Calcium channel α2δ1 subunit (CACNA2D1) enhances radioresistance in cancer stem-like cells in non-small cell lung cancer cell lines.

PURPOSE: Radiotherapy is a major treatment method for patients with non-small cell lung cancer (NSCLC). However, the presence of radioresistant cancer stem cells (CSCs) may be associated with disease relapse or a poor outcome after radiotherapy. Voltage-gated calcium channel α2δ1 subunit (encoded by the gene CACNA2D1) isoform 5 is a marker of CSCs in hepatocellular carcinoma. This study aimed to investigate the radiosensitivity of α2δ1-high cells in NSCLC cell lines. MATERIALS AND METHODS: NSCLC cell lines A549, H1975, H1299, and PC9 were used. CACNA2D1-knockdown and CACNA2D1-overexpressing cell lines were established by lentiviral infection. Colony formation assay was performed to determine radiosensitivity. Sphere formation assay in serum-free medium was performed to evaluate self-renewal capacity. Proteins associated with DNA damage repair were analyzed by immunofluorescence or Western blot. The monoclonal antibody of α2δ1 was applied alone or in combination with radiation either in vitro or in vivo to determine the anti-tumor effect of the antibody. RESULTS: α2δ1-high cells showed greater sphere-forming efficiency than α2δ1-low cells and were relatively resistant to radiation. CACNA2D1 knockdown in A549 cells enhanced radiosensitivity, whereas CACNA2D1 overexpression in PC9 and H1975 cells reduced radiosensitivity, suggesting that α2δ1 imparted radioresistance to NSCLC cells. Analysis of proteins involved in DNA damage repair suggested that α2δ1 enhanced the efficiency of DNA damage repair. The monoclonal antibody of α2δ1 had a synergistic effect with that of radiation to block the self-renewal of α2δ1-high cells and enhanced the radiosensitivity of α2δ1-positive cells in colony formation assays. The combination of the α2δ1 antibody with radiation repressed A549 xenograft growth in vivo. CONCLUSION: α2δ1 enhances radioresistance in cancer stem-like cells in NSCLC. The α2δ1 monoclonal antibody sensitizes α2δ1-high cells to radiation, suggesting that the antibody may be used to improve the treatment outcome when combined with radiation in NSCLC.

Recombinant Adenovirus-p53 Gene Therapy for Advanced Unresectable Soft-Tissue Sarcomas.

Patients with unresectable advanced soft-tissue sarcomas (STS) receiving radiotherapy or/and chemotherapy still have a poor prognosis. This study aimed to evaluate retrospectively the efficacy and safety of recombinant adenovirus-p53 (rAd-p53) gene therapy combined with radiotherapy and hyperthermia for advanced STS. A total of 71 patients with advanced unresectable STS treated at the authors' center from April 2007 to November 2014 were included. Of these 71 patients, 36 cases received rAd-p53 therapy combined with radiotherapy and hyperthermia (p53 group), while 35 cases received radiotherapy and hyperthermia alone (control group). Short-term therapeutic efficacies, long-term survival outcomes, and adverse events were evaluated and compared between groups. Compared to the control group, the p53 group had a significantly higher disease control rate (83.33% vs. 54.29%; p = 0.008) and a lower progressive disease rate (16.67% vs. 45.71%; p = 0.018). In addition, rAd-p53 treatment significantly improved the progression-free survival and overall survival of STS patients. Cox regression indicated that rAd-p53 treatment significantly reduced the risks for disease progression or death event for STS patients. Furthermore, there was no significant difference in all adverse events, except for transient fever, which occurred in 89% of patients with rAd-p53 therapy. rAd-p53 combined with radiotherapy and hyperthermia can effectively improve the therapeutic efficacy and survival outcomes in patients with advanced unresectable STS, providing a new therapeutic strategy.

A consensus on liquid biopsy from the 2016 Chinese Lung Cancer Summit expert panel.

The diagnosis and treatment of lung cancer have evolved into the era of precision medicine. Liquid biopsy, a minimally invasive approach, has emerged as a promising practice in genetic profiling and monitoring of lung cancer. Translating liquid biopsy from bench to bedside has encountered various challenges, including technique selection, protocol standardisation, data analysis and cost management. Regarding these challenges, the 2016 Chinese Lung Cancer Summit expert panel organised a trilateral forum involving oncologists, clinicians, clinical researchers, and industrial expertise on the 13th Chinese Lung Cancer Summit to formally discuss these controversies. Six consensuses were reached to guide the use of liquid biopsy and perform precision medicine in both clinic and research.

