Immunotherapy in the treatment of chemoresistant gestational trophoblastic neoplasia - systematic review with a presentation of the first 4 Brazilian cases

Case report: Multidrug resistant gestational trophoblastic neoplasia: focus on failure of immunotherapy and success of high-dose chemotherapy

Gestational trophoblastic neoplasia (GTN) is extremely rare, but has a very good prognosis, with a cure rate close to 100%, for low-risk diseases. This article describes the case of a healthy 28-year-old nulliparous patient with GTN resistant to multiple lines of treatment. The era of immunotherapy is revolutionizing oncology, having already proved its worth in the treatment of many cancers. This article will have a specific focus on the emerging role of immunotherapy in the treatment of GTN. Unfortunately, the use of an immune checkpoint inhibitor (ICI) failed in our case, emphasizing on the necessity to clearly define the future role of immune therapy in GTN. Finally, given the rapid progression of the disease after hysterectomy, induction with Paclitaxel- Ifosfamide and then intensification with high-dose Carboplatin and Etoposide with peripheral blood stem cell support was given as a rescue therapy with still curative intent.

Molecular profiling of gestational trophoblastic neoplasia: Identifying therapeutic targets

OBJECTIVE

The treatment for high risk or recurrent gestational trophoblastic neoplasia (GTN) is a highly toxic multi-agent chemotherapy. For patients with progressive or recurrent GTN, checkpoint inhibitors have demonstrated anti-tumor activity; however, identification of novel therapies for GTN remain an unmet need. Therefore, we sought to characterize the molecular landscape of GTN to identify potential therapeutic targets.

METHODS

GTN samples were analyzed using a combination of molecular - next-generation sequencing (NGS) or whole exome sequencing (WES)- and protein- Immunohistochemistry (IHC) analyses. GTN samples encompassed complete moles, choriocarcinoma, epithelioid trophoblastic tumors (ETT), and placental site trophoblastic tumors (PSTT).

RESULTS

We analyzed 30 cases of GTN including 15 choriocarcinoma, 7 ETT, 5 PSTT, 1 invasive mole and 2 mixed histologies. The median age was 41.5. GTN samples were found to be PD-L1 positive (92.3%), tumor mutational burden (TMB) low (92.8%), and microsatellite stable (MSS) (100%). Forty-six percent of choriocarcinoma specimens contained a genomic alteration including TP53 (33%) and homologous recombination repair (HRR) (13%) genes. Alterations in RTK-RAS pathway signaling was present in 40% of ETT cases.

CONCLUSIONS

The high rate of PD-L1 positivity in this real-world database and reported in prior literature support continued clinical trial development evaluating immunotherapy for treatment of GTN. Other potential targeted treatments identified include Wee1, PARP and MEK inhibitors based on molecular alterations in TP53, HRR genes, and RTK-RAS pathways respectively.