Natural killer cells have a synergistic anti-tumor effect in combination with chemoradiotherapy against head and neck cancer.

BACKGROUND: The use of natural killer (NK) cells is a promising approach in the field of cancer immunotherapy; however, combination treatments are required to enhance the effects of NK cell immunotherapy. In this study, we assessed the potential of irradiation and cisplatin as a chemoradiotherapy (CRT) regimen to augment the effects of NK cell immunotherapy in head and neck squamous cell carcinoma (HNSCC). METHODS: NK cells were expanded using our recently established K562-OX40 ligand and membrane-bound interleukin (IL)-18 and IL-21 feeder cells in the presence of IL-2/IL-15 from peripheral blood of healthy donors. RESULTS: The results showed an increase in the purity of NK cells and expression of activation markers such as NKG2D and lymphocyte function-associated antigen 1 during the expansion process, which is positively correlated to the NK cell infiltration and overall survival in patients with HNSCC. CRT induced NK cell activation ligand (ULBP2) and adhesion molecules (ICAM-1, -2 and -3) on HNSCC, leading to enhanced cytotoxicity of NK cells against HNSCC. CONCLUSIONS: Our findings suggest that the NK cells have a potent anti-tumor effect in combination with CRT against HNSCC.

Flagellin synergistically enhances anti-tumor effect of EGFRvIII peptide in a glioblastoma-bearing mouse brain tumor model.

BACKGROUND: Glioblastoma (GBM) is the most aggressive type of brain tumor with heterogeneity and strong invasive ability. Treatment of GBM has not improved significantly despite the progress of immunotherapy and classical therapy. Epidermal growth factor receptor variant III (EGFRvIII), one of GBM-associated mutants, is regarded as an ideal therapeutic target in EGFRvIII-expressed GBM patients because it is a tumor-specific receptor expressed only in tumors. Flagellin B (FlaB) originated from Vibrio vulnificus, is known as a strong adjuvant that enhances innate and adaptive immunity in various vaccine models. This study investigated whether FlaB synergistically could enhance the anti-tumor effect of EGFRvIII peptide (PEGFRvIII). METHODS: EGFRvIII-GL261/Fluc cells were used for glioblastoma-bearing mouse brain model. Cell-bearing mice were inoculated with PBS, FlaB alone, PEGFRvIII alone, and PEGFRvIII plus FlaB. Tumor growth based on MRI and the survival rate was investigated. T cell population was examined by flow cytometry analysis. Both cleaved caspase-3 and CD8 + lymphocytes were shown by immunohistochemistry (IHC) staining. RESULTS: The PEGFRvIII plus FlaB group showed delayed tumor growth and increased survival rate when compared to other treatment groups. As evidence of apoptosis, cleaved caspase-3 expression and DNA disruption were more increased in the PEGFRvIII plus FlaB group than in other groups. In addition, the PEGFRvIII plus FlaB group showed more increased CD8 + T cells and decreased Treg cells than other treatment groups in the brain. CONCLUSIONS: FlaB can enhance the anti-tumor effect of PEGFRvIII by increasing CD8 + T cell response in a mouse brain GBM model.

Live cell imaging of highly activated natural killer cells against human hepatocellular carcinoma in vivo.

BACKGROUND AIMS: Tracking administered natural killer (NK) cells in vivo is critical for developing an effective NK cell-based immunotherapy against human hepatocellular carcinoma (HCC). Here the authors established a new molecular imaging using ex vivo-activated NK cells and investigated real-time biodistribution of administered NK cells during HCC progression. METHODS: Ex vivo-expanded NK cells from healthy donors were labeled with a near-infrared lipophilic cytoplasmic dye, and their proliferation, surface receptor expression and cytotoxicity activity were evaluated. Human HCC HepG2 cells were implanted into the livers of NOD.Cg-Prkdcscid IL2rgtm1Wjl/SzJ (NSG) mice. The authors administered 1,1'-dioctadecyltetramethyl indotricarbocyanine iodide (DiR)-labeled NK cells intravenously to non-tumor-bearing and intrahepatic HCC tumor-bearing NSG mice. Fluorescent imaging was performed using a fluorescence-labeled organism bioimaging instrument. Single cell suspensions from the resected organs were analyzed using flow cytometry. RESULTS: The fluorescent DiR dye was nontoxic and did not affect the proliferation or surface receptor expression levels of the NK cells, even at high doses. The administered DiR-labeled NK cells immediately migrated to the lungs of the non-tumor-bearing NSG mice, with increased NK cell signals evident in the liver and spleen after 4 h. NK cells migrated to the intrahepatic tumor-bearing livers of both early- and late-stage HCC mice within 1 h of injection. In early-stage intrahepatic tumor-bearing mice, the fluorescence signal increased in the liver until 48 h post-injection and decreased 7 days after NK injection. In late-stage HCC, the NK cell fluorescence signal was the highest in the liver for 7 days after NK injection and persisted for 14 days. The purity of long-term persistent CD45+CD56+CD3- NK cells was highest in early- and late-stage HepG2-bearing liver compared with normal liver 2 weeks after NK injection, whereas highest purity was still observed in the lungs of non-tumor-bearing mice. In addition, Ki-67 expression was detected in migrated human NK cells in the liver and lung up to 72 h after administration. With HepG2 tumor progression, NK cells reduced the expression of NKp30 and NKG2D. CONCLUSIONS: Administered NK cells were successfully tracked in vivo by labeling the NK cells with near-infrared DiR dye. Highly expanded, activated NK cells migrated rapidly to the tumor-bearing liver, where they persisted for 14 days after administration, with high purity of CD45+CD56+CD3- NK cells. Liver biodistribution and persistence of administered NK cells showed significantly different accumulation patterns during HCC progression.

