A Phase I Study of the CDK4/6 Inhibitor Palbociclib in Combination with Cetuximab and Radiotherapy for Locally Advanced Head and Neck Squamous Cell Carcinoma.

PURPOSE: Palbociclib, a cyclin D kinase 4 (CDK4)/6 inhibitor, has shown radiosensitizing effects in preclinical studies. There is a strong rationale for adding palbociclib to cetuximab and radiotherapy in locally advanced head and neck squamous cell carcinoma (LA-HNSCC), especially in p16-negative HNSCC. PATIENTS AND METHODS: We conducted a phase I dose-escalation study (NCT03024489) using a classical 3+3 design to determine safety, tolerability, and MTD of palbociclib, cetuximab, and intensity-modulated radiotherapy (IMRT) combination. At the recommended phase II dose (RP2D), additional p16-negative patients were enrolled. RESULTS: Twenty-seven patients with LA-HNSCC (13 in dose escalation, 14 in expansion) with oropharyngeal (41%) and hypopharyngeal (30%) cancers were enrolled. The MTD was not reached, and the RP2D of palbociclib was established at the full standard palbociclib dose of 125 mg/day for 21 days per cycle, administered for two cycles during IMRT. The most common grade 3-4 toxicities were mucositis (59%), radiation dermatitis (22%), and neutropenia (22%), with a febrile neutropenia rate of 7%. Common genomic alterations included mutations in TP53 (57%), GNAQ (35%), and PIK3CA (17%), and copy-number gains in CCND1 (22%), CCND2 (9%), and EGFR (9%). Overall, p16 expression was positive in 15% of patients. No correlation was observed between p16 status, genomic alterations, and preliminary efficacy. The objective response rate was 84%. The rates for 2-year locoregional control, event-free survival, and overall survival were 73%, 48%, and 71%, respectively. CONCLUSIONS: The palbociclib, cetuximab, and IMRT combination was well tolerated. The RP2D was established, while no MTD was determined. The regimen demonstrated promising preliminary efficacy, suggesting further investigation is warranted in patients with cisplatin-ineligible p16/human papilloma virus-unrelated LA-HNSCC.

CYP450 and drug efflux transporters polymorphism influence clinical outcomes of Thai osimertinib-treated non-small cell lung cancer patients.

Background: Osimertinib has shown greater efficacy than standard epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and fewer grade 3 or higher adverse drug reactions (ADRs) in patients with advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. However, the clinical outcomes of osimertinib treatment vary depending on the patient's ethnicity. Therefore, further research is necessary to evaluate the impact of single nucleotide polymorphisms (SNPs) in cytochrome P450 (CYP450) and drug transporters on the therapeutic outcomes and ADRs to osimertinib in Thai patients, to provide improved pharmacological treatments for cancer patients. Methods: This retrospective and prospective cohort study enrolled 63 Thai patients with NSCLC treated with 80 mg of osimertinib once daily as monotherapy. Seventeen SNPs in candidate genes related to drug metabolism and transport pathways were analyzed in each patient. Chi-square or Fisher's exact tests were used to evaluate the associations between SNPs and clinical outcomes, including ADR incidence and objective response rate (ORR). In addition, the correlation between the genotype and median time to treatment failure (TTF) or progression-free survival (PFS) was assessed using Kaplan-Meier analysis and a log-rank test. Results: We identified six SNPs (rs2231142 and rs2622604 in ABCG2, rs762551 in CYP1A2, rs1057910 in CYP2C9, rs28371759 in CYP3A4, and CYP2A6 deletion polymorphism (CYP2A6*4)) that significantly increased the incidence of ADRs. In addition, we found two SNPs (rs2069514 in CYP1A2 and rs1057910 in CYP2C9) that significantly decreased the median TTF, and two SNPs (rs28399433 in CYP2A6 and rs1057910 in CYP2C9) that significantly decreased the median progression-free survival (PFS). Specifically, we found that one of these SNPs (rs1057910 in CYP2C9) influenced ADRs, TTF, and PFS. Additionally, SNPs in the CYP2A6 heterozygous variant (non4/*4) significantly increased ADR incidence, leading to a high frequency of dose reduction (27.0%). Conclusion: Our study demonstrated significant SNPs associated with increased ADR incidence, decreased PFS, and decreased TTF in Thai patients with NSCLC treated with osimertinib. The CYP2C9 (*3) and CYP2A6 (*4) allele frequencies differed between ethnicities and were associated with an increased incidence of ADRs. These findings highlight the importance of considering genetic factors in NSCLC treatment and may facilitate personalized medicine approaches. Moreover, our study showed a higher incidence of ADRs than the previous trials, including FLAURA and AURA2, and a higher frequency of dose reduction than reported in the AURA 3 trial, possibly due to genetic differences among the study populations.

