A risk score model for the metastasis of level Ib lymph node based on the clinicopathological features of nasopharyngeal carcinoma in a large sample

Neck level Ib-sparing versus level Ib-irradiation in intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma with high-risk factors: A propensity score-matched cohort study

AIM

Level Ib lymph nodes metastasis is rare in nasopharyngeal carcinoma (NPC). We aimed to evaluate the feasibility of sparing level Ib-irradiation in NPC patients with high-risk factors.

MATERIALS AND METHODS

Four hundred forty-three NPC patients with radiologic extranodal extension (rENE) or level II lymph node maximal axial diameter (MAD) ≥ 20 mm treated by intensity-modulated radiotherapy (IMRT) between 2009 and 2012 were included in this study. Propensity score matching (PSM) was applied to balance potential prognostic factors (including age, sex, T and N stage, pretreatment EBV DNA level, and level II rENE and MAD) between patients who received and omitted level Ib irradiation. Kaplan-Meier analysis and the log-rank test were used to compare regional survival outcomes.

RESULTS

PSM resulted in 169 matched pairs of eligible patients. The median follow-up period was 119 months in the matched cohort. The number of level Ib failure in the level Ib-sparing and level-Ib irradiation groups were 3/169 (1.8 %) vs 2/169 (1.2 %), P > 0.999. And the 5-year regional relapse-free survival (RRFS) rates of the two groups were 88.4 % vs 92.6 %, respectively. After PSM, RRFS (hazard ratio [HR]: 1.508, 95 % confidence interval [CI]: 0.762-2.986, P = 0.239), OS (HR: 1.219, 95 % CI: 0.754-1.972, P = 0.418), distant metastasis-free survival (DMFS) (HR: 1.605, 95 % CI: 0.900-2.863, P = 0.109), and local relapse-free (LRFS) (HR: 0.956, 95 % CI: 0.436-2.095, P = 0.910) were similar in the two arms. The incidence of grade ≥ 1 dry mouth after 5 years was higher in the level Ib-irradiation group (27.5 % vs 16.5 %, P = 0.029). However, the incidences of grade 3-4 late toxicities were similar between the two groups.

CONCLUSION

Neck level Ib-sparing appears to be safe and feasible in NPC patients with rENE or level II MAD ≥ 20 mm and negative level Ib lymph nodes. Compared with cervical level Ib-irradiation, omission of irradiation to level Ib provides less dry mouth symptom.

Delineation of neck node levels for patients with locally advanced supraglottic cancer receiving radical intensity-modulated radiotherapy: a cross-sectional study in Mainland China

Background: To survey the diversity of clinical target volumes (CTVs) for locally advanced supraglottic cancer (LA-SGC) with radical radiotherapy in mainland China. Methods: Radiation oncologists from 30 provinces and four representative cases (T2N1, T3N2b, T4N0, T4N2c) were included. Results: High risk (HR)-CTV included involved and the lower adjacent level was followed by most physicians (n = 160, 97.6%). In the N0-1 stage, whether contralateral levels II-III should be included in HR- or low risk (LR)-CTV was controversial. In the N2 stage, the bilateral levels II-IVb were included in LR-CTV (75-92.5% agreement). Levels Ib, V or VIb were included in CTV requiring certain conditions. Conclusion: Involved and lower adjacent levels were as HR-CTV. Whether bilateral levels II-IV are included in HR- or LR-CTV remain controversial.

Level Ib sparing intensity-modulated radiation therapy in selected nasopharyngeal carcinoma patients based on the International Guideline

BACKGROUND AND PURPOSE

To investigate the feasibility of level Ib sparing in selected nasopharyngeal carcinoma (NPC) patients during intensity-modulated radiation therapy (IMRT) based on the International Guideline.

