Carcinogenesis of nasopharyngeal carcinoma:an alternate hypothetical mechanism

Current proposed mechanisms implicate both early and latent Epstein-Barr virus(EBV)infection in the carcinogenic cascade,whereas epidemiological studies have always associated nasopharyngeal carcinoma(NPC)with early childhood EBV infection and with chronic ear,nose,and sinus conditions.Moreover,most patients with NPC present with IgA antibody titers to EBV capsid antigen(VCA-lgA),which can precede actual tumor presentation by several years.If early childhood EBV infection indeed constitutes a key event in NPC carcinogenesis,one would have to explain the inability to detect the virus in normal nasopharyngeal epithelium of patients at a high risk for EBV infection.It is perhaps possible that EBV resides within the salivary glands,instead of the epithelium,during latency.This claim is indirectly supported by observations that the East Asian phenotype shares the characteristics of an increased susceptibility to NPC and immature salivary gland morphogenesis,the latter of which is influenced by the association of salivary gland morphogenesis with an evolutionary variant of the human ectodysplasin receptor gene(EDAR),EDARV370A.Whether the immature salivary gland represents a more favorable nidus for EBV is uncertain,but in patients with infectious mononucleosis,EBV has been isolated in this anatomical organ.The presence of EBV-induced lymphoepitheliomas in the salivary glands and lungs further addresses the possibility of submucosal spread of the virus.Adding to the fact that the fossa of Rosen Muller contains a transformative zone active only in the first decade of life,one might be tempted to speculate the possibility of an alternative carcinogenic cascade for NPC that is perhaps not dissimilar to the model of human papillomavirus and cervical cancer.

A new prognostic histopathologic classification of nasopharyngeal carcinoma

Background:The current World Health Organization(WHO) classification of nasopharyngeal carcinoma(NPC) con?veys little prognostic information.This study aimed to propose an NPC histopathologic classification that can poten?tially be used to predict prognosis and treatment response.Methods:We initially developed a histopathologic classification based on the morphologic traits and cell differentia?tion of tumors of 2716 NPC patients who were identified at Sun Yat?sen University Cancer Center(SYSUCC)(training cohort).Then,the proposed classification was applied to 1702 patients(retrospective validation cohort) from hospitals outside SYSUCC and 1613 patients(prospective validation cohort) from SYSUCC.The efficacy of radiochemotherapy and radiotherapy modalities was compared between the proposed subtypes.We used Cox proportional hazards models to estimate hazard ratios(HRs) with 95% confidence intervals(CI) for overall survival(OS).Results:The 5?year OS rates for all NPC patients who were diagnosed with epithelial carcinoma(EC;3708 patients),mixed sarcomatoid?epithelial carcinoma(MSEC;1247 patients),sarcomatoid carcinoma(SC;823 patients),and squamous cell carcinoma(SCC;253 patients) were 79.4%,70.5%,59.6%,and 42.6%,respectively(P < 0.001).In mul?tivariate models,patients with MSEC had a shorter OS than patients with EC(HR = 1.44,95% CI = 1.27–1.62),SC(HR = 2.00,95% CI = 1.76–2.28),or SCC(HR = 4.23,95% CI = 3.34–5.38).Radiochemotherapy significantly improved survival compared with radiotherapy alone for patients with EC(HR 49–0.75),and possibly for those with SCC(HR = 0.67,95% CI = 0.56–0.80),MSEC(HR = 0.58,95% CI = 0..74–1.28).= 0.63;95% CI = 0.40–0.98),but not for patients with SC(HR = 0.97,95% CI = 0Conclusions:The proposed classification offers more information for the prediction of NPC prognosis compared with the WHO classification and might be a valuable tool to guide treatment decisions for subtypes that are associ?ated with a poor prognosis.

The impact of the COVID-19 pandemic on nasopharyngeal carcinoma patients-a national cancer centre experience

Purpose or objective The COVID-19 pandemic has resulted in significant healthcare implications,with care for can-cer patients compromised due to resource diversion towards battling the pandemic.We aim to investigate the impact of the peak wave of the pandemic in 2020 on the delivery of cancer care in Singapore,specifically via our nasopharyn-geal carcinoma(NPC)treatment data.This study applies real world numbers to the impact of COVID-19 on cancer care delivery in Singapore.The choice of nasopharyngeal cancer allows a good direct estimate of common treatment measures such as time to biopsy,time to staging scans,time to treatment commencement,due to its clear protocol and algorithms for staging and treatment;thus serving as an excellent surrogate for the effectiveness and timeliness of the different aspects of cancer care delivery.Materials and methods In this retrospective study,we included all patients with newly diagnosed NPC from 1st January to 31st May from 2017 to 2020 at our centre.This time period was chosen as it coincided with the period in 2020 during the COVID-19 pandemic where there was the most strain on healthcare resources and the most restrictions on population movement within Singapore,which may impact on healthcare seeking behaviour.Narrowing down the time period to the first 5 months of the 4 respective years also allowed us to reduce the effect of annual seasonal variation in patient numbers seen as a result of holidays and festive periods such as the Lunar New Year and scheduled school holidays.Electronic medical records(EMR)were accessed.Only newly diagnosed NPC cases were included in our analysis.Patients with second synchronous primary malignancies or NPC disease recurrence were excluded.Data analysis was carried out using a combination of SPSS and Microsoft Excel.Results Significantly,there was a reduction of 37-46.3%in newly diagnosed NPC cases during the peak of the COVID-19 pandemic from January to end May 2020 compared to the preceding three years.Despite the reduction in numbers of newly diagnosed NPC,there was no statistically significant differences in delay from biopsy to the first radiation oncology visit and from biopsy to the first day of treatment in 2020 compared to the preceding years.All the patients treated in our centre also received the standard NPC treatment for their disease stage as per international guidelines.Conclusion We recommend a heightened awareness of the dangers of delaying cancer presentation and care in healthcare policies and resource allocation and at the same time,encourage patient’s confidence in their ability to seek care.With the resurgence of new COVID-19 variants and case numbers worldwide and in Singapore,this study focuses upon the need to be aware of the exigencies of other clinical groups in resource utilization.It would be instructive to compare this study with future long term follow up to investigate the trajectory of our cancer care delivery,as well as survival outcomes.