Significance of Continuous Low-Dose Lenvatinib for the Treating of the Patients with Unresectable Thyroid Carcinoma.

The tyrosine kinase inhibitor lenvatinib has been confirmed as an effective treatment option for patients with unresectable thyroid carcinoma. We conducted a retrospective analysis of the significance of the effect of continued lenvatinib treatment for the longest duration possible at a reasonable daily dose and with a minimum discontinuation period in 42 patients with unresectable thyroid carcinoma treated with lenvatinib between 2015 and 2020. A Cox proportional hazard model-based analysis revealed that the overall survival of the patients treated with a <8 mg/day mean dose of lenvatinib was significantly better than that of the patients treated with 8-24 mg/day (hazard ratio [HR] 0.38 for 1.14-4.54 mg/day, and HR 0.01 for 4.56-7.97 mg/day) adjusted for various factors (e.g., sex, age, drug interruption period). The cumulative dose of lenvatinib administered tended to be higher in the patients treated with low doses (< 8 mg/day) than in the patients treated with relatively high doses (8-24 mg/day). Considering its adverse events, the continuation of lenvatinib treatment with an adequate daily dose and drug interruption may help prolong the survival of patients with unresectable thyroid carcinoma.

The timing and methods for detection of recurrence in patients with head and neck cancer.

BACKGROUND: Early detection of head and neck cancer recurrence after curative treatment is crucial for effective salvage treatment. OBJECTIVE: We aimed to examine the timing and method that allowed early detection of recurrence in each primary and recurrence site. MATERIALS AND METHODS: We enrolled 440 patients with head and neck squamous cell carcinoma (HNSCC) in the oral cavity, oropharynx, hypopharynx, or larynx who underwent curative treatment focusing on surgery at our hospital between 2009 and 2018. We examined the timing and diagnostic method (clinical examination, patient symptoms, or imaging examination) for HNSCC recurrence according to the primary and recurrence sites. RESULTS: Recurrence was observed in 133 patients. In all primary sites, regional recurrence occurred significantly earlier than local and distant recurrences. Local recurrence occurred later in the larynx than in other primary sites. Furthermore, the clinical examination had a higher ratio of detection of local recurrence in the larynx than in the other primary site. Regardless of the primary site, more than half of the regional recurrences and most of the distant recurrences were detected by imaging examination. CONCLUSIONS AND SIGNIFICANCE: Imaging examination is preferable for achieving early detection of regional and distant recurrences.

Heterogeneous expression and role of receptor tyrosine kinase-like orphan receptor 2 (ROR2) in small cell lung cancer.

The present study investigated the expression and role of ROR2 in small cell lung cancer (SCLC). To examine the expression of ROR2, 27 surgically resected SCLC tissue samples were immunostained for ROR2. Sixteen tissue samples were positive and some showed intratumor heterogeneity in staining intensity. The heterogeneity of ROR2 expression was also observed in tumor tissues from a PDX model of SCLC, in which there were cells with high ROR2 expression (ROR2high cells) and without its expression (ROR2low cells). These cells were subjected to a RNA sequence analysis. GSEA was performed and the results obtained revealed the enrichment of molecules such as G2M checkpoint, mitotic spindle, and E2F targets in ROR2high cells. The rate of EdU incorporation was significantly higher in ROR2high cells than ROR2low cells from the PDX model and the SCLC cell lines. Cell proliferation was suppressed in ROR2 KO SBC3 cells in vitro and in vivo. Comparisons of down-regulated differentially expressed genes in ROR2 KO SBC3 cells with up-regulated DEG in ROR2high cells from the PDX model revealed 135 common genes. After a Metascape analysis of these genes, we focused on Aurora kinases. In SCLC cell lines, the knockdown of ROR2 suppressed Aurora kinases. Therefore, ROR2 appears to regulate the cell cycle through Aurora kinases. The present results reveal a role for ROR2 in SCLC and afford a candidate system (ROR2-Aurora kinase) accompanying tumor heterogeneity in SCLC.

Pulmonary Neuroendocrine Cells and Small Cell Lung Carcinoma: Immunohistochemical Study Focusing on Mechanisms of Neuroendocrine Differentiation.

Neuroendocrine (NE) differentiation has been histochemically detected in normal and cancer tissues and cells. Immunohistochemical analyses have provided a more detailed understanding of NE biology and pathology. Pulmonary NE cells are a rare lung epithelial type, and small cell carcinoma of the lung (SCLC) is a high-grade NE tumor. Pulmonary NE and SCLC cells share common mechanisms for NE differentiation. Neural or NE cell lineage-specific transcription factors, such as achaete-scute homologue 1 (Ascl1) and insulinoma-associated protein 1 (INSM1), are crucial for the development of pulmonary NE cells, and NE differentiation is influenced by the balance between Ascl1 and the suppressive neural transcription factor, hairy-enhancer of split 1, a representative target molecule of the Notch signaling pathway. In this review, we discuss the importance of Ascl1 and INSM1 in identifying pulmonary NE and SCLC cells and introduce Ascl1-related molecules detected by comparative RNA-sequence analyses. The molecular classification of SCLC based on the expression of lineage-specific transcription or co-transcription factors, including ASCL1, NEUROD1, POU2F3, and YAP1, was recently proposed. We attempted to characterize these 4 SCLC subtypes using integrated immunohistochemical studies, which will provide insights into the molecular characteristics of these subtypes and clarify the inter- and intratumor heterogeneities of SCLC.