PATIENTS AND MATERIALS

Patients with histologically-proven NPC who received definitive IMRT at our group were candidates for this analysis. Other eligibility criteria for analysis were designed according to the recommendation of International Guideline for selective coverage of level Ib. Survival outcomes focused on regional recurrence-free survival (RRFS) and level Ib recurrence rate were analyzed.

RESULTS

A total of 450 patients were included, 60 of them received level Ib-covering IMRT due to the first three principles of the International Guideline according to our protocol. Of note, patients with level Ib involvement would receive ultrasound guided puncture, only those with positive pathological results would undergo level Ib-covering IMRT. For the remaining 390 patients who only fulfilled the last two criteria and/or level Ib involvement with negative pathological results, level Ib-sparing IMRT was delivered, with a median follow-up time of 112 months (range 6 to 194 months), reported 5- and 10-year RRFS were 95.4% and 92.9%, respectively. Twenty-two patients occurred regional recurrence at censorship (median 44.5 months), only 4(4/390, 1.03%) were recorded as level Ib recurrence.

CONCLUSION

Level Ib-sparing IMRT should be safe and feasible for patients who only had level II involvement with ECE, and/or had a MAD of greater than 2 cm in level II, and/or level Ib involvement with negative pathological results. Further well-designed multi-center prospective trials should be conducted.

Contemporary management of the neck in nasopharyngeal carcinoma

Up to 85% of the patients with nasopharyngeal carcinoma present with regional nodal metastasis. Although excellent nodal control is achieved with radiotherapy, a thorough understanding of the current TNM staging criteria and pattern of nodal spread is essential to optimize target delineation and minimize unnecessary irradiation to adjacent normal tissue. Selective nodal irradiation with sparing of the lower neck and submandibular region according to individual nodal risk is now emerging as the preferred treatment option. There has also been continual refinement in staging classification by incorporating relevant adverse nodal features. As for the uncommon occurrence of recurrent nodal metastasis after radiotherapy, surgery remains the standard of care.

Implication of viral microRNAs in the genesis and diagnosis of Epstein-Barr virus-associated tumors

The Epstein-Barr virus (EBV) is tightly associated with a variety of human tumors, including Burkitt lymphoma and acquired immune deficiency syndrome-related lymphoma of B-cell origin, as well as nasopharyngeal carcinoma and gastric cancer of epithelial origin. The virus latently infects the host cells and expresses proteins and non-coding RNAs to achieve malignancy. MicroRNAs (miRNAs or miRs) are small RNAs consisting of 19-25 nucleotides, which directly bind to the 3'-untranslated region of mRNAs to promote degradation and inhibit translation of mRNAs. EBV-encoded miRs are generated from two regions of the viral genome, within the apoptosis regulator BHRF1 gene locus and near the BamHI A region in a latency type-dependent manner. In addition, EBV-encoded miRs epigenetically regulate the expression of molecules that are effectors of the cell cycle progression, migration, apoptosis and innate immunity, serving a vital role in supporting viral replication and occurrence of EBV-associated tumors. The feasibility of using such miRs as biomarkers for the diagnosis and prognosis of EBV-associated tumors is currently under investigation.

Risk factors and distribution features of level IB lymph nodes metastasis in nasopharyngeal carcinoma

OBJECTIVE

The objective of this study is to investigate the risk factors and distribution features for level IB metastasis in nasopharyngeal carcinoma (NPC) and provide clinical evidence for defining the indications and clinical target volume (CTV) of prophylactic level IB irradiation.

METHODS

We retrospectively analyzed 798 patients with newly-diagnosed, non-metastatic and histologically confirmed NPC underwent intensity-modulated radiation therapy (IMRT). Two sides of neck in each patient have been analyzed separately. The correlations of level IB metastasis and the clinical risk factors were analyzed with Chi-square test and logistic regression model. The risk score model (RSM) of level IB metastasis was calculated by totaling up the scores of each independent variable. We divided level IB into three areas, including anterolateral space of submandibular glands, medial space of the submandibular glands and submandibular glands.

