Pancreatic solid pseudopapillary neoplasm (SPN) is a low-grade malignant neoplasm with a good prognosis. Clinically aggressive SPNs have rarely been reported but have not been analyzed in detail. In this study, we referred to this highly malignant type of SPN as high-grade SPN (HG-SPN) and compared its clinicopathological and genetic characteristics with conventional SPN (C-SPN) using immunohistochemistry and gene panel analyses. Five HG-SPNs and 15 C-SPNs were evaluated in this study. HG-SPNs share many pathologic characteristics: macroscopically, solid/cystic appearances, microscopically, pseudopapillary/pseudorosette pattern (100%), tumor cell loose cohesiveness (100%), thin/delicate vasculature (100%), tumor cell cytoplasmic vacuolization (100%), immunohistochemical positivity for β-catenin (nuclear expression) (100%), CD10 (80%), CD56 (80%), and vimentin (100%). Conversely, HG-SPNs showed distinct malignant features compared with C-SPNs: mean tumor size (11.7 vs. 2.9 cm, P <0.001); true necrosis (100% vs. 0%, P <0.001); high-grade nuclear atypia (100% vs. 0%, P <0.001); lymphatic and/or venous invasion (100% vs. 20%, P =0.004); mean mitotic count (4.38 vs. 0.05/high-power field, P <0.001); and mean Ki-67 labeling index (33.9% vs. 3.4%, P <0.001). All HG-SPN patients died of primary disease 3 to 36 months after surgery, while all C-SPN patients were alive without disease. Genetic studies have shown that all analyzed HG-SPNs have CTNNB1 mutations. Two HG-SPN cases showed RB1 mutations with altered immunohistochemical findings for RB1 and p16. Two HG-SPN cases had TP53 mutation and/or p53 overexpression. In conclusion, HG-SPNs show distinct malignant features and some genetic alterations that differ from C-SPNs, indicating the importance of differentiating between these 2 subtypes.
Abstract Tumor sensitivity to platinum (Pt)‐based chemotherapy and poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors is increased by homologous recombination deficiency‐causing mutations; in particular, reversion mutations cause drug resistance by restoring protein function. Treatment response is predicted by breast cancer susceptibility gene 1/2 ( BRCA1/2 ) mutations; however, BRCA1/2 reversion mutations have not been comprehensively studied in pan‐cancer cohorts. We aimed to characterize BRCA1/2 reversion mutations in a large pan‐cancer cohort of Japanese patients by retrospectively analyzing sequencing data for BRCA1/2 pathogenic/likely pathogenic mutations in 3738 patients with 32 cancer types. We identified somatic mutations in tumors or circulating cell‐free DNA that could restore the ORF of adverse alleles, including reversion mutations. We identified 12 (0.32%) patients with somatic BRCA1 ( n = 3) and BRCA2 ( n = 9) reversion mutations in breast ( n = 4), ovarian/fallopian tube/peritoneal ( n = 4), pancreatic ( n = 2), prostate ( n = 1), and gallbladder ( n = 1) cancers. We identified 21 reversion events— BRCA1 ( n = 3), BRCA2 ( n = 18)—including eight pure deletions, one single‐nucleotide variant, six multinucleotide variants, and six deletion–insertions. Seven (33.3%) reversion deletions showed a microhomology length greater than 1 bp, suggesting microhomology‐mediated end‐join repair. Disease course data were obtained for all patients with reversion events: four patients acquired mutations after PARP‐inhibitor treatment failure, two showed somatic reversion mutations after disease progression, following Pt‐based treatment, five showed mutations after both treatments, one patient with pancreatic cancer and BRCA1 reversion mutations had no history of either treatment. Although reversion mutations commonly occur in BRCA ‐associated cancers, our findings suggest that reversion mutations due to Pt‐chemotherapy might be correlated with BRCA1/2 ‐mediated tumorigenesis even in non‐ BRCA ‐associated histologies.
of Gynecologic Oncology pembrolizumab was approved for the treatment of unresectable advanced or recurrent endometrial cancer that has progressed after chemotherapy.The management of various adverse events (AEs), including immune-related AEs, is considered important.We report a case of pneumothorax during lenvatinib and pembrolizumab combination therapy for recurrent endometrial cancer.The patient was 63-year-old female, stage IA endometrioid carcinoma grade 3, with negative MSI status.Twenty-seven months after initial therapy (modified radical hysterectomy with bilateral salpingo-oopholectomy, retroperitoneal lymphadenectomy, and postoperative radiotherapy), the cancer recurred in the lung and pleural cavity.Thoracoscopic partial resection of the right lung was performed, followed by chemotherapy with adriamycin and cisplatin for the remaining disseminated lesion in the thoracic cavity, which subsequently worsened; therefore, combination therapy of lenvatinib and pembrolizumab was started.Due to AEs, including thyroid function abnormality, hand-foot syndrome, and hypertension, the dose of lenvatinib was reduced to 14 mg.Seven months after starting combination therapy, she came to the hospital with a chief complaint of epigastric pain and was diagnosed with right pneumothorax.A thoracic drain was inserted, and pleurodesis with talc was performed twice.Lenvatinib was further reduced to 10 mg and combination therapy was resumed.To date, there has been no recurrence of pneumothorax, and combination therapy is being continued with stable disease.Pneumothorax during combination therapy with lenvatinib and pembrolizumab is rare; however, it may occur in patients with lung metastases or pleural dissemination.
