[Outcome of radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type]

Objective: To evaluate the prognosis and determine the failure patterns after radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL). Methods: A total of 557 patients from 2000-2015 with low-risk early-stage ENKTCL who received radiotherapy (RT) with or without chemotherapy (CT) from China Lymphoma Collaborative Group were retrospectively reviewed. Among them, 427 patients received combined modality therapy, whereas 130 patients received RT alone. Survivals were calculated by Kaplan-Meier method and compared with Log-rank test. Overall survival (OS) was compared with age and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Cox stepwise regression model was used for multivariate analysis. Results: The 5-year OS and progression-free survival (PFS) were 87.2% and 77.2%. The SMR was 3.59 (P<0.001) at 1 year after treatment, whereas it was 1.50 at 4 years after treatment, without significant difference between ENKTCL group and country-matched general population (P=0.146). Compared with RT alone, CMT did not result in significantly superior 5-year OS (87.0% vs 87.4%, P=0.961) or PFS (76.1% vs 80.7%, P=0.129). Local failure (11.5%, 64/557) and distant failure (10.8%, 60/557) were the main failure modes, while regional failure was rare (2.9%, 16/557). The 5-year locoregional control rate (LRC) was 87.2% for the whole group, with 89.5% for ≥50 Gy versus 73.7% for <50 Gy (P<0.001). Radiotherapy dose was an independent factor affecting LRC(P<0.05). Conclusions: Radiotherapy achieves a favorable prognosis in patients with low-risk early-stage ENKTCL. The incidence of either locoregional or distant failure is low. Radiation dose still is an important prognostic factor for LRC.

[Long-term efficacy and safety of simultaneous integrated boost radiotherapy in non-operative esophageal squamous cell carcinoma: a multicenter retrospective data analysis (3JECROG R-05)]

Objective: To analyze the survival benefits and treatment related toxic effects of simultaneous integrated boost intensity-modulated radiotherapy (SIB-RT) for non-operative esophageal squamous cell carcinoma patients. Methods: The data of 2 132 ESCC patients who were not suitable for surgery or rejected operation, and underwent radical radiotherapy from 2002 to 2016 in 10 hospitals of Jing-Jin-Ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group (3JECROG) were analyzed. Among them, 518 (24.3%) cases underwent SIB (SIB group) and 1 614 (75.7%) cases did not receive SIB (No-SIB group). The two groups were matched with 1∶2 according to propensity score matching (PSM) method (caliper value=0.02). After PSM, 515 patients in SIB group and 977 patients in No-SIB group were enrolled. Prognosis and treatment related adverse effects of these two groups were compared and the independent prognostic factor were analyzed. Results: The median follow-up time was 61.7 months. Prior to PSM, the 1-, 3-, and 5-years overall survival (OS) rates of SIB group were 72.2%, 42.8%, 35.5%, while of No-SIB group were 74.3%, 41.4%, 31.9%, respectively (P=0.549). After PSM, the 1-, 3-, and 5-years OS rates of the two groups were 72.5%, 43.4%, 36.4% and 75.3%, 41.7%, 31.6%, respectively (P=0.690). The univariate survival analysis of samples after PSM showed that the lesion location, length, T stage, N stage, TNM stage, simultaneous chemoradiotherapy, gross tumor volume (GTV) and underwent SIB-RT or not were significantly associated with the prognosis of advanced esophageal carcinoma patients who underwent radical radiotherapy (P<0.05). Cox model multivariate regression analysis showed lesion location, TNM stage, GTV and simultaneous chemoradiotherapy were independent prognostic factors of advanced esophageal carcinoma patients who underwent radical radiotherapy (P<0.05). Stratified analysis showed that, in the patients whose GTV volume≤50 cm(3), the median survival time of SIB and No-SIB group was 34.7 and 30.3 months (P=0.155), respectively. In the patients whose GTV volume>50 cm(3), the median survival time of SIB and No-SIB group was 16.1 and 20.1 months (P=0.218). The incidence of radiation esophagitis and radiation pneumonitis above Grade 3 in SIB group were 4.3% and 2.5%, significantly lower than 13.1% and 11% of No-SIB group (P<0.001). Conclusions: The survival benefit of SIB-RT in patients with locally advanced esophageal carcinoma is not inferior to non-SIB-RT, but without more adverse reactions, and shortens the treatment time. SIB-RT can be used as one option of the radical radiotherapy for locally advanced esophageal cancer.

Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study

BACKGROUND

This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL).

PATIENTS AND METHODS

We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses.

RESULTS

ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results.

CONCLUSIONS

The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.

[Efficacy analysis of the radiotherapy and chemotherapy in patients with stage Ⅳ esophageal squamous carcinoma: a multicenter retrospective study of Jing-Jin-Ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group (3JECROG R-01F)]

Objective: To evaluate the survival and prognostic factors of radiotherapy in patient with Ⅳ stage esophageal squamous carcinoma treated with radiation or chemoradiation. Methods: The medical records of 608 patients with stage Ⅳ esophageal squamous cell carcinoma who met the inclusion criteria in 10 medical centers in China from 2002 to 2016 were retrospectively analyzed. The overall survival and prognostic factors of all patients at 1, 3 and 5 years were analyzed. Results: The 1-, 3-, 5- year overall survival (OS) rates was 66.7%, 29.5% and 24.3% in stage ⅣA patients, and 58.8%, 29.0% and 23.5% in stage ⅣB patients. There was no statistical difference between the two groups (P=0.255). Univariate analysis demonstrated that the length of lesion, treatment plan, planned tumor target volume (PGTV) dose, subsequent chemotherapy, and degrees of anemia, radiation esophagitis, radiation pneumonia were related to the prognoses of patients with Ⅳ stage esophageal carcinomas after radiotherapy and chemotherapy (P<0.05). Multivariate analysis demonstrated that PGTV dose (OR=0.693, P=0.004), radiation esophagitis (OR=0.867, P=0.038), and radiation pneumonia (OR=1.181, P=0.004) were independent prognostic factors for OS. Conclusions: For patients with stage Ⅳ esophageal squamous cell carcinoma, chemoradiotherapy followed by sequential chemotherapy is recommended, which can extend the total survival and improve the prognosis of the patients. PGTV dose more than 60 Gy has better efficacy.

[Prognostic analysis of definitive radiotherapy for early esophageal carcinoma(T1-2N0M0): a multi-center retrospective study of Jing-Jin-ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group]

Objective: To evaluate the prognostic factors of T1-2N0M0 esophageal squamous cell carcinoma (ESCC) treated with definitive radiotherapy. Methods: The clinical data of 196 patients with T1-2N0M0 ESCC who were treated with definitive radiotherapy in 10 hospitals were retrospectively analyzed. All sites were members of Jing-Jin-Ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group (3JECROG). Radiochemotherapy were applied to 78 patients, while the other 118 patients received radiotherapy only. 96 patients were treated with three-dimensional conformal radiotherapy (3DCRT) and 100 treated with intensity-modulated radiotherapy (IMRT). The median dose of plan target volume(PTV) and gross target volume(GTV) were both 60 Gy. The median follow-up time was 59.2 months. Log rank test and Cox regression analysis were used for univariat and multivariate analysis, respectively. Results: The percentage of normal lung receiving at least 20 Gy (V(20)) was (18.65±7.20)%, with average dose of (10.81±42.05) Gy. The percentage of normal heart receiving at least 30 Gy (V(30)) was (14.21±12.28)%. The maximum dose of exposure in spinal cord was (39.65±8.13) Gy. The incidence of radiation pneumonia and radiation esophagitis were 14.80%(29/196) and 65.82%(129/196), respectively. The adverse events were mostly grade 1-2, without grade 4 toxicity. Median overall survival (OS) and progression-free survival (PFS) were 70.1 months and 62.3 months, respectively. The 1-, 3- and 5-year OS rates of all patients were 75.1%、57.4% and 53.2%, respectively. The 1-, 3- and 5-year PFS rates were 75.1%、57.4% and 53.2%, respectively. Multivariate analysis demonstrated that patients'age (HR=1.023, P=0.038) and tumor diameter (HR=1.243, P=0.028)were the independent prognostic factors for OS, while tumor volume were the independent prognostic factor for PFS. Conclusions: Definitive radiotherapy is a promising therapeutic method in patients with T1-2N0M0 ESCC. Patients' age, tumor diameter and tumor volume may impact patients' prognosis.

