Radiation-induced squamous cell carcinoma of the nasopharynx after radiotherapy for nasopharyngeal carcinoma

Developing a nomogram model and prognostic analysis of nasopharyngeal squamous cell carcinoma patients: a population-based study

BACKGROUND

Nasopharyngeal squamous cell carcinoma (NPSCC) is a common histo-logical subtype of nasopharyngeal cancer with a generally poor prognosis. The aim of this study is to identify factors affecting the survival prognosis of NPSCC patients and develop a specialized nomogram model.

METHODS

We extracted clinical data of 1235 diagnosed cases of NPSCC from the SEER database using SEER*Stat software. Univariate and multivariate Cox proportional hazards regression analyses were conducted to explore clinical factors that impact the prognosis of NPSCC patients. Based on significant independent factors, we developed a nomogram to predict the 1, 3, and 5 years overall survival rates. The discriminative and predictive abilities of the nomogram were evaluated using C-index, calibration curve, area under the curve (AUC), and receiver operating characteristic curve. We evaluated the clinical value of the nomogram using decision curve analysis (DCA) and clinical impact curve (CIC).

RESULTS

We performed a cohort analysis on 846 patients with nasopharyngeal cancer in the training cohort. Multivariate Cox regression analysis revealed age, race, marital status, primary tumor, radiation therapy, chemotherapy, SJCC stage, primary tumor size, Lung metastasis and brain metastasis as independent prognostic factors for NPSCC patients, which we used to construct the nomogram prediction model. The C-index of the training cohort was 0.737. The ROC curve analysis indicated that the AUC of the OS rate at 1, 3, and 5 years in the training cohort was > 0.75. The calibration curves of the two cohorts showed good consistency between the predicted and observed results. DCA and CIC demonstrated that the nomogram prediction model had good clinical benefits.

CONCLUSIONS

The nomogram risk prediction model for NPSCC patient survival prognosis, constructed in this study, has exhibited excellent predictive capability. This model can be employed for swift and precise assessment of individualized survival prognosis. It can offer valuable guidance to clinical physicians in diagnosing and treating NPSCC patients.

Radiosensitization of Nasopharyngeal Carcinoma by Graphene Oxide Nanosheets to Reduce Bcl-2 Level

There are many treatments for nasopharyngeal carcinoma (NPC), but none of them are very effective. Radiotherapy is used extensively in NPC treatment, but radioresistance is a major problem. Graphene oxide (GO) has been previously studied in cancer treatment, and this study is aimed to explore its role in radiosensitization of NPC. Therefore, graphene oxide nanosheets were prepared, and the relationship between GO and radioresistance was explored. The GO nanosheets were synthesized by a modified Hummers' method. The morphologies of the GO nanosheets were characterized by field-emission environmental scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphological changes and radiosensitivity of C666-1 and HK-1 cells with or without the GO nanosheets were observed by an inverted fluorescence microscopy and laser scanning confocal microscopy (LSCM). Colony formation assay and Western Blot were applied for analysis of NPC radiosensitivity. The as-synthesized GO nanosheets have lateral dimensions (sizes ∼1 μm) and exhibit a thin wrinkled two-dimensional lamellar structure with slight folds and crimped edges (thickness values ∼1 nm). C666-1 cells with the GO was significantly changed the morphology of cells postirradiation. The full field of view visualized by a microscope showed the shadow of dead cells or cell debris. The synthesized graphene oxide nanosheets inhibited cell proliferation, promoted cell apoptosis, and inhibited the expression of Bcl-2 in C666-1 and HK-1 cells but increased the level of Bax. The GO nanosheets could affect the cell apoptosis and reduce the pro-survival protein Bcl-2 related to the intrinsic mitochondrial pathway. The GO nanosheets could enhance radiosensitivity, which might be a radioactive material in NPC cells.

Clinical Characteristics and Predictive Outcomes of Recurrent Nasopharyngeal Carcinoma-A Lingering Pitfall of the Long Latency

Purpose: To investigate the clinical characteristics, risk factors, and clinical outcomes of long-latent recurrence (>five years) of nasopharyngeal carcinoma (NPC). Methods: This retrospective study enrolled newly diagnosed NPC patients from the Chang Gung Research Database between January 2007 and December 2019. We analyzed the patients’ characteristics and survival outcomes after recurrence. Results: A total of 2599 NPC patients were enrolled. The overall recurrence rate was 20.5%, while 8.1% of patients had long-latent recurrence (>five years). These patients had a higher percentage of initial AJCC (The American Joint Committee on Cancer) stage I/II (60.5%, p = 0.001) and local recurrence (46.5%, p < 0.001). Unresectable rT3 and rT4 were found in 60% of patients when recurrence and 30% of local recurrence occurred in the skull base, which could not be detected by the regular endoscopy. The five-year overall survival rate of long-latent recurrence was 19.7%. Alive patients tended to be asymptomatic but have regular follow-ups with the interval less than six months. Multivariate analysis showed age and initial advanced AJCC stages were independent risk factors of death after recurrence. In contrast, patients with recurrence between two and five years, salvage surgeries, and regional recurrence had favorable survival outcomes. Conclusion: Long-latent NPC recurrence is not rare, and the survival outcome is poor. Regular follow-up for early detection of NPC recurrence is necessary even after five years of disease-free period.