The role of YAP1 in small cell lung cancer.

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ, also known as WWTR1) are core downstream effectors of the Hippo pathway, which is involved in diverse biological processes. The oncogenic effects of YAP and TAZ in non-small cell lung cancer (NSCLC) have recently been reported; however, their roles in SCLC remain unclear. Immunohistochemistry (IHC) on lung cancer tissues and Western blotting (WB) on lung cancer cell lines were performed to examine the expression of YAP1. Genome editing using CRISPR/Cas9 was then used to knockout the YAP1 gene in the H69AR cell line. An RNA-sequence analysis, gene ontology (GO) analysis, WB, cell counting assay, invasion assays, and xenograft studies were conducted on these cells to investigate the biological roles of YAP1. IHC revealed that insulinoma-associated protein 1 was expressed in most cases (28 out of 32 cases), while only four cases expressed YAP1. The knockout of YAP1 in H69AR cells, a chemically induced SCLC-Y subtype, reduced cell proliferation and invasion capacity and restored drug sensitivity. Xenograft assays revealed that the knockout of YAP1 suppressed cell proliferation. Tumor tissues showed the expression of neuroendocrine markers and a low Ki-67 index. In SCLC, YAP1 plays an important role in biological functions, such as cell proliferation, EMT, drug sensitivity, and neuroendocrine differentiation.

Optimal Management of the Unilateral Recurrent Laryngeal Nerve Involvement in Patients with Thyroid Cancer.

We aimed to determine the optimal management of recurrent laryngeal nerve (RLN) involvement in thyroid cancer. We enrolled 80 patients with unilateral RLN involvement in thyroid cancer between 2000 and 2016. Eleven patients with preoperatively functional vocal folds (VFs) underwent sharp tumor resection to preserve the RLN (shaving group). Thirty-three patients underwent RLN reconstruction with RLN resection (reconstruction group). We divided the reconstruction group into two subgroups based on preoperative VF mobility (normal-reconstruction and paralyzed-reconstruction subgroups). In the cases where RLN reconstruction was difficult, phonosurgeries including arytenoid adduction (AA), with or without thyroplasty type I, or nerve muscle pedicle implantation with AA were performed later (phonosurgery group). We evaluated and compared vocal function among the evaluated periods and different groups. Postoperative vocal function in the shaving and normal-reconstruction subgroups was favorable. There were no significant differences between the two groups. In the paralyzed-reconstruction and phonosurgery groups, postoperative vocal function was significantly improved, and vocal function in the paralyzed-reconstruction subgroup was significantly better than that in the phonosurgery group. For optimal management of unilateral RLN involvement in thyroid cancer, first, sharp dissection should be performed, and if this is impossible, a simultaneous RLN reconstruction procedure should be adopted whenever possible.

Treatment Outcomes of Pulmonary Metastases from Head and Neck Squamous Cell Carcinoma.

Although the lung is the most common site of distant metastases from head and neck squamous cell carcinoma (HNSCC), the number of reports about the effects of pulmonary metastasectomy for the treatment of lung metastasis from HNSCC is limited. Metachronous pulmonary metastases were detected in 45 HNSCC patients at Kumamoto University Hospital from 1998 to 2018. Twenty-two patients underwent an operative resection (Ope group) and 23 underwent chemotherapy (Chemo group). The 3-year overall survival (OS) rate and median OS were evaluated. The effects of adjuvant chemotherapy after pulmonary metastasectomy and of new drugs (cetuximab and nivolumab), in the chemo group were also assessed. The 3-year OS rates and median OS were: Ope, 66.1% and 31.5 months; Chemo, 39.7% and 18 months, respectively. In the Ope group, addi-tional recurrences were significantly fewer in the patients who underwent adjuvant chemotherapy post-surgery versus the patients who underwent surgery alone (p = 0.013). In the Chemo group, the 3-year OS rate of the patients who received new drugs was significantly better than that of the patients who did not (p = 0.021). Adjuvant chemotherapy after pulmonary metastasectomy may be a preferable treatment option for preventing recurrences. Cetuximab and nivolumab have a potential to improve OS.

Integrated Immunohistochemical Study on Small-Cell Carcinoma of the Lung Focusing on Transcription and Co-Transcription Factors.