Application of stereotactic body radiation therapy to cancer liver metastasis.

As an accurate external beam irradiation method, stereotactic body radiotherapy (SBRT) has been increasingly used to deliver high dose in less fractions. The liver is one of the most common organs for cancer metastasis. Recently, there have been several trials applying SBRT to cancer liver metastasis and have proved to be effective and safe with local control (LC) rates ranging from 70% to 100% within one or two years and 2-year overall survival (OS) rates ranging from 30% to 38%. Many published studies indicate that SBRT for cancer liver metastasis results in good outcomes without severe toxicities. However, the validated contribution of SBRT to an improved progression-free survival is still missing and more randomized trials should be conducted.

Volumetric-modulated arc therapy vs. c-IMRT in esophageal cancer: a treatment planning comparison.

AIM: To compare the volumetric-modulated arc therapy (VMAT) plans with conventional sliding window intensity-modulated radiotherapy (c-IMRT) plans in esophageal cancer (EC). METHODS: Twenty patients with EC were selected, including 5 cases located in the cervical, the upper, the middle and the lower thorax, respectively. Five plans were generated with the eclipse planning system: three using c-IMRT with 5 fields (5F), 7 fields (7F) and 9 fields (9F), and two using VMAT with a single arc (1A) and double arcs (2A). The treatment plans were designed to deliver a dose of 60 Gy to the planning target volume (PTV) with the same constrains in a 2.0 Gy daily fraction, 5 d a week. Plans were normalized to 95% of the PTV that received 100% of the prescribed dose. We examined the dose-volume histogram parameters of PTV and the organs at risk (OAR) such as lungs, spinal cord and heart. Monitor units (MU) and normal tissue complication probability (NTCP) of OAR were also reported. RESULTS: Both c-IMRT and VMAT plans resulted in abundant dose coverage of PTV for EC of different locations. The dose conformity to PTV was improved as the number of field in c-IMRT or rotating arc in VMAT was increased. The doses to PTV and OAR in VMAT plans were not statistically different in comparison with c-IMRT plans, with the following exceptions: in cervical and upper thoracic EC, the conformity index (CI) was higher in VMAT (1A 0.78 and 2A 0.8) than in c-IMRT (5F 0.62, 7F 0.66 and 9F 0.73) and homogeneity was slightly better in c-IMRT (7F 1.09 and 9F 1.07) than in VMAT (1A 1.1 and 2A 1.09). Lung V30 was lower in VMAT (1A 12.52 and 2A 12.29) than in c-IMRT (7F 14.35 and 9F 14.81). The humeral head doses were significantly increased in VMAT as against c-IMRT. In the middle and lower thoracic EC, CI in VMAT (1A 0.76 and 2A 0.74) was higher than in c-IMRT (5F 0.63 Gy and 7F 0.67 Gy), and homogeneity was almost similar between VMAT and c-IMRT. V20 (2A 21.49 Gy vs. 7F 24.59 Gy and 9F 24.16 Gy) and V30 (2A 9.73 Gy vs. 5F 12.61 Gy, 7F 11.5 Gy and 9F 11.37 Gy) of lungs in VMAT were lower than in c-IMRT, but low doses to lungs (V5 and V10) were increased. V30 (1A 48.12 Gy vs. 5F 59.2 Gy, 7F 58.59 Gy and 9F 57.2 Gy), V40 and V50 of heart in VMAT was lower than in c-IMRT. MUs in VMAT plans were significantly reduced in comparison with c-IMRT, maximum doses to the spinal cord and mean doses of lungs were similar between the two techniques. NTCP of spinal cord was 0 for all cases. NTCP of lungs and heart in VMAT were lower than in c-IMRT. The advantage of VMAT plan was enhanced by doubling the arc. CONCLUSION: Compared with c-IMRT, VMAT, especially the 2A, slightly improves the OAR dose sparing, such as lungs and heart, and reduces NTCP and MU with a better PTV coverage.

Double CT imaging can measure the respiratory movement of small pulmonary tumors during stereotactic ablative radiotherapy.

