Long-term results of CT-guided percutaneous radiofrequency ablation of inoperable patients with stage Ia non-small cell lung cancer: A retrospective cohort study.

BACKGROUND: This study was performed to retrospectively evaluate the 10-year overall survival (OS), progression-free survival (PFS), and local control rates of patients with inoperable stage Ia non-small cell lung cancer (NSCLC) who underwent computed tomography (CT)-guided radiofrequency ablation (RFA) in a single center. MATERIALS AND METHODS: Fifty patients with inoperable NSCLC underwent RFA between 2004 and 2016. Thoracic surgeons evaluated the patients and performed RFA under CT guidance. Follow-up CT and positron emission tomography/CT scans were obtained. Local control rates and recurrence patterns were analyzed. RESULTS: Seventy-three lesions in 50 patients (M:F = 22:28; median age: 73 years; range: 52-82 years) were treated with CT-guided RFA. The mean lesion size was 2.2 cm (range: 1-3 cm). No procedure-related deaths occurred. Low-grade fever was the most common post-ablation complication, with an incidence rate of 36%. The 1-, 2-, 3-, 5-, and 10-year OS rates of patients with Ia NSCLC were 96.0%, 86.5%, 67.1%, 36.3%, and 1%, respectively, and the 1-, 2-, 3-, and 5-year PFS rates were 94.0%, 77.5%, 43.5%, and 10.8%, respectively. The most common pattern of recurrence was local, and 15 patients with recurrence were treated with repeat RFA. Tumor size <2.0 cm was associated with a significantly improved 3-year survival rate of 78.9%. CONCLUSION: CT-guided RFA is feasible and well tolerated by inoperable patients with inoperable stage Ia NSCLC.

Long-term Observation of CT-guided Radiofrequency Ablation of Lung Neoplasm in 476 Consecutive Patients by a Thoracic Surgical Service: A Single-institutional Experience.

RATIONALE AND OBJECTIVES: The aim of the study was to evaluate the overall survival (OS) rate, progression survival rate, and local control rate over 10 years of medically inoperable patients with lung cancer undergoing computed tomography (CT)-guided radiofrequency ablation (RFA). MATERIALS AND METHODS: Between September 2004 to March 2016, 668 neoplasms were treated in 476 medically inoperable patients (294 men, 60 women; median age 74 years; range 29-84) who underwent CT-guided RFA. All patients had clinical or pathologic evidence of the neoplastic lesion: 22.1% patients with primary non-small cell lung cancer (NSCLC), 22.3% patients with recurrent NSCLC, 45.2% with metastases, and 10.3% with small cell lung cancer. The mean size of the lesions was 3.8 cm (range of 1-16 cm). Twenty-one lesions were re-treated from one to as many as four times. RESULTS: The procedure was technically successful in all cases. No procedure-related deaths occurred in the RFA procedures. Major complications consisted in 104 (21.8%) cases of low-grade fever, 46 (9.6%) of the pneumothorax. The mean follow-up was 32 months. The probabilities of 1-, 2-, 3-, 5-, and 10-year OS rate were 98.1%, 86.6%, 68.9% 34.5%, and 9.5% for primary NSCLC; 59.7%, 18.5%, 8%, 3.4%, and 1.5% for metastases; 93.3%, 59.1%, 49.6%, 19.7%, and 0% for recurrence; and 89.4%, 67.5%, 39.1%, 16.5%, and 0% for small cell lung cancer. In primary NSCLC, progression-free survival (PFS) and OS were significantly related to tumor size, but there was no significant difference in recurrent NSCLC, metastasis, and peripheral SCLC. The median OS of metastases of NSCLC was significantly related to nodal or distant metastases. The most common pattern of recurrence was local; any type of recurrence at 1-year follow-up imaging was seen in 7.1% of primary NSCLC diameter less than 3 cm. CONCLUSIONS: Our experience indicates that CT-guided RFA done by the thoracic surgeons is feasible and safe in high-risk patients. Maximum tumor diameter less than 3 cm and lack of extrapulmonary metastasis are all positive prognostic factors of survival after RFA. RFA offers good local control of recurrent NSCLC, lung metastases, and SCLC, also in the long-term period. RFA should continue to offer an alternative option in medically inoperable patients.

[Association of epithermal growth factor receptor expression and its downstream gene mutation status with radiosensitivity of colorectal carcinoma cell lines in vitro].

