Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial.

BACKGROUND: Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented. PATIENTS AND METHODS: KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population. RESULTS: Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage). CONCLUSION: Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Improved risk stratification of nasopharyngeal cancer by targeted sequencing of Epstein-Barr virus DNA in post-treatment plasma.

BACKGROUND: Quantitative measurement of plasma Epstein-Barr virus (EBV) DNA by real-time PCR at the end of primary treatment is a robust prognostic marker for nasopharyngeal carcinoma (NPC) patients. However, up to 40% of patients who would later develop disease recurrence had undetectable post-treatment plasma EBV DNA. Targeted sequencing for the entire EBV genome potentially allows a more comprehensive and unbiased detection of plasma EBV DNA and enables the use of other parameters such as fragment size as biomarkers. Hence, we explored if plasma EBV DNA sequencing might allow more accurate prognostication of NPC patients. PATIENTS AND METHODS: Plasma samples collected from 769 patients with stage IIB-IVB NPC at 6-8 weeks after radiotherapy were analysed using targeted sequencing for EBV DNA. RESULTS: The sensitivities of the PCR-based analysis, at a cut-off of any detectable levels of plasma EBV DNA, for prediction of local and distant recurrences were 42.3% and 85.3%, respectively. The sequencing-based analysis (involving quantitation and size profiling) achieved better performance for both local and distant recurrences than PCR. Using a cut-off of the proportion of plasma EBV DNA deduced by sequencing at 0.01%, the sensitivities of the sequencing-based analysis for local and distant recurrences were 88.5% and 97.1%, with the resultant negative predictive values of 99.1% and 99.4%, respectively. Among patients with undetectable EBV DNA on quantitative PCR, sequencing could further define a subgroup that enjoyed superior survival outcomes based on the proportion of plasma EBV DNA, with a 5-year progression-free survival (PFS) approaching 90%. On multivariate analysis, sequencing-based quantitative level of plasma EBV DNA was the independent prognostic factor with the highest hazard ratio for prediction of overall survival and PFS. CONCLUSION: NPC prognostication using post-treatment plasma EBV DNA could be enhanced through sequencing.

Integrating postradiotherapy plasma Epstein-Barr virus DNA and TNM stage for risk stratification of nasopharyngeal carcinoma to adjuvant therapy.

BACKGROUND: After curative radiotherapy (RT) or chemoradiation (CRT), there is no validated tool to accurately identify patients for adjuvant therapy in nasopharyngeal carcinoma (NPC). Post-RT circulating plasma Epstein-Barr virus (EBV) DNA can detect minimal residual disease and is associated with recurrence and survival independent of TNM (tumor-lymph node-metastasis) stage. We aimed to develop and validate a risk model for stratification of NPC patients after completion of RT/CRT to observation or adjuvant therapy. PATIENTS AND METHODS: The prospective multicenter 0502 EBV DNA screening cohort (Hong Kong NPC Study Group 0502 trial) enrolled from 2006 to 2015 (n = 745) was used for model development. For internal validation, we pooled independent patient cohorts from prospective clinical studies enrolled from 1997 to 2006 (n = 340). For external validation, we used retrospective cohort of NPC patients treated at Sun Yat-sen University Cancer Center from 2009 to 2012 (n = 837). Eligible patients had histologically confirmed NPC of Union for International Cancer Control (UICC) 7th Edition stage II-IVB who completed curative RT/CRT with or without neoadjuvant chemotherapy, had post-RT EBV DNA tested within 120 days after RT and received no adjuvant therapy. The primary end point was overall survival (OS). We used recursive-partitioning analysis (RPA) to classify patients into groups of low, intermediate, and high risk of death. RESULTS: Combining post-RT EBV DNA level (0, 1-49, 50-499, and ≥500 copies/ml) and TNM stage (II, III, IVAB), RPA model classified patients into low-, intermediate-, and high-risk groups with 5-year OS of 89.4%, 78.5% and 37.2%, respectively. The RPA low-risk group had comparable OS to TNM stage II (5-year OS 88.5%) but identified more patients (64.8% versus stage II 28.1%) that could potentially be spared adjuvant therapy toxicity. The RPA model (c-index 0.712) showed better risk discrimination than either the TNM stage (0.604) or post-RT EBV DNA alone (0.675) with improved calibration and consistence. These results were validated in both internal and external cohorts. CONCLUSION: Combining post-RT EBV DNA and TNM stage improved risk stratification in NPC.