RESULTS

Maximal axial diameter (MAD) of level IIA nodes >20mm or extra capsular spread (ES) of level IIA nodes, anterior half of nasal cavity involvement and submandibular gland involvement/compression were independently significantly risk factors for level IB lymph nodes (LNs) metastasis at diagnosis. Two groups based on RSM were obtained: low risk (total score=0-2.5); high risk (4-8.5). The incidence of IB LNs metastasis at diagnosis of the two groups were 0.9% and 6.3%, respectively (P<0.001). The cervical lymph nodes of level IB were distributed in the anterolateral space of submandibular glands. There was no positive/negative LNs inside or medial space of the submandibular glands.

CONCLUSION

Level IB LNs metastasis is associated with MAD of level IIA nodes >20mm or ES of level IIA nodes, anterior half of nasal cavity involvement and submandibular gland involvement/compression in NPC patients. Omission of level IB irradiation may be feasible for patients with low-risk IB LNs metastasis at diagnosis. The submandibular gland should not be included in level IB.

The feasibility analysis of omission of elective irradiation to level IB lymph nodes in low-risk nasopharyngeal carcinoma based on the 2013 updated consensus guideline for neck nodal levels

Background

Level IB metastasis is rare in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the high-risk factors for level IB metastasis and evaluate the feasibility of omission of elective irradiation to level IB in the low-risk subgroups in NPC.

Methods

This retrospective study identified 532 patients with NPC treated by definitive radiation in our institution from 2009 to 2010. Level IB nodes were electively irradiated based on the physician’s decision. Diagnostic head and neck MRIs were reviewed. The involvements of nodal levels were evaluated according to 2013 updated guidelines of RTOG. The correlations of level IB metastasis and other factors were studied using Chi-square test and logistic regression model. Log-rank tests were used to compare survival rates. Cox proportional-hazards models were used to evaluate the effect of various factors. Patient-reported xerostomia was recoded in every follow-up and the extents of delayed xerostomia at 1 year post-radiation were compared between those with/without elective level IB irradiation.

Results

N stage, bilateral nodal metastasis, level II involvement, level IIA involvement, level IIA with multiple levels involvement, maximal axial diameter (MAD) of level IIA nodes > 20 mm, MAD of neck lymph nodes > 30 mm, necrosis of level IIA nodes, extracapsular spread of level IIA correlated with level IB metastasis by univariate analysis. In multivariate analysis (MVA), bilateral nodal involvement, MAD of level IIA nodes > 20 mm or extracapsular spread of level IIA nodes, were independent predictive factors for level IB metastasis. Patients without either these factors were denoted low-risk group and the rest high-risk group. Of the low-risk group, there was no significant difference of regional control and overall survival (OS) between those with or without elective irradiation. The percentage of level IB recurrence of those without elective irradiation was 0.46%. Elective level IB irradiation was not significant upon MVA both for regional control and OS. Of the high-risk group, elective level IB irradiation was marginal significant for regional control, but not for OS upon MVA. No regional recurrence located at level IB. Overall, omission of elective irradiation to level IB reduced the mean doses of submandibular glands, but did not improve patient-reported xerostomia.

Conclusion

For patients without high-risk factors of level IB metastasis, omission of elective level IB irradiation did not impair regional control and OS in NPC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-017-0869-x) contains supplementary material, which is available to authorized users.

Comparative diagnostic value of 18F-fluoride PET-CT versus MRI for skull-base bone invasion in nasopharyngeal carcinoma

PURPOSE

This study compared the diagnostic value of F-fluoride PET-computed tomography (PET-CT) and MRI in skull-base bone erosion in nasopharyngeal carcinoma (NPC) patients.