[Impact factor of postoperative prognosis of esophageal cancer patients with stage pT2N0~1M0]

Objective: To investigate the postoperative prognosis and the related factors of patients with stage pT2N0-1M0 of thoracic esophageal carcinoma(EC). Methods: From 2008 to 2011, clinical data of 275 cases with stage pT2N0-1M0 of thoracic EC treated by esophagectomy were enrolled. These cases includ 180 male and 95 female. Among them, 32 cases were upper thoracic EC, 186 cases were middle thoracic EC and 57 cases were lower thoracic EC. Alternatively, 205 cases were stage pN0, 70 cases were stage pN1. 155 cases received esophagectomy alone and 120 cases received esophagectomy and postoperative adjuvant therapy. Results: The end of follow-up time was on September 30th, 2014. The 1-, 3-, 5-year overall survival (OS) rates were 91.6%, 70.2% and 63.7%, respectively. The 1- 3-, 5-year progression-free survival (PFS) rates were 83.9%, 64.0% and 60.0%, respectively. The result of univariate analysis showed that the depth of tumor invasion, pathological type, pN stage and number of metastatic lymph nodes were significantly associated with OS (all of P<0.05). Moreover, the gender, the depth of tumor invasion, pathological type, pN stage and number of metastatic lymph nodes were significantly associated with PFS (all of P<0.05). Cox multivariate analysis showed that the location of primary tumor and pN stage were the independent factors of OS (both P<0.05). The gender, pN stage and postoperative adjuvant therapy were the independent factors of PFS (all of P<0.05). Conclusion: Among the patients with pT2N0~1M0 stage of thoracic EC, patients with upper thoracic EC or pN1 stage have poorer postoperative prognosis compared with others, and postoperative adjuvant treatment is recommended for these patients.

Oral immunization with a Lactobacillus casei-based anti-porcine epidemic diarrhoea virus (PEDV) vaccine expressing microfold cell-targeting peptide Co1 fused with the COE antigen of PEDV

AIMS

The aims of this study were to develop an effective M cell-targeting oral vaccine, involving Lactobacillus casei to deliver the porcine epidemic diarrhoea virus (PEDV) core neutralizing epitope (COE) antigen conjugated with M cell-targeting peptide Co1 as an adjuvant, against PEDV infection.

METHODS AND RESULTS

Genetically engineered L. casei 393 (L393) strains expressing PEDV COE antigen only (pPG-COE/L393) or fused-expressing COE and M cell-targeting peptide Co1 (pPG-COE-Co1/L393) were constructed, and the immunogenicity upon administration as an oral vaccine was evaluated. The results showed that higher anti-PEDV serum IgG and mucosal SIgA antibody responses were induced in mice orally immunized with strain pPG-COE-Co1/L393 as compared to the mice immunized with strain L393 expressing COE alone or carrying the empty plasmid. In addition, the use of the Co1 ligand elicited a splenocyte proliferative response more effectively in comparison with the COE antigen alone and supported a skewed T helper 2 type of immune response against PEDV.

CONCLUSIONS

pPG-COE-Co1/L393 can effectively induce mucosal, humoural and Th2-type cellular immune responses against PEDV infection via oral administration. Furthermore, M cell-targeting peptide ligand Co1 is a good mucosal adjuvant.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactobacillus casei delivering the COE antigen of PEDV conjugated with a M cell-targeting peptide Co1 as an immune adjuvant is a promising oral vaccine candidate for PEDV.

[Patterns of recurrence in patients with stage Ⅲ thoracic esophageal squamous cell carcinoma after radical resection]