Small-cell lung cancer (SCLC) is an aggressive malignant cancer that is classified into four subtypes based on the expression of the following key transcription and co-transcription factors: ASCL1, NEUROD1, YAP1, and POU2F3. The protein expression levels of these key molecules may be important for the formation of SCLC characteristics in a molecular subtype-specific manner. We expect that immunohistochemistry (IHC) of these molecules may facilitate the diagnosis of the specific SCLC molecular subtype and aid in the appropriate selection of individualized treatments. We attempted IHC of the four key factors and 26 candidate SCLC target molecules selected from the gene expression omnibus datasets of 47 SCLC samples, which were grouped based on positive or negative results for the four key molecules. We examined differences in the expression levels of the candidate targets and key molecules. ASCL1 showed the highest positive rate in SCLC samples, and significant differences were observed in the expression levels of some target molecules between the ASCL1-positive and ASCL1-negative groups. Furthermore, the four key molecules were coordinately and simultaneously expressed in SCLC cells. An IHC study of ASCL1-positive samples showed many candidate SCLC target molecules, and IHC could become an essential method for determining SCLC molecular subtypes.

Relationship between clinicopathological characteristics and CYLD expression in patients with cholesteatoma.

Middle ear cholesteatoma is a destructive disease in which inflammation plays an important role in development and progression, and there are currently no biomarkers predicting prognosis or recurrence. Cylindromatosis (CYLD), a tumor suppressor deubiquitinase, serves as a negative regulator of inflammation expressed in tissues including the middle ear. To determine the clinical significance of CYLD in acquired cholesteatoma, we evaluated CYLD expression in acquired cholesteatoma tissue by immunostaining and analyzed its correlation with clinicopathological characteristics. Our immunohistochemical analysis revealed that CYLD expression levels were varied in the tissues of acquired cholesteatoma patients. The relative expression levels of CYLD in cholesteatoma exhibited a significant correlation with the grade of otorrhea (R = 0.532, p = 0.039). Moreover, the period of epithelialization was also significantly associated with the relative expression levels of CYLD (R = 0.720, p = 0.002). In addition, CYLD expression tended to be lower in the group with recurrence. These results suggest that low CYLD expression correlates with postoperative recovery of acquired cholesteatoma, while potentially affecting the induction of recurrence. This is the first report showing that low CYLD expression correlates with accelerated disease recovery, and suggests a new aspect of CYLD as a prognostic predictor of acquired cholesteatoma.

Distinct transcriptional programs of SOX2 in different types of small cell lung cancers.

SOX2 is recognized as an oncogene in human small cell lung cancer (SCLC), which is an aggressive neuroendocrine (NE) tumor. However, the role of SOX2 in SCLC is not completely understood, and strategies to selectively target SOX2 in SCLC cells remain elusive. Here, we show, using next-generation sequencing, that SOX2 expressed in the ASCL1-high SCLC (SCLC-A) subtype cell line is dependent on ASCL1, which is a lineage-specific transcriptional factor, and is involved in NE differentiation and tumorigenesis. ASCL1 recruits SOX2, which promotes INSM1 and WNT11 expression. Immunohistochemical studies revealed that SCLC tissue samples expressed SOX2, ASCL1, and INSM1 in 18 out of the 30 cases (60%). Contrary to the ASCL1-SOX2 signaling axis controlling SCLC biology in the SCLC-A subtype, SOX2 targets distinct genes such as those related to the Hippo pathway in the ASCL1-negative, YAP1-high SCLC (SCLC-Y) subtype. Although SOX2 knockdown experiments suppressed NE differentiation and cell proliferation in the SCLC-A subtype, they did not sufficiently impair the growth of the SCLC-Y subtype cell lines in vitro and ex vivo. The present results support the importance of the ASCL1-SOX2 axis as a main subtype of SCLC, and suggest the therapeutic potential of targeting the ASCL1-SOX2 axis.

Swallowing dysfunction following surgery for well-differentiated thyroid cancer with extrathyroid invasion.

BACKGROUND: Differentiated thyroid carcinoma (DTC) can invade the surrounding aerodigestive tract. Radical surgery for locally advanced DTC will require resection of the trachea, recurrent laryngeal nerve (RLN), inferior pharyngeal constrictor muscles (IPCMs), or a part of the esophagus. The purpose of this study was to demonstrate the effect of resection of these surrounding tissues combined with total thyroidectomy and neck dissection on swallowing function following surgery. METHODS: We performed total thyroidectomy combined with neck dissection and resection of the RLN in 24 patients with DTC with extrathyroidal invasion (19 unilateral, 1 bilateral), IPCMs (n = 5), or muscle layers of esophagus (n = 9). Nine patients received a tracheostomy placement due to a window resection of the trachea for tumor invasion (n = 6) and necessary upper airway management (n = 3). We used the duration of nasogastric tube feeding to evaluate swallowing function following surgery. RESULTS: Patients who underwent tracheostomy or IPCM resection showed significantly longer periods of tube feeding (p = 0.0057 and 0.0017, respectively). In contrast, resection of the unilateral RLN or esophageal muscle layer showed no difference in tube feeding duration. Multiple regression analysis indicated that tracheostomy and IPCM resection were significant independent predictors of longer periods of tube feeding (p = 0.04583 and 0.00087, respectively). CONCLUSION: These results indicate that tracheostomy placement and resection of the IPCMs, together with total thyroidectomy, extends the tube feeding duration in the postoperative period.