Complementary roles of MRI and endoscopic examination in the early detection of nasopharyngeal carcinoma.

BACKGROUND: Early-stage nasopharyngeal carcinoma (NPC) evades detection when the primary tumor is hidden from view on endoscopic examination. Therefore, in a prospective study of subjects being screened for NPC using plasma Epstein-Barr virus (EBV) DNA, we conducted a study to investigate whether magnetic resonance imaging (MRI) could detect endoscopically occult NPC. PATIENTS AND METHODS: Participants with persistently positive EBV DNA underwent endoscopic examination and biopsy when suspicious for NPC, followed by MRI blinded to the endoscopic findings. Participants with a negative endoscopic examination and positive MRI were recalled for biopsy or surveillance. Diagnostic performance was assessed by calculating sensitivity, specificity and accuracy, based on the histologic confirmation of NPC in the initial study or in a follow-up period of at least two years. RESULTS: Endoscopic examination and MRI were performed on 275 participants, 34 had NPC, 2 had other cancers and 239 without cancer were followed-up for a median of 36 months (24-60 months). Sensitivity, specificity and accuracy were 76.5%, 97.5% and 94.9%, respectively, for endoscopic examination and 91.2%, 97.5% and 96.7%, respectively, for MRI. NPC was detected only by endoscopic examination in 1/34 (2.9%) participants (a participant with stage I disease), and only by MRI in 6/34 (17.6%) participants (stage I = 4, II = 1, III = 1), two of whom had stage I disease and follow-up showing slow growth on MRI but no change on endoscopic examination for 36 months. CONCLUSION: MRI has a complementary role to play in NPC detection and can enable the earlier detection of endoscopically occult NPC.

Identifying an early indicator of drug efficacy in patients with metastatic colorectal cancer-a prospective evaluation of circulating tumor cells, 18F-fluorodeoxyglucose positron-emission tomography and the RECIST criteria.

BACKGROUND: This study investigated the predictive and prognostic significance of assessing early drug response with both positron-emission computerized tomography (PET-CT) and circulating tumor cells (CTCs) in patients receiving first-line chemotherapy for metastatic colorectal cancer. PATIENTS AND METHODS: Eligible patients had PET-CT and CTC analysis at baseline and 4-6 weeks after starting chemotherapy, and then a CT scan at 10-12 weeks to assess the Response Evaluation Criteria In Solid Tumors (RECIST) response. Early response was defined as achieving a dual-endpoint consisting of PET-CT (30% drop in the sum of maximum standard uptake values-SUVmax-of target lesions) and CTC response (CTC < 3 cells/7.5 ml blood) at 4-6 weeks after starting chemotherapy. RESULTS: About 84 patients were enrolled with a median follow-up of 32.9 months (95% confidence interval, CI, 24.5 months-not reached, NR), and 70 patients (84.3%) completed all assessments. Achieving an early response based on the dual-endpoint was independently associated with progression-free survival (hazard ratio, HR = 0.452, 95% CI 0.267-0.765). The median progression-free survival of early responders was 7.41 months (95% CI, 6.05-9.11) compared with 5.37 months (95% CI, 4.68-6.24) in non-responders (log-rank, P = 0.0167). RECIST response at 10 weeks was independently associated with overall survival (OS) (HR = 0.484, 95% CI, 0.275-0.852). Early response based on the dual-endpoint could predict the subsequent RECIST response with a sensitivity, specificity and positive predictive value of 64%, 70% and 74%, respectively. CONCLUSIONS: Early response based on both PET-CT and CTC analysis has prognostic and probably predictive significance in patients undergoing first-line chemotherapy for metastatic colorectal cancer. Its utility as a new tool for assessing early drug response should be further validated.

Multicenter phase II study of the AKT inhibitor MK-2206 in recurrent or metastatic nasopharyngeal carcinoma from patients in the mayo phase II consortium and the cancer therapeutics research group (MC1079).

