Alexander T. Nelson

Prognostic Significance of Germline DICER1 Pathogenic or Likely Pathogenic Variants in Outcomes of Ovarian Sertoli-Leydig Cell Tumor

PURPOSE Sertoli-Leydig cell tumors (SLCTs) are rare sex cord-stromal tumors, representing <0.5% of all ovarian tumors. We analyze the role of germline DICER1 status in outcomes of ovarian SLCT. METHODS Patients with SLCT were enrolled in the International Pleuropulmonary Blastoma/ DICER1 Registry and/or the International Ovarian and Testicular Stromal Tumor Registry. Medical records were systematically abstracted, and those with known germline DICER1 status were selected for analysis. RESULTS Of 162 patients with SLCT, 60% had a germline DICER1 pathogenic or likely pathogenic (P/LP) variant. The adjusted 3-year recurrence-free survival (RFS) was 87.2% (95% CI, 79.4 to 95.8) for patients with a germline DICER1 P/LP variant compared with 78.1% (95% CI, 66.4 to 91.9) for those without a germline DICER1 P/LP variant ( P = .043). The adjusted 3-year and 5-year overall survival (OS) was 93.9% (95% CI, 87.3 to 100.0) for those with a germline DICER1 P/LP variant compared with the 3-year OS of 91.3% (95% CI, 83.4 to 100.0) and the 5-year OS of 78.2% (95% CI, 63.8 to 95.9) for those without a germline DICER1 P/LP variant ( P = .021). Among patients with a germline DICER1 P/LP variant, the risk of a subsequent, nonrecurrent event was 36.2% (95% CI, 21.4 to 48.1) within 10 years. Previous/concurrent and subsequent neoplasms were rare among those without a germline DICER1 P/LP variant. CONCLUSION This cohort study of patients with SLCT demonstrated that those with germline DICER1 P/LP variants had superior RFS and OS even when adjusting for other prognostic factors. Beyond prognostic implications of a germline DICER1 P/LP variant, germline testing helps identify patients at risk of subsequent neoplasms, including metachronous SLCT.

Thoracic Sertoli–Leydig cell tumor: An alternative type of pleuropulmonary blastoma associated with DICER1 variation

AbstractA 2‐year‐old boy presented with a large cystic and solid chest mass arising from the lung, radiographically consistent with pleuropulmonary blastoma (PPB). He underwent right lower lobectomy with resection of a well‐circumscribed, mixed solid and cystic mass. The solid areas were composed of cords and nests of tumor cells in the myxoid stroma and retiform foci whose pathologic and immunophenotypic findings were consistent with a sex cord‐stromal tumor with features of a Sertoli–Leydig cell tumor. Tumor testing showed a pathogenic variant in the DICER1 RNase IIIb hotspot domain. Family history was suggestive of DICER1 germline pathogenic DICER1 variation in absence of a detectable germline variant. He received 12 cycles of chemotherapy with ifosfamide, vincristine, dactinomycin and doxorubicin (IVADo) and surgery with complete response. One year after completion of chemotherapy, imaging studies showed concern for recurrence confirmed by thorascopic biopsy of a pleural‐based mass. He is currently receiving cisplatin‐based chemotherapy with reduction in tumor size. Review of the literature showed no similar cases; however, review of our pathology files revealed a single similar case of anterior mediastinal Sertoli cell tumor in a 3‐year‐old girl.

DICER1-Related Tumor Predisposition: Identification of At-risk Individuals and Recommended Surveillance Strategies

Abstract Purpose: DICER1-related tumor predisposition increases risk for a spectrum of benign and malignant tumors. In 2018, the International Pleuropulmonary Blastoma (PPB)/DICER1 Registry published guidelines for testing- and imaging-based surveillance of individuals with a known or suspected germline DICER1 pathogenic or likely pathogenic (P/LP) variant. One of the goals of the Registry is to continue to refine these guidelines as additional data become available. Experimental Design: Individuals were enrolled in the International PPB/DICER1 Registry, the International Ovarian and Testicular Stromal Tumor Registry, and/or the NCI Natural History of DICER1 Syndrome study. Results: Review of participant records identified 713 participants with a germline DICER1 P/LP variant from 38 countries. To date, 5 cases of type I and 29 cases of type Ir PPB have been diagnosed by surveillance in enrolled individuals. One hundred and three individuals with a germline P/LP variant developed a primary ovarian Sertoli–Leydig cell tumor at a median age of 14 years (range: 11 months–66 years); 13% were diagnosed before 8 years of age, the current age of onset of pelvic surveillance. Additionally, 4% of Sertoli–Leydig cell tumors were diagnosed before 4 years of age. Conclusions: Ongoing data collection highlights the role of lung surveillance in the early detection of PPB and suggests that imaging-based detection and early resection may decrease the risk of advanced PPB. DICER1-related ovarian tumors were detected before 8 years of age, prompting the Registry to recommend earlier initiation of ovarian surveillance with pelvic ultrasound beginning at the time of detection of a germline DICER1 P/LP variant.

International PPB/DICER1 Registry

Pleuropulmonary blastoma (PPB) is a rare malignant neoplasm of the lung presenting in early childhood. Type I PPB is a purely cystic lesion, Type II is a partially cystic, partially solid tumor, Type III is a completely solid tumor. Treatment of children with PPB is at the discretion of the treating institution. This study builds off of the 2009 study and will also seek to enroll individuals with DICER1-associated conditions, some of whom may present only with the DICER1 gene mutation, which will help the Registry understand how these tumors and conditions develop, their clinical course and the most effective treatments.