Prioritizing sufficient dose to gross tumor volume over normal tissue sparing in intensity-modulated radiotherapy treatment of T4 nasopharyngeal carcinoma.

BACKGROUND: In intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC), priority is often given minimize dose to the critical organs at risk (OARs) to avoid potential morbid sequelae. However, in T4 NPC, dosimetric inadequacy enforced by dose constraints on OARs may significantly impact tumor control. METHODS: This was a single-institute cohort that patients diagnosed between July 2005 and December 2010 with T4 NPC treated with IMRT. All patients were re-classification according to the 7th-AJCC stage. RESULTS: Overall, the average doses such as Dmax , D1% , D2% and D1cc for various Central nervous system (CNS) OARs including brainstem, optic nerve, chiasm, temporal lobes and spinal cord were found to exceed published guidelines as RTOG0225. However, no clinical toxicities were seen during the follow-up period except for 13% patients with temporal lobe necrosis. CONCLUSION: Our retrospective review showed that its feasible to maximize gross tumor volume dose coverage while exceeding most CNS OAR constraint standards, with ideal local control and no obvious increase of craniocerebral toxicity.

Identifying the optimal candidates for locoregional radiation therapy in patients with de novo metastatic nasopharyngeal carcinoma.

BACKGROUND: To evaluate the value of locoregional radiation therapy (LRRT) in de novo metastatic nasopharyngeal carcinoma (mNPC) and identify suitable candidates for additional LRRT after palliative chemotherapy (PCT). METHODS: Patients with de novo mNPC received platinum-based chemotherapy for a minimum of four cycles with or without definitive LRRT via intensity-modulated radiation therapy (IMRT) were all candidates for this study. RESULTS: A total of 168 patients were included for this analysis. Additional LRRT was associated with significantly longer median OS (69.5 vs. 17.8 months, p < 0.001) when compared with PCT alone. However, this survival benefit of LRRT was only reflected in patients with oligometastatic diseases (90.8 vs. 17 months, p < 0.001), but not for those with polymetastatic disease (p = 0.86). CONCLUSIONS: Additional LRRT after PCT may only improve OS for oligometastatic patients. For patients with polymetastatic disease, intensive systemic treatment such as the combination of immunotherapy and adequate PCT might be necessary.

Prognostic significance of expression of cyclooxygenase-2, vascular endothelial growth factor, and epidermal growth factor receptor in nasopharyngeal carcinoma.

BACKGROUND: The association between expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), and the long-term outcomes in treated nasopharyngeal carcinoma (NPC) was studied. METHODS: Expression of COX-2, VEGF, and EGFR by immunohistochemical (IHC) staining was assessed in 128 patients with NPC. Overall survival (OS), disease-free survival (DFS), locoregional control, and distant metastasis-free survival rates were compared for different expression levels of each marker. Multivariate analysis was by the Cox regression model. RESULTS: Median follow-up after radiation therapy ± chemotherapy was 116 months. Univariate and multivariate analyses demonstrated that COX-2, VEGF, EGFR, and clinical stage were all independent predictors for OS, DFS, locoregional control, and distant metastasis-free survival rates. CONCLUSIONS: High expression of COX-2, VEGF, and EGFR were independent adverse prognostic factors for long-term outcomes in nonmetastatic NPC independent of clinical stage.

Factors associated with overall survival in 1706 patients with nasopharyngeal carcinoma: significance of intensive neoadjuvant chemotherapy and radiation break.

BACKGROUND AND PURPOSE: To exam factors associated with overall survival (OS) in patients with nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: This study is a retrospective study of a total of 1706 consecutive NPC patients from a single institution between January 1995 and December 1998. One thousand eighty-one patients were treated with radiotherapy (RT) alone and 625 with an intensive course of neoadjuvant chemotherapy followed by RT. Patient, tumor and treatment factors were analyzed for their significance on 5-year overall survival (OS). RESULTS: Younger age, female gender, absence of anemia pre-RT, early tumor stage, interruption of RT, and neoadjuvant chemotherapy were significantly associated with survival under multivariate analysis (all P<0.05). The 5-year OS rates were 100%, 75.9% (95%CI 71.6-80.2%), 66.5% (95%CI 62.8-70.2%), and 49.3% (95%CI 45.0-53.6%) for stage I, II, III, and IV (P<0.05); 68.9% (95%CI 66.2-71.5%) and 63.7% (95%CI 61.5-65.8%), for patients treated with or without neoadjuvant chemotherapy (P=0.0051), and 51.7% (95%CI 45.0-58.4%) and 69.5% (95%CI 67.2-71.7%) for patients with or without treatment break (P<0.0001), respectively. CONCLUSION: Intensive neoadjuvant chemotherapy and absence of radiation break seem to be favorable factors associated with long-term survival in patients with NPC.

The clinical significance of coexpression of cyclooxygenases-2, vascular endothelial growth factors, and epidermal growth factor receptor in nasopharyngeal carcinoma.

OBJECTIVES/HYPOTHESIS: To investigate the inter-relationship of the expressions of cyclooxygenases-2 (COX-2), vascular endothelial growth factors (VEGF), and epidermal growth factor receptor (EGFR) in nasopharyngeal cancer (NPC) cells, and their clinical significance in association with the extent of disease at diagnosis. STUDY DESIGN: Prospective. METHODS: Expressions of COX-2, VEGF, and EGFR protein were detected using immunohistochemistry in 111 patients with pathologically confirmed stage II to IV nasopharyngeal carcinoma. The correlation between the expressions of the three tumor markers and the stages of disease at diagnosis were investigated. RESULTS: COX-2, VEGF, and EGFR were over-expressed in 76.6, 66.7, and 73.9% of NPC cells, respectively. The staining patterns was cytoplasmic for VEGF, membranous for EGFR, and both cytoplasmic and membranous for COX-2 in tumor cells. Linear associations were observed between the intensity of the expressions of COX-2 vs. VEGF, COX-2 vs. EGFR, or VEGF vs. EGFR. Furthermore, the intensity of the expressions of all three markers was significantly associated with the extent of the tumor measured by the Tumor, Node, Metastasis classification and staging grouping of the American Joint Committee on Cancer/International Union Against Cancer staging system. CONCLUSION: COX-2, VEGF, and EGFR expressions in NPC cells were interrelated, and the intensity of the expressions of all three markers were significantly associated with the stage of the disease at diagnosis. Further investigation is needed to determine the clinical applications of COX-2, VEGF, and EGFR in predicting the long-term outcome of NPC after definitive therapy.