BACKGROUND: This study investigated the activity of MK-2206, an AKT inhibitor, in metastatic or recurrent nasopharyngeal carcinoma (NPC). METHOD: Oral MK-2206 at a dose of 200 mg was administered on days 1, 8, 15 and 22 of a 28-day cycle until progression. Plasma EBV DNA clearance during the first month of treatment was measured, and archived tumors were analyzed for the expression of AKT and PIK3CA mutation and PIK3CA amplification. The dual primary endpoint was objective response rate and 6-month progression-free survival (PFS) rate. RESULTS: 21 patients were enrolled and one patient achieved a partial response (5 %) and 11 had stable disease (52 %), with a median PFS of 3.5 months (95 % confidence interval, CI: 0.9-7.3). The 6-month PFS rate was 43 % (95 % CI: 22-66 %) and the median OS was 10 months (95 % CI: 5.9 months-not reached). Seven patients (33 %) experienced grade 3 toxicities which could be related to MK-2206. Macular-papular rash was the most common (n = 6), followed by hyperglycemia (n = 2) and fatigue (n = 1). In the 12 tumor samples analyzed, PIK3CA amplification was detected in one patient's primary NPC, who had SD lasting over 12 months. Patients with decreasing EBV DNA values over time were more likely to be alive and progression-free for at least 6 months than those without a decrease (p = 0.001). CONCLUSION: The study was terminated due to the limited activity observed in this heavily pre-treated group of patients. Further studies are needed to elucidate the optimal way of selecting patients for AKT inhibitors.

Plasma Epstein-Barr viral DNA load at midpoint of radiotherapy course predicts outcome in advanced-stage nasopharyngeal carcinoma.

BACKGROUND: To test the hypothesis that prognostication of treatment outcome is feasible by biomarker response at midcourse of chemoradiotherapy (CRT)/radiotherapy (RT), with respect to the plasma load of Epstein-Barr viral (EBV) DNA in nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: One hundred seven patients with stage IIB-IV NPC were prospectively studied. Plasma EBV DNA load was measured by quantitative PCR before therapy (pre-DNA), at completion of 4 weeks of CRT/RT (mid-DNA), and within 3 months of completion of therapy (post-DNA). The end points are post-DNA load, a recognized surrogate of survival, and clinical outcome. RESULTS: Ninety-three percent of patients had detectable EBV DNA before therapy (median load = 972 copies/ml). EBV DNA became undetectable in 55 (51%) patients at the end of week 4 of therapy. Detectable mid-DNA was associated with worse clinical outcome (median follow-up time, 6.2 years), for distant failure [hazard ratio (HR) 12.02, 95% confidence interval (CI) 2.78-51.93; P < 0.0001], progression-free survival (PFS; HR 4.05, 95% CI 1.89-8.67, P < 0.0001), and overall survival (OS; HR 3.29, 95% CI 1.37-7.90, P = 0.0077). Seventy-four percent of all failures were associated with detectable mid-DNA, whereas 34% of all failures were associated with detectable post-DNA. Stratification by tumor stage (IIB, III, IV) has no significant prognostic effect. CONCLUSIONS: Unfavorable EBV DNA response at midcourse of RT/CRT is an adverse prognosticator for treatment outcome, is linked to majority of all failures, and discriminates outcome better than tumor stage. The data could provide a basis for trial design that addresses alteration of therapy intensity during the latter phase of CRT, and adjuvant therapy. Validation studies are awaited.

Efficacy and toxicity of intensity-modulated radiation therapy for prostate cancer in Chinese patients.

OBJECTIVE: To report the treatment efficacy and toxicity profile of intensitymodulated radiation therapy in Chinese patients with clinically localised prostate cancer. DESIGN: Historical cohort study. SETTING: Oncology unit in a university teaching hospital in Hong Kong. PATIENTS: Patients with clinically localised prostate cancer undergoing intensity-modulated radiation therapy in our institution between May 2001 and November 2009 were reviewed. MAIN OUTCOME MEASURES: The 5-year biochemical failure­free survival, 5-year overall survival, as well as acute/late gastro-intestinal toxicities and genito-urinary toxicities. RESULTS: A total of 182 patients were treated with prostate intensitymodulated radiation therapy with or without whole-pelvic radiotherapy. The median follow-up was 44 months. The median patient age was 72 years. Overall survival of the cohort was 92% after 5 years. The favourable, intermediate, and unfavourable risk category distributions of the National Comprehensive Cancer Network were 21 (12%), 42 (23%), and 119 (65%), respectively. The 5-year actuarial biochemical failure­free survival rates for patients in these categories were 95%, 82%, and 80%, respectively. Multivariate analysis identified early tumour stage, low pre-treatment prostate-specific antigen levels, and the use of adjuvant androgen deprivation as independent prognostic factors for better biochemical failure­free survival. Grade 2 and 3 late gastro-intestinal/genito-urinary toxicities occurred in 8%/3% and 4%/3% of the patients, respectively. CONCLUSION: Intensity-modulated radiation therapy for prostate cancer is feasible and safe in the Chinese population. These data are consistent with the results of other series in Caucasian populations.

