PARP Inhibitors in the Management of Ovarian Cancer: ASCO Guideline.

PURPOSE: To provide recommendations on the use of poly(ADP-ribose) polymerase inhibitors (PARPis) for management of epithelial ovarian, tubal, or primary peritoneal cancer (EOC). METHODS: Randomized, controlled, and open-labeled trials published from 2011 through 2020 were identified in a literature search. Guideline recommendations were based on the review of the evidence, US Food and Drug Administration approvals, and consensus when evidence was lacking. RESULTS: The systematic review identified 17 eligible trials. RECOMMENDATIONS: The guideline pertains to patients who are PARPi naïve. All patients with newly diagnosed, stage III-IV EOC whose disease is in complete or partial response to first-line, platinum-based chemotherapy with high-grade serous or endometrioid EOC should be offered PARPi maintenance therapy with niraparib. For patients with germline or somatic pathogenic or likely pathogenic variants in BRCA1 (g/sBRCA1) or BRCA2 (g/sBRCA2) genes should be treated with olaparib. The addition of olaparib to bevacizumab may be offered to patients with stage III-IV EOC with g/sBRCA1/2 and/or genomic instability and a partial or complete response to chemotherapy plus bevacizumab combination. Maintenance therapy (second line or more) with single-agent PARPi may be offered for patients with EOC who have not received a PARPi and have responded to platinum-based therapy regardless of BRCA mutation status. Treatment with a PARPi should be offered to patients with recurrent EOC that has not recurred within 6 months of platinum-based therapy, who have not received a PARPi and have a g/sBRCA1/2, or whose tumor demonstrates genomic instability. PARPis are not recommended for use in combination with chemotherapy, other targeted agents, or immune-oncology agents in the recurrent setting outside the context of a clinical trial. Recommendations for managing specific adverse events are presented. Data to support reuse of PARPis in any setting are needed.Additional information is available at www.asco.org/gynecologic-cancer-guidelines.

Claudin-3 and claudin-4 expression in serous papillary, clear-cell, and endometrioid endometrial cancer.

OBJECTIVE: Tight junction (TJ) proteins claudin-3 and claudin-4 may be differentially expressed in uterine serous papillary carcinoma (USPC), a rare form of endometrial cancer characterized by a particularly poor prognosis. Our aim was to determine the expression pattern and prognostic relevance of claudin-3 and claudin-4 in a large cohort of endometrial cancer patients of diverse histological type and stage. METHODS: Claudin-3 and claudin-4 expression was studied in a cohort of 287 patients with endometrial cancer including 137 cases of USPC or clear-cell histology using immunohistochemistry. Patients were completely surgically staged. Outcome data is available on all 287 patients. RESULTS: The rate of claudin-3 and claudin-4 expression was significantly higher in USPC and clear-cell endometrial cancer compared to endometrioid endometrial cancer (claudin-3: 78% and 61% versus 38%, p<.0001; claudin-4: 56% and 44% versus 9%, p<.0001). Furthermore, expression of both TJ proteins was significantly associated with poor clinical outcome (claudin-3, DFS RR 1.70, p=.0087, OS RR 1.62, p=.0247; claudin-4, DFS RR 2.66, p<0.0001, and OS RR 2.50, p<0.0001). However, both markers did not maintain prognostic independence in multivariate analyses, as their expression was tightly associated with more advanced disease stages (p<.0001 for both), and higher nuclear grade (p<.0001 for both). CONCLUSION: These clinical observations confirm the hypothesis based on preclinical evidence that increased expression of claudin-3 and claudin-4 may contribute to the aggressive phenotype of endometrial cancer of serous papillary or clear-cell histology and suggest their potential utility as diagnostic biomarkers and possible targets for therapeutic intervention.

Borderline ovarian tumors: current concepts for prognostic factors and clinical management.

Since their original description in 1929, our knowledge of the natural history and molecular pathology of borderline ovarian tumors (BOTs) has advanced most dramatically over the last decade. It has been estimated that at the time of abdominal exploration for a serous ovarian neoplasm, a BOT will be discovered in approximately 15% of cases. These tumors commonly affect women of reproductive age, have an excellent overall prognosis and the majority are cured with surgery. Nevertheless, a subset of patients with these tumors have an adverse clinical outcome and the molecular features of the associated tumor subtype is currently being defined. These data have caused some to place this more aggressive subtype of BOT, called micropapillary serous with invasive extraovarian implants, into the pathologic continuum with frankly invasive carcinomas. This chapter will explore advances in our understanding of the natural history, clinical and pathologic features of BOTs and will conclude with a discussion of the molecular prognostic factors that might be targets for future therapy. A special emphasis will be placed on points of agreement identified during a recent workshop on BOTs sponsored by the National Cancer Institute (NCI).

The granulin-epithelin precursor is a steroid-regulated growth factor in endometrial cancer.