Six-MicroRNA Prognostic Signature in Patients With Locally Advanced Head and Neck Squamous Cell Carcinoma.

PURPOSE: MicroRNAs (miRNAs) have been evaluated as biomarkers in cancers. Therefore, we aimed to identify a prognostic miRNA signature from The Cancer Genome Atlas (TCGA) database and validate it in the Ramathibodi (RA) locally advanced head and neck squamous cell carcinoma (LA-HNSCC) cohort. METHODS: The correlation between candidate miRNAs and the survival of patients with LA-HNSCC in TCGA database was analyzed. A prognostic miRNA signature model was generated that classified patients into high-risk and low-risk groups. This candidate miRNA signature was further validated in the independent RA cohort using droplet-digital polymerase chain reaction. RESULTS: In TCGA database, we compared the expression of 277 miRNAs between 519 head and neck squamous cell carcinoma tissues and 44 normal tissues. The expression of hsa-miR-10b, hsa-miR-148b, hsa-miR-99a, hsa-miR-127, hsa-miR-370, and hsa-miR-500a was independently associated with overall survival (OS). Thus, we established the miRNA signature risk score from these six miRNAs and categorized patients into low-risk and high-risk groups. The median OS of TCGA patients was significantly shorter in the low-risk group than in the high-risk group (P < .001). The six-miRNA signature was further validated in the RA cohort (N = 87). The median OS of the low-risk group was significantly shorter compared with the high-risk group (P = .03). In multivariate analysis, the six-miRNA signature was an independent prognostic factor for OS in the RA cohort (HR, 1.958; 95% CI, 1.006 to 3.812; P = .048). CONCLUSION: We identified a prognostic six-miRNA signature for patients with LA-HNSCC from TCGA cohort and validated it in our independent cohort. However, larger studies are warranted to confirm these results.

Healthcare coverage affects survival of EGFR-mutant Thai lung cancer patients.

Background: Despite significant benefits of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment in patients with EGFR-mutated NSCLC, access remains limited in Thailand and elsewhere. Methods: Retrospective analysis of patients with locally advanced/recurrent NSCLC and known EGFR mutation (EGFRm) status treated at Ramathibodi Hospital (2012-2017). Prognostic factors for overall survival (OS), including treatment type and healthcare coverage, were analyzed using Cox regression. Results: Of 750 patients, 56.3% were EGFRm-positive. After first-line therapy (n=646), 29.4% received no subsequent (second-line) treatment. EGFR-TKI-treated EGFRm-positive patients survived significantly longer than EGFRm-negative patients without EGFR-TKIs (median OS [mOS] 36.4 vs. 11.9 months; hazard ratio HR=0.38 [95%CI 0.32-0.46], P<0.001). Cox regression indicated significantly longer OS in patients with comprehensive healthcare coverage that included reimbursement of EGFR-TKIs, versus basic coverage (mOS 27.2 vs. 18.3 months; adjusted HR=0.73 [95%CI 0.59-0.90]). Compared with best supportive care (BSC; reference), EGFR-TKI-treated patients survived significantly longer (mOS 36.5 months; adjusted HR (aHR)=0.26 [95%CI 0.19-0.34]), and versus chemotherapy alone (14.5 months; aHR=0.60 [95%CI 0.47-0.78]). In EGFRm-positive patients (n=422), relative survival benefit of EGFR-TKI treatment remained highly significant (aHR[EGFR-TKI]=0.19 [95%CI 0.12-0.29]; aHR(chemotherapy only)=0.50 [95%CI 0.30-0.85]; reference:BSC), indicating that healthcare coverage (reimbursement) affected treatment choice and survival. Conclusion: Our analysis describes EGFRm prevalence and survival benefit of EGFR-TKI therapy for EGFRm-positive NSCLC patients treated from 2012-2017, one of the largest such Thai datasets. Together with research by others, these findings contributed evidence supporting the decision to broaden erlotinib access on healthcare schemes in Thailand from 2021, demonstrating the value of local real-world outcome data for healthcare policy decision-making.

Clinical correlations with EGFR circulating tumor DNA testing in all-stage lung adenocarcinoma.