A phase II study of concurrent cetuximab-cisplatin and intensity-modulated radiotherapy in locoregionally advanced nasopharyngeal carcinoma.

BACKGROUND: Based on our previous work on the clinical activity of cetuximab in recurrent nasopharyngeal carcinoma (NPC), we evaluated the feasibility of adding cetuximab to concurrent cisplatin and intensity-modulated radiotherapy (IMRT) in locoregionally advanced NPC. PATIENTS AND METHODS: Patients with American Joint Committee on Cancer stage III-IVB NPC were given an initial dose of cetuximab (400 mg/m(2)) 7-10 days before receiving concurrent IMRT, weekly cisplatin (30 mg/m(2)/week) and cetuximab (250 mg/m(2)/week). RESULTS: Thirty patients (median age of 45 years) with stage III (67%), IVA (30%) and IVB (3%) nonkeratinizing NPC were enrolled. Grade 3-4 oropharyngeal mucositis occurred in 26 (87%) patients and 10 (33%) patients required short-term nasogastric feeding. Grade 3 radiotherapy-related dermatitis occurred in six patients (20%) and three patients (10%) had grade 3 cetuximab-related acneiform rash. These grade 3-4 skin and mucosal toxic effects were manageable and reversible. At a median follow-up of 31.8 months [95% confidence interval (CI) 26.2-32.1 months], the 2-year progression-free survival was 86.5% (95% CI 74.3% to 98.8%). CONCLUSIONS: Concurrent administration of cetuximab, weekly cisplatin and IMRT is a feasible strategy against locoregionally advanced NPC. Preliminary survival data compare favorably with historic data and further follow-up is warranted.

Clinical significance of CDX2-positive circulating tumour cells in colorectal cancer patients.

BACKGROUND: Our recent work has shown the feasibility of using a refined immunomagnetic enrichment (IE) assay to detect cytokeratin 20-positive circulating tumour cells (CK20 pCTCs) in colorectal cancer (CRC) patients. We attempted to improve the sensitivity for CRC by detecting another intestinal-type differentiation marker, CDX2 pCTCs, using the same methodology. METHODS: CDX2 pCTCs were detected in patients with CRC, colorectal adenoma (CAD), benign colorectal diseases (BCD), other common cancers (OCC) and normal subjects (NS). Statistical analysis was used to correlate CDX2 pCTCs to the clinicohistopathological factors, recurrence, metastasis and survival after follow-up for 42 months in CRC patients. RESULTS: CDX2 pCTCs were detected in 81% CRC patients (73 out of 90, median number=21.5 CTCs), 7.5% CAD patients (3 out of 40), 0% patients with BCD (0 out of 90), 2.5% patients with OCC (2 out of 80) and 0% NS (0 out of 40). Furthermore, statistical analysis showed that CDX2 pCTC numbers were associated with tumour- node-metastasis stage and lymph node status. Using the median CDX2 pCTC numbers as the cutoff points, stratified groups of CRC patients had significant differences in their recurrence and survival. CONCLUSIONS: This study showed that the refined IE assay can detect CDX2 pCTCs with high sensitivity and that CDX2 pCTCs can generate clinically important information for CRC patients.

Hemorrhagic complications in a phase II study of sunitinib in patients of nasopharyngeal carcinoma who has previously received high-dose radiation.

