea, and elevated blood pressure. The total adverse reactions in the observation group were reduced compared with the control group but showed no significant difference (all p > 0.05) (Table 3).

Table 3. Comparison of adverse reactions during treatment.

Adverse reactions	Observation group (N = 124)	Control group (N = 124)	χ^2	p value	95%CI
Leukopoenia	7	9
Thrombocytopenia	4	6
Haemoglobin reduction	6	7
Bone marrow suppression	6	3
Nausea and vomiting	4	2
Fatigue	3	7
Weight loss	4	6
Fever	3	4
Diarrhoea	1	2
Elevated blood pressure	4	5
Total (%)	42 (33.87%)	51 (41.13%)	1.394	0.238	0.8137–2.313

CI: confidence interval. Numeration data were expressed as number of cases and percentage and analysed by the χ² test. The p value < 0.05 indicated statistical significance.

Expression levels of serum lncRNA H19 and VEGF before and after treatment

Meanwhile, we analysed the changes in serum lncRNA H19 and VEGF levels in OC patients with peritoneal effusion before and post-treatment. RT-qPCR revealed that the two groups showed no evident difference in serum lncRNA H19 level prior to treatment (p > 0.05, 95%CI: −0.09002 to 0.04098) (Figure 1A). After treatment, the observation group had lower serum lncRNA H19 levels than the control group (p < 0.05, 95%CI: −0.3572 to −0.2341) (Figure 1(B)). ELISA suggested that serum VEGF level was 93.21 ± 18.74 (pg/mL) in the observation group and 94.39 ± 18.32 (pg/mL) in the control group prior to treatment, showing no significant difference (p > 0.05, 95%CI: −5.815 to 3.456) (Figure 1(C)). After treatment, serum VEGF level was 83.56 ± 15.74 (pg/mL) in the control group but 74.65 ± 12.38 (pg/mL) in the observation group, showing significant differences (p < 0.05, 95%CI: −12.45 to −5.368) (Figure 1(D)). Taken together, serum lncRNA H19 and VEGF levels were prominently downregulated in OC individuals with peritoneal effusion after treatment with intraperitoneal bevacizumab combined with HIPEC.

Figure 1. Levels of serum lncRNA H19 and VEGF before and after treatment. (A-B) Serum lncRNA H19 level before and after treatment was determined by RT-qPCR; (C-D) Serum VEGF level before and after treatment was measured by ELISA. Measurement data were displayed as mean ± SD, and an independent sample t-test was used for comparisons between the two groups. **p < 0.01.

Discussion

OC is primarily considered a disease of older people with a median age of 68 years old at diagnosis, and elderly women with OC exhibit a poorer survival prognosis than younger patients, and are undertreated and underrepresented in clinical trials (Mamguem et al. 2021). Indeed, the therapeutic options and effects vary apparently by age, and older women are more candidates for single-modality treatments (such as surgery, chemotherapy, or hormonal therapy) while multimodality therapy is preferably administered in younger women (Vitale et al. 2019). As reported by Bizzarri et al, patients undergoing comprehensive lymphadenectomy are younger, experience a higher number of serious post-operative complications, and have a longer time to start chemotherapy (Bizzarri et al. 2021). Therefore, the management of OC should be personalised taking into account the performance status of the patient, in particular in elderly women. Despite advances in targeted agents, debulking surgery, immunotherapy, and platinum-based chemotherapy, the clinical outcome of OC patients remains suboptimal because the majority of patients present with widely metastatic and locally advanced tumours at diagnosis (Jiang et al. 2020). Importantly, there is evidence to suggest that aggressive behaviours of OC and immune compromise induced by aggressive surgery can lead to a superimposable progression-free survival rate independently from the residual tumour (Fagotti et al. 2020). On a separate note, the initial clinical response is primarily due to the therapeutic effects of chemotherapy against the differentiated cancer cells that constitute the bulk of the tumour, while the high recurrence rate is attributed to the remaining drug-resistant cells (Lagana et al. 2015). It is noteworthy that OC is often accompanied by an abnormal intraperitoneal accumulation of ascites, and ascites are shown to be extensively related to peritoneal dissemination, poor prognoses (Ghoneum et al. 2021, Pascual-Anton et al. 2021), and resistance to chemotherapy (Rodrigues et al. 2020), thus making peritoneal effusion a troublesome obstacle in OC treatment. Herein, the current study sought to explore the curative effect of intraperitoneal bevacizumab combined with HIPEC in treating peritoneal effusion in OC patients.

Bevacizumab, one of the most studied target therapies for OC, is approved for first- and second-line treatment of advanced epithelial ovarian, fallopian tube, and primary peritoneal tumours, and its combination with conventional antiblastic drugs and has provided noticeable improvements in the progression-free survival of OC patients both in first- and second-line settings (Musella et al. 2017). There is also evidence to demonstrate the use of bevacizumab in combination with chemotherapy for the frontline and maintenance therapy for women with newly diagnosed OC (Haunschild and Tewari 2020). Additionally, primary cytoreductive surgery with the purpose of leaving no residual tumour is considered a standard surgical treatment for patients with advanced OC, and the estimated 30-day mortality for this surgery is 4.64% (Di Donato et al. 2017). Meanwhile, a number of polyadenosine diphosphate-ribose polymerase (PARP) inhibitors have been developed, and such agents are under investigation in clinical trials to determine their impact on the treatment of OC (Musella et al. 2015).

