Recurrent urothelial carcinoma-like FGFR3 genomic alterations in malignant Brenner tumors of the ovary

Immunohistochemistry as an adjunct for challenging histological patterns of borderline Brenner tumors: An illustrative study of 4 cases

Borderline Brenner tumors (BBT) have a range of morphology that shows considerable overlap with that of malignant Brenner tumors (MBT). In particular, two histological patterns of BBT can be particularly challenging: 1) BBT with intraepithelial carcinoma (BBT-IEC) and 2) BBT with a small nested pattern (BBT-SNP). BBT-IEC is characterized by a tumor with the low-power non-infiltrative silhouette of a conventional BBT, but with increased cytological atypia and mitotic activity similar to that of MBT. Conversely, BBT-SNP is characterized by a complex proliferation of small tumor nests that closely resemble the infiltrative growth pattern of MBT, but without the obligate cytologic atypia and mitotic activity of MBT. We suggest that the combination of p16, p53 and Ki-67 may be helpful in distinguishing these 2 patterns of BBT from both conventional BBT and from MBT. While both conventional BBT and BBT-IEC show a null pattern of p16 expression, our case of BBT-IEC showed aberrant p53 overexpression, albeit with a maturation pattern similar to that described for TP53 mutant mucinous ovarian carcinoma and differentiated vulvar intraepithelial neoplasia (dVIN). Similarly, while BBT-SNP shows an infiltrative-like growth pattern similar to that of MBT, our case also showed a wild-type pattern of p53 expression and a Ki-67 proliferative index similar to areas with conventional BBT histology. In conclusion, in our small case series, we show that the use of immunohistochemistry for p53 and Ki-67 may help to distinguish challenging patterns of BBT from MBT. Further studies are needed to validate this finding in a larger case cohort.

Aberrant angiogenic signaling pathways: Accomplices in ovarian cancer progression and treatment

Ovarian cancer is one of the most common malignant tumors in women, and treatment options are limited. Despite efforts to adjust cancer treatment models and develop new methods, including tumor microenvironment (TME) therapy, more theoretical support is needed. Increasing attention is being given to antiangiogenic measures for TME treatment. Another important concept in ovarian cancer TME is angiogenesis, where tumor cells obtain nutrients and oxygen from surrounding tissues through blood vessels to support further expansion and metastasis. Many neovascularization signaling pathways become imbalanced and hyperactive during this process. Inhibiting these abnormal pathways can yield ideal therapeutic effects in patients, even by reversing drug resistance. However, these deep TME signaling pathways often exhibit crosstalk and correlation. Understanding these interactions may be an important strategy for further treating ovarian cancer. This review summarizes the latest progress and therapeutic strategies for these angiogenic signaling pathways in ovarian cancer.

Phase II Study of Erdafitinib in Patients With Tumors With Fibroblast Growth Factor Receptor Mutations or Fusions: Results From the NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol K2

PURPOSE

Subprotocol K2 (EAY131-K2) of the NCI-MATCH platform trial was an open-label, single-arm, phase II study designed to evaluate the antitumor efficacy of the oral FGFR1-4 inhibitor, erdafitinib, in patients with tumors harboring FGFR1-4 mutations or fusions.

METHODS

Central confirmation of tumor FGFR1-4 mutations or fusions was required for outcome analysis. Patients with urothelial carcinoma were excluded. Enrolled subjects received oral erdafitinib at a starting dose of 8 mg daily continuously until intolerable toxicity or disease progression. The primary end point was objective response rate (ORR) with key secondary end points of safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

Thirty-five patients were enrolled, and 25 patients were included in the primary efficacy analysis as prespecified in the protocol. The median age was 61 years, and 52% of subjects had received ≥3 previous lines of therapy. The confirmed ORR was 16% (4 of 25 [90% CI, 5.7 to 33.0], P = .034 against the null rate of 5%). An additional seven patients experienced stable disease as best-confirmed response. Four patients had a prolonged PFS including two with recurrent WHO grade IV, IDH1-/2-wildtype glioblastoma. The median PFS and OS were 3.6 months and 11.0 months, respectively. Erdafitinib was manageable with no new safety signals.

CONCLUSION

This study met its primary end point in patients with several pretreated solid tumor types harboring FGFR1-3 mutations or fusions. These findings support advancement of erdafitinib for patients with fibroblast growth factor receptor-altered tumors outside of currently approved indications in a potentially tumor-agnostic manner.

Genomic alterations in gynecological malignancies: histotype-associated driver mutations, molecular subtyping schemes, and tumorigenic mechanisms

There are numerous histological subtypes (histotypes) of gynecological malignancies, with each histotype considered to largely reflect a feature of the "cell of origin," and to be tightly linked with the clinical behavior and biological phenotype of the tumor. The recent advances in massive parallel sequencing technologies have provided a more complete picture of the range of the genomic alterations that can persist within individual tumors, and have highlighted the types and frequencies of driver-gene mutations and molecular subtypes often associated with these histotypes. Several large-scale genomic cohorts, including the Cancer Genome Atlas (TCGA), have been used to characterize the genomic features of a range of gynecological malignancies, including high-grade serous ovarian carcinoma, uterine corpus endometrial carcinoma, uterine cervical carcinoma, and uterine carcinosarcoma. These datasets have also been pivotal in identifying clinically relevant molecular targets and biomarkers, and in the construction of molecular subtyping schemes. In addition, the recent widespread use of clinical sequencing for the more ubiquitous types of gynecological cancer has manifested in a series of large genomic datasets that have allowed the characterization of the genomes, driver mutations, and histotypes of even rare cancer types, with sufficient statistical power. Here, we review the field of gynecological cancer, and seek to describe the genomic features by histotype. We also will demonstrate how these are linked with clinicopathological attributes and highlight the potential tumorigenic mechanisms.

Ovarian Low-grade Basaloid Carcinoma Arising in Brenner Tumor: A New Variant of Malignant Brenner Tumor

Brenner tumors are uncommon ovarian neoplasms, most of which are benign, although borderline and malignant variants occur. We report 2 unusual ovarian neoplasms composed of an admixture of typical benign Brenner tumor and a low-grade epithelial neoplasm which we designate as low-grade basaloid carcinoma. The latter component morphologically and immunohistochemically resembled "salivary gland-type/myoepithelial" neoplasms with variable positive staining with cytokeratins, p63, S100, and CD117. One tumor exhibited aggressive behavior with local recurrence and distant metastasis. This neoplasm exhibited focal "high-grade" transformation with diffuse mutation-type p53 staining, in contrast to the wild-type immunoreactivity in the low-grade component. As far as we are aware, such neoplasms have not previously been reported in the literature and this represents a newly described morphologic variant of malignant Brenner tumor.