Gastric-type adenocarcinoma of the cervix: Genomic drivers and clinical outcomes.

6030 Background: Cervical Gastric-type adenocarcinoma (CGA) is a non-HPV-associated adenocarcinoma, comprising 10% of all cervical adenocarcinomas (Park et al, 2019). The optimal management approach is unclear, given that most data in advanced cervical cancer is driven by HPV-positive disease. We summarize our experience with this rare tumor type at a large cancer center. Methods: A retrospective review was performed for all women diagnosed with CGA 6/1/2002- 7/1/2019. Patients who did not follow up after a single visit were excluded. Kaplan-Meier survival analysis was performed to determine progression-free survival (PFS) and overall survival (OS) from date of diagnosis. Tumors from a subset of patients were subjected to MSK-IMPACT targeted sequencing and analysis (Zehir et al, 2017). Results: A total of 68 women were identified; 47 met inclusion criteria. The median age at diagnosis was 52 years (range 27-83). The majority of patients were white (70%), an additional 19% were Asian. The majority of patients (60%, n=28) presented with advanced disease (FIGO 2018, stage II-IV), while 40% (n=19) were Stage I. Of note, 26% (n=12) had positive pelvic lymph nodes and 13% (n=6) had ovarian metastases at time of surgical resection. For upfront treatment: 13% (n=6) had surgery alone of whom 83% had stage 1 disease, 36% (n=17) had surgery followed by adjuvant therapy, 30% (n =14) received definitive chemo-radiation (CRT). All patients with stage IV disease 15% (n=7) received chemotherapy alone. At completion of primary treatment, 19% (n=9) of patients had persistent disease. In patients who received CCRT, 65% (n=22) recurred, the majority (64%) within 12 months of completion of upfront therapy. Pelvic recurrence was the most common site (n=14, 64%). With a median follow up time of 30 months (range 1-159), the median PFS for Stage I was 34.4 months, compared to 17.5 months in patients with Stage II-IV disease (p= 0.29). Of the 24 patients that had MSK-IMPACT, the most common mutation was TP53 (n=16, 64%) followed by mutations in the RAS pathway (n=8, 33%), PIK3CA (n=3, 12.5%), STK11 (n=3, 12.5%), and ERBB2 alterations (n=2, 8.3 %). 2 (8.3%) women enrolled on a clinical trial based on their NGS results, one targeting ERBB2 and one targeting PIK3CA. Conclusions: Consistent with prior published literature, CGA is an aggressive form of cervical cancer with poor median OS in the advanced setting. With universal HPV vaccination, HPV negative cervical cancer will represent a larger percentage of newly diagnosed cancers and further research is needed to identify the optimal management approach.