Pathological and genomic phenotype of second neuroendocrine carcinoma during long-term follow-up after radical radiotherapy for nasopharyngeal carcinoma

Background

Second head and neck neuroendocrine carcinoma (NEC) after radical radiotherapy for nasopharyngeal carcinoma (NPC) treatment is rarely reported. The prognosis of second cancer is poor, and our research focuses on finding a breakthrough in the treatment. In this study, we aimed to investigate clinicopathological characteristics and to identify the genomic landscape of second head and neck NECs.

Methods

We collected five second head and neck NEC cases in the recent three years from our patient database. Clinicopathological data and images were obtained. Genomic analysis was performed using high-throughput second generation sequencing. KEGG pathway enrichment analyses between high-frequency mutations were performed using the STRING database.

Results

All patients had been diagnosed with second NEC, according to the pathological observations. The interval between diagnosis of NPC and NEC ranged from 10 to 18 years. Two patients had brain or liver metastasis at three and nine months, respectively, after the diagnosis of NEC. Three patients died of the disease with the overall survival time ranging from three to nine months. Commonly altered genes (50%) in second head and neck NECs included TP53, RB1, NOTCH2, PTEN, POLG, KMT2C, U2AF1, EPPK1, ELAC2, DAXX, COL22A1, and ABL1. Those genetic lesions might affect p53 signaling, MAPK signaling, PI3K-Akt signaling, sphingolipid signaling, and neurotrophin signaling pathways.

Conclusions

Second head and neck NECs had poor prognosis. We revealed, for the first time, the mutational landscape, high-frequency somatic mutations, and potential signaling pathways of second head and neck NECs. Its optimal treatment model needs to be further studied in future clinical trials.

FOXG1 improves mitochondrial function and promotes the progression of nasopharyngeal carcinoma

Forkhead‑box gene 1 (FOXG1) has been reported to serve an important role in various malignancies, but its effects on nasopharyngeal cancer (NPC) remain unknown. Thus, the present study aimed to investigate the specific regulatory relationship between FOXG1 and NPC progression. Tumor tissues and matching para‑carcinoma tissues were obtained from patients with NPC. Small interfering (si)RNA‑FOXG1 and pcDNA3.1‑FOXG1 were transfected into SUNE‑1 and C666‑1 cells to knockdown and overexpress FOXG1 expression, respectively. FOXG1 expression was detected using reverse transcription‑quantitative PCR and immunohistochemistry. Cell proliferation was detected using MTT and 5‑ethynyl‑20‑deoxyuridine assays. Transwell invasion assay, wound healing assay and flow cytometry were used to detect cell invasion, migration and apoptosis, respectively. Western blotting was conducted to detect the expression levels of mitochondrial markers (succinate dehydrogenase complex flavoprotein subunit A, heat shock protein 60 and pyruvate dehydrogenase), epithelial‑mesenchymal transition (EMT) related proteins (N‑cadherin, Snail and E‑cadherin) and apoptosis‑related proteins [Bax, Bcl‑2, poly(ADP‑ribose) polymerase 1 (PARP), cleaved PARP, cleaved caspase‑3, cleaved caspase‑8, cleaved caspase‑9, caspase‑3, caspase‑8 and caspase‑9]. The mitochondrial membrane potential was detected via flow cytometry, while the ATP/ADP ratio was determined using the ADP/ATP ratio assay kit. The present results demonstrated that FOXG1 expression was upregulated in NPC tissues and cells, and was associated with distant metastasis and TNM stage. Moreover, knockdown of FOXG1 inhibited the proliferation, migration, invasion, EMT and mitochondrial function of SUNE‑1 cells, as well as promoted cell apoptosis, while the opposite results were observed in C666‑1 cells. In conclusion, FOXG1 enhanced proliferation, migration and invasion, induced EMT and improved mitochondrial function in NPC cells. The current findings provide an adequate theoretical basis for the treatment of NPC.

