Evolution of tumor stress response during cytoreductive surgery for ovarian cancer

Abstract

Upfront treatment for patients with advanced high-grade serous ovarian cancer (HGSOC) includes a multi-hour cytoreductive surgery. Although the procedure is necessary for maximal tumor cytoreduction, understanding of the biology of systemic and intratumoral responses induced by surgical cytoreduction is limited. Through analysis of matched tumor and normal tissues and peripheral blood collected at multiple time points during cytoreductive surgery in patients with HGSOC, we demonstrate that surgery leads to rapid induction of systemic inflammatory response and activation of inflammatory signaling in the tumor and normal tissue, with interleukin-6 emerging as a dominant inflammatory pathway. A parallel study in a syngeneic murine HGSOC model recapitulated these findings and demonstrated accelerated tumor growth in response to surgery. This study highlights the previously unappreciated impact of specimen collection timing on the tumor signaling networks and provides insights into stress pathways activated by surgery, generating rationale for perioperative therapeutic interventions to reduce protumorigenic effects.

Keywords: Cancer; Cell biology.

Graphical abstract

Figure 1

Methodology for human subject tissue and plasma collection and cohort selection (A) Experimental design for human subject tumor/normal tissue and plasma collection during and after primary cytoreductive surgery for advanced-stage high-grade serous ovarian cancer. (B) CONSORT (Consolidated Standards of Reporting Trials) flow chart of high-grade serous ovarian cancer case selection and downstream analyses. FFPE, formalin-fixed paraffin-embedded; H&E, hematoxylin and eosin; IHC, immunohistochemistry, HGSOC, high-grade serous ovarian cancer.

Figure 2

Tumor and normal tissue transcriptomic and plasma cytokine changes in patients with high-grade serous ovarian cancer undergoing cytoreductive surgery (A) Hierarchical clustering of genes differentially expressed between high-grade serous ovarian cancer specimens from time of incision (0 h; TP1, black) and 4 h into surgery (TP2, blue). Clustered heatmap comparing upregulated genes from normal specimens from 0 h (N1, black) and 4 h (N2, blue). (B) GSEA for tumor and normal specimens from 0 h to 4 h. ∗p < 0.05; ∗∗p < 0.01. (C) Volcano plot of differentially expressed genes in high-grade serous ovarian cancer tumor specimens and normal specimens from 0 h to 4 h. (D) Human plasma cytokine concentrations (pg/mL) from the start of surgery (blue), during surgery (3–4 h after laparotomy; red), and postoperatively (20–24 h after laparotomy; green). One-way analysis of variance with Dunnett’s multiple comparisons test used for comparisons between sTP2 or sTP3 and sTP1, respectively. Data are represented as mean with standard error of mean. ∗p < 0.05; ∗∗p < 0.01. FC, fold change; GSEA, gene set enrichment analysis; IL, interleukin; KEGG, Kyoto Encyclopedia of Genes and Genomes; ns, not significant; VST, variance-stabilizing transformation.

Figure 3

Surgical interventions promote tumor progression in murine cancer models and lead to immune dysfunction in the tumor microenvironment (A) Experimental design. (B) Representative bioluminescence imaging of a mouse inoculated with the ovarian cancer cell line and undergoing laparotomy or not, over time. (C) Representative experiment: graphical representation of bioluminescence by luciferin uptake in ovarian cancers in mice undergoing laparotomy or not, by total flux (p/s). p = 0.017; we used Mann-Whitney U test to compare mean area under the curve between the two cohorts. (D) Bar graph representation of various immune cell populations detected via flow cytometry of ovarian cancer tumors dissected from mice 8 days after mice either underwent laparotomy or not. We used Wilcoxon matched-pairs signed-rank test to compare percent of immune cell populations between the two groups. Data are represented as mean with standard error of mean. ICOS, inducible T cell co-stimulator; MFI, mean fluorescence intensity; NK, natural killer cell.

Figure 4

IL-6 receptor blockade partially restores tumor control in the setting of surgical intervention (A) Pre- and postoperative plasma IL-6 cytokine concentration (pg/μL) for mice with ovarian cancers undergoing laparotomy or not. We used the Mann-Whitney test to compare plasma IL-6 concentration of mice undergoing laparotomy or not. (B) Experimental design. (C) Representative experiment: graphical representation of bioluminescence by luciferin uptake in ovarian cancer tumors in mice undergoing laparotomy treated with either control IgG or anti-IL6R antibody, by total flux (p/s). We also compared bioluminescence by luciferin uptake in ovarian cancer tumors in mice not undergoing laparotomy treated with either control IgG or anti-IL6R antibody, by total flux (p/s). We used Mann-Whitney U test to compare mean area under the curve between the two groups. Data are represented as mean with standard error of mean. ∗p < 0.05. IL, interleukin; IL-6R, interleukin-6 receptor; ns, not significant.