Is the 1997 AJCC staging system for nasopharyngeal carcinoma prognostically useful for Chinese patient populations?

The 5th edition of the American Joint Committee on Cancer (AJCC) staging manual defines new rules for classifying nasopharyngeal carcinoma (NPC). The study was conducted to assess its effectiveness in predicting the prognosis for Chinese patient populations.

Between June 1993 and June 1994, 621 consecutively admitted patients with nondisseminated NPC were treated with definitive-intent radiation therapy alone. All had computed tomography of the nasopharynx, skull base, and the upper neck. A computer database containing all information for staging was formed on presentation. The extent of disease of each patient was restaged according to the 1997 AJCC system.

Of the 621 patients, The 5-year overall survival (OS) rate was 60%. The 1997 AJCC system creates subgroups (Stages I to IV) that are assigned to 38 (6.1%), 270 (43.5%), 157 (25.3%), and 156 (25.1%) patients, respectively. The incidence of parapharyngeal extension was 74.1% (460/621). Of these patients (460) with parapharyngeal extension, 310 (67.4%) patients were classified as T2b disease. The 1997 AJCC system showed highly significant differences between the overall stages for both OS and relapse-free survival (RFS). The 1997 AJCC T classifications showed significant correlation with local failure, and N classification was accurate in predicting FDM. Multivariate analysis showed that paraoropharyngeal involvement was an independently significant prognostic factor for OS, freedom from local recurrence (FLR), and freedom form distant metastasis (FDM).

The 1997 AJCC staging system for NPC is prognostically useful for Chinese patient populations. We proposed that subdivision of parapharyngeal extension should be included in future revisions of the staging system.     

Incorporation of perineural invasion of gastric carcinoma into the 7th edition tumor–node–metastasis staging system

The aim of this study was to determine the prognostic value of perineural invasion (PNI) in patients with gastric cancer who underwent curative resection. We retrospectively analyzed 518 patients who had undergone curative gastrectomy. Paraffin sections of surgical specimens from all patients were stained with hematoxylin and eosin. PNI was defined when carcinoma cells infiltrated into the perineurium or neural fascicles. Patients with PNI had a significantly larger tumors (≥5.0 cm), lymphatic venous invasion (positive), deeper tumor invasion (T4), more number of lymph node metastases (N3), and higher tumor stage (III). Regarding survival, multivariate analysis showed that PNI emerged as an independent prognostic factor for survival (hazard ratio (HR)?=?1.901, P?PNI and TNMIII_PNI stage both had lower ?2loglikelihood value (?2loglikelihood?=?3,306.608; ?2loglikelihood?=?2,535.151) and higher HR and 95 % CI (HR?=?1.879, 95 % CI?=?1.720–2.053; HR?=?2.268, 95 % CI?=?1.900–2.707), which represented the optimum prognostic stratification, together with better homogeneity, discriminatory ability. Our results showed that the frequency of PNI was high in patients with gastric cancer who underwent curative gastrectomy and the proportion of PNI positivity increased with progression and clinical stage of disease. PNI may be useful in detecting patients who had poor prognosis after curative resection in gastric cancer and it should be incorporated into TNM staging.     

基于鼻咽癌临床Ⅲ期探讨第8版AJCC/UICC分期系统

目的 基于调强放疗临床Ⅲ期鼻咽癌的生存分析中探讨第8版AJCC/UICC鼻咽癌分期系统。方法 2008-2014年在汕头大学医学院附属肿瘤医院首次治疗的 1351例鼻咽癌患者中按第7、8版标准重新分期,确定Ⅲ期患者分别为742、784例,将其各自分为3个亚组:T3N0-1期为 G1(226、245例),T1-2N2期为 G2(180、187例),T3N2期为G3(336、352例)。Kaplan-Meier法分别计算3个组 5年总生存(OS)、无进展生存(PFS)、无远处转移生存(DMFS)、无局部区域复发生存(LRRFS),并log-rank检验组间差异。结果 第8版病例中93.6%与第7版的相同。第8版与第7版总体的OS、PFS、DMFS、LRRFS分别为84.8%与85.4%、76.2%与77.0%、80.4%与81.3%、89.8%与90.6%(P均>0.05)。第8版分期3个亚组的OS、PFS和DMFS均不同(P均<0.001);G1与 G2、G1与G3也不同(P均<0.05),G2与G3间相近(P=0.183、0.310、0.248)。结论 第8版AJCC/UICC分期系统对临床Ⅲ期病例的分布特点及临床终点相对于第7版变化不大,亚组间仍有明显的组内生存风险分布差异,其中N2对Ⅲ期患者的生存风险评估起到主要作用。可能在IMRT联合化疗时代局部肿瘤对预后的影响已经减弱,第8版分期系统仍然有改进的空间。     

