Currently, the features and prognosis of nasopharyngeal carcinoma (NPC) with distant metastases are still rarely reported. Thus, the main purpose of our study was to investigate the metastasis patterns of different histological types of NPC and to clarify the prognostic characteristics of metastases at different sites. Patients were enrolled from the SEER program from 2010 to 2016. Chi‐squared tests were used to compare features between groups. The tendency to develop combined metastases was assessed with the odds ratio. The Kaplan‐Meier method was used for the survival analysis. Univariate and multivariate Cox analyses were used to select the independent prognostic risk factors for inclusion in the nomogram. In the present study, we found the following: (1) tumors are highly likely to metastasize if they have a larger volume, the regional lymph nodes are relatively large, or the regional lymph nodes are biopsied but not removed; (2) the bone and the brain were the most and least common metastatic sites among all histological types and N stages. Metastasis at two sites was the most common pattern, and bone metastasis was generally associated with metastasis to the liver or brain; (3) the prognostic analyses in metastatic patients showed that cancer‐specific survival (CSS) was relatively worse in patients with multiple metastases, and in those with liver metastasis regardless of the number of other metastatic sites; (4) A nomogram was constructed for clinical use based on four independent prognostic risk indicators, including histology, radiation therapy, chemotherapy, and metastatic status. Our findings provide a reference for clinical decision‐making and future diagnostic screening tests for NPC with distant metastases.

Objectives: PD-1 and PD-L1 overexpression in malignant tumors in response to radiotherapy is correlated with a poor prognosis. Human papilloma virus (HPV) infection impacts intrinsic radiosensitivity of head and neck cancers (HNCs). Herein, this study aims to determine PD-1/PD-L1 expression differences in tumors with different HPV statuses and their prognostic value in patients with different radiosensitivity gene signatures to define the characteristics of patients who will benefit from radiotherapy combined with anti-PD-1/PD-L1 therapy.

Endoplasmic reticulum stress (ERS) plays a key role in the pathogenesis and development of tumors and protects tumor cells from radiation damage and drug‐induced stress. We previously demonstrated that EGFR confers radioresistance in human papillomavirus (HPV)‐negative human oropharyngeal carcinoma by activating ERS signaling through PERK and IRE1α. In addition, PERK confers radioresistance by activating the inflammatory cytokine NF‐κB. However, the effect of IRE1 on radiosensitivity has not yet been fully elucidated. Here, we clarified that IRE1 overexpression was associated with poor outcome in HPV‐negative patients treated with radiotherapy (P = 0.0001). In addition, a significantly higher percentage of radioresistant HPV‐negative patients than radiosensitive HPV‐negative patients exhibited high IRE expression (66.7% vs 27.8%, respectively; P = 0.001). Silencing IRE1 and XBP1 increased DNA double‐strand break (DSB) and radiation‐induced apoptosis, thereby increasing the radiosensitivity of HPV‐negative oropharyngeal carcinoma cells. IRE1‐XBP1 silencing also inhibited radiation‐induced IL‐6 expression at both the RNA and protein levels. The regulatory effect of IRE1‐XBP1 silencing on DNA DSB‐induced and radiation‐induced apoptosis was inhibited by pretreatment with IL‐6. These data indicate that IRE1 regulates radioresistance in HPV‐negative oropharyngeal carcinoma through IL‐6 activation, enhancing X‐ray‐induced DNA DSB and cell apoptosis.

Metastatic upper urinary tract urothelial carcinoma (mUTUC) is a relatively rare urothelial carcinoma, and little attention has been given to it. Our study established a nomogram by analyzing the prognostic factors of mUTUC to predict the survival of patients and revealed that the role of surgery at the primary tumor site. We extracted our data (2010–2016) from the Surveillance, Epidemiology, and End Results (SEER) database, and 628 patients with distant metastasis were identified. Propensity score matching (PSM) was used to balance the clinical variable bias in a 1:1 ratio. After PSM, we enrolled 502 patients in our study cohort. Univariate and multivariate Cox regression analyses and Kaplan–Meier curves showed that T stage, N stage, hepatic metastasis, surgery, and chemotherapy were prognostic factors for mUTUC before and after PSM. Based on the findings, a nomogram was constructed to predict the 12‐month survival of patients with distant metastasis. The analysis of subgroups of T stage, N stage, and different metastatic sites demonstrated that the survival of patients with T1/T2, N0/N1/N2/N3, metastasis including liver, and metastasis including bone could be improved by a combination of surgery and chemotherapy, while for the patients with T3/T4/TX, NX, metastasis including lung, and metastasis including distant lymph nodes, chemotherapy alone was a better choice to improve their overall survival. Radiotherapy has been proven to be useful for patients with N1/N2/N3 stage. We have provided more precise treatment strategies for stage IV patients. Our research fully affirms the role of surgery on primary site in UTUC patients with distant metastasis and the significance of classifying the patients into subgroups by integrating variables including T stage, N stage, and different metastatic sites to select the optimal treatment method.

The EGFR-specific mAb cetuximab is one of the most effective treatments for oropharyngeal carcinoma, while patient responses to EGFR inhibitors given alone are modest. Combination treatment with radiation can improve the efficacy of treatment through increasing radiosensitivity, while resistance to radiation after administration of cetuximab limits its efficiency. Radiation and drugs can damage the endoplasmic reticulum (ER) homeostatic state and result in ER stress (ERS), subsequently causing resistance to radiation and drugs. Whether the ERS pathway is involved in radioresistance after administration of cetuximab has not been reported. Herein, we show that cetuximab could increase the radiosensitivity of FaDu cells but not Detroit562 cells. In addition, cetuximab inhibited the radiation-induced activation of the ERS signalling pathway IRE1α/ATF6-GRP78 in FaDu cells, while this effect was absent in Detroit562 cells. Silencing GRP78 increased the radiosensitivity of oropharyngeal carcinoma cells and inhibited radiation-induced DNA double-strand-break (DSB) repair and autophagy. More interestingly, silencing GRP78 abrogated resistance to cetuximab and radiation in Detroit562 cells and had a synergistic effect with cetuximab in increasing the radiosensitivity of FaDu cells. Immunohistochemistry showed that overexpression of both GRP78 and EGFR was associated with a poor prognosis in oropharyngeal carcinoma patients (P<0.05). Overall, the results of this study show that radioresistance after EGFR inhibition by cetuximab is mediated by the ERS signalling pathway IRE1α/ATF6-GRP78. This suppression was consequently unable to inhibit radiation-induced DSB repair and autophagy in oropharyngeal carcinoma cells, which conferred resistance to radiotherapy and cetuximab. These results suggest that the cooperative effects of radiotherapy and cetuximab could be further improved by inhibiting GRP78 in non-responsive oropharyngeal carcinoma patients.