Prognostic value of early response assessment using (18F)FDG-PET in patients with advanced non-small cell lung cancer treated with tyrosine-kinase inhibitors

An Exploratory Study of Neoadjuvant Cetuximab Followed by Cetuximab and Chemoradiotherapy in Women With Newly Diagnosed Locally Advanced Cervical Cancer

OBJECTIVES

This study explored the feasibility of cetuximab with chemoradiation in women with cervical carcinoma and evaluated fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) to assess early response to cetuximab (NCT00292955).

PATIENTS AND METHODS

Eligible patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB-IVB invasive carcinoma of the uterine cervix were treated on 1 of 3 dose levels (DL). DL1 consisted of neoadjuvant cetuximab, then concurrent radiotherapy with cetuximab 250 mg/m2/cisplatin 40 mg/m2, followed by weekly cetuximab. DL2 consisted of radiotherapy with cetuximab 200 mg/m2 and cisplatin 30 mg/m2. DL3 consisted of radiotherapy with cetuximab 250 mg/m2 and cisplatin 30 mg/m2. Patients underwent 18F-FDG-PET/CT before treatment, after neoadjuvant cetuximab, and at the end of treatment.

RESULTS

Of the 21 patients enrolled, 9, 3, and 9 were treated in DL1, DL2, and DL3, respectively. DL1 required dose reductions due to gastrointestinal toxicities. DL2 and 3 were tolerated with 1 dose-limiting toxicity (grade 4 renal failure) at DL3. Following 3 weekly treatments of neoadjuvant cetuximab in DL1, 7 patients had maximum standardized uptake value changes on 18F-FDG-PET/CT consistent with response to cetuximab. Of the 12 patients with locally advanced disease, eleven evaluable patients had no evidence of disease on 18F-FDG-PET/CT at treatment end. Five-year progression-free survival and overall survival rates for all patients were 57.5% and 58.5%, respectively.

CONCLUSIONS

Cetuximab with cisplatin 30 mg/m2 and radiotherapy was tolerated. 18F-FDG-PET/CT demonstrated early evidence of response to neoadjuvant cetuximab. With advances in precision oncology and the recent approval of pembrolizumab in metastatic cervical cancer, dual-target inhibition with an epidermal growth factor receptor inhibitor may be a promising treatment in the future.

Early Changes of the Standardized Uptake Values (SUVmax) Predict the Efficacy of Everolimus-Exemestane in Patients with Hormone Receptor-Positive Metastatic Breast Cancer

Background: The mTORC1 inhibitor everolimus has been approved in combination with the aromatase inhibitor exemestane for the treatment of hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (HR+ mBC) progressing on prior therapy with a non-steroidal aromatase inhibitor. To date, no predictive biomarkers of tumor sensitivity/resistance for everolimus-based treatments have been identified. We hypothesized that precocious changes in the Standardized Uptake Volume (∆SUV%), as assessed by ¹⁸F-Fluorodeoxyglucosepositron-emission tomography (¹⁸F-FDG PET/CT), may be a marker of everolimus efficacy. Methods: This was a retrospective study including 31 HR+ HER2- patients treated with everolimus and exemestane in two Italian centers between 2013 and 2018. The objective of the study was to investigate ∆SUV% as a predictive marker of everolimus antitumor efficacy. ¹⁸F-FDG PET/CT scans were performed at baseline and after three months of treatment. Patients were defined as long responders (LRs) if disease progression occurred at least 10 months after treatment initiation and long survivors (LSs) if death occurred later than 36 months after starting therapy. ROC analysis was used to determine the optimal cut-off values of ∆SUV% to distinguish LRs from non-LRs and LSs from non-LSs. Progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method. Results: The SUVmax values decreased significantly from baseline to 3 months after therapy (p = 0.003). Dynamic changes of SUVmax (Delta SUV) had a higher accuracy in discriminating long-responders from non-long-responders (AUC = 0.67, Delta SUV cut-off = 28.8%) respects to its ability to identify long survivors from no-long survivors (AUC = 0.60, Delta SUV cut-off = 53.8%). Patients were divided into groups according to the Delta SUV cut-offs and survival outcomes were evaluated: patients with a decrease of ∆SUV% ≥ 28.8% had significantly better PFS (10 months-PFS: 63.2%, 95% CI: 37.9-80.4% and 16.7%, 95% CI: 2.7-41.3% respectively, p = 0.005). As regard as OS, patients with ∆SUV% ≥ 53.8% had longer OS when compared to patients with ∆SUV% < 53.8% (36 month-OS: 82.5% vs. 45.9% vs. p = 0.048). Conclusion: We found two precocious ∆SUV% thresholds capable of identifying HR+ HER2-mBC patients, which would achieve long-term benefit or long-term survival during everolimus-exemestane therapy. These results warrant further validation in prospective studies and should be integrated with molecular biomarkers related to tumor metabolism and mTORC1 signaling.

Involvement of GLUT1-mediated glucose transport and metabolism in gefitinib resistance of non-small-cell lung cancer cells

Use of epidermal growth factor receptor (EGFR) inhibitors represented by gefitinib and erlotinib has become the standard of treatment for non-small-cell lung cancers (NSCLCs) with activating EGFR mutations. However, the majority of NSCLCs, which overexpress EGFR without such mutations, are resistant to EGFR inhibitors, and the mechanism(s) behind such primary resistance of NSCLCs without activating EGFR mutations to EGFR inhibitors still remains poorly understood. Here in this study, we show that glucose metabolism mediated by GLUT1, a facilitative glucose transporter, is involved in gefitinib resistance of NSCLC cells. We found that GLUT1 expression and glucose uptake were increased in resistant NSCLC cells after gefitinib treatment and that genetic as well as pharmacological inhibition of GLUT1 sensitized not only NSCLC cells with primary resistance but also those with acquired resistance to gefitinib. In vivo, the combination of systemic gefitinib and a GLUT1 inhibitor, both of which failed to inhibit tumor growth when administered alone, significantly inhibited the growth of xenograft tumors formed by the implantation of NSCLC cells with wild-type EGFR (wt-EGFR). Since our data indicated that GLUT1 was similarly involved in erlotinib resistance, our findings suggest that the activity of GLUT1-mediated glucose metabolism could be a critical determinant for the sensitivity of NSCLC cells to EGFR inhibitors and that concurrent GLUT1 inhibition may therefore be a mechanism-based approach to treating NSCLCs resistant to EGFR inhibitors, including those with wt-EGFR.