The role of concurrent chemotherapy in intensity-modulated radiotherapy for patients with stage Ⅲ nasopharyngeal carcinoma

Objective To investigate the clinical efficacy of concurrent chemotherapy in intensity-modulated radiotherapy (IMRT) for patients with stage Ⅲ nasopharyngeal carcinoma (NPC). Methods Clinical data of 251 patients with stage Ⅲ NPC treated with IMRT alone or concurrent chemoradiotherapy (CCRT) at Sun Yat-sen University Cancer Center from February 2001 to December 2008 were retrospectively analyzed. The prognostic factors of NPC were analyzed and the efficacy of CCRT was assessed. The survival rate was calculated by Kaplan-Meier method. The differences between two groups were analyzed by log-rank test. The prognostic factors were analyzed by Cox model. Results The 10-year locoregional-free survival (LRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) for NPC patients were 88.6%, 81.1%, 68.8% and 75.1%, respectively. Univariate and multivariate analyses demonstrated that N staging and nasopharyngeal tumor volume were the most important prognostic factors, and concurrent chemotherapy significantly improved PFS and OS (both P<0.05). In T3N0-1 patients, there was no significant difference in survival indexes between IMRT alone and CCRT (10y-LRFS:93.8% vs. 93.2%, P=0.933;10y-DMFS:80.9% vs. 86.8%, P=0.385;10y-PFS:70.6% vs. 77.7%, P=0.513;10y-OS:71.8% vs. 83.6%, P=0.207). For T1-3N2 patients, CCRT was significantly better than radiotherapy alone in LRFS, PFS, and OS (10y-LRFS:87.3% vs. 66.7%, P=0.016;10y-PFS:70.2% vs. 41.0%, P=0.003;10y-OS:78.5% vs. 51.7%, P=0.008), whereas there was an increasing trend in DMFS (10y-DMFS:80.3% vs. 66.4%, P=0.103). Conclusions Concurrent chemotherapy can improve clinical prognosis of stage Ⅲ NPC patients, and the most survival benefits are obtained in the N2 group. Individualized treatment options should be delivered based on the risk of treatment failure.     

The clinical trial research of preoperative induced hypertension chemotherapy on the Ⅲ staging cardia or fundus of stomach carcinoma

Objective： To observation the therapeutic effect and the adverse reaction of preoperative induced hypertension chemotherapy （IHC） on the Ⅲ staging cardia or fundus of stomach carcinoma. Methods： 49 cases of the Ⅲ staging cardia or fundus of stomach carcinoma were divided into two groups at random. The observation group included 19 cases and the control group included 30 cases. Every case used one cycle chemotherapy. The observation group （IHC group） used chemotherapy and AT Ⅱ. The control group （simple chemotherapy group） used simple chemotherapy. All cases of the two groups operated after 3 weeks rest. The specimen＇s DNA was analyzed by flow cytometry. Results： The effective power of observation group was 63.2% （12/19）, exairesis ratio was 84.2% （16/19）. The effective power of control group was 30% （9/30）, exairesis ratio was 63.3% （19/30）. DNA ploid determination： 13 cases were diploid and 5 cases were heteropioid in the observation group, 9 cases were diploid and 16 cases were heteroploid in the control group. The operative complications and risks of the two groups did not increase. Conclusion： IHC can increase the therapeutic effect of Ⅲ staging cardia or fundus of stomach carcinoma obviously. IHC is one of the chemotherapy methods that have good future, it has good value of clinic enlarge trial.     

