Factors influencing the incidence of sinusitis in nasopharyngeal carcinoma patients after intensity-modulated radiation therapy.

The aim of the study was to investigate the incidence of sinusitis in nasopharyngeal carcinoma (NPC) patients before and after intensity-modulated radiation therapy (IMRT) and to analyze factors associated with the incidence of sinusitis following IMRT. We retrospectively analyzed 283 NPC patients who received IMRT in our hospital from March 2009 to May 2011. The diagnostic criteria for sinusitis are based on computed tomography (CT) or magnetic resonance imaging (MRI) findings. CT or MRI scans were performed before and after IMRT to evaluate the incidence of sinusitis. Factors influencing the incidence of sinusitis were analyzed by log-rank univariate and logistic multivariate analyses. Among the 283 NPC patients, 128 (45.2 %) suffered from sinusitis before radiotherapy. The incidence rates of sinusitis in patients with T1, T2, T3, and T4 NPC before radiotherapy were 22.6, 37.5, 46.8, and 61.3 %, respectively (χ 2 = 14.548, p = 0.002). Among the 155 NPC patients without sinusitis before radiotherapy, the incidence rates of sinusitis at the end of radiotherapy and at 1, 3, 6, 9, 12, and 18 months after radiotherapy were 32.9, 43.2, 61.3, 68.4, 73.5, 69.7, and 61.3 %, respectively (χ 2 = 86.461, p < 0.001). Univariate analysis showed that T stage, invasion of the nasal cavity, nasal irrigation, and radiation dose to the nasopharynx were associated with the incidence of sinusitis in NPC patients after IMRT (p = 0.003, 0.006, 0.002, and 0.020). Multivariate analysis showed that T stage, invasion of the nasal cavity, and nasal irrigation were influential factors for the incidence of sinusitis in NPC patients after IMRT (p = 0.002, 0.002, and 0.000). There was a higher incidence of sinusitis with higher T stage among NPC patients before radiotherapy, and the incidence of sinusitis in NPC patients after IMRT was high (45.2 %). The incidence of sinusitis increased rapidly within the first 3 months after IMRT, and the number of sinusitis cases peaked at 6-9 months after IMRT and showed a trend toward stabilization after 1 year. Advanced T stage, invasion of the nasal cavity, and nasal irrigation were positively associated with the incidence of sinusitis in NPC patients after IMRT.

Prognostic value of expression of EGFR and nm23 for locoregionally advanced nasopharyngeal carcinoma.

The purpose of this study was to evaluate the prognostic value of expression of EGFR and nm23 in patients with advanced-stage nasopharyngeal carcinoma (NPC). The study population comprised 127 patients with stage III-IVa NPC with sufficient pretreatment tumor biopsy specimens from 2003 to 2004 and clinical follow-up data. The expression of EGFR and nm23 was detected by immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The correlation between pretreatment expression of EGFR and nm23, and the effectiveness of chemoradiotherapy was analyzed. The EGFR expression was correlated with primary lesion stage and clinical stage (P = 0.001, 0.002, respectively). There was a statistically significant association between nm23 expression and local lymph node stage (P = 0.000). The positive EGFR expression had a higher recurrent rate than the negative (P = 0.015). The positive nm23 expression had a lower distant metastasis rate than the negative (P = 0.021). Negative expression of EGFR had a significantly better 5-year OS and DFS than positive expression (P = 0.015, 0.013, respectively). Positive expression of nm23 had a significantly higher 5-year OS and DFS than negative expression (P = 0.001, 0.006, respectively). Multivariate analysis indicated that both pretreatment EGFR and nm23 expression were strong independent factors for the overall survival of patients with NPC (P = 0.000, 0.000, respectively). Our data suggested that EGFR and nm23 can serve as reliable biomarkers for prognosis prediction in patients with NPC who may benefit from alternate treatment strategy and targeted treatment.

A mutation inactivating the methyltransferase gene in avirulent Madrid E strain of Rickettsia prowazekii reverted to wild type in the virulent revertant strain Evir.

Rickettsia prowazekii Madrid E (E) strain is an effective vaccine, but can revert to virulent status when passaged in animals. The aim of this study is to identify the reverse mutation that may determine the virulence of R. prowazekii by comparing the genetic structures of E strain and its virulent revertant Evir strain. We determined that the gene (Rp028/Rp027) encoding the methyltransferase was mutated by frameshift in avirulent E strain but not in virulent revertant Evir strain and wild type virulent Breinl strain. We conclude that the mutation in the E strain gene reverts to wild type in the virulent revertant Evir strain. Whether the mutation plays an essential role in the attenuation of E strain needs to be further investigated.