BACKGROUND: Information on genetic alterations, notably EGFR mutations, is important for guiding non-small-cell lung cancer (NSCLC) treatment. Circulating tumor DNA (ctDNA) analysis represents a less invasive alternative to tissue biopsy for analyzing mutation status, but its clinical value may vary across disease stages. OBJECTIVE: To explore clinical correlates of ctDNA and tissue/plasma-based EGFR mutation (EGFRm) status across all NSCLC stages. METHODS: Ninety patients were analyzed, representing three cohorts: newly-diagnosed early-stage, advanced-stage, and recurrent NSCLC. Relationships among clinical/surgical parameters, ctDNA, EGFRm status, and survival outcomes were analyzed. RESULTS: Plasma/tissue EGFRm concordance was lower in early-stage (58.6%) than in advanced-stage patients (87.5%). In early-stage patients, ctDNA levels were variable and not significantly associated with clinical/surgical parameters. In advanced-stage patients, time to EGFR-TKI treatment failure (TTF), but not overall survival (OS), was significantly longer in EGFRm-positive vs. EGFRm-negative patients. In patients with recurrent disease, 40% of plasma samples were EGFRT790M-positive at recurrence. In T790M-positive patients, we noted slight trends toward longer OS with vs. without osimertinib treatment and longer OS and TTF with second-line vs. later-line osimertinib. CONCLUSIONS: Our results affirm the use of ctDNA testing in advanced-stage and recurrent NSCLC. Further studies on osimertinib as early-line therapy, clinical correlates and the utility of plasma-based testing in early-stage NSCLC are warranted.

Gastrointestinal microbiota profile and clinical correlations in advanced EGFR-WT and EGFR-mutant non-small cell lung cancer.

INTRODUCTION: Difference in clinical responses to cancer therapy in each patient is from several factors. Gastrointestinal microbiota is one of the reasons. However, this correlation remains unknown. This study aims to explore correlation between gastrointestinal microbiota profile and clinical outcomes in Thai advanced non-small cell lung cancer (NSCLC) according to epidermal growth factor receptor (EGFR) status. METHODS: We enrolled 13 patients with advanced EGFR-wild-type (WT) NSCLC who received chemotherapy and 15 patients with EGFR-mutant NSCLC who received EGFR tyrosine kinase inhibitors. We collected fecal samples at baseline and first disease evaluation and performed 16S rRNA gene sequencing by NGS to assess microbiota profile. The correlations between gastrointestinal microbiota and clinical variables were studied. RESULTS: The clinical characteristics were balanced between the cohorts, excluding significantly higher albumin levels in the EGFR-mutant group. Albumin was the only significant clinical factor affecting the treatment response in multivariate analysis (ORR 15.6%, P = 0.03). Proteobacteria counts were higher in the EGFR-WT group, whereas Bacteroidetes and Firmicutes counts were higher in the EGFR-mutant group. The alpha diversity of the gastrointestinal microbiome was significantly higher in the EGFR-mutant group (Shannon index: 3.82 vs. 3.25, P = 0.022). Following treatment, Proteobacteria counts were lower and Bacteroidetes and Firmicutes counts were higher in both cohorts; the changes were more prominent in the EGFR-WT cohort. No significant correlation between microbiota profile and treatment response were demonstrated in our study. However, beta diversity was significantly different according to severity of adverse events. Enrichment of Clostridia and Bacteroidia was associated with higher adverse event risk in the EGFR-WT cohort. CONCLUSIONS: Proteobacteria was dominant in Thai lung cancer patients both EGFR-WT and EGFR-mutant, and this phylum maybe associate with lung cancer carcinogenesis. Chemotherapy altered the gastrointestinal microbiota, whereas EGFR-TKIs had less effects. Our findings highlight the potential predictive utility of the gastrointestinal microbiota for lung cancer carcinogenesis. Studies with larger cohorts and comparison with the healthy Thai population are ongoing to validate this pilot study.

Plasma extracellular vesicle microRNA-491-5p as diagnostic and prognostic marker for head and neck squamous cell carcinoma.

