Hyperthermic intraperitoneal chemotherapy in ovarian cancer: Qui Bono?

No obvious advantage of hyperthermic intraperitoneal chemotherapy after interval debulking surgery in the treatment of advanced ovarian cancer: A retrospective study

Objective

To study the efficacy of interval debulking surgery (IDS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) compared to IDS alone for the treatment of ovarian cancer after neoadjuvant chemotherapy (NACT).

Methods

We conducted a retrospective study of patients with stage IIIC/IV high-grade serous ovarian carcinoma who underwent surgery at our center from January 2018 to December 2019. Patients who underwent IDS after NACT with (N = 20) or without (N = 42) HIPEC were included. HIPEC was administered after surgery and was combined with 1–2 courses of intraperitoneal hyperthermic perfusion with normal saline only. We analyzed clinical information and outcomes for the two groups.

Results

The median progression-free survival (PFS) was 14.05 months in the IDS plus HIPEC group and 12.97 months in the IDS group (P = 0.597). The median overall survival (OS) was not reached. After adjustment for age between the two groups, the differences in PFS and OS remained nonsignificant. The change ratio of postoperative CA-125 to preoperative CA-125 was 0.66 in the IDS plus HIPEC group and 0.53 in the IDS group (P = 0.341). The difference in human epididymis protein 4 (HE-4) change ratio between the two groups was nonsignificant (P = 0.225). No significant difference was observed in the occurrence of grade 3 and 4 adverse events between the two groups (P = 0.201).

Conclusion

After NACT, IDS plus HIPEC did not show significant PFS and tumor index change ratio benefits over IDS alone in patients with primary ovarian cancer. Further investigations are needed to assess the role of HIPEC in the treatment of ovarian cancer.

Hyperthermia enhances the efficacy of chemotherapeutic drugs in heat-sensitive cells through interfering with DNA damage repair

Background

Hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to be clinically effective, but the mechanisms by which hyperthermia enhances the sensitivity of cells to chemotherapeutic drugs has not yet been elucidated.

Methods

To identify the key molecules involved in thermochemotherapy, this study used mass spectrometry (MS)-based quantitative proteomics technology to analyze the effects of thermochemotherapy on the heat-sensitive ovarian cancer cell line A2780. We divided the A2780 cell line into four groups, one group served as blank control, and the other three groups were stimulated by oxaliplatin, stimulated by hyperthermia at 42 ℃, and stimulated by hyperthermia combined with oxaliplatin. Samples were then collected for tandem mass tag (TMT) labeling, high-performance liquid chromatography fractionation, and MS-based quantitative proteomics for analysis The differentially expressed proteins were quantitatively compared and identified, and Gene Ontology (GO) assessment and cluster analyses were performed. Finally, the above MS results were verified again by Western blotting experiments.

Results

A total of 349 differentially expressed proteins were identified between cells treated with chemotherapy alone (group B) and cells treated with a combination of chemotherapy and hyperthermia (group D). There were 145 upregulated proteins and 204 downregulated proteins. Among the top 20 proteins with significantly different expression levels, nearly two-thirds were involved in DNA damage repair. These proteins were subsequently verified by Western blot analysis. Indeed, consistent with MS data, the expression of the RBL1 protein was significantly upregulated in cells treated with thermochemotherapy (group D) compared to cells treated with chemotherapy alone (group B).

Conclusions

In heat-sensitive ovarian cancer cells, the damage repair of tumor cell DNA is disturbed by hyperthermia, making it unable to fully repair when damaged by chemotherapeutic drugs. As a result, hyperthermia enhances the efficacy of chemotherapeutic drugs. RBL1, as a tumor suppressor gene, may be associated with the repair of DNA damage, and thus it may be a key target for hyperthermia to enhance the sensitivity of thermosensitive cells to chemotherapeutic drugs.