BACKGROUND: We aimed to evaluate the safety and efficacy of single-agent sunitinib in nasopharyngeal carcinoma (NPC). METHODS: Eligible patients had progressive disease after prior platinum-based chemotherapy. Sunitinib was given as continuous once-daily dosing of 37.5 mg in 4-week cycles until progression. RESULTS: Thirteen patients were enrolled. Recruitment was stopped after two patients died of hemorrhagic events. All patients had previously received curative radiotherapy (RT) to nasopharynx/neck (including nine patients who had chemoradiotherapy). Patients received a median of three cycles of sunitinib. One patient was still on sunitinib with stable disease after 24 cycles. Hemorrhagic events occurred in nine patients (64%), including epistaxis in six, hemoptyses in three and hematemesis in two patients. Prior RT to thorax was significantly associated with hemoptyses (P = 0.03). Two patients with local tumor invasion into the carotid sheath developed fatal epistaxis/hematemesis within the first cycle of sunitinib, likely due to internal carotid blowout after tumor shrinkage. CONCLUSIONS: Sunitinib demonstrated modest clinical activity in heavily pretreated NPC patients. However, the high incidence of hemorrhage from the upper aerodigestive tract in NPC patients who received prior high-dose RT to the region is of concern. Direct vascular invasion by tumors appeared to increase the risk of serious bleeding.

Nasopharyngeal carcinoma.

With the improvement in local control achieved by more precise imaging and radiotherapy, the predominant mode of failure for nasopharyngeal carcinoma is distant metastases. Concurrent cisplatin-radiotherapy with or without adjuvant chemotherapy is the standard treatment approach for stages IIB and above disease. The addition of neoadjuvant chemotherapy has been most promising, and phase III trial results are awaited. Quantitative Epstein-Barr virus (EBV) DNA can be applied clinically for disease monitoring and follow-up, and may in future be used for risk stratification strategies. Targeted therapies against epidermal growth factor receptor and angiogenesis have demonstrated activity, and immunotherapeutic approaches are being investigated.

Early Detection of Cancer: Evaluation of MR Imaging Grading Systems in Patients with Suspected Nasopharyngeal Carcinoma.

BACKGROUND AND PURPOSE: We evaluated modifications to our contrast-enhanced MR imaging grading system for symptomatic patients with suspected nasopharyngeal carcinoma, aimed at improving discrimination of early-stage cancer and benign hyperplasia. We evaluated a second non-contrast-enhanced MR imaging grading system for asymptomatic patients from nasopharyngeal carcinoma plasma screening programs. MATERIALS AND METHODS: Dedicated nasopharyngeal MR imaging before (plain scan system) and after intravenous contrast administration (current and modified systems) was reviewed in patients from a nasopharyngeal carcinoma-endemic region, comprising 383 patients with suspected disease without nasopharyngeal carcinoma and 383 patients with nasopharyngeal carcinoma. The modified and plain scan systems refined primary tumor criteria, added a nodal assessment, and expanded the system from 4 to 5 grades. The overall combined sensitivity and specificity of the 3 systems were compared using the extended McNemar test (a χ2 value [Formula: see text]> 5.99 indicates significance). RESULTS: The current, modified, and plain scan MR imaging systems yielded sensitivities of 99.74%, 97.91%, and 97.65%, respectively, and specificities of 63.45%, 89.56% and 86.42%, respectively. The modified system yielded significantly better performance than the current ([Formula: see text] = 122) and plain scan ([Formula: see text] = 6.1) systems. The percentages of patients with nasopharyngeal carcinoma in grades 1-2, grade 3, and grades 4-5 for the modified and plain scan MR imaging systems were 0.42% and 0.44%; 6.31% and 6.96%; and 90.36% and 87.79%, respectively. No additional cancers were detected after contrast administration in cases of a plain scan graded 1-2. CONCLUSIONS: We propose a modified MR imaging grading system that improves diagnostic performance for nasopharyngeal carcinoma detection. Contrast was not valuable for low MR imaging grades, and the plain scan shows potential for use in screening programs.

DLEC1 is a functional 3p22.3 tumour suppressor silenced by promoter CpG methylation in colon and gastric cancers.