Effect of irradiation-induced intercellular adhesion molecule-1 expression on natural killer cell-mediated cytotoxicity toward human cancer cells.

BACKGROUND AIMS: Irradiation enhances the adhesion between natural killer (NK) cells and target cells by up-regulating intercellular adhesion molecule-1 (ICAM-1) on target cells. Therefore, we investigated the effect of irradiation-induced ICAM-1 expression on human cancer cells on NK cell-mediated cytotoxicity. METHODS: Expression levels of ICAM-1 on the target cell surface before and after irradiation of six human cancer cell lines (HL60, SKBR-3, T47D, HCT-116, U937 and U251) were analyzed by flow cytometry. Ex vivo expansion of NK cells from human peripheral blood mononuclear cells was performed by co-culture with irradiated K562 cells. The related adhesion molecule lymphocyte function-associated antigen 1 (LFA-1) on NK cells was analyzed by flow cytometry. An enzyme-linked immunosorbent assay was used to detect interferon-γ (IFN-γ), and WST-8 assays were performed to check NK cell cytotoxicity. Finally, blocking assays were performed using monoclonal antibodies against ICAM-1 or LFA-1. RESULTS: LFA-1 expression increased on NK cells after expansion (P <0.001). The expression of ICAM-1 was significantly upregulated by irradiation after 24 h in various cell lines, including HL60 (P <0.001), SKBR-3 (P <0.001), T47D (P <0.001) and U937 (P <0.001), although the level of expression depended on the cell line. ICAM-1 expression was extremely low before and after irradiation in U251 cells. NK cell-mediated cytotoxicity increased after irradiation of HL60 (P <0.001), SKBR-3 (P <0.001), T47D (P = 0.003), and U937 (P = 0.004) cells, in which ICAM-1 expression was significantly increased after irradiation. IFN-γ production by NK cells in response to HL60 (P <0.001) and T47D (P = 0.011) cells significantly increased after irradiation. NK cell-mediated cytotoxicity against irradiated SKBR-3 (P <0.001) and irradiated T47D cells (P = 0.035) significantly decreased after blocking of ICAM-1. Blocking of LFA-1 on NK cells resulted in reduced cytotoxicity against irradiated HL60 (P <0.001) and irradiated SKBR-3 (P <0.001). CONCLUSIONS: Irradiation upregulates ICAM-1 expression on the surface of human cancer cells and enhances activated NK cell-mediated cytotoxicity. Therefore, irradiation combined with NK cell therapy may improve the antitumor effects of NK cells.

Correlation of biologically effective dose and the tumor control in Stage I (<5 cm) non-small cell lung cancer with stereotactic ablative radiotherapy: a single institutional cohort study.

