西野 宏

BACKGROUND: BRAF V600E mutation is a significant therapeutic target for thyroid cancer, including anaplastic thyroid cancer (ATC). Although targeted therapy for this mutation requires genomic testing in Japan, turnaround time (TAT) is often unacceptably long, especially for certain conditions, such as ATC, which is one of the most aggressive cancers. Here, we evaluated concordance between immunohistochemistry (IHC) with a relatively short TAT of a few days and genomic testing in thyroid cancer. METHODS: Immunohistochemical staining was performed with BRAF (VE1) antibody (Ventana) using the OptiView method on samples already undergoing genomic testing. A pathologist blindly annotated each staining expression with a cut-off of 1% in the cytoplasm. We then calculated the positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement (OPA). RESULTS: We identified 62 samples, including 12 of ATC, that underwent genomic testing using different methods: Oncomine Dx Target Test (ODxTT) (n = 32), MEBGEN BRAF 3 Kit (MEBGEN3) (n = 14), FoundationOne CDx (F1CDx) (n = 13), and GenMineTOP (TOP) (n = 1). Annotation results of IHC were positive for 31, negative for 29, and undeterminable for 2 samples due to low tumor content. PPA, NPA, and OPA were 100%, 91.7%, 96.9% for ODxTT; 100%, 100%, 100% for MEBGEN3; 100%, 80.0%, 93.9% for F1CDx; and incalculable, 100%, 100% for TOP, respectively. Discordance was found in the two undeterminable samples only. CONCLUSION: Concordance between IHC and genomic testing in assessing BRAF V600E was encouragingly high; its reliability and potentially short TAT should benefit patients, especially those with ATC.

The tumor microenvironment is highly heterogeneous and consists of neoplastic cells and diverse stromal components, including fibroblasts, endothelial cells, pericytes, immune cells, local and bone marrow-derived stromal stem and progenitor cells, and the surrounding extracellular matrix. Although the significance of p16 and p53 has been reported in various tumor types, their involvement in the stromal cells of oral squamous cell carcinoma (OSCC) remains unclear. We performed immunohistochemical analyses of p16 and p53 expression in OSCC samples, Of the 116 samples, 74 showed p16-positive stromal cells, and 33 showed p53-positive stromal cells. Both p16 and p53 positivity were associated with an increased histological grade, lymphovascular invasion, an immature stromal pattern with abundant amorphous extracellular matrix material, infiltrative invasion patterns (Yamamoto Kohama classification-4C and 4D), and poor prognosis. Multivariate analyses identified p16 and p53 positivity in the stroma as independent prognostic factors for overall survival (P = 0.032 and P = 0.020, respectively); moreover, stromal p16 positivity correlated with stromal p53 positivity. These findings indicated that p16 and p53 stroma positivity may regulate OSCC tumor aggressiveness.

BACKGROUND:  Treatment options for patients with differentiated thyroid cancer (DTC) who experience disease progression on lenvatinib treatment are limited. Although dose escalation of treatment with tyrosine kinase inhibitors at disease progression has been reported across cancer types, clinical significance in patients with DTC has not been investigated. METHODS: We retrospectively reviewed patients with DTC who experienced disease progression on lenvatinib treatment from September 2011 to June 2022. We compared subjects who received dose-escalation treatment with standard treatment of termination at the time of initial disease progression. The escalated dose was decided by referencing to the previous effective and tolerated dose. RESULTS: Thirty-three patients were identified, 15 with dose escalation and 18 with lenvatinib termination. In both groups, the starting dose of lenvatinib was 24 mg/day, and the median dose at initial disease progression was 10 mg/day. In the former, the median dose escalation was 6 mg/day (range: 4-12). Objective response rate, clinical benefit rate by escalation, and median treatment duration of the dose-escalation phase were 13.3%, 73.3%, and 9.9 months (95% confidence interval [CI] 5.71-27.6), respectively. Median overall survival from initial disease progression was significantly longer in the dose-escalation group (median OS: 20.4 months [95% CI 7.0-NA] vs. 3.9 months [95% CI 1.7-7.9], log-rank p-value; 0.0004, hazard ratio; 0.22 [95% CI 0.09-0.55]). There were no grade 5 adverse events, and one patient discontinued due to a grade 3 lung abscess. CONCLUSION: The dose-escalation strategy appears to be a safe and effective treatment option after disease progression in patients treated with lenvatinib for DTC.

BACKGROUND AND PURPOSE: Hypothyroidism is a recognized late adverse event following radiotherapy for head and neck cancer (HNC). In the JCOG1008 trial, we treated patients with high-risk HNC with postoperative chemoradiotherapy. We aimed to elucidate factors associated with hypothyroidism by analyzing the JCOG1008 data. MATERIALS AND METHODS: In 2012-2018, 261 patients from 28 institutions were enrolled in JCOG1008. Thyroid function tests were conducted to assess hypothyroidism, including free thyroxine (FT4) and thyroid-stimulating hormone assays. Hypothyroidism was defined as Grade 2 or higher in CTCAE v4.0. Various clinical and dosimetric parameters were analyzed. In radiotherapy, there were no dose constraints for the thyroid. Multivariable analysis was conducted on these variables to identify predictive factors for hypothyroidism. RESULTS: The analysis included 162 patients (57 with 3D-CRT and 105 with IMRT), with a median follow-up of 4.7 years (0.3-9.3 years). Among these, 27 (16.7 %) developed hypothyroidism within 2 years after radiotherapy. In a multivariable analysis, the weekly cisplatin [OR=7.700 (CI: 1.632-36.343, p = 0.010)] and baseline FT4 [OR=0.009 (CI: <0.001-0.313, p = 0.010)] were significantly associated with hypothyroidism in the IMRT group. Regarding dosimetric characteristics, V60Gy [OR=1.069 (CI: 0.999-1.143, p = 0.054)] was potentially associated with the development of hypothyroidism. CONCLUSION: The study revealed that the incidence of hypothyroidism within 2 years after postoperative chemoradiotherapy for high-risk HNC was 16.7 % based on analytical results from prospective clinical trials.