OBJECTIVE: To investigate the effect of epithermal growth factor receptor (EGFR) expression and K-ras, B-raf and PIK3CA mutation status on the radiosensitivity of human colorectal carcinoma (CRC) cell lines in vitro. METHODS: Real-time RT-PCR was used to measure EGFR mRNA expression in nine human CRC cell lines, and K-ras, B-raf and PIK3CA mutation status of each CRC cell line was also identified respectively. After treatment with irradiation at graded dose, the cell viability was measured by clonogenic survival assay. The rate of cell apoptosis and cell cycle distribution were tested by flow cytometry. The cell morphology was observed with hoechst 33258 staining to analyze the correlation between EGFR mRNA expression and radiosensitivity of CRC cell lines. RESULTS: A positive correlation between EGFR mRNA expression and survival fraction of 2 Gy(SF2) was observed (r=0.717, P=0.030). Association was also identified between the mutation status of PIK3CA and radiosensitivity (t=2.401, P=0.047), while mutation status of K-ras and B-raf was not associated with radiosensitivity. At 48-hour after exposing to irradiation, the apoptosis rate of radiosensitive cell line (HCT116) was significantly increased in a dose-dependent manner (P<0.05), while the apoptosis rate of radioresistant cell line (HT29) was significantly increased only when radiation dose increased to 6 Gy. The ratio of G0/G1 phase was reduced significantly with the increase of radiation dose in radiosensitive cell line (HCT116, P<0.05), while this trend was not observed in radioresistant cell line (HT29, P>0.05). CONCLUSIONS: Over-expression of EGFR mRNA is correlated to radioresistance of human CRC cell lines, and mutation status of PIK3CA is closely related with radiosensitivity of CRC cells. The inhibition of apoptosis and G0/G1 arrest may induce the radioresistance of CRC cell lines.

Downregulation of ATP-binding cassette subfamily C member 4 increases sensitivity to neoadjuvant radiotherapy for locally advanced rectal carcinoma.

OBJECTIVE: This study was designed to verify the effect of ATP-binding cassette subfamily C member 4 on radiosensitivity of locally advanced rectal carcinoma. SETTING: The expression of ATP-binding cassette subfamily C member 4 protein in 121 pretreatment tissue samples from locally advanced rectal carcinoma patients was detected by immunohistochemistry. DESIGN: Pathological response to radiotherapy was evaluated according to tumor regression grading by postoperative histological examinations after they received long-course preoperative neoadjuvant radiotherapy, and the association between clinicopathological data and tumor regression grading was analyzed retrospectively. For further validation, short hairpin RNA was constructed and transfected into colorectal carcinoma cell line HT29. The knockdown efficiency was confirmed at both RNA and protein levels. The altered radiosensitivity was evaluated by methylthiazolyl tetrazolium assay, colony formation assay, flow cytometry, and Hoechst 33258 staining. RESULTS: Univariate analysis revealed that ATP-binding cassette subfamily C member 4 expression (p < 0.001), P53 type (p = 0.069), and CEA (p = 0.100) were possibly associated with tumor regression grading, and multivariate analysis demonstrated that ATP-binding cassette subfamily C member 4 expression (p < 0.001) and P53 type (p = 0.039) were positively correlated with response to neoadjuvant radiotherapy in locally advanced rectal carcinoma patients. Lentiviral vector was successfully introduced into HT29 cells and inhibited ATP-binding cassette subfamily C member 4 expression efficiently and persistently. Downregulation of ATP-binding cassette subfamily C member 4 expression significantly enhanced inhibition of cell proliferation, decreased colony formation capacity, and increased cell apoptosis induced by irradiation, as examined by a series of experiments in vitro. In addition, radiobiological parameters calculated according to the single-hit multitarget model were also decreased significantly. CONCLUSIONS: Our data indicate that ATP-binding cassette subfamily C member 4 may be a useful molecular marker in predicting radiosensitivity, and a potential target in improving the response to neoadjuvant radiotherapy in locally advanced rectal carcinoma patients.

Expression of ZNF148 in different developing stages of colorectal cancer and its prognostic value: a large Chinese study based on tissue microarray.