Promoter CpG methylation of tumour suppressor genes (TSGs) is an epigenetic biomarker for TSG identification and molecular diagnosis. We screened genome wide for novel methylated genes through methylation subtraction of a genetic demethylation model of colon cancer (double knockout of DNMT1 and DNMT3B in HCT116) and identified DLEC1 (Deleted in lung and oesophageal cancer 1), a major 3p22.3 TSG, as one of the methylated targets. We further found that DLEC1 was downregulated or silenced in most colorectal and gastric cell lines due to promoter methylation, whereas broadly expressed in normal tissues including colon and stomach, and unmethylated in expressing cell lines and immortalised normal colon epithelial cells. DLEC1 expression was reactivated through pharmacologic or genetic demethylation, indicating a DNMT1/DNMT3B-mediated methylation silencing. Aberrant methylation was further detected in primary colorectal (10 out of 34, 29%) and gastric tumours (30 out of 89, 34%), but seldom in paired normal colon (0 out of 17) and gastric (1 out of 20, 5%) samples. No correlation between DLEC1 methylation and clinical parameters of gastric cancers was found. Ectopic expression of DLEC1 in silenced HCT116 and MKN45 cells strongly inhibited their clonogenicity. Thus, DLEC1 is a functional tumour suppressor, being frequently silenced by epigenetic mechanism in gastrointestinal tumours.

Multicenter phase II study of gemcitabine and oxaliplatin in advanced nasopharyngeal carcinoma--correlation with excision repair cross-complementing-1 polymorphisms.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a platinum-sensitive cancer and excision repair cross-complementing group 1 (ERCC1) polymorphisms have been shown to predict survival in several cancers following platinum therapy. PATIENTS AND METHODS: This multicenter study evaluated the activity of oxaliplatin and prolonged infusion of gemcitabine ('GEMOX' regimen) in recurrent NPC. Baseline blood samples were genotyped for the presence of ERCC1-118 gene polymorphisms. RESULTS: Forty-two patients were recruited, of whom most (61%) had metastatic disease. Of the 40 patients evaluated for response, the respective overall response and disease control rates were 56.1% and 90.2%. At a median follow-up of 14.8 months, the respective median overall survival and time to progression were 19.6 months [95% confidence interval (CI) = 12.8-22 months] and 9 months (95% CI = 7.3-10 months). Grade 3-4 toxic effects were uncommon. The distribution of ERCC1-118 genotypes from 29 patients was C/C (n = 17, 40.5%), C/T (n = 10, 23.8%) and T/T (n = 2, 4.8%). No differences in survival or response rates were found between genotypes. CONCLUSIONS: GEMOX is active in the treatment of recurrent NPC. Detection of single-nucleotide gene polymorphisms from genomic DNA in peripheral blood is feasible in NPC and further studies are warranted.

The Use of Post-ablation Stimulated Thyroglobulin in Predicting Clinical Outcomes in Differentiated Thyroid Carcinoma - What Cut-off Values Should We Use?

AIMS: Recently published international guidelines recommended using the stimulated thyroglobulin (sTg) post-radioactive iodine (RAI) ablation, in conjunction with tumour stage, as a risk stratification factor. The choice of cut-off values for sTg, namely 1 and 10 ng/ml, was, however, largely based on the functional sensitivities of the assays used, with relatively few published data addressing the prognostic impact of alternative cut-off values. Our study aims to provide data on the prognostic value of sTg at different levels of sensitivities and specificities. MATERIALS AND METHODS: We conducted a retrospective review of all adult cases of differentiated thyroid carcinoma receiving RAI ablation at our centre from 2008 to 2010. All patients had sTg measured at around 6 months post-ablation. The functional sensitivity of our assay was 0.5 ng/ml. The outcome was adverse clinical event, defined as cancer-related death, persistent macroscopic disease demonstrable on imaging (including radioisotope scan) and/or receiving further treatment for persistent or recurrent disease. A receiver operating characteristic (ROC) analysis was carried out. RESULTS: We identified 140 patients treated in the review period, with 106 of them suitable for further analysis. The reasons for exclusion included the presence of anti-thyroglobulin antibodies and medullary or anaplastic histological subtypes. Most (54.7%) had intermediate-risk disease as per the American Thyroid Association classification (2009). The median follow-up duration was 6.4 years; the minimum, excluding deaths, was 5.0 years. ROC analysis showed that the optimal cut-off value of sTg for predicting adverse clinical events was >1.0 ng/ml, associated with a sensitivity of 90.9%, a specificity of 81.0%, a positive predictive value of 55.6% and a negative predictive value of 97.1%. CONCLUSION: Based on ROC analysis of sensitivities and specificities, our data showed that a post-ablation sTg value of 1 ng/ml is the optimal cut-off in prognostication of adverse clinical events.