BACKGROUNDS: Stereotactic ablative radiotherapy (SABR) is one of the newly developed innovative radiotherapy and of which optimal dose prescription needs to be standardized. We aimed to investigate the dose-response relationship for patients with SABR. METHODS: Fifty-three patients with Stage I non-small cell lung cancer patients, who underwent SABR between November 2006 and January 2015, were evaluated retrospectively. Thirteen patients (24.5%), who refused the surgery were included and 40 patients (75.5%) were medically inoperable at diagnosis. The median age was 74 years. The median SABR dose was 50 Gy in 3-8 fractions and the median biologically effective dose (BED;α/ß = 10) was 105.6 Gy (range: 60-160.53 Gy). RESULTS: The median follow-up was 37.1 months. The 1 and 3 year local control rates were 91.7% and 85.1%. The 3 year overall and progression-free survival rate were 63.3% and 47.5%, respectively, and freedom from progression was 62.2%. Local control rate and 3-year overall survival according to tumor size was 100% and 79.4% in T1 tumors in a while 61.8% and 45% in T2a tumors. The 3-year local and regional control by BED10 was 79.4% and 69.4% in ≤100 Gy vs. 89.1% and 100% in >100 Gy (P = 0.526, 0.004). Dyspnea more than Grade 3 was reported in six (11.3%) patients and Grade 1 chest pain was shown in five (9.4%) patients. CONCLUSIONS: The excellent regional control was conferred with a prescription of more than BED10 of 100 Gy, which also might be needed to achieve better local tumor control in T2a patients with tolerable lung function.

Tumour size, volume, and marker expression during radiation therapy can predict survival of cervical cancer patients: a multi-institutional retrospective analysis of KROG 16-01.

OBJECTIVE: The aim of this multi-institutional study was to determine the prognostic impact of tumour parameters, such as tumour size (TS), tumour volume (TV), and marker expression, on survival during radiation therapy (RT) for cervical cancer patients. METHODS: A total of 231 patients with histologically confirmed cervical cancer, classified as Federation of Gynecology and Obstetrics (FIGO) Ib2-IVa, were enrolled in this study. Pre- and mid-RT pelvic magnetic resonance imaging (MRI) and squamous cell carcinoma antigen (SCC-ag) analysis were performed twice, during RT and just before brachytherapy. RESULTS: The median follow-up time was 27.8months (range, 2-116months). Multivariate analysis revealed that stage (odds ratio [OR], 2.936 and 95% confidence interval [CI], 1.119-7.707; P=0.029), tumour volume reduction rate (TVRR) (OR, 3.435 and 95% CI, 1.062-11.106; P=0.039), and SCC-ag reduction rate (SCCRR) (OR, 5.104 and 95% CI, 1.769-14.727; P=0.003) were independently associated with overall survival (OS), while pre-RT TS (OR, 2.148 and 95% CI, 1.221-3.810; P=0.009), mid-RT TV (OR, 3.106 and 95% CI, 1.685-5.724; P<0.0001) and SCCRR (OR, 1.954 and 95% CI, 1.133-3.369; P=0.016) were associated with progression-free survival (PFS). Based on the prognostic factor analysis, patients with the highest prognostic risk score of 3 showed poorer overall survival and progression free survival than patients with lower prognostic risk scores. CONCLUSION: We identified that tumour parameters such as TVRR, SCCRR, pre-RT TS, and mid-RT TV areindependent and strong prognostic parameters for patients with cervical cancer receiving RT. This scoring system-based prognostic factor analysis could be used to help develop optimized treatment plans for cervical cancer patients during RT.

Magnetic resonance imaging during definitive chemoradiotherapy can predict tumor recurrence and patient survival in locally advanced cervical cancer: A multi-institutional retrospective analysis of KROG 16-01.

OBJECTIVE: Definitive chemoradiotherapy (CRT) followed by brachytherapy is a standard treatment for locally advanced cervical cancer. During CRT, marked reduction of cervical tumor is often observed in magnetic resonance imaging (MRI). The primary aim of this study was to assess the association between tumor response in MRI using FIGO classification and clinical outcomes. METHODS: Multi-institutional data were retrospectively reviewed to identify the significance of MR tumor response on tumor recurrence and patient survival. 225 patients with histologically confirmed squamous cell carcinoma of the cervix, staged as FIGO Ib2-IVa on initial pelvic MRI, were included. Post-CRT MRI was performed median 35days after the beginning of CRT and before brachytherapy. A median 54Gy of external radiation was given with weekly cisplatin during CRT. RESULTS: 112 (49.7%) of the 225 patients showed a positive response in post-CRT MRI and were named the responsive arm. After a median follow-up time of 36.2months, the responsive arm had significantly lower para-aortic recurrence (7.5% vs. 12.4%; p=0.04) and distant metastasis (13.2% vs. 27.6%; p=0.03) rates than did the non-responsive arm. The responsive arm had significantly higher 3-year cause-specific survival rate (94.6% vs. 81.1%, p<0.01) than did the non-responsive arm. In the multivariate analysis, tumor size (hazard ratio, 1.91 and 95% confidence interval, 1.07-3.43; p=0.028) and positive MR response (hazard ratio, 1.75 and 95% confidence interval, 1.06-2.27; p=0.045) were significant factors for recurrence-free survival CONCLUSION: Early tumor response evaluation with MRI using FIGO classification effectively predicted distant tumor metastasis and disease-specific survival in locally advanced cervical cancer.