Poor survival of patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is partly due to early diagnosis difficulties and the lack of reliable biomarkers for predicting treatment outcomes. In the discovery cohort, plasma-derived extracellular vesicles (EVs) from LA-HNSCC patients (n = 48) and healthy volunteers (n = 12) were used for profiling for microRNA (miRNA) expression by NanoString analysis. Ten EV-associated miRNAs were differentially expressed between LA-HNSCC patients and healthy volunteers. Subsequently, the results were validated in the individual discovery and additional cases (HNSCC, n = 73; control, n = 20) by quantitative RT-PCR. Among 10 EV-miRNAs, four (miR-27b-3p, miR-491-5p, miR-1910-5p, and miR-630) were significantly dysregulated in LA-HNSCC patients (n = 73) compared with healthy volunteers (n = 20). The miRNA prediction models were developed to discriminate HNSCC patients from healthy volunteers. The model using miR-491-5p was selected as a diagnostic biomarker for LA-HNSCC with a sensitivity and specificity of 46.6% and 100%, respectively (P < .001). The dynamic changes of miRNA model score (ΔmiRNAs) were determined using scores pre- and postdefinitive treatment to further investigate the prognostic value of miRNA prediction models. The univariate and multivariate analyses indicated that ΔmiR-491-5p was the most powerful and independent prognostic indicator for overall survival (hazard ratio [HR] 5.66, 95% confidence interval, 1.77-18.01; P = .003) and disease-free survival (HR 2.82, 95% CI, 1.13-7.05; P = .027) of HNSCC patients. In summary, the miR-491-5p prediction model could serve as a blood-based diagnostic marker for LA-HNSCC. Moreover, ΔmiR-491-5p could be a potential monitoring prognostic marker to reflect the survival of HNSCC patients.

Discrepancy in p16 expression in patients with HPV-associated head and neck squamous cell carcinoma in Thailand: clinical characteristics and survival outcomes.

BACKGROUND: Lower prevalence HPV infection has been previously reported in Thai population when compared with Western countries. p16 expression indicates HPV-associated oropharyngeal squamous cell carcinoma (OPSCC), but not non-OPSCC. We therefore evaluated the characteristic and association of p16 and HPV in Thai patients with HNSCC. METHODS: We used immunohistochemistry and qPCR, respectively, to detect p16 and HPV DNA in archrival formalin-fixed paraffin-embedded HNSCC tissues. Patient characteristics and survival were analyzed. RESULTS: p16 expression was detected in tumors of 72 of 662 (10.9%) patients with HNSCC and was significantly associated with higher-grade histology, advanced nodal stage, and oropharynx. p16 was expressed in 28 and 6.5% of patients with OPSCC or non-OPSCC, respectively, and HPV DNA was detected in 15.6 and 1% of patients, respectively. Using p16 as a surrogate for HPV status, sensitivities were 80 and 25% in OPSCC and non-OPSCC, respectively. Positive and negative predictive rates of OPSCC were 38 and 95%. Discordance rates between HPV and p16 were 23 and 7% in OPSCC and non-OPSCC, respectively. Overall survival (OS) were significantly longer in both p16-positive OPSCC (p = 0.049), and non-OPSCC (p = 0.003). CONCLUSIONS: Low prevalence of p16 and HPV associated OPSCC and non-OPSCC were confirmed in Thai patients. High discordance and low positive predictive rates of p16 were observed in HPV-associated OPSCC. p16 was a significant prognostic factor for OS for patients with OPSCC or non-OPSCC. Therefore, HPV testing should be performed to assess the association of HPV with HNSCC regardless of p16 expression.

Exosomal microRNAs as potential biomarkers for osimertinib resistance of non-small cell lung cancer patients.

BACKGROUND: Osimertinib is an epidermal growth factor receptor-tyrosine kinase inhibitor that specifically targets the T790M mutation in cancer.Unfortunately, most non-small cell lung cancer (NSCLC) patients develop osimertinib resistance. Currently, the molecular biomarkers for monitoring osimertinib resistance are not available. OBJECTIVE: This study aimed to examine the profile of exosomal miRNA in the plasma of osimertinib-resistant NSCLC patients. METHODS: Plasma exosomal miRNA profiles of 8 NSCLC patients were analyzed by next-generation sequencing at osimertinib-sensitive and osimertinib-resistance stage.The expression of dysregulated exosomal miRNAs was validated and confirmed in another cohort of 19 NSCLC patients by qPCR. The relationship between exosomal miRNA upregulation and clinical prognosis, survival analysis was evaluated by Kaplan-Meier curves. RESULTS: In osimertinib-resistant NSCLC patients, 10 exosomal miRNAs were significantly dysregulated compared to baseline. Upregulation of all 10 candidate exosomal miRNAs tended to correlate with increased latency to treatment failure and improved overall survival. Among them, 4 exosomal miRNAs, miR-323-3p, miR-1468-3p, miR-5189-5p and miR-6513-5p were essentially upregulated and show the potential to be markers for the discrimination of osimertinib-resistance from osimertinib-sensitive NSCLC patients with high accuracy (p< 0.0001). CONCLUSIONS: Our results highlight the potential role of these exosomal miRNAs as molecular biomarkers for the detection of osimertinib resistance.