The major 8p22 tumor suppressor DLC1 is frequently silenced by methylation in both endemic and sporadic nasopharyngeal, esophageal, and cervical carcinomas, and inhibits tumor cell colony formation.

Identification of tumor suppressor genes (TSG) silenced by methylation uncovers mechanisms of tumorigenesis and identifies new epigenetic tumor markers for early cancer detection. Both nasopharyngeal carcinoma (NPC) and esophageal carcinoma are major tumors in Southern China and Southeast Asia. Through expression subtraction of NPC, we identified Deleted in Liver Cancer 1 (DLC1)/ARHGAP7 (NM_006094)--an 8p22 TSG as a major downregulated gene. Although expressed in all normal tissues, DLC1 was silenced or downregulated in 11/12 (91%) NPC, 6/15 (40%) esophageal, 5/8 (63%) cervical and 3/9 (33%) breast carcinoma cell lines. No genetic deletion of DLC1 was detected in NPC although a hemizygous deletion at 8p22-11 was found by 1-Mb array-CGH in some cell lines. We then located the functional DLC1 promoter by 5'-RACE and promoter activity assays. This promoter was frequently methylated in all downregulated cell lines and in a large collection of primary tumors including 89% (64/72) NPC (endemic and sporadic types), 51% (48/94) esophageal, 87% (7/8) cervical and 36% (5/14) breast carcinomas, but seldom in paired surgical marginal tissues and not in any normal epithelial tissue. The transcriptional silencing of DLC1 could be reversed by 5-aza-2'-deoxycytidine or genetic double knock-out of DNMT1 and DNMT3B. Furthermore, ectopic expression of DLC1 in NPC and esophageal carcinoma cells strongly inhibited their colony formation. We thus found frequent epigenetic silencing of DLC1 in NPC, esophageal and cervical carcinomas, and a high correlation of methylation with its downregulation, suggesting a predominant role of epigenetic inactivation. DLC1 appears to be a major TSG implicated in the pathogenesis of these tumors, and should be further tested as a molecular biomarker in patients with these cancers.

A split-organ delineation approach for dose optimisation for intensity-modulated radiotherapy for advanced T-stage nasopharyngeal carcinoma.

AIMS: To assess the dosimetric effect of using a split-organ delineation approach during intensity-modulated radiotherapy (IMRT) treatment planning for advanced T-stage nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Twenty NPC patients with T3-4 tumours were studied. A reference (REF) IMRT plan was generated based on a standard treatment planning protocol, with a set of user-defined dose constraints for optimisation. An investigative (INV) IMRT plan was then generated based on the same protocol, but treating several organs at risk (OARs; parotid glands, temporal lobes, cochlea, auditory nerves and planning organ at risk volume [PRV] of the brainstem) as split organs consisting of target-overlapping and non-target-overlapping sub-segments. These sub-segments were assigned independent dose constraints. The REF and INV plans were compared with respect to target coverage and OAR sparing. Target coverage was evaluated by the Dmin (minimum dose), V66/V60 (percentage volume of gross target volume [GTV]/planning target volume [PTV] receiving 66 Gy/60 Gy), target conformity index (CI), and tumour control probability (TCP). The sparing of OARs was evaluated by the commonly used dose end points for the respective OAR, and normal tissue complication probability (NTCP). RESULTS: For PTV coverage, the INV plan was superior to the REF plan in terms of Dmin (P=0.000), CI (P=0.005) and TCP (P=0.002). This is attributed to an increase in dose to the PTV-OAR overlapping sub-segments. Regarding the sparing of OARs, there was a significant reduction in the mean dose of the parotid glands (P=0.002), and a slight, but non-significant, increase in NTCP of the temporal lobes, cochlea and brainstem. CONCLUSIONS: Using a split-organ delineation approach in IMRT treatment planning for advanced T-stage NPC, a significant improvement in the target coverage and TCP could be achieved, whereas the mean dose of the parotid was reduced significantly. There was insignificant change in the NTCP of the temporal lobe, parotid gland, cochlea and brainstem, but a significant change in the NTCP of the auditory nerve. The approach provides the planner extra room to manipulate the dose constraints during optimisation, and to obtain the desired result in less attempts. This approach also has the potential to be used in a broader context for IMRT planning for other tumour sites.

