Clinical impact of a dose-escalation strategy for lenvatinib in differentiated thyroid cancer.

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.

Orotate phosphoribosyltransferase as a predictor of benefit from S-1 adjuvant chemotherapy for cholangiocarcinoma patients.

BACKGROUND AND AIM: To improve the prognosis of cholangiocarcinoma, we investigated potential biomarkers that may enable the selection of patients for whom postoperative adjuvant chemotherapy is likely effective. METHODS: The cohort of this retrospective study included 170 surgically resected cholangiocarcinoma patients, 26 with gemcitabine adjuvant chemotherapy (GEM group), 36 with S-1 adjuvant chemotherapy (S-1 group), and 103 receiving no adjuvant chemotherapy (NC group). Propensity score matching was performed to adjust patient backgrounds; 36 patients from the NC group then were selected. Immunohistochemistry of orotate phosphoribosyltransferase (OPRT) and human equilibrative nucleoside transporter 1 (hENT1) was performed to determine the correlation between their expression and disease-free survival (DFS). RESULTS: After matching, the backgrounds of these three groups were unbiased. No significant improvement of DFS by adjuvant chemotherapy was observed in the whole cohort. However, among the high-OPRT-expression patients, DFS of GEM, S-1, and NC groups at 5 years was 28.8%, 53.8%, and 25.5%, respectively. The DFS of the S-1 group was significantly longer than that of the NC group (P = 0.034). On the other hand, no significant differences in DFS were observed among the low OPRT expression patients. hENT1 expression was shown to have no predictive value. Multivariate analysis of the high-OPRT-expression patients demonstrated that S-1 adjuvant chemotherapy can reduce tumor recurrence (HR, 0.303; P = 0.013). CONCLUSION: Cholangiocarcinoma patients with high OPRT expression would benefit from postoperative adjuvant S-1 therapy, which increases the DFS. Assessment of OPRT expression may contribute to the optimization of adjuvant chemotherapy for cholangiocarcinoma.