Irradiation of breast cancer cells enhances CXCL16 ligand expression and induces the migration of natural killer cells expressing the CXCR6 receptor.

BACKGROUND AIMS: Few studies have examined the migration pattern of natural killer (NK) cells, especially after radiation treatment for cancer. We investigated whether irradiation can modulate the expression of chemokines in cancer cells and the migration of NK cells to irradiated tumor cells. METHODS: The expression of chemokine receptors (CXCR3, CXCR4 and CXCR6) on interleukin-2 (IL-2)/IL-15-activated NK cells was assessed using flow cytometry. Related chemokine ligands (CXCL11, CXCL12 and CXCL16) in human breast cancer cell lines (MCF7, SKBR3 and MDA-MB231) irradiated at various doses were assessed using reverse transcription-polymerase chain reaction (RT-PCR), fluorescence-activated cell sorting (FACS) and enzyme-linked immunosorbent assay (ELISA). The cell-free culture supernatant was collected 96 h after irradiation of breast cancer cell lines for migration and blocking assays. RESULTS: The activated NK cells expressed CXCR6. Expression of the CXCR6 ligand CXCL16 increased in a time- and dose-dependent manner in all analyzed cancer cell lines. CXCL16 expression was statistically significantly enhanced in all breast cancer cell lines on day 3 after 20 Gy irradiation. Activated NK cells migration correlated with CXCL16 concentration (R2 = 0.91; P <0.0001). Significantly enhanced migration of NK cells to irradiated cancer cells was observed for a dose of 20 Gy in MCF7 (P = 0.043) and SKBR3 (P = 0.043) cells, but not in MDA-MB231 (P = 0.225) cells. A blocking assay using a CXCR6 antibody showed a significant decrease in the migration of activated NK cells in all cancer cell lines. CONCLUSIONS: Our data indicate that irradiation induces CXCL16 chemokine expression in cancer cells and enhances the migration of activated NK cells expressing CXCR6 to irradiated breast cancer cells. These results suggest that radiation would improve the anti-tumor effect of NK cells through enhanced migration of NK cells to tumor site for the treatment of patients with breast cancer.

Predictive factors for survival and correlation to toxicity in advanced Stage III non-small cell lung cancer patients with concurrent chemoradiation.

OBJECTIVE: Concurrent chemoradiotherapy is the standard treatment for locally advanced Stage III non-small cell lung cancer in patients with a good performance status and minimal weight loss. This study aimed to define subgroups with different survival outcomes and identify correlations with the radiation-related toxicities. METHODS: We retrospectively reviewed 381 locally advanced Stage III non-small cell lung cancer patients with a good performance status or weight loss of <10% who received concurrent chemoradiotherapy between 2004 and 2011. Three-dimensional conformal radiotherapy was administered once daily, combined with weekly chemotherapy. The Kaplan-Meier method was used for survival comparison and Cox regression for multivariate analysis. Multivariate analysis was performed using all variables with P values <0.1 from the univariate analysis. RESULTS: Median survival of all patients was 24 months. Age > 75 years, the diffusion lung capacity for carbon monoxide ≤80%, gross tumor volume ≥100 cm(3) and subcarinal nodal involvement were the statistically significant predictive factors for poor overall survival both in univariate and multivariate analyses. Patients were classified into four groups according to these four predictive factors. The median survival times were 36, 29, 18 and 14 months in Groups I, II, III and IV, respectively (P < 0.001). Rates of esophageal or lung toxicity ≥Grade 3 were 5.9, 14.1, 12.5 and 22.2%, respectively. The radiotherapy interruption rate differed significantly between the prognostic subgroups; 8.8, 15.4, 22.7 and 30.6%, respectively (P = 0.017). CONCLUSION: Severe toxicity and interruption of radiotherapy were more frequent in patients with multiple adverse predictive factors. To maintain the survival benefit in patients with concurrent chemoradiotherapy, strategies to reduce treatment-related toxicities need to be deeply considered.

A multicenter analysis of adjuvant therapy after surgery for stage IIIC endometrial adenocarcinoma: A Korean Radiation Oncology Group study (KROG 13-17).

