Using clinical and radiomic feature-based machine learning models to predict pathological complete response in patients with esophageal squamous cell carcinoma receiving neoadjuvant chemoradiation.

OBJECTIVE: This study aimed to build radiomic feature-based machine learning models to predict pathological clinical response (pCR) of neoadjuvant chemoradiation therapy (nCRT) for esophageal squamous cell carcinoma (ESCC) patients. METHODS: A total of 112 ESCC patients who underwent nCRT followed by surgical treatment from January 2008 to December 2018 were recruited. According to pCR status (no visible cancer cells in primary cancer lesion), patients were categorized into primary cancer lesion pCR (ppCR) group (N = 65) and non-ppCR group (N = 47). Patients were also categorized into total pCR (tpCR) group (N = 48) and non-tpCR group (N = 64) according to tpCR status (no visible cancer cells in primary cancer lesion or lymph nodes). Radiomic features of pretreatment CT images were extracted, feature selection was performed, machine learning models were trained to predict ppCR and tpCR, respectively. RESULTS: A total of 620 radiomic features were extracted. For ppCR prediction models, radiomic model had an area under the curve (AUC) of 0.817 (95% CI: 0.732-0.896) in the testing set; and the combination model that included rad-score and clinical features had a great predicting performance, with an AUC of 0.891 (95% CI: 0.823-0.950) in the testing set. For tpCR prediction models, radiomic model had an AUC of 0.713 (95% CI: 0.613-0.808) in the testing set; and the combination model also had a great predicting performance, with an AUC of 0.814 (95% CI: 0.728-0.881) in the testing set. CONCLUSION: This study built machine learning models for predicting ppCR and tpCR of ESCC patients with favorable predicting performance respectively, which aided treatment plan optimization. CLINICAL RELEVANCE STATEMENT: This study significantly improved the predictive value of machine learning models based on radiomic features to accurately predict response to therapy of esophageal squamous cell carcinoma patients after neoadjuvant chemoradiation therapy, providing guidance for further treatment. KEY POINTS: • Combination model that included rad-score and clinical features had a great predicting performance. • Primary tumor pCR predicting models exhibit better predicting performance compared to corresponding total pCR predicting models.

Outcomes of SBRT for lung oligo-recurrence of non-small cell lung cancer: a retrospective analysis.

The benefit of local ablative therapy (LAT) for oligo-recurrence has been investigated and integrated into the treatment framework. In recent decades, stereotactic body radiation therapy (SBRT) has been increasingly used to eliminate metastasis owing to its high rate of local control and low toxicity. This study aimed to investigate the outcomes of SBRT for patients with lung oligo-recurrence of non-small cell lung cancer (NSCLC) from our therapeutic center. Patients with lung oligo-recurrence of NSCLC treated with SBRT between December 2011 and October 2018 at Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) were reviewed. The characteristics, treatment-related outcomes, and toxicities of the patients were analyzed. Univariable and multivariable Cox regression were performed to identify the factors associated with survival. A total of 50 patients with lung oligo-recurrence of NSCLC were enrolled. The median follow-up period was 23.6 months. The 3-year local progression-free survival (LPFS), progression-free survival (PFS) and overall survival (OS) after SBRT were 80.2%, 21.9% and 45.3%, respectively. Patients in the subgroup with LAT to all residual diseases showed significantly improved OS and PFS. No treatment-related death occurred after SBRT. SBRT is a feasible option to treat patients with lung oligo-recurrence of NSCLC, with high rates of local control and low toxicity. LAT to all residual diseases was associated with better survival outcomes. Future prospective randomized clinical trials should evaluate SBRT strategies for such patients.

A propensity-matched analysis of stereotactic body radiotherapy and sublobar resection for stage I non-small cell lung cancer in patients at high risk for lobectomy: the results in a Chinese population.