Potential factors associated with clinical stage of nasopharyngeal carcinoma at diagnosis:a case–control study

Background: In China, most patients with nasopharyngeal carcinoma (NPC) are diagnosed at a late stage and con-sequently have a poor prognosis. This study aimed to investigate potential factors associated with the clinical stage of NPC at diagnosis. Methods: Data were obtained from 118 patients with early-stage NPC and 274 with late-stage NPC who were treated at Sun Yat-sen University Cancer Center between August 2014 and July 2015. Patients were individually matched by age, sex, and residence, and a conditional logistic regression model was applied to assess the associa-tions of clinical stage at diagnosis with socioeconomic status indicators, knowledge of NPC, physical examinations, patient interval, and risk factors for NPC. Results: Although knowledge of early NPC symptoms, smoking cessation, and patient interval were important fac-tors, the number of cigarettes smoked per day, motorbike ownership, and physical examination exhibited the strong-est associations with the clinical stage of NPC at diagnosis. Compared with smoking fewer than ten cigarettes a day, smoking 10–30 cigarettes [odds ratio (OR) 4.03; 95% confidence interval (CI) 1.11–14.68] or more than 30 cigarettes (OR 11.46; 95% CI 1.26–103.91) was associated with an increased risk of late diagnosis. Compared with not owning a motorbike, owning a motorbike (OR 0.38; 95% CI 0.23–0.64) was associated with early diagnosis. Subjects who under-went physical examinations were less likely to receive a late diagnosis than those who did not undergo examinations (OR 0.50; 95% CI 0.28–0.89). However, indicators of wealth were not significant factors. Conclusions: Initiatives to improve NPC patient prognosis should aim to promote knowledge about early symptoms and detection, health awareness, and accessibility to health facilities among all patients, regardless of socioeconomic status.     

Prognostic scoring system for stage IV colorectal cancer: is the AJCC sub-classification of stage IV colorectal cancer appropriate?

Background

Stage IV colorectal cancer encompasses various clinical conditions. The aim of this study was to validate the utility of the recent AJCC stage IV colorectal cancer sub-classification, and to establish a prognostic scoring system using independent factors.

Methods

We conducted a retrospective analysis using data from the multicenter registry. Factors affecting the curative resection and prognosis were analyzed in patients with stage IV colorectal cancer.

Results

Of the 60,176 patients who received surgery for colorectal cancer, 9,624 (16.0 %) were classified as stage IV. The prognoses of patients with peritoneum-only metastasis were superior to those of patients with a stage IVB (P < 0.0001). Of the 11 independent prognostic factors identified, eight with a hazard ratio greater than 1.3 (depth of tumor invasion, regional lymph node metastasis, histologic grade, liver metastasis, lung metastasis, distant lymph node metastasis, peritoneal metastasis, and curative resection) were used in the prognostic scoring system. The scoring system gave one or two points for the presence of each prognosis risk factor, resulting in a total score ranging from 0 to 9. The 5-year overall survival rates of patients with a total score of 0–2, 3, 4, 5, and 6–9 were 50.4, 30.4, 17.7, 7.7, and 4.0 %, respectively (P < 0.0001).

Conclusion

Although the AJCC staging for patients with stage IV colorectal cancer reflected the prognosis, patients with peritoneum-only metastases should be classified as stage IVA. The prognostic scoring system using eight independent factors is useful in predicting the survival of patients with stage IV colorectal cancer.     

The addition of pretreatment plasma Epstein–Barr virus DNA into the eighth edition of nasopharyngeal cancer TNM stage classification

The eighth edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) stage classification (TNM) for nasopharyngeal carcinoma (NPC) was launched. It remains unknown if incorporation of nonanatomic factors into the stage classification would better predict survival. We prospectively recruited 518 patients with nonmetastatic NPC treated with radical intensity-modulated radiation therapy ± chemotherapy based on the eighth edition TNM. Recursive partitioning analysis (RPA) incorporating pretreatment plasma Epstein–Barr virus (EBV) DNA derived new stage groups. Multivariable analyses to calculate adjusted hazard ratios (AHRs) derived another set of stage groups. Five-year progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS) were: Stage I (PFS 100%, OS 90%, CSS 100%), II (PFS 88%, OS 84%, CSS 95%), III (PFS 84%, OS 84%, CSS 90%) and IVA (PFS 71%, OS 75%, CSS 80%) (p < 0.001, p = 0.066 and p = 0.002, respectively). RPA derived four new stages: RPA-I (T1–T4 N0–N2 & EBV DNA <500 copies per mL; PFS 94%, OS 89%, CSS 96%), RPA-II (T1–T4 N0–N2 & EBV DNA ≥500 copies per mL; PFS 80%, OS 83%, CSS 89%), RPA-III (T1–T2 N3; PFS 64%, OS 83%, CSS 83%) and RPA-IVA (T3–T4 N3; PFS 63%, OS 60% and CSS 68%) (all with p < 0.001). AHR using covariate adjustment also yielded a valid classification (I: T1–T2 N0–N2; II: T3–T4 N0–N2 or T1–T2 N3 and III: T3–T4 N3) (all with p < 0.001). However, RPA stages better predicted survival for PS and CSS after bootstrapping replications. Our RPA-based stage groups revealed better survival prediction compared to the eighth edition TNM and the AHR stage groups.     