Characteristics and Impact of HPV-Associated p16 Expression on Head and Neck Squamous Cell Carcinoma in Thai Patients.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is a common malignancy in Asia. Infection by human papilloma virus (HPV) has been recognized as an etiological risk for HNSCC, especially oropharyngeal region. While the association between HPV and HNSCC has been well evaluated in Western countries, only a few investigated the HPV-associated HNSCC in Southeast Asia. This study evaluated the prevalence, the characteristics, and the impact of HPV on the treatment outcomes in Thai HNSCC patients. METHODS: Non-nasopharyngeal HNSCC patients treated at Ramathibodi Hospital during 2007-2013 were identified through the cancer registry database. Baseline patient, treatment data and survivals were retrospectively reviewed. The formalin-fixed paraffin-embedded (FFPE) tissue sections were retrieved for p16 analysis. The HPV status was determined by p16 immunohistochemistry. The survival outcomes were analyzed in cases which p16 status was confirmed. RESULTS: Total of 200 FFPE tissues of HNSCC patients was evaluated for p16 expression. Positive p16 status was observed in 24 cases (12%); majority of p16-positive were men (20:4 cases). The oropharynx (37.9%) was the most common site found in p16-positive while oral cavity (3.2%) was the least common site. Interestingly, 66.7% of p16-positive were former/current smokers, and 70.8% of this subgroup was categorized as clinical AJCC stage III-IV. The p16-positive HNSCC was significantly superior in 5-year overall survival [5-yrs OS 63% vs. 40%, p=0.03], 5-year disease-free survival [5-yrs DFS 61% vs. 36%, p=0.03] and in 5-year locoregional relapse-free survival [5-yrs LRFS 93% vs. 68%, p=0.018] when compared with p16-negative. CONCLUSIONS: In comparison to the results from the Western countries, the prevalence of HPV-related HNSCC in Thai patients was less, and differences in some characteristics were observed. Nevertheless, improvement in OS, DFS and LRFS were observed in p16-positive patients. Our analyses suggested that p16 status is also a strong prognostic marker for HNSCC patients in Thailand.

Role of BIM Deletion Polymorphism and BIM Expression as Predictive Biomarkers to Maximize the Benefit of EGFR-TKI Treatment in EGFR-Positive NSCLC.

OBJECTIVE: BIM is a modulator of apoptosis that is triggered by EGFR-TKIs. This study evaluated the role of BIM deletion and its expression as predictor of EGFR-TKI treatment outcome. METHODS: The medical record of 185 EGFR-positive advanced non-small cell lung cancer (NSCLC) patients with/ without EGFR-TKI treatment between 9/2012 and 12/2014 were retrospectively reviewed. BIM deletion polymorphism and expression were tested by RT-PCR and immunohistochemistry, respectively. Survival outcomes in EGFR-TKI-treated patients were analyzed according to treatment sequence and EGFR mutation. The correlation between BIM deletion polymorphism, expression, response rate (as a function of EGFR-TKI treatment) and schedule was also explored. RESULT: EGFR-TKIs were administered to 139 (75.1%) of the 185 patients: as the first-line in 52 (37.4%) patients and as later-line treatment in 87 (62.6%) patients. Median overall survival (mOS) was significantly longer in EGFR-TKIs treated patients (28.9 vs. 7.4 months, P<0.001). Among L858R-mutated patients, median progression-free survival (mPFS) was significantly longer in first-line EGFR TKI treatment than a later-line (12.6 vs. 6.3 months, P=0.03). BIM deletion polymorphism and expression was detected in 20.2% and 52.7%, respectively. Patients without BIM deletion polymorphism had a significantly longer mOS when treated with a first-line than with a later-line EGFR-TKI (28.9 vs. 20.7 months, P= 0.04). Patients without BIM expression had a significantly longer mPFS (9.6 vs. 7.3 months, P=0.01) better mOS and response rate (RR). CONCLUSION: BIM deletion polymorphism and expression may predict an EGFR-TKI response in patients with EGFR-positive during therapy.