PURPOSE: The purpose of this study was to investigate the application of double CT imaging to measuring the respiratory movement of small pulmonary tumors during stereotactic ablative radiotherapy (SABR). METHODS: A total of 122 small pulmonary tumors were measured in 45 patients. CT scans were conducted twice in all 122 tumors, once at the end of quiet inhalation and once at the end of exhalation. CT scans were conducted three times including at the end of quiet inhalation, at the end of exhalation and at free breathing in 36 tumors of 17 patients. The displacement of the tumor center in three directions was measured. RESULTS: The 3D motion of 122 tumors was 10.10±7.16 mm. On average, the tumors moved 1.96±2.03 mm (rang, 0-9 mm) in the X direction, 5.19±4.69 mm (rang, 0-19 mm) in the Y direction, and 7.38±6.48 mm (rang, 0-26 mm) in the Z direction. The 3D motion of tumors in the lower lung (13.00±7.64 mm) was significantly greater than that in the upper lung (7.15±5.14 mm), P<0.01. The 3D motion of the lower left lung was 16.35±7.31 mm, which was significantly greater than that of the lower right lung (11.40±7.04 mm), P<0.05. Movement in the anterior lung in the Y direction was significantly larger than in the posterior lung. The motion was 7.49±5.43 mm and 4.04±3.82 mm respectively, P<0.01. CONCLUSIONS: Double CT imaging provides accurate data for determining the outline of each target area during stereotactic ablative radiotherapy plane. The location of small pulmonary tumor foci was significantly affected by respiratory and cardiac motion.

Phase I Study to Determine MTD of Docetaxel and Cisplatin with Concurrent Radiation Therapy for Stage III Non-Small Cell Lung Cancer.

OBJECTIVE: To evaluate the maximum tolerated dose (MTD) of docetaxel (DCT) and cisplatin (DDP) concurrently with three dimensional (3D) conformal radiotherapy or IMRT for patients with locally advanced non-small cell lung cancer (stage IIIa and IIIb) after 2-4 cycles of induction chemotherapy. METHODS: Fourteen patients with histological/cytological proven stage III non-small-cell lung cancer were eligible. 3D or IMRT radiotherapy (60-70Gy in 30-35 fractions, 6-7weeks, 2 Gy/fraction) was delivered concurrently with cisplatin and docetaxel, 2 cycles during concurrent chemoradiotherapy (CCRT). The level I dosage was composed of 56 mg/m(2) DCT, on day 1 and 28mg/m(2) DDP, on day 1 and day 2. The level II was composed of 60 mg/m(2) DCT, on day 1 and 30 mg/ m(2) DDP, on day 1 and day 2. The level III was composed of 64 mg/m(2) DCT, on day 1 and 32 mg/ m(2) DDP, on day 1 and day 2. RESULTS: Fourteen patients were allocated and finished concurrent chemoradiotherapy. The dose-limiting neutropenia was at the dose Level III (64 mg/m(2)) and occurred in 2 of 5 patients. No dose limiting non-hematologic or hematologic toxicity occurred in the other patients. CONCLUSIONS: Patients with locally advanced non-small cell lung cancer may tolerate 60mg/m(2) docetaxel and 60mg/m(2) cisplatin for 2 cycles during concurrent radiotherapy after 2-3 cycles of induction chemotherapy.

Using diffusion-weighted MR imaging for tumor detection in the collapsed lung: a preliminary study.

The usefulness of diffusion-weighted magnetic resonance (MR) imaging (DWI) for differentiating central lung cancer from postobstructive lobar collapse (POC) was investigated. Thirty-three cases suspected of lung cancer and POC on chest bolus computed tomography (CT) underwent thoracic MR imaging examinations. MR examinations were performed using a 1.5-T clinical scanner. Scanning sequences were T1-weighted imaging, T2-weighted imaging (T2WI) and DWI with b=0, 500 s/mm(2), four excitations and segmented breath-holding. The densities and signals of cancer and postobstructive collapsed lung were compared on bolus-enhanced CT, T2W and DW images. Statistical analyses were performed with chi-square test, paired t-test, non-parameter test and kappa statistics. Differentiation between cancer and POC was possible on bolus CT, T2W and DW images in 14, 21 and 26 patients, respectively. Eight cases that were impossible to differentiate on T2W images were distinguishable on DWI, demonstrating that DWI is complementary to T2WI. Using a combination of T2W and DW images, 88% (29/33) of cases were differentiated on MR imaging. Thus, a combination of T2W and DW imaging is superior to bolus-CT or T2WI alone. The contrast-to-noise ratio of DWI was significantly higher than that of T2WI. Agreement between two independent observers on the differential ability of lung cancer and POC was higher for DWI (kappa=0.474) than for T2WI (kappa=0.339). The degree of consolidation around the cancer was negatively correlated with the degree of artifact and degree of deformation. It is feasible to use DWI to differentiate lung cancer from POC. DWI played a role in confirming and providing complementary information to that obtained from T2WI. Our data indicate that using a combination of the two scanned sequences was the best means of distinguishing between lung cancer and POC.