MR Imaging Criteria for the Detection of Nasopharyngeal Carcinoma: Discrimination of Early-Stage Primary Tumors from Benign Hyperplasia.

BACKGROUND AND PURPOSE: MR imaging can detect nasopharyngeal carcinoma that is hidden from endoscopic view, but for accurate detection carcinoma confined within the nasopharynx (stage T1) must be distinguished from benign hyperplasia of the nasopharynx. This study aimed to document the MR imaging features of stage T1 nasopharyngeal carcinoma and to attempt to identify features distinguishing it from benign hyperplasia. MATERIALS AND METHODS: MR images of 189 patients with nasopharyngeal carcinoma confined to the nasopharynx and those of 144 patients with benign hyperplasia were reviewed and compared in this retrospective study. The center, volume, size asymmetry (maximum percentage difference in area between the right and left nasopharyngeal halves), signal intensity asymmetry, deep mucosal white line (greater contrast enhancement along the deep tumor margin), and absence/distortion of the adenoidal septa were evaluated. Differences were assessed with logistic regression and the χ2 test. RESULTS: The nasopharyngeal carcinoma center was lateral, central, or diffuse in 134/189 (70.9%), 25/189 (13.2%), and 30/189 (15.9%) cases, respectively. Nasopharyngeal carcinomas involving the walls showed that a deep mucosal white line was present in 180/183 (98.4%), with a focal loss of this line in 153/180 (85%) cases. Adenoidal septa were absent or distorted in 111/111 (100%) nasopharyngeal carcinomas involving the adenoid. Compared with benign hyperplasia, nasopharyngeal carcinoma had a significantly greater volume, size asymmetry, signal asymmetry, focal loss of the deep mucosal white line, and absence/distortion of the adenoidal septa (P < .001). Although size asymmetry was the most accurate criterion (89.5%) for nasopharyngeal carcinoma detection, use of this parameter alone would have missed 11.9% of early-stage T1 nasopharyngeal carcinomas. CONCLUSIONS: MR imaging features can help distinguish stage T1 nasopharyngeal carcinoma from benign hyperplasia in most cases.

Functional epigenetics identifies a protocadherin PCDH10 as a candidate tumor suppressor for nasopharyngeal, esophageal and multiple other carcinomas with frequent methylation.

Protocadherins constitute the largest subgroup in the cadherin superfamily of cell adhesion molecules. Their major functions are poorly understood, although some are implicated in nervous system development. As tumor-specific promoter methylation is a marker for tumor suppressor genes (TSG), we searched for epigenetically inactivated TSGs using methylation-subtraction combined with pharmacologic demethylation, and identified the PCDH10 CpG island as a methylated sequence in nasopharyngeal carcinoma (NPC). PCDH10 is broadly expressed in all normal adult and fetal tissues including the epithelia, though at different levels. It resides at 4q28.3--a region with hemizygous deletion detected by array-CGH in NPC cell lines; however, PCDH10 itself is not located within the deletion. In contrast, its transcriptional silencing and promoter methylation were frequently detected in multiple carcinoma cell lines in a biallelic way, including 12/12 nasopharyngeal, 13/16 esophageal, 3/4 breast, 5/5 colorectal, 3/4 cervical, 2/5 lung and 2/8 hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell line. Aberrant methylation was further frequently detected in multiple primary carcinomas (82% in NPC, 42-51% for other carcinomas), but not normal tissues. The transcriptional silencing of PCDH10 could be reversed by pharmacologic demethylation with 5-aza-2'-deoxycytidine or genetic demethylation with double knockout of DNMT1 and DNMT3B, indicating a direct epigenetic mechanism. Ectopic expression of PCDH10 strongly suppressed tumor cell growth, migration, invasion and colony formation. Although the epigenetic and genetic disruptions of several classical cadherins as TSGs have been well documented in tumors, this is the first report that a widely expressed protocadherin can also function as a TSG that is frequently inactivated epigenetically in multiple carcinomas.