OBJECTIVES: The majority of endometrial cancers arise as a result of estrogen stimulation, the molecular targets of which remain incompletely defined. We hypothesize that the granulin-epithelin precursor (GEP) may be one such target. In this study, we examined the frequency of GEP and estrogen receptor (ER) co-expression in human endometrial cancers. Once we established the co-expression of GEP with the estrogen receptor we examined the potential estrogen regulation of GEP expression, as well as the functional significance of GEP expression in vitro. METHODS: Double immunofluorescence and confocal microscopy were used to compare GEP and ER expression among 41 endometrial cancers. The effects of estradiol and tamoxifen treatment on GEP expression in two endometrial cancer cell lines, KLE and HEC-1-A, were assessed through reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. The antiproliferative effect of GEP silencing by short hairpin (sh)RNA, was evaluated in HEC-1-A cells using an MTT assay. RESULTS: GEP co-expression with ER was observed in 63% of the cancers examined. A two- to fivefold increase in GEP expression with estradiol and/or tamoxifen treatment was observed in KLE cells. Silencing of GEP in HEC-1-A cells using shRNA resulted in a decrease in proliferation among transfected cells. CONCLUSIONS: Co-expression of GEP and ER in endometrial cancer cells, and the regulation of GEP by estrogen, suggests a role for GEP in steroid-mediated endometrial cancer cell growth. Further characterization of GEP as a steroid-mediated growth factor in these cells may broaden our understanding of endometrial cancer biology and also provide guidance in the development of novel therapeutic targets.

The granulin-epithelin precursor/PC-cell-derived growth factor is a growth factor for epithelial ovarian cancer.

PURPOSE: The role of growth factors in ovarian cancer development and progression is complex and multifactorial. We hypothesized that new growth factors may be identified through the molecular analysis of ovarian tumors as they exist in their native environment. EXPERIMENTAL DESIGN: RNA extracted from microdissected serous low malignant potential (LMP) and invasive ovarian tumors was used to construct cDNA libraries. A total of 7300 transcripts were randomly chosen for sequencing, and those transcripts were statistically evaluated. Reverse transcription-PCR and immunohistochemistry were used to validate the findings in tumor tissue samples. Ovarian cancer cell lines were used to test gene effects on monolayer growth, proliferative capacity, and density-independent growth. RESULTS: Analysis of the pooled library transcripts revealed 26 genes differentially expressed between LMP and invasive ovarian cancers. The granulin-epithelin precursor [GEP/PC-cell derived growth factor (PCDGF)] was expressed only in the invasive ovarian cancer libraries (P < 0.028) and was absent in the LMP libraries (0 of 2872 clones). All of the invasive tumor epithelia, 20% of the LMP tumor epithelia, and all of the stroma from both subsets expressed GEP by reverse transcription-PCR. Immunohistochemical staining for GEP was diffuse and cytosolic in invasive ovarian cancer tumor cells compared with occasional, punctate, and apical staining in LMP tumor epithelia. Antisense transfection of GEP into ovarian cancer cell lines resulted in down-regulation of GEP production, reduction in cell growth (P < 0.002), decrease in the S-phase fraction (P < 0.04), and loss of density-independent growth potential (P < 0.01). CONCLUSION: cDNA library preparation from microdissected tumor epithelium provided a selective advantage for the identification of growth factors for epithelial ovarian cancer. Differential granulin expression in tumor samples and the antiproliferative effects of its antisense down-regulation suggest that GEP may be a new autocrine growth factor and molecular target for epithelial ovarian cancer.

Proteomic analysis and identification of new biomarkers and therapeutic targets for invasive ovarian cancer.

Epithelial ovarian cancer kills almost 16 000 women each year in part due to late stage of presentation and lack of reliable biomarkers for disease detection. CA-125, the currently accepted serum marker, alone lacks the sensitivity for early stage diagnosis, as only 50% of early stage cases are detected with this marker. Although more early stage cases may be detected by lysophosphatidic acid, this marker is also elevated in other cancers. One major objective of the NCI-FDA Tissue Proteomics Initiative has been to combine the technique of laser capture microdissection (LCM) of epithelial tumor cells in human tissue specimens with two-dimensional gel electrophoresis (2-D PAGE) to identify proteins that may serve as invasive ovarian cancer-specific biomarkers for early detection and/or new therapeutic targets. We performed 2-D PAGE on lysates from five microdissected ovarian tumors (three invasive ovarian cancers and two noninvasive, low malignant potential (LMP) ovarian tumors). We then compared silver stained 2-D gels created from microdissected lysates with SYPRO-Ruby stained 2-D PAGE profiles of the patient-matched undissected bulk tumor lysates from all five patients. Twenty-three proteins were consistently differentially expressed between both the LMP and three invasive ovarian tumors in the limited study set. Thirteen were uniquely present in all three of the invasive ovarian cancer cases and absent or underexpressed in the two LMP cases. Ten were uniquely present in the LMP cases but absent or underexpressed in all invasive ovarian cancer cases. Credentialing and preliminary target validation of the mass spectrometry identified proteins cut from the Ruby-red stained gels was performed by LCM coupled Western blot and reverse-phase array technology in a study set of six cases (the aforementioned five cases used in the 2-D PAGE profiling component of the study plus one additional LMP case). The analysis revealed that the 52 kDa FK506 binding protein, Rho G-protein dissociation inhibitor (RhoGDI), and glyoxalase I are found to be uniquely overexpressed in invasive human ovarian cancer when compared to the LMP form of this cancer. The direct comparison of LCM generated proteomic profiles of invasive vs. LMP ovarian cancer may more directly generate important markers for early detection and/or therapeutic targets unique to the invasive phenotype.