For platinum-resistant OC patients with poor prognoses, combining immune checkpoint blockage with PARP inhibitors emerges as a novel and promising therapeutic modality (Bogani et al. 2020). Among symptomatic women with chemotherapy-resistant OC, intraperitoneal bevacizumab following drainage of malignant ascites is effective and has an acceptable safety profile (Sjoquist et al. 2021). Additionally, intraperitoneal administration of cisplatin combined with bevacizumab is safe and effective for the therapy of malignant ascites in epithelial OC (Zhao et al. 2015). Similar to bevacizumab, other agents such as catumaxumab and aflibercept are shown to be effective in the symptomatic control of ascites, causing a reduction of effusion and prolonging the time interval between paracenteses (Smolle et al. 2014). The catumaxomab is the first approved EpCAM-targeted antibody and targeting EpCAM contributes to a depletion of epithelial cancer cells in the peritoneal cavity and a reduction of malignant ascites production (Tsikouras et al. 2013). It is well-known that VEGF exerts an essential role in recurrence, metastasis, and ascites in epithelial OC, and bevacizumab is regarded as a monoclonal antibody that binds to VEGF, whereas aflibercept binds to VEGF-1 and 2 receptors forming a chimeric protein, which binds strongly to VEGF (Jackson et al. 2015). In previously published studies, researchers have reported that 65% of patients receiving intraperitoneal chemotherapy have disease progression, and others have indicated 18% of patients exhibit a response to the bevacizumab therapy and 42% of those patients have arrest of disease progression for minimally 6 months (Malayev et al. 2012).

HIPEC has the potential to eliminate OC cells from the peritoneal surface more efficiently than systemic chemotherapy through enhanced pharmacokinetic and hyperthermia effects, and clinical trials using HIPEC to treat advanced OC show promising survival results (Farrell and Burling 2021) and effectiveness at controlling ascites (Ba et al. 2016), and the patients present improved quality of life (Cui et al. 2012). The application of docetaxel, intraperitoneal cisplatin HIPEC, and hyperthermia in treating advanced OC can improve curative effects, accompanied by little toxicity (Zhang et al. 2016). Interestingly, the addition of HIPEC after interval cytoreductive surgery following neoadjuvant chemotherapy is shown to reduce recurrence and mortality rates in women with primary stage III or IV epithelial OC (Lim et al. 2022). In our study, the enrolled OC patients with peritoneal effusion underwent different therapeutic regimens: intraperitoneal bevacizumab combined with HIPEC or conventional infusion chemotherapy. The results uncovered that patients treated with intraperitoneal bevacizumab + HIPEC exhibited increased PR rate, RR, and DCR, decreased number and proportion of patients with SD or PD, and slightly reduced total adverse reactions. In addition to a better clinical curative efficacy, intraperitoneal bevacizumab combined with HIPEC significantly improved the quality of life in OC patients. Collectively, the aforementioned findings and evidence underscore the great promise of HIPEC in treating peritoneal effusion in OC patients.

Compelling evidence reveals that lncRNA H19 is upregulated in OC cells and tissues, and H19 overexpression is associated with a poor prognosis in OC patients (Wang and Gao 2021). Knockdown of lncRNA H19 impedes OC cell migration, proliferation, and invasion (Zhao et al. 2021). In addition, recent investigations have indicated that lncRNA H19 can enhance the chemoresistance to carboplatin in epithelial OC through miR-29b-3p and STAT3 (Tian et al. 2021). Indeed, angiogenesis is exceedingly essential for cancer progression and metastasis mainly by supplying nutrients, oxygen, and metastatic conduits (He et al. 2019). VEGF, an angiogenic factor, is strongly correlated with tumour depth of invasion, ovarian lymph node metastasis, and overall survival of patients, which effectively elevates vessel permeability and potentiates the growth, differentiation, migration, and proliferation of endothelial cells (Wang et al. 2014). Anti-angiogenesis therapy that targets VEGF emerges as an imperative treatment strategy in advanced OC (Chen et al. 2018). It is interesting to note that increased microvascular permeability is a contributor to ascites, whereas the generation of malignant ascites is decreased with VEGF blockage (Shimizu et al. 2019). Therefore, we determined the pre- and post-treatment levels of serum lncRNA H19 and VEGF and innovatively uncovered that intraperitoneal bevacizumab alongside HIPEC could diminish lncRNA H19 and VEGF levels in OC patients complicated with peritoneal effusion.

As a novel surgical modality, intraperitoneal infusion is frequently utilised to hamper tumour cell proliferation and promote drug absorption through direct infusion of chemotherapeutic agents into the peritoneal cavity, thus effectively inhibiting tumour growth. Importantly, hyperthermic therapy can increase the permeability of tumour cells and subsequently allow the chemotherapeutic agents to act faster and more directly in tumour cells to induce apoptosis, directly killing intraperitoneal tumour cells and improving the survival of patients.

To conclude, findings uncovered in the current study highlighted that intraperitoneal bevacizumab combined with HIPEC in the treatment of peritoneal effusion in OC patients showed better clinical efficacy, improved the quality of life, and relieved adverse reactions, with high safety and reliability. In addition, this treatment method could reduce the serum lncRNA H19 and VEGF levels in patients, which is worthy of promotion and application. However, there are a few limitations to our study, starting with a small sample size. It is necessary to further conduct larger multi-center studies and expand the sample size to increase the credibility of the results. Additionally, we solely determined the serum VEGF level in serum of patients, and future studies shall be carried out to investigate the effect of peritoneal fluid/serum VEGF level on the treatment and prognosis of OC patients complicated with peritoneal effusion, as well as its precise mechanism.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All the data generated or analysed during this study are included in this published article.