Gynecol Oncol. 2024 Mar 06. pii: S0090-8258(24)00137-9. [Epub ahead of print]185 194-201
Deep Pandya,
Shannon Tomita,
Maria Padron Rhenals,
Sabina Swierczek,
Katherine Reid,
Olga Camacho-Vanegas,
Catalina Camacho,
Kelsey Engelman,
Stephanie Polukort,
Jordan RoseFigura,
Linus Chuang,
Vaagn Andikyan,
Samantha Cohen,
Paul Fiedler,
Steven Sieber,
Ie-Ming Shih,
Jean-Noël Billaud,
Robert Sebra,
Boris Reva,
Peter Dottino,
John A Martignetti.
OBJECTIVE: Endometrial cancer (EndoCA) is the most common gynecologic cancer and incidence and mortality rate continue to increase. Despite well-characterized knowledge of EndoCA-defining mutations, no effective diagnostic or screening tests exist. To lay the foundation for testing development, our study focused on defining the prevalence of somatic mutations present in non-cancerous uterine tissue.
METHODS: We obtained ≥8 uterine samplings, including separate endometrial and myometrial layers, from each of 22 women undergoing hysterectomy for non-cancer conditions. We ultra-deep sequenced (>2000× coverage) samples using a 125 cancer-relevant gene panel.
RESULTS: All women harbored complex mutation patterns. In total, 308 somatic mutations were identified with mutant allele frequencies ranging up to 96.0%. These encompassed 56 unique mutations from 24 genes. The majority of samples possessed predicted functional cancer mutations but curiously no growth advantage over non-functional mutations was detected. Functional mutations were enriched with increasing patient age (p = 0.045) and BMI (p = 0.0007) and in endometrial versus myometrial layers (68% vs 39%, p = 0.0002). Finally, while the somatic mutation landscape shared similar mutation prevalence in key TCGA-defined EndoCA genes, notably PIK3CA, significant differences were identified, including NOTCH1 (77% vs 10%), PTEN (9% vs 61%), TP53 (0% vs 37%) and CTNNB1 (0% vs 26%).
CONCLUSIONS: An important caveat for future liquid biopsy/DNA-based cancer diagnostics is the repertoire of shared and distinct mutation profiles between histologically unremarkable and EndoCA tissues. The lack of selection pressure between functional and non-functional mutations in histologically unremarkable uterine tissue may offer a glimpse into an unrecognized EndoCA protective mechanism.
Keywords: Endometrial cancer; Histological normal uterus; Liquid biopsy; cancer-driver gene mutation in normal tissue