MiRNA-506 presents multiple tumor suppressor activities by targeting EZH2 in nasopharyngeal carcinoma

OBJECTIVE

MiR-506 has been reported to be associated with multiple malignancies, but its roles in nasopharyngeal cancer (NPC) are not fully understood. Our objective is to demonstrate its effects on NPC and the underlying mechanisms.

METHODS

Totally fifteen pairs of NPC and adjacent non-tumorous tissues were collected for the detection of miR-506 and enhancer of zeste homolog 2 (EZH2) expression. Dual luciferase reporter assay was employed for verifying the relationship between miR-506 and EZH2. The flow cytometry and MTT assays were employed to explore the effects of miR-506 and EZH2 on the cell apoptosis and proliferation, respectively. Wound closure and transwell assays were used to evaluate the cell migration and invasion abilities. Western blotting or RT-qPCR assays were applied to detect the alterations of miR-506, EZH2 and epithelial-mesenchymal transition (EMT)-related markers. Morphological changes of cells with EMT were assessed by light microscopy.

RESULTS

MiR-506 was significantly decreased and EZH2 was obviously increased in NPC tissues. Overexpression of miR-506 decreased the EZH2 level, promoted apoptosis, inhibited proliferation, invasion and migration of NPC cells. Accordingly, miR-506 overexpression attenuated EMT process of NPC cells as demonstrated by the alterations of EMT-related markers and the morphological changes. In addition, the luciferase assay proved that miR-506 directly targeted EZH2. Furthermore, the overexpression of EZH2 reversed the tumor-suppressive effects induced by miR-506 mimics.

CONCLUSION

MiR-506 acted as a tumor suppressor to promote apoptosis and inhibit invasion and migration via directly targeting EZH2. MiR-506 can be a candidate target for gene therapy against NPC.

Radiation-induced secondary malignancies for nasopharyngeal carcinoma: a pilot study of patients treated via IMRT or VMAT

Background

Patients treated with radiotherapy are at risk of developing a second cancer during their lifetime, which can directly impact treatment decision-making and patient management. The aim of this study was to qualify and compare the secondary cancer risk (SCR) after intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in nasopharyngeal carcinoma (NPC) patients.

Patients and methods

We analyzed the treatment plans of a cohort of 10 NPC patients originally treated with IMRT or VMAT. Dose distributions in these plans were used to calculate the organ equivalent dose (OED) with Schneider’s full model. Analyses were applied to the brain stem, spinal cord, oral cavity, pharynx, parotid glands, lung, mandible, healthy tissue, and planning target volume.

Results

We observed that the OED-based risks of SCR were slightly higher for the oral cavity and mandible when VMAT was used. No significant difference was found in terms of the doses to other organs, including the brain stem, parotids, pharynx, submandibular gland, lung, spinal cord, and healthy tissue. In the NPC cohort, the lungs were the organs that were most sensitive to radiation-induced cancer.

Conclusion

VMAT afforded superior results in terms of organ-at-risk-sparing compared with IMRT. Most OED-based second cancer risks for various organs were similar when VMAT and IMRT were employed, but the risks for the oral cavity and mandible were slightly higher when VMAT was used.

Outcomes and Prognostic Factors of Radiation-Induced and De Novo Head and Neck Squamous Cell Carcinomas

Objective

We sought to compare clinical outcomes, pathological features, treatment patterns, and survival outcomes between radiation-induced squamous cell carcinoma (RISCC) and de novo SCC (DNSCC) of the head and neck, as well as identify prognostic factors in these patients.

Study Design

Case-control study.

Setting

Tertiary medical center.

Subjects and Methods

Retrospective case-control analysis of 34 RISCCs and 136 DNSCCs matched by age at diagnosis, sex, smoking status, and primary tumor site.

Results

Median latency of RISCC development was 13 years. Radiation-induced squamous cell carcinomas were more likely to present with node-negative disease than DNSCCs (70.6% vs 42.9%; P = .024). A greater proportion of DNSCCs was treated with curative intent (92.6% vs 79.4%; P = .048) and achieved no residual disease posttreatment (82.2% vs 41.2%; P < .001) compared with RISCCs. Patients with RISCC had poorer overall survival (OS) (median, 1.67 vs 5.03 years; P = .018) and disease-specific survival (DSS) (median, 1.67 vs 8.65 years; P = .001) than those with DNSCC. Among patients who underwent curative treatment with no residual disease after treatment, there were, however, no survival differences between RISCC and DNSCC.

Conclusion

In our cohort, RISCCs have a poorer prognosis than DNSCCs. However, those able to undergo curative treatment and have no residual disease after treatment have comparable survival outcomes. Locoregional control of these tumors appears paramount in achieving the best outcomes for patients with RISCC.