基于SEER数据库的大样本人群中UICC/AJCC第8版分期鼻咽癌Ⅲ期预后分析

[目的]基于鼻咽癌第7版与第8版UICC/AJCC(Union for International Cancer Control,UICC/American Joint Committee on Cancer,AJCC)分期,对流行病学和结局数据库(Surveillance,Epidemiology,and End Results Program,SEER)人群的预后进行回顾性分析,验证和比较两版分期系统对鼻咽癌人群,特别是Ⅲ期人群的分期效果。[方法]纳入SEER数据库2010—2019年鼻咽癌患者,利用Kaplan-Meier生存曲线分析总生存情况,用Log-rank检验检测组间生存差异,Cox回归分析总生存相关预后影响因素,评价指标为风险比及P值。用时间依赖ROC曲线、AUC值评估变量对于生存结局的预测效能。[结果]对于总分期,第7版、第8版2年生存率AUC值分别为0.65、0.75,T分期分别为0.65、0.72,N分期分别为0.53、0.57。对于Ⅲ期人群,第7版分期组内存在生存差异(P<0.05),而第8版分期除T₁N₂M     

Magnetic resonance imaging as a supplement for the clinical staging system of Durie and Salmon?

BACKGROUND: This study evaluated the prognostic value of a three-grade staging system of spinal involvement using magnetic resonance imaging (MRI) in patients with multiple myeloma and determined its usefulness as an independent parameter in the staging system of Durie and Salmon. METHODS: Seventy-seven previously untreated patients with multiple myeloma underwent MRI of the thoracic and lumbar spine with unenhanced T1-weighted spin echo and short-tau inversion time inversion recovery sequences. The patients were evaluated according to their infiltration patterns and the extent of bone marrow involvement was staged using a three-grade scale: Stage I, no focal or diffuse infiltration; Stage II, 1-10 foci or mild diffuse infiltration; Stage III, more than 10 foci or strong diffuse infiltration. RESULTS: The infiltration patterns had no significant effect on survival. Of 77 patients, 25 would have been understaged using the standard staging system of Durie and Salmon without the findings of MRI and 8 patients would have been understaged if the staging was based only on MRI. The combination of the staging system of Durie and Salmon and MRI was highly significant with respect to survival (P < 0.0001, log rank analysis). MRI staging I-III was independent of the staging system of Durie and Salmon (Cox regression model). CONCLUSIONS: A three-grade staging of spinal MRI provides a significant prognostic tool for patients with multiple myeloma. The authors propose including it in the staging system of Durie and Salmon.     

The clinical trial research of preoperative induced hypertension chemotherapy on the III staging cardia or fundus of stomach carcinoma

Objective: To observation the therapeutic effect and the adverse reaction of preoperative induced hypertension chemotherapy (IHC) on the III staging cardia or fundus of stomach carcinoma. Methods: 49 cases of the III staging cardia or fundus of stomach carcinoma were divided into two groups at random. The observation group included 19 cases and the control group included 30 cases. Every case used one cycle chemotherapy. The observation group (IHC group) used chemotherapy and AT II. The control group (simple chemotherapy group) used simple chemotherapy. All cases of the two groups operated after 3 weeks rest. The specimen’s DNA was analyzed by flow cytometry. Results: The effective power of observation group was 63.2% (12/19), exairesis ratio was 84.2% (16/19). The effective power of control group was 30% (9/30), exairesis ratio was 63.3% (19/30). DNA ploid determination: 13 cases were diploid and 5 cases were heteroploid in the observation group, 9 cases were diploid and 16 cases were heteroploid in the control group. The operative complications and risks of the two groups did not increase. Conclusion: IHC can increase the therapeutic effect of III staging cardia or fundus of stomach carcinoma obviously. IHC is one of the chemotherapy methods that have good future. It has good value of clinic enlarge trial.     