Characteristics and impact of programmed death-ligand 1 expression, CD8+ tumor-infiltrating lymphocytes, and p16 status in head and neck squamous cell carcinoma.

BACKGROUND: No predictive biomarker of immune checkpoint inhibitors in head and neck squamous cell carcinoma (HNSCC) has been well established. The impact of programmed death-ligand 1 (PD-L1) expression, CD8+ tumor-infiltrating lymphocytes (TILs), and p16 status in HNSCC is unclear and may vary according to ethnicity. METHODS: HNSCC patients treated between 2007 and 2013 were reviewed. Archival tissues were retrieved for PD-L1, CD8+ TILs, and p16 analyses. PD-L1 expression was evaluated by using the validated SP142 assay on the VENTANA platform. CD8+ TILs were defined by using semiquantitative scoring. RESULTS: A total of 203 patients were analyzed. PD-L1 expression was observed in 80% of patients and was significantly associated with older age (P < 0.001). A high CD8+ TIL score (≥ 6) was significantly associated with never-smoking (P = 0.020), oral cavity cancer (P < 0.001), and stage M0 at presentation (P = 0.025). The p16 status was positive in 12% of patients. Patients with a high TIL score had a significantly longer OS (P = 0.032). Patients with PD-L1 expression of 1-49% and ≥ 50% were associated with a significantly shorter OS compared with those with PD-L1 < 1% (P = 0.027 and P = 0.011, respectively). Multivariate analysis showed that PD-L1 ≥ 50% was significantly associated with a poor OS. (HR 2.98 [95% CI 1.2-7.39]; P = 0.019.) CONCLUSIONS: A high prevalence of PD-L1 expression was observed in HNSCC using the validated SP142 assay. PD-L1 expression was associated with older age, while highly PD-L1 expression (≥ 50%) was an independent prognostic factor for poor OS in anti-PD1/PD-L1 untreated HNSCC patients.

Characterization of PD-L1 and PD-1 Expression and CD8+ Tumor-infiltrating Lymphocyte in Epstein-Barr Virus-associated Nasopharyngeal Carcinoma.

OBJECTIVES: Immunotherapies that target the programmed death-1/ programmed death-1 ligand (PD-1/PD-L1) immune checkpoint pathway have shown promise in nasopharyngeal carcinoma (NPC) in early phases clinical studies. Here, we evaluated PD-1 and PD-L1 expression and CD8+ tumor-infiltrating lymphocytes (TILs) in NPC patients. MATERIALS AND METHODS: Newly diagnosed NPC patients were identified through the institutional database between January 2007 and December 2012. PD-L1 and PD-1 expression, Epstein-Barr virus (EBV) status, and CD8+ TIL numbers were measured in archival tumor samples at diagnosis and their correlations with clinicopathologic features, including survival, were evaluated. RESULTS: A total of 114 NPC patients were analyzed. Most patients (96%) were EBV positive. PD-L1 was expressed in ≥1% of tumor cells (TCs) in 69% of patients, in ≥50% of TCs in 12% of patients, and in ≥5% of either TCs or infiltrating immune cells in 71% of patients. CD8+ TILs were present in tumors from all patients, whereas only 11% of tumors expressed PD-1. There were no correlations between PD-L1 expression and CD8+ TIL abundance, PD-1 expression, or survival. CONCLUSIONS: Approximately 70% of EBV-positive NPC expressed PD-L1, but this did not correlate with patient survival or clinicopathologic features. The findings of this study represent the immune biomarker profile of confirmed EBV-associated NPC in an endemic region. Since the current clinical development of immune checkpoint inhibitor for NPC is mostly focusing on an EBV-associated tumor, differences in immune biomarker profiles and EBV status of endemic and nonendemic regions should be further explored.

ABCB1 and ABCC2 and the risk of distant metastasis in Thai breast cancer patients treated with tamoxifen.

