2757 - Outcomes of Patients with Gastric-Type Adenocarcinoma of the Uterine Cervix after Definitive or Adjuvant Chemoradiotherapy

10:45am - 12:00pm PT

Hall F

Screen: 2

POSTER

Presenter(s)

Harshath Gupta, MD - MD Anderson Cancer Center, Houston, TX

H. Gupta¹, C. Y. Mollings Puentes¹, L. Colbert¹, P. J. Eifel¹, A. Jhingran¹, M. M. Joyner¹, A. Z. Kesaria¹, A. H. Klopp¹, L. L. Lin¹, P. Ramalingam², T. Sims³, N. Taku¹, and C. R. Weil¹; ¹Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, ²Department of Pathology/Laboratory Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, ³Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX

Purpose/Objective(s): Gastric-type adenocarcinoma of the cervix (GAS) is a rare, recently described mucinous adenocarcinoma that is generally independent of human papillomavirus (HPV). It accounts for approximately 10% of cervical adenocarcinomas. Due to its rarity and diagnostic uncertainties, optimal management strategies, particularly regarding the role of definitive or adjuvant chemoradiation, remain unclear. This study describes our institutional experience with GAS.

Materials/Methods: We conducted a retrospective review of patients diagnosed with GAS between 2013 and 2024. Clinical and demographic data were obtained from electronic medical records. Patients who received either adjuvant or definitive chemoradiation (CRT) within our institution were included for analysis. Kaplan-Meier estimators were used to describe progression-free survival (PFS) and overall survival (OS), defined from date of diagnosis to either event or last follow-up.

Results: A total of 62 women with GAS were identified, of whom 42 underwent surgery without radiation, and 16 received definitive or adjuvant CRT. The median age at diagnosis was 51 years (range 32-67), and median follow-up was 2.7 years. Most patients were either Asian (38%, n=6) or White (38%, n=6), and 38% (n=6) identified as Hispanic or Latino. At presentation, most patients had locally advanced or metastatic disease (69%, n=11) while 31% (n=5) had disease localized to the cervix (FIGO 2018 stage I), and 13% (n=2) had ovarian involvement. Only 14% (n=2/14) were HPV-positive. FIGO 2018 stage IIB was the most common (n=8). Among the 16 patients who received CRT, 44% (n=7) underwent definitive CRT and 56% (n=9) received postoperative adjuvant CRT. One patient underwent surgical resection after definitive CRT. For definitive CRT patients, the median equivalent dose in 2 Gray (Gy) fractions (EQD2) after external beam radiotherapy (EBRT) and either high-dose rate (HDR) or pulse-dose rate brachytherapy was 90.1 Gy to the high-risk CTV (range 69.7-98.6) and 78.4 Gy to Point A (range 64.1-80.6). For adjuvant CRT, patients received EBRT +/- HDR vaginal cuff brachytherapy, with a median vaginal cuff EQD2 of 56.8 Gy (range: 56.8-63.0). Eight patients had recurrences; five after definitive CRT and 3 after adjuvant CRT. The 1- and 3-yr PFS were 88% and 40%, respectively. The 3-yr PFS for definitive versus adjuvant CRT subgroups was 21% vs 57%, respectively. The most common site of first recurrence was within the pelvis (88%, n=7/8). The 3- and 5-yr OS was 92% and 73%, respectively. The 5-yr OS for definitive versus adjuvant CRT subgroups was 75% versus 86%, respectively.

Conclusion: GAS is a rare and aggressive subtype of cervical cancer with high local recurrence rates. Further studies are warranted to identify optimal treatment strategies in these patients, including evaluation of novel post-CRT therapies given the high recurrence risk.