[Whole brain irradiation for non-small-cell lung cancer with brain metastasis].

OBJECTIVE: To investigate the time of whole brain irradiation and the prognostic factors for non-small lung cancer patients with brain metastasis. METHODS: From August 1996 to December 2003, 147 patients with brain metastasis from non-small cell lung cancer received whole brain irradiation. The patients were divided into two groups: with or without symptoms caused by brain metastasis, each group was then divided into two sub-groups, early whole brain irradiation group (the interval between the diagnosis of brain metastasis and the brain irradiation < or = one month) and late group ( the interval > one month ). Univariate and multivariate analysis (Cox regression) as well as Kaplan-Meier method in SPSS software package 11.5 was used to analyze the data of the 147 patients including 72 with brain metastasis symptom and 75 without. RESULTS: The median survival time (MS) of patients with or without extracranial metastasis was 9.9 months and 11.3 months (P = 0.0002). Multivariate analysis indicated that extracranial metastasis was an independent prognostic factor (P = 0.0004). For 72 patients with brain metastasis symptom, the MS of the patients with and without extracranial metastasis was 9.3 months and 11.3 months (P = 0.0036). The MS of patients with early and late whole brain irradiation was 11.4 months and 9.2 months (P = 0.001). Multivariate analysis showed that extracranial metastasis, the interval between the diagnosis of brain metastasis and the whole brain irradiation were independent prognostic factors. However, for 75 patients without brain metastasis symptom, the MS difference of those with early or late whole brain irradiation was not statistically significant (P = 0.1643). CONCLUSION: The extracranial metastasis in non-small cell lung cancer patients with brain metastasis is an independent prognostic factors. Early whole brain irradiation may improve the survival for those with brain metastasis symptoms.

[Survival status of stage IV non-small cell lung cancer patients after radiotherapy--a report of 287 cases].

BACKGROUND & OBJECTIVE: The patients with stage IV non-small cell lung cancer (NSCLC) usually need radiotherapy and have good responses, particularly in those with brain or bone metastases. This study was to evaluate the influence of radiotherapy on the survival of stage IV NSCLC patients. METHODS: Clinical data of 287 patients with stage IV NSCLC were retrospectively analyzed. Whole brain was treated with two parallel fields irradiation; bone metastases were treated with one local field irradiation. Primary tumors, regional lymph nodes and other distant metastases were treated by conventional fractionation radiotherapy or 3-dimensional conformal radiotherapy. Whole brain and bone radiotherapy was delivered with a total dose of 40 Gy in 20 fractions in 4 weeks or with a total dose of 30 Gy in 10 fractions in 2 weeks. The median dose for primary tumors and regional lymph nodes was 50 Gy (20-70 Gy), and the median dose for other distant metastases was 46 Gy (40-60 Gy). RESULTS: The median survival time of the 287 patients was 9 months (8-10 months). The 1- and 2-year overall survival rates were 30.2% and 8.9%. The median survival time was significantly longer in the patients received chemotherapy than in the patients didn't (10 months vs. 8 months, P = 0.049). In the patients with brain, bone, or other distant metastases, the median survival time was 8, 9, and 10 months, respectively; the 1-year survival rates were 24.8%, 28.7%, and 37.5%, respectively; the 2-year survival rates were 6.7%, 7%, and 15.3%, respectively. By unitivariate analysis, histological type and patients' age were prognostic factors of NSCLC. The median survival time was significantly longer in adenocarcinoma patients than in squamous cell carcinoma patients and other carcinoma patients (10 months vs. 7 and 9 months, P = 0.046), longer in the patients of < or =60 years old than in those of >60 years old (11 months vs. 8 months, P = 0.012), and longer in the patients with only bone metastases than in the patients with concomitant other distant metastases (10 months vs. 6 months, P = 0.033), but there was no significant difference between the patients with only brain metastases and those with concomitant other distant metastases (9 months vs. 8 months, P = 0.374). Radiotherapy for primary tumors and lymph nodes, complications of other chronic diseases, and irradiation dose and pattern had no effect on the survival. CONCLUSIONS: Histological type and patients' age may affect the efficacy of radiotherapy on stage IV NSCLC. The irradiation patterns of 40 Gy in 20 fractions in 4 weeks or 30 Gy in 10 fractions in 2 weeks have no effect on the survival of patients with brain or bone metastases.