Tumor–ratio–metastasis staging system as an alternative to the 7th edition UICC TNM system in gastric cancer after D2 resection—results of a single-institution study of 1343 Chinese patients

BackgroundIn this study, we assessed the prognostic value of the lymph node ratio (LNR), established a hypothetical tumor–ratio–metastasis (TRM) staging system and compared it with the 7th edition International Union Against Cancer pathological N (pN) and tumor–node–metastasis (TNM) system.Patients and methodsA total of 1343 gastric cancer patients undergoing D2 resection were staged using the TRM staging system and the 7th edition TNM system. Optimal cut points of LNR were calculated using X-tile software and validated by bootstrapping. Homogeneity, discriminatory ability, and monotonicity of gradients of the TRM and TNM systems were compared using linear trend χ², likelihood ratio χ² statistics, and Akaike information criterion (AIC) calculations.ResultsOptimal cut points classified patients into LNR0 (0%), LNR1 (1%–30%), LNR2 (31%–60%), and LNR3 (61%–100%) groups. In univariate, multivariate and stratified analyses, the LNR staging showed superiority to the 7th edition pN staging. The TRM staging system had higher linear trend and likelihood ratio χ² scores and smaller AIC values compared with those for the TNM system, which represented the optimum prognostic stratification.ConclusionsThe novel TRM staging system predicts survival of gastric cancer more accurately than the 7th edition TNM system. It may be considered as an alternative to TNM system.     

Trimodality therapy of esophagectomy plus neoadjuvant chemoradiotherapy improves the survival of clinical stage II/III esophageal squamous cell carcinoma patients

The prognosis of advanced esophageal cancer patients is poor. Trimodality therapy of surgical resection plus neoadjuvant chemoradiotherapy (CRT) has been developed to improve survival through locoregional control, leading to prevention of micrometastasis. We investigated whether or not neoadjuvant CRT led to survival benefits in TNM stage?II/III esophageal cancer patients. We retrospectively reviewed 62 patients with stage II or III esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant CRT. All patients received esophagectomy 4-7 weeks after CRT consisting of 40?Gy irradiation and chemotherapy (5-FU, 500?mg/m2/day, days 1-5 and cisplatin, 10-20?mg/body, days 1-5). Clinical response and survival rates were analyzed using Kaplan-Meier methods, with p<0.05 considered as significant. The clinical effect rate of CRT for both primary tumors and metastatic nodes was 82.3%. Operative and hospital mortality rates were 1.65 and 6.5%, respectively. The 3-year overall survival (OS) and disease-free survival (DFS) rates were 52.6 and 49.2%, respectively. A significant difference was noted between stages?II and III for both OS and DFS. The 5-year OS rates were 64.2% for stage II, 33.1% for stage III (T4 and non-T4) and 46.9% for stage III (non-T4 only) patients. The depth of tumor invasion (T3 vs. T4), resectability (R0 vs. R1, R2), lymph node metastasis (positive vs. negative), and the effect of CRT were proven to be independent prognostic factors for univariate analysis, with resectability and the effect of CRT for multivariate analysis. These data suggest that CRT in stage II/III (non-T4) ESCC patient contributed to tumor shrinkage, leading to higher resectability and longer survival. Neoadjuvant CRT appears to be a promising option for these patients.     

Efficacy of Yanshu injection (a compound Chinese traditional medicine) combined with concurrent radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma

