Uncovering the immune-modulating role of anti-RANKL therapy for cervical cancer: Preliminary results.

Abstract

e18028 Background: Conventional treatments for cervical cancer (CC) have reached a plateau and only limited progress for targeted therapy has been made over the last decades, resulting in a meager five-year survival rate of only 17% for the advanced stages. To improve long-term benefits for the patient, a promising hot field of research in oncology that opens new perspectives is immunotherapy. Even though CC has shown to be immunogenic, only a minority of patients respond to this type of treatment. In recent years, the RANKL/RANK signaling pathway has been implicated as a key immune modulating factor in the tumor microenvironment, allowing the cancer cells to evade the immune response by disrupting the immune-intrinsic crosstalk. Both RANKL and RANK are highly co-expressed in CC, which correlates with inferior clinicopathological parameters and an increased risk of death. Targeting this pathway may therefore be of great value in the treatment of CC and the quest to release the brakes on the immune system, thereby reinvigorating the tumors’ susceptibility to immunotherapy. Hence, we aim to elucidate the effects of anti-RANKL therapy on the tumor-immune microenvironment in CC. Methods: Two cervical biopsies were taken before and after anti-RANKL therapy in CC patients. One fresh biopsy was immediately processed to a single cell suspension for flow cytometry (FCM) using enzymatic digestion, while the other was formalin-fixed and paraffin-embedded for immunohistochemistry (IHC) and RNA sequencing. For FCM and IHC, the samples were stained with different markers for RANK/L signaling, the immune infiltrate and immune checkpoints. FCM was performed on a BD FACSAria IIä cytometer and analyzed with FlowJo. IHC staining was performed on a Ventana Benchmark Ultra and Ventana Discovery Ultra and scored by a pathologist or by HistoScientist using Visiopharm, while RNA sequencing was performed with the Truseq RNA exome panel on the NextSeq 500 system. Results: Our preliminary results show a relative increase of the CD8+ population, while a trend is observed in increased lymphocyte activation after anti-RANKL therapy. Updated results will be presented in more detail at the conference, including RNA sequencing data. Conclusions: Preliminary findings indicate that anti-RANKL therapy modifies the tumor-immune microenvironment in CC. Higher patient accrual will allow to dissect targets for combination therapy with anti-RANKL to further optimize this treatment strategy.