BACKGROUND: Genetic polymorphisms of drug-metabolizing enzymes and transporters have been extensively studied with regard to tamoxifen treatment outcomes. However, the results are inconclusive. Analysis of organ-specific metastasis may reveal the association of these pharmacogenetic factors. The aim of this study is to investigate the impact of CYP3A5, CYP2D6, ABCB1, and ABCC2 polymorphisms on the risk of all distant and organ-specific metastases in Thai patients who received tamoxifen adjuvant therapy. METHODS: Genomic DNA was extracted from blood samples of 73 patients with breast cancer who received tamoxifen adjuvant therapy. CYP3A5 (6986A>G), CYP2D6 (100C>T), ABCB1 (3435C>T), and ABCC2 (-24C>T) were genotyped using allelic discrimination real-time polymerase chain reaction assays. The impacts of prognostic clinical factors and genetic variants on disease-free survival were analyzed using the Kaplan-Meier method and Cox regression analysis. RESULTS: In the univariate analysis, primary tumor size >5 cm was significantly associated with increased risk of distant metastasis (P=0.004; hazard ratio [HR] =3.05; 95% confidence interval [CI], 1.44-6.47). In the multivariate analysis, tumor size >5 cm remained predictive of distant metastasis (P<0.001; HR=5.49; 95% CI, 2.30-13.10). ABCC2 -24CC were shown to be associated with increased risk of distant metastasis (P=0.040; adjusted HR=2.34; 95% CI, 1.04-5.27). The combined genotype of ABCC2 -24CC - ABCB1 3435 CT+TT was associated with increased risk of distant and bone metastasis (P=0.020; adjusted HR=2.46; 95% CI, 1.15-5.26 and P=0.040; adjusted HR=3.70; 95% CI, 1.06-12.89, respectively). CONCLUSION: This study indicates that polymorphisms of ABCC2 and ABCB1 are independently associated with bone metastasis. Further prospective studies with larger sample sizes are needed to verify this finding.

Association of CYP3A4/5, ABCB1 and ABCC2 polymorphisms and clinical outcomes of Thai breast cancer patients treated with tamoxifen.

BACKGROUND: Pharmacogenetic study of cytochrome P450 (CYP) gene CYP2D6 and tamoxifen outcomes remain controversial. Apart from CYP2D6, other drug-metabolizing enzymes and transporters also play a role in tamoxifen metabolic pathways. The aim of this study is to investigate the impact of CYP3A4/5, ABCB1, and ABCC2 polymorphisms on the risk of recurrence in Thai patients who received tamoxifen adjuvant therapy. METHODS: Patients with early-stage breast cancer who received tamoxifen adjuvant therapy were recruited in this study. All six single-nucleotide polymorphisms (SNPs), including CYP3A4*1B (-392 A>G)/*18(878 T>C), CYP3A5*3(6986 G>A), ABCB1 3435 C>T, ABCC2*1C(-24 C>T), and ABCC2 68231 A>G, were genotyped using real-time polymerase chain reaction assays. The impacts of genetic variants on disease-free survival (DFS) were analyzed using the Kaplan-Meier method and Cox regression analysis. RESULTS: The ABCB1 3435 C>T was found to have the highest allele frequency among other variants; however, CYP3A4*1B/*18 could not be found in this study. Patients with heterozygous ABCB1 3435 CT genotype showed significantly shorter DFS than those with homozygous 3435 CC genotype (P = 0.041). In contrast, patients who carried homozygous 3435 TT genotype showed no difference in DFS from wild-type 3435 CC patients. Cox regression analysis showed that the relative risk of recurrence was increased by five times (P = 0.043; hazard ratio = 5.11; 95% confidence interval: 1.05-24.74) in those patients carrying ABCB1 3435 CT genotype compared to those with ABCB1 3435 CC. CONCLUSION: ABCB1 3435 C>T is likely to have a clinically significant impact on recurrence risk in Thai patients with breast cancer who receive tamoxifen adjuvant therapy.

Association of CYP2D6 and CYP2C19 polymorphisms and disease-free survival of Thai post-menopausal breast cancer patients who received adjuvant tamoxifen.