Objective: To evaluate the patterns of recurrence and their value on target delineation for postoperative radiotherapy (RT) in patients with stage Ⅲ thoracic esophageal squamous cell carcinoma (ESCC) after esophagectomy. Methods: 395 patients (302 male and 93 female) of stage Ⅲ thoracic ESCC after radical resection were enrolled in this study. Among them, 375 patients were treated with two-field and other 20 with three-field esopahgectomy. 97 patients were treated with surgery alone, 212 with adjuvant postoperative chemotherapy (CT), 56 with radiotherapy (RT) and 30 with CT plus RT. Diagnosis of recurrence was primarily based on CT images, some of which were biopsy confirmed. The location and patterns of tumor recurrence were analyzed. Results: The overall failure rates was 75.7% (299/395). Locoregional recurrence (LR) was found in 48.4% of the patients, distant metastasis (DM) in 16.2%, and LR plus DM in 4.3%. There were 208 patients occurred with LR, 26.9% (56) recurred in supraclavicular/neck (51 in supraclavicular), 69.7% (145) in mediastinum (88.7% in upper-mediastinum), and 19.7% (41) in upper abdomen (38 in para-aortic lymph node). Chi-square test and logistic multivariate regression analysis showed that TNM stage and adjuvant therapy were significantly associated with LR (P<0.05). Postoperative RT reduced LR (mainly LR in mediastinum), but postoperative CT did not decrease LR. Conclusions: The recurrence rate is very high in stage Ⅲ thoracic ESCC patients, LR is the main pattern of failure. TNM stage is one of the most important factors for LR. Postoperative radiotherapy can reduce LR but postoperative chemotherapy does not decrease LR. Upper-mediastinum is the most common site of recurrence, followed by supraclavicular and para-aortic regions; these areas should be considered as the key target of postoperative radiotherapy.

[Impact of number of dissected lymph nodes on survival in patients with thoracic esophageal squamous cell carcinoma after radical resection]

OBJECTIVE

To evaluate the impact of the number of dissected lymph nodes on survival of patients with stage T3N0M0 thoracic esophageal squamous cell carcinoma (ESCC).

METHODS

The clinicopathlogical dada of 249 patients with stage T3N0M0 thoracic ESCC were analyzed retrospectively. The median age of the 249 patients (171 males and 78 females) was 60-year old. The primary lesions were located in the upper- in 40, middle- in 177, and lower-thoracic esophagus in 45 patients. The median length of the lesions was 5 cm (range 2-12 cm). As for the severity of adhesion after surgery, there were 35 with no adhesion, 90 with mild-, and 124 patients with severe adhesion. The median number of dissected lymph nodes (dissected LN) at surgery was 9 (range 1-27), among them, less than 6 dissected LNs in 55, 6-11 dissected LNs in 133, and 11 or more dissected LNs in 61 cases. There were 210 patients with moderately or highly, and 39 with poorly differentiated cancer. 98 patients were treated with surgery alone, and 151 with postoperative adjuvant treatment.

RESULTS

The follow-up deadline was July 2013. The 1-, 3-, and 5-year overall survival rates were 90.0%, 68.7% and 55.2%, respectively. The 1-, 3-, and 5-year survival rates were 85.5%, 63.6% and 39.1% in patients with <6 dissected LNs, 89.5%, 67.7% and 56.9% in patients with 6-11 dissected LNs, and 95.1%, 75.4% and 66.2% in patients with >11 dissected LNs, respectively (P=0.073). The survival was shorter in patients with <6 dissected LNs than patients with >11 dissected LNs (P=0.022). The subgroup analysis showed that in patients with middle-thoracic ESCC, the length of lesion ≤5 cm or mild adhesion after surgery and the number of dissected LNs were associated with survival after surgery.

CONCLUSIONS

For patients with stage T3N0M0 thoracic ESCC after surgery, the number of dissected LNs is an important factor affecting the survival, and at least 6 or more lymph nodes should be dissected. If lymphadenectomy is not adequately performed, postoperative adjuvant therapy should be recommend.

Analysis of the genome sequence of infectious hematopoietic necrosis virus HLJ-09 in China

Infectious hematopoietic necrosis virus (IHNV) is a highly contagious disease of juvenile salmonid fish. Six genome target fragments of the complete genome sequence of IHNV HLJ-09 were amplified by RT-PCR, and the 3'-terminal and 5'-terminal region of the genomic RNA were amplified using the RACE method. The complete genome sequence of HLJ-09 comprises 11,132 nucleotides (nt) (Accession number JX649101) and is different from that of other IHNV strains published in GenBank. Homology comparison and phylogenetic analysis of six ORF sequences were carried out using HLJ-09 and other IHNV strains published in GenBank. From phylogenetic tree analysis, the N gene, M gene, and P gene had the closest genetic relationship to IHNV-PRT from Korea. Phylogenetic analysis for the full length of the G gene showed that the HLJ-09 strain exhibited very close homology to the ChYa07, RtNag96, RtUi02, and RtGu01 strains from Korea and Japan, indicating that the HLJ-09 strain belonged to the genotype JRt. Ultimately, the Chinese IHNV HLJ-09 strain may have originated in Korea and Japan.