OBJECTIVE: To investigate whether combined chemoradiotherapy (CTRT) confers a benefit for survival outcome over radiotherapy (RT) alone after primary surgery in patients with FIGO stage IIIC endometrial adenocarcinoma. METHODS: We conducted a multicenter retrospective study of patients with surgical stage IIIC endometrial cancer from 1990 to 2011. Adjuvant RT alone was performed in 85 patients (40.3%) and adjuvant CTRT in 126 patients (59.7%). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazards model. RESULTS: Stage IIIC1 and stage IIIC2 accounted for 63% and 37%, respectively. FIGO IIIC2 had a higher recurrence rate than FIGO IIIC1 (38.5% vs. 29.3%, p=0.172). Five-year OS and DFS were lower in FIGO IIIC2 than FIGO IIIC1 (85.1% vs. 76.9%, p=0.417; 71.0% vs. 59.2%, p=0.108, respectively). Eighteen patients (13.5%) in stage IIIC1 developed PALN recurrence, whereas only one (3.3%) in stage IIIC2 had PALN recurrence (p=0.001). In multivariate analysis, predictors of DFS were parametrial invasion (HR, 3.49; 95% CI, 1.83-6.64; p<0.001), higher grade (HR, 2.78; 95% CI, 1.31-5.89; p=0.008), and >3 positive pelvic nodes (HR, 1.84; 95% CI, 1.11-3.05; p=0.019). Combined CTRT did not affect DFS or OS in IIIC1 and IIIC2 compared with RT alone. CONCLUSION: CTRT showed comparable survival outcome to RT alone. Half of relapses (46%) in stage IIIC1 occurred in PALN region, whereas relapse in stage IIIC2 primarily occurred in distant metastasis (90%). Future randomized studies are needed to determine which subgroup may be most likely to benefit from CCRT.

Comparison of clinical outcomes of adenocarcinoma and adenosquamous carcinoma in uterine cervical cancer patients receiving surgical resection followed by radiotherapy: a multicenter retrospective study (KROG 13-10).

OBJECTIVE: To evaluate the prognostic influence of adenocarcinoma (AC) and adenosquamous carcinoma (ASC) in patients with FIGO stage IB-IIA cervical cancer who received radical hysterectomy followed by adjuvant radiotherapy (RT) or concurrent chemoradiotherapy (CCRT). METHODS: We analyzed 1323 patients who satisfied the following criteria: histologically proven squamous cell carcinoma (SCC), AC, or ASC of the uterine cervix; FIGO stage IB-IIA disease; no history of neoadjuvant chemotherapy; and a history of radical hysterectomy with pelvic lymph node (PLN) dissection, followed by postoperative pelvic RT at a dose ≥ 45 Gy. The median age was 50 years. Median RT dose delivered to the whole pelvis was 50.4 Gy, and 219 (16.6%) patients received brachytherapy at a median dose of 24 Gy. Concurrent chemotherapy was delivered to 492 (37.2%) patients. RESULTS: Pathologic risk factors were not different according to pathologic subtype. The median follow-up duration was 75.7 months. Locoregional recurrence-free survival, relapse-free survival (RFS), and overall survival were significantly affected by histology, tumor size, PLN metastasis, parametrial invasion, lymphovascular invasion, and deep stromal invasion. The 5-year RFS rates were 83.7%, 66.5%, and 79.6% in patients with SCC, AC, and ASC histology, respectively (P<0.0001). By multivariate analysis, AC histology was the only significant prognostic factor affecting all survival outcomes. CONCLUSIONS: AC histology was associated with poor survival outcomes in patients with FIGO stage IB-IIA cervical cancer who received adjuvant RT or CCRT. Prognosis of ASC histology was closer to that of SCC histology than that of AC histology.

Efficacy of hypofractionated preoperative chemoradiotherapy in rectal cancer.