BACKGROUND: It has been speculated that zinc finger protein 148 (ZNF148) is a tumor suppressor. However, to the authors' knowledge, little is known about the clinical significance of ZNF148 expression in patients with colorectal cancer (CRC). The objective of the current study was to clarify the association between ZNF148 expression and the postoperative prognosis of patients with CRC. METHODS: Tissue microarrays containing 56 normal mucosa, 51 adenoma, 742 CRC (TNM stage I-IV), 16 familial adenomatous polyposis, and 21 metastatic CRC specimens were examined immunohistochemically for ZNF148 expression. RESULTS: Expression of ZNF148 was found to increase consecutively from normal mucosa to stage I CRC, and then decreased consecutively from stage I to stage IV CRC. Lower expression of ZNF148 in tumors was found to be significantly associated with lymph node metastases, advanced TNM disease stage, poor differentiation, higher rate of disease recurrence, worse overall survival (OS), and shorter disease-free survival. High expression of ZNF148 was also associated with improved OS (P = .025) and disease-free survival (P = .042) in patients with stages II to III CRC. On multivariate Cox analysis, lower ZNF148 expression in tumors, advanced TNM stage, colon cancer, and elevated serum carbohydrate antigen 19-9 (CA19-9) were found to be significant factors for a worse OS. In 16 patients with familial adenomatous polyposis, ZNF148 expression was upregulated at steps toward carcinogenesis. In 21 patients with metastatic CRC, although ZNF148 expression was higher in primary tumors compared with adjacent mucosa, its expression in metastatic tumors was significantly lower than that in primary tumors. CONCLUSIONS: Although ZNF148 expression is related to colorectal carcinogenesis, high ZNF148 expression in patients with CRC appears to be inversely associated with malignant phenotypes and may serve as a significant prognostic factor after surgery for patients with CRC.

[Impacts of preoperative radiochemotherapy on operation and postoperative complications in patients with mid-low rectal carcinomas].

OBJECTIVE: To investigate the impact of preoperative radiochemotherapy on postoperative complications in patients with mid-low rectal carcinomas. METHODS: Clinicopathologic data of T3 and T4 patients with mid-low rectal carcinomas in the Department of Colorectal Surgery at the Changhai Hospital of The Second Military Medical University from January 2009 to December 2010 were analyzed retrospectively. This cohort included 81 patients treated with preoperative radiochemotherapy followed by operation(radiochemotherapy group) and 93 cases who underwent surgery alone(control group). RESULTS: Both resection rate and sphincter preservation rate were higher in the radiochemotherapy group(100% and 86.4%) than those in the control group(94.6% and 73.1%), and the difference in sphincter preservation rate was statistically significant(P=0.039). There were no significant differences in the mean operative time [(130±15) min vs.(125±20) min, P>0.05] and mean amount of bleeding [(100±15) ml vs. (95±10) ml, P>0.05] between the two groups. The overall incidence of postoperative complications was similar(9.9% vs. 9.7%, P>0.05). CONCLUSIONS: Preoperative radiochemotherapy can significantly increase sphincter preservation rate of mid-low rectal carcinomas, and does not increase the difficulty in surgical procedure and postoperative complications.

[Long non-coding RNA influences radiosensitivity of colorectal carcinoma cell lines by regulating cyclin D1 expression].

OBJECTIVE: To screen long non-coding RNA which influences radiosensitivity of colorectal carcinoma cell lines and investigate the mechanism. METHODS: Under different doses of radiation, colony formation assay and single-hit multi-target model were conducted to draw dose-survival curve and SF2 value of colorectal carcinoma cell lines(RKO, Lovo) was calculated. High-throughput lncRNA/mRNA chips were used to screen lncRNA genes and protein coding genes with expression differences more than 2 folds between RKO, Lovo cell lines and RKO cell line receiving 2Gy radiation. The main action pathway was computed by Gene Ontology analysis combined with Pathway analysis in order to explore the mechanism which induces the effect of lncRNA on radiosensitivity of colorectal carcinoma cell lines. Further experiment on P53, P21, cyclin D1 expression contents of RKO cell line was confirmed by real-time RT-PCR. RESULTS: Lovo(SF2=0.47) was more sensitivity to radiation than RKO(SF2=0.53) according to the outcome of colony formation assay. High-throughput lncRNA/mRNA chips identified a total of 268 lncRNA genes and 270 protein coding genes. Gene Ontology analysis showed that the expression of genes associated with cell cycle process were significantly different (38.6%). There was a significant relationship between expression of several lncRNAs and CCND1 gene. Real-time RT-PCR showed no significant differences of P53 and P21 expression in RKO and Lovo cell lines(P>0.05), while cyclin D1 expression of RKO cell line was higher than that of Lovo cell lines(P<0.05). After exposed to 2 Gy doses of radiation, there was an obvious decrease of cyclin D1 expression in RKO cell lines(P<0.05), while P53 and P21 expressions were not different(P>0.05). CONCLUSION: The possible mechanism is that lncRNAs compose transcription compound to combine with CCND1 gene and influence radiosensitivity of colorectal carcinoma cell lines by regulating expression of cyclin D1, which is independent of P53-P21-cyclin D1 pathway.

[Down regulation of multidrug resistance-associated protein 4 expression by RNA interference enhances radiosensitivity of colorectal carcinoma cell lines in vitro].

