Gynecological cancer accounts for an elevated incidence worldwide requiring responsiveness regarding its care. The comprehensive genomic approach agrees with the classification of certain tumor types. We evaluated 49 patients with gynecological tumors undergoing high-throughput sequencing to explore whether identifying alterations in cancer-associated genes could characterize concrete histological subtypes. We performed immune examination and analyzed subsequent clinical impact. We found 220 genomic aberrations mostly distributed as single nucleotide variants (SNV, 77%). Only 3% were classified as variants of strong clinical significance in BRCA1 and BRCA2 of ovarian high-grade serous (HGSC) and uterine endometrioid carcinoma. TP53 and BRCA1 occurred in 72% and 28% of HGSC. Cervical squamous cell carcinoma was entirely HPV-associated and mutations occurred in PIK3CA (60%), as well as in uterine serous carcinoma (80%). Alterations were seen in PTEN (71%) and PIK3CA (60%) of uterine endometrioid carcinoma. Elevated programmed death-ligand 1 (PD-L1) was associated with high TILs. Either PD-L1 augmented in deficient mis-matched repair (MMR) proteins or POLE mutated cases when compared to a proficient MMR state. An 18% received genotype-guided therapy and a 4% immunotherapy. The description of tumor subtypes is plausible through high-throughput sequencing by recognizing clinically relevant alterations. Additional concomitant assessment of immune biomarkers identifies candidates for immunotherapy.

Claudin 18 isoform 2 (CLDN18.2) has emerged as a novel therapeutical target for HER2-negative, locally advanced, or metastatic gastroesophageal adenocarcinoma. However, reported prevalence rates vary widely (24–47%), underscoring the need for accurate population-specific data. This study investigates the CLDN18.2 prevalence in Spanish patients with gastroesophageal adenocarcinoma and explores its correlation with other biomarkers and clinicopathological factors. We retrospectively analyzed endoscopic biopsy samples from gastroesophageal adenocarcinoma patients across three Spanish institutions. CLDN18.2 expression was evaluated by immunohistochemistry using the Ventana CLDN18 (43-14A) assay and PS2+ scoring, with cases showing membranous 2+ or 3+ staining in ≥ 75% of tumor cells classified as positive. Clinicopathological and biomarker data were retrieved from medical records. CLDN18.2 was positive in 33% (89/270) of cases. Although histological type was not correlated with CLDN18.2 status, cases with poorly cohesive morphology exhibited heterogeneous staining, with a predominance of moderately and strongly stained cells. A weak to moderate inverse correlation was identified between signet ring cell content and CLDN18.2 staining (r = −0.29, p = 0.028). No significant differences were observed in clinical outcome. However, among patients with advanced-stage disease, CLDN18.2-positive intestinal tumors were associated with worse progression-free survival (HR 2.58, 95% CI 1.18–5.63; p = 0.029). These findings confirm a 33% prevalence of CLDN18.2 expression in the Spanish population, aligning with reports from other Western European cohorts. The significant heterogeneity in poorly cohesive cases and an inverse correlation with signet ring cell content pose diagnostic challenges for pathologists. Moreover, the association between CLDN18.2 positivity and worse progression-free survival in intestinal adenocarcinoma supports a potential role in tumor progression and metastasis, warranting further research.

Complex RNA-seq signatures involving the transcription factors ASCL1, NEUROD1, and POU2F3 classify Small Cell Lung Cancer (SCLC) into four subtypes: SCLC-A, SCLC-N, SCLC-P, and SCLC-I (triple negative or inflamed). Preliminary studies suggest that identifying these subtypes can guide targeted therapies and potentially improve outcomes. This study aims to evaluate whether the expression levels of these three key transcription factors can effectively classify SCLC subtypes, comparable to the use of individual antibodies in immunohistochemical (IHC) analysis of formalin-fixed, paraffin-embedded (FFPE) tumor samples. We analyzed preclinical models of increasing complexity, including eleven human and five mouse SCLC cell lines, six patient-derived xenografts (PDXs), and two circulating tumor cell (CTC)-derived xenografts (CDXs) generated in our laboratory. RT-qPCR conditions were established to detect the expression levels of ASCL1, NEUROD1, and POU2F3. Additionally, protein-level analysis was performed using Western blot for cell lines and IHC for FFPE samples of PDX and CDX tumors, following our experience with patient tumor samples from the CANTABRICO trial (NCT04712903). We found that the analyzed SCLC cell line models predominantly expressed ASCL1, NEUROD1, and POU2F3, or showed no expression, as identified by RT-qPCR, consistently matching the previously assigned subtypes for each cell line. The classification of PDX and CDX models demonstrated consistency between RT-qPCR and IHC analyses of the transcription factors. Our results show that single-gene analysis by RT-qPCR from FFPE-extracted RNA simplifies SCLC subtype classification. This approach provides a cost-effective alternative to IHC staining or expensive multi-gene RNA sequencing panels, making SCLC subtyping more accessible for both preclinical research and clinical applications.

Trophoblast cell-surface antigen 2 (Trop-2) is a key therapeutic target in metastatic triple-negative breast cancer (TNBC), yet its prognostic significance