The efficacy and toxicity of hypofractionated preoperative chemoradiotherapy (HPCRT) combined with oral capecitabine was evaluated in patients with rectal cancer. HPCRT was delivered by intensity-modulated radiotherapy of either 33 Gy to the whole pelvis or 35 Gy in 10 fractions to the primary tumor and 33 Gy to the surrounding pelvis. Surgery was performed 4-8 weeks after HPCRT completion. Oral capecitabine was administered concurrently. A total of 76 patients were eligible for this study, and patient numbers in clinical stages I, II, III and IVA were 5, 29, 36 and 6, respectively. Tumor response, toxicity and survival were analyzed. A total of 9/76 patients (11.8%) achieved a pathological complete response. Sphincter preservation was achieved in 23/32 (71.9%) and 44/44 (100%) of patients with a distal extent from the anal verge of ≤5 and >5 cm, respectively. A total of 28/76 patients (36.8%) achieved tumor-downstaging and 25/76 (32.9%) achieved nodal (N)-downstaging. The 5-year disease-free survival (DFS) and overall survival rates were 76.5% and 90.6%, respectively. In the multivariate analysis for DFS, pathological N stage and lymphovascular space invasion were notable prognostic factors. A total of 6 patients in stage IVA underwent salvage treatments for lung or liver metastasis after HPCRT completion, and all 6 were alive at the last follow-up. Only 4 patients experienced grade 3 postoperative complications. No grade 4 toxicities were observed. HPCRT of 33 or 35 Gy in 10 fractions showed similar results to those of long-course fractionation. This fractionation scheme could be beneficial for patients with early stage disease, locally advanced rectal cancer, simultaneous distant metastasis requiring early intervention or for patients who wish to avoid multiple hospital visits.

Randomized, Multicenter, Phase 3 Study of Accelerated Fraction Radiation Therapy With Concomitant Boost to the Gross Tumor Volume Compared With Conventional Fractionation in Concurrent Chemoradiation in Patients With Unresectable Stage III Non-Small Cell Lung Cancer: The Korean Radiation Oncology Group 09-03 Trial.

PURPOSE: We designed the Korean Radiation Oncology Group 09-03 phase III clinical trial to compare accelerated hypofractionated radiation therapy (RT) using a concomitant boost to the gross tumor volume (GTV) with conventionally fractionated 60-Gy RT in patients with stage III unresectable non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: A conventionally fractionated RT group (arm 1; 124 patients) received a 2-Gy daily dose to a total cumulative dose of 44 Gy to the planning target volume (PTV) in 22 fractions and 60 Gy to the GTV in 30 fractions over 6 weeks. A hypofractionated RT group (arm 2; 142 patients) received a 1.8-Gy daily dose to the PTV with a synchronous boost of 0.6 Gy to the GTV, for total cumulative doses of 45 Gy to the PTV and 60 Gy to the GTV in 25 fractions over 5 weeks. All patients received concurrent weekly chemotherapy consisting of paclitaxel and cisplatin. RESULTS: The objective response rate of all patients was 86.5% (arm 1, 84.6%; arm 2, 88.1%; P = .612). The median overall survival was 26 months (arm 1, 26 months; arm 2, 27 months; P = .508). The median progression-free survival was 11 months (arm 1, 10 months; arm 2, 13 months; P = .295). The local tumor control rates at 2 and 5 years were 58.3% and 50.7%, respectively (arm 1, 62.4% and 51.0%, respectively; arm 2, 54.0% and 48.6%, respectively; P = .615). There were no significant between-group differences in the cumulative incidence of grade ≥3 radiation pneumonitis (P = .134) or radiation esophagitis (P = .539). CONCLUSIONS: This clinical trial did not confirm the superiority of accelerated 2.4-Gy hypofractionated RT compared with conventional 2-Gy fractionation in patients with unresectable stage III NSCLC undergoing concurrent chemoradiation therapy.

PIVKA-II as a surrogate marker for prognosis in patients with localized hepatocellular carcinoma receiving stereotactic body radiotherapy.

PURPOSE: This study aimed to determine the correlation between protein induced by vitamin K absence or antagonist-II (PIVKA-II) and stereotactic body radiotherapy (SBRT) in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Sixty-one patients received SBRT between 2015 and 2020 with a median dose of 48 Gy (range, 39 to 60 Gy) with a median of 4 fractions. Changes in tumor markers before and after SBRT were analyzed. RESULTS: The median follow-up period was 31 months (range, 12 to 64 months). The estimated 2-year in-field failure-free survival, progression-free survival (PFS), and overall survival rates were 82.0%, 39.3%, and 96.7%, respectively. Patients with decreased PIVKA-II levels through SBRT had significantly few in-field failures (p = 0.005). Patients with PIVKA-II levels of ≤25 mAU/mL after SBRT had significantly long PFS (p = 0.004). CONCLUSION: PIVKA-II could be a useful surrogate marker for response or survival outcomes in patients with localized HCC receiving SBRT.

Metabolic response of pelvic and para-aortic lymph nodes during radiotherapy for carcinoma of the uterine cervix: using positron emission tomography/computed tomography.