[Recombinant adenovirus-p53 gene therapy combined with radiotherapy for head and neck squamous-cell carcinoma].

OBJECTIVE: To evaluate the efficacy and safety of recombinant adenovirus-p53 gene (Gendicine) therapy combined with radiotherapy for head and neck squamous-cell carcinoma (HNSCC). METHODS: From Oct. 2001 to May 2003, a randomized controlled clinical trial on Gendicine combined with radiation in 36 patients (gene therapy + radiotherapy, GTRT) vs. radiotherapy alone in 33 patients (RT) with HNSCC was completed. In the GTRT group, Gendicine 1 x 10(12) VP (virus particle) was injected intratumorally once a week for eight weeks, and concurrently followed by irradiation. For both groups, the conventional fractionation 2 Gy/f, five fractions a week to a total dose of 70 Gy, was given to either primary tumor or neck lymph nodes. Tumor response was assessed by CT image at 40 Gy, 70 Gy, 2 months after treatment to evaluate the response rate of CR, PR, SD and PD. RESULTS: Wild-type p53 gene significantly enhanced radiotherapeutic effectiveness in patients with HNSCC (P < 0.05). The CR rate of tumors treated by GTRT was increased by nearly 2.31 times more than that of tumors treated by RT alone. No dose-limiting toxicity and adverse events were noted, except transient fever after Gendicine administration. CONCLUSION: Intratumoral injection of Gendicine to HNSCC patients is safe and effective. The apparent improved results of combined therapy with Gendicine and radiation suggest that p53 gene therapy has promising therapeutic potential in cancer treatment.

[Treatment of head and neck squamous cell carcinoma by recombinant adenovirus-p53 combined with radiotherapy: a phase II clinical trial of 42 cases].

OBJECTIVE: To evaluate the efficacy and safety of recombinant adenovirus-p53 (Adp53, SBN-1) combined with radiotherapy in treatment of head and neck squamous cell carcinoma (HNSCC). METHODS: Forty-two patients with HNSCC were randomly divided into 2 groups: gene therapy + radiotherapy group (GTRT group. n = 20, SBN-1 solution 1 x 10(12) VP was injected intratumorally once a week for 8 weeks and radiotherapy was begun since the 3rd day of gene therapy 5 fractions a week with the with the fraction dosage of 2 Gy and total dosage of 70 GY) and radiotherapy group (RT group. n = 22, the above regimen of radiotherapy was conducted). CT was conducted 5 weeks and 8 weeks after the beginning of treatment and 2 months after the finish of treatment (validation point) to calculate the size of tumor. Patients were monitored for adverse event and serum level of anti-adenoviral antibody. A comparative study was also performed on the immediate response rate by CT at the times when the dosages of 40 Gy and 70 Gy had been given. RESULTS: The average tumor reduction rates were (63 +/- 17)%, (82 +/- 18)%, and (90 +/- 16)% at the 40 Gy time point, 70 Gy time point, and validation point respectively in the GTRT group, all higher than those in the RT group (37 +/- 26)%, (62 +/- 39)%, and (70 +/- 34)% respectively, all P < 0.05. Random control study showed that the radio-sensitized enhancement rate was 1.72 at 40 Gy time point and the CR rate of the GRTR group at the validation point was 1.68 times higher than that of the RT group. Self-controlled study showed that the SBN-1 radio-sensitized enhancement ratio in the 4 GTRT group was 1.69 at 40 Gy time point and the CR rate of the GTRT group at validation point was 253% that of the RT group (P < 0.01). No dose-limiting toxicity and adverse events were noted, except transient fever after SBN-1 administration. CONCLUSION: A potentially effective gene therapeutic agent for HNSCC treatment, intratumoral injection of SBN-1 is safe.