BACKGROUND: To investigate the comparative effectiveness of stereotactic body radiotherapy (SBRT) and sublobar resection (SLR) in patients with stage I non-small cell lung cancer (NSCLC) considered to be high-risk lobectomy patients. METHODS: From January 2012 to December 2015, patients who underwent SBRT or SLR for clinical stage I NSCLC were examined retrospectively. Propensity score matching (PSM) was performed to reduce selection bias in SBRT and SLR patients. RESULTS: Data from 86 SBRT and 79 SLR patients was collected. Median follow-up periods of the SBRT and SLR groups were 32 and 37 months, respectively. Patients treated with SBRT exhibited significantly higher age, higher likelihood of being male, larger tumor diameter, lower forced expiratory volume in 1 second (FEV1), and poorer performance status compared with SLR patients. There were no significant differences between SBRT and SLR patients for 3-year overall survival (OS) (80.3% and 82.3%, P=0.405), cause-specific survival (CSS) (81.3% and 83.4%, P=0.383), and local control (LC) (89.7% and 86.0%, P=0.501). Forty-nine patients were identified from each group after performing PSM. After patients were matched for age, gender, performance status, tumor characteristics and pulmonary function, no significant differences were observed in 3-year OS (85.4% and 73.3%, P=0.649), CSS (87.2% and 74.9%, P=0.637) and LC (95.6% and 82.1%, P=0.055). Prevalence of significant adverse events (grade 3 or worse) was 0% and 10.2% in the matched SBRT and SLR groups (P=0.056), respectively. CONCLUSIONS: Disease control and survival in the SBRT patients was equivalent to that seen in SLR patients with stage I NSCLC considered high-risk lobectomy candidates. SBRT could therefore be an alternative option to SLR in treating patients with a high operative risk.

A novel circular RNA hsa_circRNA_103809/miR-377-3p/GOT1 pathway regulates cisplatin-resistance in non-small cell lung cancer (NSCLC).

BACKGROUND: Cisplatin is the first-line chemotherapeutic drug for non-small cell lung cancer (NSCLC), and emerging evidences suggests that targeting circular RNAs (circRNAs) is an effective strategy to increase cisplatin-sensitivity in NSCLC, but the detailed mechanisms are still not fully delineated. METHODS: Cell proliferation, viability and apoptosis were examined by using the cell counting kit-8 (CCK-8) assay, trypan blue staining assay and Annexin V-FITC/PI double staining assay, respectively. The expression levels of cancer associated genes were measured by using the Real-Time qPCR and Western Blot analysis at transcriptional and translated levels. Dual-luciferase reporter gene system assay was conducted to validated the targeting sites among hsa_circRNA_103809, miR-377-3p and 3' untranslated region (3'UTR) of GOT1 mRNA. The expression status, including expression levels and localization, were determined by immunohistochemistry (IHC) assay in mice tumor tissues. RESULTS: Here we identified a novel hsa_circRNA_103809/miR-377-3p/GOT1 signaling cascade which contributes to cisplatin-resistance in NSCLC in vitro and in vivo. Mechanistically, parental cisplatin-sensitive NSCLC (CS-NSCLC) cells were subjected to continuous low-dose cisplatin treatment to generate cisplatin-resistant NSCLC (CR-NSCLC) cells, and we found that hsa_circRNA_103809 and GOT1 were upregulated, while miR-377-3p was downregulated in CR-NSCLC cells but not in CS-NSCLC cells. In addition, hsa_circRNA_103809 sponged miR-337-3p to upregulate GOT1 in CS-NSCLC cells, and knock-down of hsa_circRNA_103809 enhanced the inhibiting effects of cisplatin on cell proliferation and viability, and induced cell apoptosis in CR-NSCLC cells, which were reversed by downregulating miR-377-3p and overexpressing GOT1. Consistently, overexpression of hsa_circRNA_103809 increased cisplatin-resistance in CS-NSCLC cells by regulating the miR-377-3p/GOT1 axis. Finally, silencing of hsa_circRNA_103809 aggravated the inhibiting effects of cisplatin treatment on NSCLC cell growth in vivo. CONCLUSIONS: Analysis of data suggested that targeting the hsa_circRNA_103809/miR-377-3p/GOT1 pathway increased susceptibility of CR-NSCLC cells to cisplatin, and this study provided novel targets to improve the therapeutic efficacy of cisplatin for NSCLC treatment in clinic.