OBJECTIVES: We evaluated the metabolic response of lymph nodes (LNs) using consecutive F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) and correlated the metabolic response with the volumetric response measured by consecutive CT. METHODS: Twenty-two patients with cervical cancer that had positive LNs underwent preradiotherapy (pre-RT) and inter-RT PET/CT. The metabolic response of the LNs was assessed quantitatively and semiquantitatively by measurement of the maximal standardized uptake value. All patients underwent inter-RT CT simulation after 45 Gy to the whole pelvis and inter-RT PET/CT scans after median 63 Gy to the gross LNs. RESULTS: A total of 48 pelvic and para-aortic LNs were found on the pre-RT PET/CT. The mean maximal standardized uptake value of nodal disease decreased from the pre-RT of 5.2 (SD, 3.1; range, 1.8-15.6) to the inter-RT of 1.1 (SD, 2.1; range, 0-11.1). Classifying the metabolic response of all 48 nodal lesions on the inter-RT PET/CT, 38 had a complete metabolic response. The initial volume of LNs had no correlation with the metabolic response (r = 0.194, P = 0.186). The metabolic response between the pre-RT PET/CT and inter-RT PET/CT was significantly associated with the volume response between the pre-RT CT and inter-RT CT (r = 0.314, P < 0.05). However, 18 (38%) LNs showed discrepancy between metabolic response and residual LN volume. Six (27%) patients had modified RT during treatment based on inter-RT PET/CT. CONCLUSIONS: We suggest that the PET/CT can be a useful tool for the evaluation of the interim response of the LNs and aid in selecting patients that need further treatment. The results showed a significant correlation between the metabolic and volumetric responses during RT, although the anatomical changes of LNs would not always represent the metabolic status.

VEGF as a predictor for response to definitive chemoradiotherapy and COX-2 as a prognosticator for survival in esophageal squamous cell carcinoma.

We investigated the patterns of pretreatment expression of the epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) by immunohistochemical staining and determined their correlation with treatment response and survival in 44 patients with esophageal squamous cell carcinoma (ESCC) treated with definitive concurrent chemoradiotherapy (CCRT). The definitive CCRT consisted of a median dose of 54 Gy (range: 40.0-68.4 Gy) and two cycles of concurrent administration of mostly 5-fluorouracil + cisplatinum. High expression of EGFR, VEGF, and COX-2 was found in 79.5%, 31.8%, and 38.6%, respectively. The Cox regression analysis for overall survival (OS) showed that both the treatment response and COX-2 expression were significant. The 3-yr OS rates of patients that achieved a complete response and those that did not were 46.7% and 5.3%, respectively (P = 0.006). The logistic regression analysis for treatment response with various parameters showed that only a high expression of VEGF was significantly associated with a complete response. Unlike other well-known studies, higher expression of VEGF was significantly correlated with a complete response to CCRT in this study. However, higher expression of COX-2 was significantly associated with shorter survival. These results suggest that VEGF might be a predictive factor for treatment response and COX-2 a prognostic factor for OS in patients with ESCC after definitive CCRT.

Imaging Calreticulin for Early Detection of Immunogenic Cell Death During Anticancer Treatment.

Surface-exposed calreticulin (ecto-CRT) is a well-known "eat-me" signal exhibited by dying cells that contributes to their recognition and destruction by the immune system. We assessed the use of a CRT-specific binding peptide for imaging ecto-CRT during immunogenic cell death and its utility for early prediction of treatment response. Methods: A synthetic CRT-specific peptide, KLGFFKR (CRTpep), was labeled with fluorescein isothiocyanate or 18F, and the characteristics of ecto-CRT were evaluated in a colon cancer cell line in vitro and in vivo. Results: In vitro flow cytometry, immunofluorescence staining, and in vivo small-animal PET imaging results showed that CRTpep detected preapoptotic cells treated with immunogenic drugs or radiation but not those treated with the nonimmunogenic drug or a nontherapeutic dose of immunogenic drug. Conclusion: The present results indicate that the CRT-specific peptide would enable the prediction of therapeutic response, thereby facilitating early decisions on continuation or discontinuation of immunogenic treatment.

A dummy-run evaluation of postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trials for cervical cancer.

The postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trial is a phase II study to evaluate toxicity following hypofractionated intensity modulated radiation therapy (IMRT) for cervical cancer. This study describes the results of a benchmark procedure for RT quality assurance of the POHIM-RT trial. Six participating institutions were provided computed tomography for RT planning and an IMRT plan for a sample and were instructed to delineate volumes, create a treatment plan and quality assurance (QA) plan, and submit the results of all procedures. The inter-institutional agreements on RT volume and plan results were evaluated using the kappa value and dice similarity coefficients. The simultaneous truth and performance level estimation (STAPLE) method was employed to generate a consensus target volume. The treatment volumes, organs-at-risk volumes, and results of the RT plan and QA reported by the institutions were acceptable and adhered well to the protocol. In terms of clinical target volume (CTV) delineation, there were differences between the institutions, particularly in vaginal cuff and paracolpium subsites. Consensus CTV was generated from the collected CTVs with the STAPLE method. The participating institutions showed considerable agreement regarding volume, dose and QA results. To improve CTV agreement in CTV, we provided feedback with images of the consensus target volume and detailed written guidelines for specific subsites that were the most heterogeneous.

Favorable prognosis of patients who received adjuvant androgen deprivation therapy after radiotherapy achieving undetectable levels of prostate-specific antigen in high- or very high-risk prostate cancer.

INTRODUCTION: To determine the prognostic significance of long-term adjuvant androgen deprivation therapy (A-ADT) over 1 year in achieving undetectable levels of prostate-specific antigen (PSA) less than 0.001 ng/mL in prostate cancer patients with high- or very high-risk prostate cancer who underwent radiotherapy (RT). MATERIALS AND METHODS: A total of 197 patients with prostate cancer received RT, with a follow-up of ≥12 months. Biochemical failure was defined as PSA ≥nadir + 2 ng/mL after RT. We analyzed clinical outcomes, including survival, failure patterns, and prognostic factors affecting outcomes. RESULTS: Biochemical failure-free survival (BCFFS), clinical failure-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival (OS) rates at 5 years were 91.1%, 95.4%, 96.9%, 99.5%, and 89.1%, respectively. Administration of long-term A-ADT significantly predicted favorable BCFFS (p = 0.027) and OS (p < 0.001) in multivariate analysis. Nadir PSA ≤0.001 ng/mL was an independent prognostic factor for BCFFS (p = 0.006) and OS (p = 0.021). The use of long-term A-ADT significantly affected nadir PSA ≤0.001 ng/mL (p < 0.001). The patients with A-ADT for 1 year or longer had better BCFFS or OS than those for less than 1 year or those without A-ADT (p < 0.001). The best prognosis was demonstrated in patients treated with long-term A-ADT and nadir PSA ≤0.001 ng/mL in BCFFS (p < 0.001). CONCLUSION: The addition of long-term A-ADT over 1 year to RT demonstrated good treatment outcomes in patients with locally advanced prostate cancer. Achieving a nadir PSA value ≤0.001 ng/mL using combination therapy with RT and A-ADT is a powerful clinical predictor of treatment outcomes.

Treatment time to the end of thoracic radiotherapy has more predictive power for survival than radiation dose intensity in patients with limited-stage small-cell lung cancer receiving concurrent chemoradiation of more than 45 Gy.

The optimal protocol for thoracic radiotherapy (TRT) in combination with chemotherapy in patients with limited-stage small-cell lung cancer (LS-SCLC) remains elusive. The present study aimed to evaluate radiation parameters in association with survival outcomes. A total of 101 patients with LS-SCLC who completed TRT at ≥45 Gy and concurrent chemotherapy were retrospectively reviewed. The median dose and duration of TRT were 50 Gy and 38 days, respectively. The median duration from the start of either therapy to the end of TRT (SER) was 60 days. The median survival for all patients was 26.9 months. The 3-year local control (LC), progression-free survival (PFS) and overall survival (OS) rates were 52.0, 29.5 and 37.6%, respectively, and the 5-year LC, PFS and OS rates were 50.1, 28.3 and 26.7%, respectively. Univariate analysis revealed that patient age, tumor stage, timing and dose of TRT, SER, prophylactic cranial irradiation (PCI), and tumor response were significantly associated with treatment outcomes. Multivariate analysis revealed that stage was the only significant prognostic factor for LC (P=0.011), PFS (P<0.001) and OS (P<0.001). Tumor response (P=0.014), PCI (P=0.007) and SER (P=0.005) were significant predictors of OS. OS was improved in patients who achieved complete response, and their SER was ≤70 days (P<0.001). Short treatment duration (SER ≤70 days) was a significant predictor of OS in patients with LS-SCLC who completed planned TRT at ≥45 Gy with concurrent chemoradiotherapy.