Construction of a transducing virus from double-stranded RNA bacteriophage phi6: establishment of carrier states in host cells

Bacteriophage phi 6 contains three double-stranded RNA (dsRNA) genomic segments. We have constructed a plasmid that contains a cDNA copy of the middle (M) segment, with a gene for kanamycin resistance (kan) inserted into the PstI site. A transcript of this cDNA was incorporated in vitro into procapsids along with natural transcripts of the S and L segments. The procapsids were coated with nucleocapsid surface protein P8 and transfected into Pseudomonas syringae pv. phaseolicola. The resulting infectious virus, phi 6 K1, was found to contain an M segment that was 1.2 kbp larger than the normal 4.1 kbp. K1 formed small, turbid plaques, and its genome was unstable. Preparations of K1 contained from about 0.1 to 10% large, clear-plaque forms of the virus which were usually missing the kan gene, and in some cases, the resulting segment M was smaller than its normal size. Cells picked from lawns of host cells infected with K1 yielded colonies that were resistant to kanamycin (Kan). These colonies could be passaged on kanamycin-containing medium. The cells were found to contain large amounts of dsRNA corresponding to the viral genomic segments. Some strains continued to produce viable phage, while others lost this ability. One strain completely lost the small genomic segment S. Approximately 1 in 10,000 infected cells acquired the carrier state with the original phage isolate K1. However, we isolated a viral mutant that was able to induce the carrier state in 10 to 20% of the infected cells. The ability to use drug resistance as a test for the carrier state makes this system very useful for the study of the mechanisms of induction of persistent infections.

In vitro packaging of the bacteriophage phi 6 ssRNA genomic precursors

Bacteriophage phi 6 contains three segments of double-stranded RNA within a nucleocapsid. Plasmids containing cDNA copies of the large genomic segment direct the synthesis of viral proteins that assemble into procapsids in Escherichia coli or Pseudomonas phaseolicola. These structures are dodecahedral assemblages of proteins P1, P2, P4, and P7. We report in this paper that these particles are capable of packaging viral single-stranded plus-sense RNA in vitro. The packaging reaction requires the presence of ATP or dATP. Synthesis of minus strands takes place within this filled procapsid in the presence of all four nucleoside triphosphates. Packaged ssRNA is found to be protected from added ribonuclease.

In vitro assembly of infectious nucleocapsids of bacteriophage phi 6: formation of a recombinant double-stranded RNA virus

A system is described for assembling infectious bacteriophage phi 6 nucleocapsids in vitro. Procapsids encoded by cDNA copies of genomic segment L in Escherichia coli were used to package and replicate viral RNA segments. The resulting filled particles were shown to be capable of infecting host cell spheroplasts after incubation with purified nucleocapsid shell protein P8. The infected spheroplasts yielded infectious virions. A modified cDNA-derived RNA segment was inserted into virions by this method. The resulting infectious virions contained the same 4-base-pair deletion as the modified cDNA. These findings support the contention that the preformed procapsids are the "machine" that replicates the phi 6 genome, by showing that the cDNA-derived procapsids are competent to package and replicate RNA properly.

In vitro replication, packaging, and transcription of the segmented double-stranded RNA genome of bacteriophage phi 6: studies with procapsids assembled from plasmid-encoded proteins

The genome of the lipid-containing bacteriophage phi 6 contains three segments of double-stranded RNA (dsRNA). We prepared cDNA copies of the viral genome and cloned this material in plasmids that replicate in Escherichia coli and Pseudomonas phaseolicola, the natural host of phi 6. These plasmids direct the formation of viral proteins and the assembly of structures similar to viral procapsids containing proteins P1, P2, P4, and P7. We found that these particles are capable of taking up viral single-stranded RNA and synthesizing the minus strands to produce dsRNA structures. Once the dsRNA is formed, it is then used as a template for the production of viral plus strands in a reaction that resembles normal transcription. The particles were also capable of directly transcribing exogenous dsRNA. The replicase reactions were specific for phi 6 RNA, were specific for procapsids, and resulted in substantial incorporation of product dsRNA into particles. These results offer strong support to a model in which genomic packaging is done by preformed procapsids.