OBJECTIVE: To investigate the effect of multidrug resistance-associated protein 4 (MRP4) expression on the radiosensitivity of colorectal carcinoma cell lines in vitro. METHODS: The vector of shRNA for RNA interference was constructed and then transfected into HCT116 cell line to steadily down-regulate the expression of MRP4. HCT116 cells were divided into 3 groups including the CON group(non-transfected), NC group (negative control virus was added), and KD group (RNAi target was added for transfection). To test the effectiveness of RNA interference, real-time polymerase chain reaction and Western blot were used to measure the expression pattern of MRP4 at both mRNA and protein levels, respectively. For the examination of the effect of RNA interference of MRP4 on the radiosensitivity, flow cytometry was used to calculate the rate of apoptotic cells 24 h after 4 Gy radiation. Proliferation of the cells was measured via MTT assay at different time points. RESULTS: ShRNA plasmid was successfully constructed. Transfection of this constructed vector into HCT116 cell line caused steady silencing of MRP4 expression (HCT116-KD). MRP4 mRNA and protein expression were significantly down-regulated following RNA interference(P<0.05). Twenty-four hours after radiation, the apoptosis rate of KD cell line was (71.7±0.8)%, significantly higher than that in the CON group [(56.1±0.9)%] and NC group[(59.8±0.8)%](P<0.05). Fourty-eight hours and 72 hours after radiation, the proliferation was significantly inhibited in KD cells compared to the control groups(P<0.05). CONCLUSIONS: Expression of MRP4 is closely related to radio-tolerance of colorectal carcinoma. Down-regulation of MRP4 expression by RNA interference enhances radiosensitivity of colorectal carcinoma cell lines in vitro. MRP4 may be an effective molecular marker for predicting the radiosensitivity of colorectal carcinoma.

DNA topoisomerase II alpha: a favorable prognostic factor in colorectal caner.

PURPOSE: There is a lack of study concerning expression of Topoisomerase IIα (Topo IIα) and long-term results in colorectal cancer patients. We aimed to investigate the relationship between expression of Topo IIα and clinicopathological parameters including overall survival in colorectal cancer. METHODS: Paraffin-fixed specimens from a large prospective cohort of colorectal cancer patients who had been followed up for 4 years were assayed immunohistochemically. RESULTS: Of 490 colorectal cancer patients accessible for Topo IIα expression, expression of Topo IIα was scored as (-) in 4 (0.8%) patients, (+) in 41 (8.4%) patients, (++) in 396 (80.8%) patients, and (+++) in 49 (10.0%) patients. Overexpression of Topo IIα was found to be related with lower T stage (p = 0.042), lower N stage (p = 0.038), and a lower incidence of recurrence with nearly significance (p = 0.053). Kaplan-Meier analyses showed that overexpression of Topo IIα was related with prolonged overall survival (p = 0.022) and disease-free survival (p = 0.036). Multivariate analyses showed that elevated serum CEA (p < 0.001), elevated serum CA199 (p = 0.002), poor differentiation (p = 0.001), advanced Dukes stage (p < 0.001), and lower expression of Topo IIα (p = 0.017) were independent predictive factors for poor prognosis. CONCLUSIONS: Topo IIα expression is a valuable prognostic indicator for colorectal cancer and would be useful in treatment selection for early colorectal cancer and malignant colorectal polyps resected under endoscopy, especially when it is used in combination with serum CEA, CA199, and differentiation.

[Preliminary study on relationship between multi-drug resistance-associated protein 4 and radiosensitivity of rectal cancer].

OBJECTIVE: To explore the correlation between multi-drug resistance-associated protein 4(MRP4) and the sensitivity of rectal cancer to radiation. METHODS: A total of 95 patients with advanced rectal cancer and received radiation therapy between January 2000 and January 2009. MRP4 and P53 protein expression in the paraffin-embedded specimen were detected by immunohistochemistry. Logistic regression analysis was used to evaluate factors associated with the sensitivity of rectal cancer to radiation. RESULTS: Forty patients(42%) were sensitive to radiation therapy, of whom 10(11%) achieved pathological complete remission. Fifty-five patients were (58%) not responsive to radiation. Patients with low expression of MRP4 had a 66.7%(24/36) response rate, significantly higher than that of patients with high MRP4 expression (29.1%,16/59)(P<0.05). Patients with low expression of P53 had a 63.9%(23/36) response rate, significantly higher than that of patients with high P53 expression(28.8%,17/59)(P<0.01). The response rate after long course radiation therapy was 83.3%(20/24), significantly higher than that of patients who underwent short and medium course radiation[(31.3%, 5/16) and(27.3%,15/55)](P<0.01). Multivariate Logistic regression analysis showed radiation regimen, the expression of P53 and MRP4 protein were independently associated with the sensitivity of rectal cancer to radiation(P<0.05). CONCLUSION: MRP4 may serve as a predictive marker for the sensitivity of rectal cancer to preoperative radiation.