Abstract Background: Various malignancies exhibit high microsatellite instability (MSI-H) or mismatch repair deficiency (dMMR). The MSI-IVD kit, which can detect MSI status using a polymerase chain reaction (PCR)-based method, was approved as the first tumor-agnostic companion diagnostic for pembrolizumab in patients with MSI-H solid tumors in Japan. Recently, next-generation sequencing (NGS), which can also detect MSI-H/dMMR, has been made clinically available. However, the real-world concordance in MSI-H/dMMR between the PCR-based testing and NGS is yet to be thoroughly investigated. Methods: A retrospective study was conducted to evaluate the utility of MSI testing using PCR-based testing and NGS assay in patients eligible for both MSI testing and any NGS platform. Co-primary endpoints included positive and negative predictive values of MSI-H/dMMR. Results: Between December 2018 and June 2020, 40 patients underwent both PCR-based MSI testing and NGS assay for MSI. Two patients with gastric neuroendocrine carcinoma and ovarian cancer were confirmed to have MSI-H/dMMR in both examinations. Among the 38 patients diagnosed as microsatellite stable by PCR-based testing, 2 (5.2%) with pancreatic cancer were diagnosed as MSI-H after NGS analyses. NGS had positive and negative predictive values of 100% (2/2) and 94.7% (36/38), respectively, for MSI-H, while the concordance between NGS and PCR-based testing was 94.9% (38/40). Conclusion: Similar to PCR-based MSI testing, NGS can be useful for evaluating MSI/MMR status in clinical practice and could be an important alternative method for detecting MSI-H/dMMR in the future.
Abstract Background Precision medicine based on genomic analysis of germline or tumor tissue is attracting attention. However, there is no consensus on how to apply the results of genomic analysis to treatment. Case presentation A 59-year-old man diagnosed with metastatic prostate cancer was diagnosed with castration-resistant prostate cancer. Although he was sequentially treated with enzalutamide and abiraterone, bone metastasis progression was identified by skeletal scintigraphy. Therefore, we sequentially performed docetaxel therapy followed by cabazitaxel. After the third cycle of cabazitaxel, his prostate-specific antigen level was stable at < 10 ng/mL, and no radiological progression was detected. The patient’s formalin-fixed paraffin-embedded tumor biopsy specimen underwent multiple-gene testing by next-generation sequencing, which identified a FANCA homodeletion. No significant germline mutation was observed. Conclusions We describe a case of aggressive, castration-resistant prostate cancer with FANCA homodeletion. Genomic analysis of prostate cancer tissue can be useful to determine optimal treatment of such cancers.
We established an outpatient service in November 2017 to provide cancer gene profiling test services to cancer patients. To date, we have seen approximately 100 patients. Our staff includes genetic counselors and nurses specialized in genetic medicine. Our experience highlights the importance of healthcare professionals having in-depth knowledge of cancer therapeutic drugs and/or investigational drugs based on cancer genome medicine. Recently, poly(ADP-ribose) polymerase (PARP) inhibitors have been approved for treating breast cancer patients with germline BRCA mutation; thus, in-depth knowledge of genetics and skills for genetic counseling are often considered indispensable in working with cancer patients. However, because the prompt treatment of clear and present cancer is the top priority in clinical settings, providing genetic information at that time, including that of unaffected family members, is of low priority for most patients who are dealing with the severe side effects of anti-cancer therapies. Pharmacists have an essential role to play in cancer therapeutics, talking with patients in order to assess their condition and to clarify the status of their treatment with anticancer agents. Genetic pharmacists should therefore work closely with genetics nurses and genetic counselors in the clinical practice of cancer genomic medicine. In this symposium, I would like to describe our experience caring for patients through our outpatient service, and to discuss the ideal framework for multidisciplinary cooperation to promote cancer genomic medicine.
Advances in genomic medicine have enabled the development of precise cancer therapies (precision cancer medicine) through multigene testing. Toward this end, we have developed a novel clinical sequencing system called PleSSision (Pathologist edited, Mitsubishi Space Software supervised clinical sequence system for personalized medicine) that performs amplicon exome sequencing targeting 160 cancer genes. Using this system, we have examined more than 600 cases over 3 years, and have identified druggable gene alteration in approximately 60% of the cases. Performing such clinical sequencing requires management of the sample quality and sequencing by pathologists and laboratory technicians; bioinformatics analysis by biomedical scientists; and patient care by nurses and pharmacists, all based on specific skills and knowledge of genomics. In addition, patients diagnosed with a hereditary cancer syndrome based on clinical sequencing results must receive care from a genetic counselor and a medical doctor with expertise in genetics. Recently, poly(ADP-ribose)polymerase (PARP) inhibitors and immune checkpoint inhibitors have been used in the treatment of patients with hereditary cancer syndromes, so collaboration involving other medical staff, especially genomic pharmacists, is also required. In this session, we provide an overview of cancer genomic medicine and emphasize the role that genomic pharmacists play in cancer precision medicine.
Abstract Immune checkpoint inhibitor (ICI) therapy has been successfully applied to various cancers; however, not all patients respond to ICI therapy. Tumors with an immune‐activated environment are highly responsive to ICIs. To identify the cells and molecules essential to the formation of an immune‐activated cancer microenvironment, we focused on the tertiary lymphoid structure (TLS) and performed histological and genomic analyses using endometrial cancer material. In the high immunogenic group, numerous TLSs were observed, and CXCL9 and CXCL13 expression was markedly increased. CXCL9‐positive antigen‐presenting and CXCL13‐positive follicular dendritic cells were distributed in the T‐ and B‐cell zones of TLSs, respectively. A group of molecules whose expression was upregulated along with CXCL9 and CXCL13 expression was strongly associated with cellular immunity. These results suggest that CXCL9‐expressing antigen‐presenting cells and CXCL13‐expressing follicular dendritic cells coordinately shape the immune‐activated microenvironment through TLS formation. The current findings will contribute to a better understanding of the mechanisms underlying the activated cancer immune microenvironment, thereby advancing the field of precision cancer medicine.