PURPOSE: To investigate the impact of CYP2D6 and CYP2C19 polymorphisms in predicting tamoxifen efficacy and clinical outcomes in Thai breast cancer patients. METHODS: Polymorphisms of CYP2D6 and CYP2C19 were genotyped by the AmpliChip™ CYP450 Test (Roche Molecular Diagnostics, Branchburg, NJ, USA) for 57 patients, who were matched as recurrent versus non-recurrent breast cancers (n = 33 versus n = 24, respectively, with a 5-year follow-up). RESULTS: Based on the genotype data, five CYP2D6 predicted phenotype groups were identified in this study including homozygous extensive metabolizer (13 of 57, 22.80%), extensive/intermediate metabolizer (23 of 57, 40.40%), extensive/poor metabolizer (3 of 57, 5.30%), homozygous intermediate metabolizer (14 of 57, 24.50%), and intermediate/poor metabolizer (4 of 57, 7.00%), and three CYP2C19 genotype groups including homozygous extensive metabolizer (27 of 57, 47.40%), extensive/intermediate metabolizer (27 of 57, 47.40%), and homozygous poor metabolizer (3 of 57, 5.30%). The CYP2D6 variant alleles were *10 (52 of 114, 45.60%), *5 (5 of 114, 4.40%), *41 (2 of 114, 1.80%), *4 (1 of 114, 0.90%), and *36 (1 of 114, 0.90%); the CYP2C19 variant alleles were *2 (27 of 114, 23.70%) and *3 (6 of 114, 5.30%). Kaplan-Meier estimates showed significantly shorter disease-free survival in patients with homozygous TT when compared to those with heterozygous CT or homozygous CC at nucleotides 100C>T and 1039C>T (CYP2D6*10) post-menopausal (log-rank test; P = 0.046). They also had increased risk of recurrence, but no statistically significant association was observed (hazard ratio 3.48; 95% confidence interval 0.86-14.07; P = 0.080). CONCLUSION: The CYP2D6 and CYP2C19 polymorphisms were not involved in tamoxifen efficacy. However, in the subgroup of post-menopausal women, the polymorphisms in CYP2D6 and CYP2C19 might be useful in predicting tamoxifen efficacy and clinical outcomes in breast cancer patients receiving adjuvant tamoxifen treatment. As the number of breast cancer patients was relatively small in this study, results should be confirmed in a larger group of prospective patients.

CYP2D6 polymorphisms influence the efficacy of adjuvant tamoxifen in Thai breast cancer patients.

AIM: We evaluated single nucleotide polymorphisms (SNPs) of CYP2D6 to identify those that influence the efficiency of tamoxifen in adjuvant treatment of breast cancer through a matched case-control study. METHODS: Peripheral blood DNA was collected from 20 patients with disease recurrence during adjuvant tamoxifen treatment and from 19 patients who had completed 5 years of tamoxifen therapy without recurrence of breast cancer. CYP2D6*4 (1846G > A; rs3892097), CYP2D6*10 (100C > T, rs1065852), and CYP2D6*5 (deletion) were genotyped. The correlation between disease-free survival (DFS) and genotype and clinical outcome were assessed using Kaplan-Meier analysis and a log-rank test. RESULTS: We found the allelic frequency of CYP2D6*10 during this study. Patients with the CYP2D6*10 homozygous variant T/T genotype had a significantly shorter median of DFS than those with C/T (P = 0.036), but DFS was not significantly different from that of patients with the C/C genotype (P = 0.316). One patient who was a carrier both of CYP2D6 G/A (1846G > A) and T/T (100C > T) had DFS of 22.7 months. CONCLUSIONS: This study demonstrated that CYP2D6*10/*10 was significantly associated with shorter DFS in Thai breast cancer patients receiving tamoxifen. This was a pilot study investigating the correlation of CYP2D6 polymorphisms and their influence on clinical outcomes in Thai estrogen receptor-positive breast cancer patients.

Impact of CYP2D6 polymorphisms on tamoxifen responses of women with breast cancer: a microarray-based study in Thailand.

This study was designed to investigate the frequency of CYP2D6 polymorphisms and evaluate the association between genetic polymorphisms of CYP2D6 and tamoxifen therapeutic outcome in Thai breast cancer patients. We recruited 48 breast cancer patients who received adjuvant tamoxifen for evaluating CYP2D6 genetic polymorphisms using microarray-based technology. Associations between genotypes-phenotypes and disease free survival were analyzed. Median follow up time was 5.6 years. The mean age of the subjects was 50 years. The 3 common allelic frequencies were 43.8% (*10), 36.5 (*1) and 10.4% (*2) which are related to extensive metabolizer (EM) and intermediate metabolizer (IM) with 70.8% and 29.2 %, respectively. No association between CYP2D6 genotypes and DFS was demonstrated. Nevertheless, exploratory analysis showed statistically significant shorter DFS in the IM group of post-menopause patients (HR, 6.85; 95% CI, 1.48 -31.69; P = 0.005). Furthermore, we observed statistically significant shorter DFS of homozygous CYP2D6*10 when compared with heterozygous CYP2D6*10 and other genotypes (P=0.005). CYP2D6*10 was the most common genotype in our subjects. Post-menopause patients with homozygous CYP2D6*10 and IM have shorter DFS. To confirm this relationship, larger samples and comprehensively designed trials in Thailand are required.