Objective To evaluate the efficacy and toxicity of Yanshu injection (a compound Chinese traditional medicine from Sophora flauescens Ait) combined with concomitant radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma. Methods Sixty patients with stage Ⅲ nasopharyngeal carcinoma were randomized into Yanshu group and control group (n =30, each). Patients in the Yanshu group received Yanshu injection in addition to intensity modulated radiation therapy ( IMRT) and concomitant chemotherapy, and those in the control group were treated with IMRT and concurrent chemotherapy. Results The 1-year, 2-year, 3-year and 4-year overall survival rates were 100%, 93.3%, 86.7% , 80. 0% for Yanshu group, and 96. 7% , 90. 0% , 83. 3% , 76. 7% for the control group, respectively, with no significant difference between the two groups ( P = 0.565). The 1 -year, 2-year, 3-year and 4-year progression-free survival rates were 96.7% , 90. 0% , 83. 3% , 70. 0% for Yanshu group, and 90.0% , 86.7% , 76. 7% , 66. 7% for control group, respectively, with no significant difference (P = 0.554). However, the reaction of mucosa of oral cavity, myelosuppression and thrombocytopenia in the Yanshu group were significantly lower than that in the control group (P < 0. 05). The quality of life of the patients in the Yanshu group was significantly higher than that in the control group ( P < 0. 05 ). Conclusions Yanshu injection combined with radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma show a good efficacy and can reduce the side effects of radiochemotherapy of nasopharygeal carcinoma, and improve the quality of life of the patients.     

Efficacy of Yanshu injection (a compound Chinese traditional medicine) combined with concurrent radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma

Objective To evaluate the efficacy and toxicity of Yanshu injection (a compound Chinese traditional medicine from Sophora flauescens Ait) combined with concomitant radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma. Methods Sixty patients with stage Ⅲ nasopharyngeal carcinoma were randomized into Yanshu group and control group (n =30, each). Patients in the Yanshu group received Yanshu injection in addition to intensity modulated radiation therapy ( IMRT) and concomitant chemotherapy, and those in the control group were treated with IMRT and concurrent chemotherapy. Results The 1-year, 2-year, 3-year and 4-year overall survival rates were 100%, 93.3%, 86.7% , 80. 0% for Yanshu group, and 96. 7% , 90. 0% , 83. 3% , 76. 7% for the control group, respectively, with no significant difference between the two groups ( P = 0.565). The 1 -year, 2-year, 3-year and 4-year progression-free survival rates were 96.7% , 90. 0% , 83. 3% , 70. 0% for Yanshu group, and 90.0% , 86.7% , 76. 7% , 66. 7% for control group, respectively, with no significant difference (P = 0.554). However, the reaction of mucosa of oral cavity, myelosuppression and thrombocytopenia in the Yanshu group were significantly lower than that in the control group (P < 0. 05). The quality of life of the patients in the Yanshu group was significantly higher than that in the control group ( P < 0. 05 ). Conclusions Yanshu injection combined with radiochemotherapy in patients with stage Ⅲ nasopharyngeal carcinoma show a good efficacy and can reduce the side effects of radiochemotherapy of nasopharygeal carcinoma, and improve the quality of life of the patients.     

Pathologic study of tumour extension for clinically localized unilateral nasopharyngeal carcinoma: Should the contralateral side be included in the clinical target volume?

Introduction

The clinical target volume (CTV) delineation is crucial for tumour control and normal tissue protection. This study investigated the contralateral extension of nasopharyngeal carcinoma (NPC) in patients with a clinically diagnosed unilateral tumour to pursue the possibility of CTV reduction.

Methods

Twenty NPC patients with localized tumours confined to only one side of the nasopharynx as shown by magnetic resonance imaging and fibreoptic endoscopy were selected for biopsy. The tissues of the contralateral pharyngeal recess (CPR) and the contralateral posterosuperior wall (CPSW) of the nasopharynx were obtained in each case and prepared for pathological examination. The factors associated with contralateral tumour infiltration were analysed.

Results

Five of 20 (25.0%) patients were pathologically confirmed to have carcinoma cell infiltration in the CPSW, including 2 (10.0%) that had carcinoma cell infiltration in the CPR. The T classification (P = 0.014) and primary tumour volume (P = 0.033) were positively associated with the infiltration of the CPSW, but none of the primary tumour factors affected the involvement of the CPR. The contralateral retropharyngeal lymph node (LN) metastasis (P = 0.016), but not the contralateral cervical LN, was significantly associated with the infiltration of the CPR. Positive Epstein–Barr virus DNA (EBV‐DNA) was another factor that increased the probability of CPR invasion (P = 0.044).

Conclusions

Contralateral pharyngeal recess infiltration is rare in patients with clinically diagnosed unilateral primary NPC. Reduced CTV coverage, including the CPSW but not CRP, is feasible for patients with unilateral cancer of the nasopharynx without contralateral LN metastasis or positive EBV‐DNA. Further large‐sample studies are needed.