METHODS

A total of 93 patients with biopsy-confirmed NPC were enrolled, including 68 men and 25 women between 23 and 74 years of age. All patients were evaluated by both F-fluoride PET-CT and MRI, and the interval between the two imaging examinations was less than 20 days. The patients received no treatment either before or between scans. The studies were interpreted by two nuclear medicine physicians or two radiologists with more than 10 years of professional experience who were blinded to both the diagnosis and the results of the other imaging studies. The reference standard was skull-base bone erosion at a 20-week follow-up imaging study.

RESULTS

On the basis of the results of the follow-up imaging studies, 52 patients showed skull-base bone erosion. The numbers of true positives, false positives, true negatives, and false negatives with F-fluoride PET-CT were 49, 4, 37, and 3, respectively. The numbers of true positives, false positives, true negatives, and false negatives with MRI were 46, 5, 36, and 6, respectively. The sensitivity, specificity, and crude accuracy of F-fluoride PET-CT were 94.23, 90.24, and 92.47%, respectively; for MRI, these values were 88.46, 87.80, and 88.17%. Of the 52 patients, 43 showed positive findings both on F-fluoride PET-CT and on MRI. Within the patient cohort, F-fluoride PET-CT and MRI detected 178 and 135 bone lesions, respectively.

CONCLUSION

Both F-fluoride PET-CT and MRI have high sensitivity, specificity, and crude accuracy for detecting skull-base bone invasion in patients with NPC. F-fluoride PET-CT detected more lesions than did MRI in the skull-base bone. This suggests that F-fluoride PET-CT has a certain advantage in evaluating the skull-base bone of NPC patients. Combining the two methods could improve the diagnostic accuracy of skull-base bone invasion for NPC.

Investigation of the feasibility of elective irradiation to neck level Ib using intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma: a retrospective analysis

BACKGROUND

To assess the feasibility of elective neck irradiation to level Ib in nasopharyngeal carcinoma (NPC) using intensity-modulated radiation therapy (IMRT).

METHODS

We retrospectively analyzed 1438 patients with newly-diagnosed, non-metastatic and biopsy-proven NPC treated with IMRT.

RESULTS

Greatest dimension of level IIa LNs (DLN-IIa) ≥ 20 mm and/or level IIa LNs with extracapsular spread (ES), oropharynx involvement and positive bilateral cervical lymph nodes (CLNs) were independently significantly associated with metastasis to level Ib LN at diagnosis. No recurrence at level Ib was observed in the 904 patients without these characteristics (median follow-up, 38.7 months; range, 1.3-57.8 months), these patients were classified as low risk. Level Ib irradiation was not an independent risk factor for locoregional failure-free survival, distant failure-free survival, failure-free survival or overall survival in low risk patients. The frequency of grade ≥ 2 subjective xerostomia at 12 months after radiotherapy was not significantly different between low risk patients who received level Ib-sparing, unilateral level Ib-covering or bilateral level Ib-covering IMRT.

CONCLUSION

Level Ib-sparing IMRT should be safe and feasible for patients without a DLN-IIa ≥ 20 mm and/or level IIa LNs with ES, positive bilateral CLNs or oropharynx involvement at diagnosis. Further investigations based on specific criteria for dose constraints for the submandibular glands are warranted to confirm the benefit of elective level Ib irradiation.

Safety and efficacy study of nasopharyngeal cancer stem cell vaccine

In this trial, nasopharyngeal cancer stem cells (CSCs) were separated and cultured to produce a vaccine; its safety and efficacy were prospectively evaluated in low-, medium-, and high-dose groups. Between April and September 2014, we enrolled 90 patients who met the enrolment criteria, and assigned them to three groups (n=30). Throughout the trial, injection site reaction was the most common reaction (81%), and fever was least common (31%); however, there was no difference among the three groups. When the immune responses pre- and post-vaccination were compared, we found that the CSC-specific and -nonspecific response in the medium- and high-dose groups were both significantly enhanced. This study is the first clinical trial of a nasopharyngeal CSC vaccine and preliminarily proves its safety and efficacy.