Pretreatment systemic inflammation response index (SIRI) is an independent predictor of survival in unresectable stage III non-small cell lung cancer treated with chemoradiotherapy: a two-center retrospective study.

BACKGROUND: Circulating immune cells influence the efficacy of cancer therapy. This study aimed to investigate the prognostic values of different peripheral blood leukocyte (PBL) biomarkers in non-small lung cancer (NSCLC) patients treated with chemoradiotherapy. METHODS: An independent cohort of 176 stage III NSCLC patients who were diagnosed at Shanghai Pulmonary Hospital and Zhejiang Cancer Hospital between April, 2010, and September, 2018, and had available pretreatment peripheral blood tests was enrolled. The patients were all treated with concurrent or sequential chemoradiotherapy according to international clinical guidelines, with conventional fractionated radical radiotherapy. The receiver operating characteristic curve and the Youden index were used to determine the optional cutoff values of PBL biomarkers for distinguishing prognosis. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the factors significantly correlated with overall survival. RESULTS: The cohort had a median follow-up time of 21.7 (3.1-121) months. The 3- and 5-year OS rates of all patients were 34.7% and 27.5%, respectively. Univariate analysis showed that gender (P=0.011), smoking (P=0.011), tumor-node-metastasis (TNM) stage (P=0.002), pretreatment peripheral blood neutrophil-to-leukocyte ratio (P=0.013), and systemic inflammation response index (SIRI, P<0.001) were all correlated with OS in NSCLC patients. Moreover, multivariate analysis revealed that TNM stage (HR =1.541, 95% CI: 1.166-2.036, P=0.010) and SIRI (HR =1.868, 95% CI: 1.016-3.436, P=0.018) were significantly and independently associated with OS. However, the median OS of stage IIIB NSCLC patients with low SIRI (≤2.0) was longer than that of stage IIIA NSCLC patients with high SIRI (>2.0) (33.9±4.1 vs. 19.6±2.5 months). CONCLUSIONS: Pretreatment peripheral blood SIRI was found to be a simple independent predictor of OS in stage III NSCLC patients who underwent chemoradiotherapy. As a novel prognostic marker, the prognostic value of the SIRI is superior to that of the NLR. Low SIRI could be a better prognostic stratification factor for NSCLC patients with different TNM stages.

Four-year follow-up outcomes after stereotactic body radiation therapy for central early-stage non-small cell lung cancer.

BACKGROUND: Previous research has shown that stereotactic body radiation therapy (SBRT) can achieve a high level of tumor control in patients with early-stage non-small cell lung cancer (NSCLC). However, to date, such studies have mainly focused on peripheral early-stage patients. This study aimed to assess the clinical outcomes and toxicity of patients with central lung cancer treated with SBRT in our institution. METHODS: A total of 31 consecutive central early-stage NSCLC patients who were treated with SBRT using the biologically effective dose (BED; α/ß =10) 100-119 Gy in 4-10 fractions between April, 2013, and August, 2016, were reviewed. The RTOG 0813 trial standard was used to define whether the NSCLC was centrally located. All patients received four-dimensional computed tomography (4D CT) simulation. Intensity modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D CRT) techniques were used in treatment planning. The dose to the planning target volume (PTV) was prescribed to the 95% isodose line. Mainly dosimetric parameters, clinical outcomes, and toxicity were analyzed. RESULTS: The 31 patients enrolled in the study had a median follow-up time of 47.7 months, and the median tumor diameter was 2.2 cm (range, 1.3-5.0 cm). A total of 15 patients (48.4%) developed disease recurrence. The incidences of local, regional, and distant disease recurrence at 3 years were 11.7%, 9.7%, and 30.7%, respectively; at 5 years, they were 21.5%, 15.0%, and 35.0%, respectively. The 3- and 5-year progression-free survival (PFS) rates were 55.1% and 40.5%, respectively; the corresponding overall survival (OS) rates were 85.3% and 68.4%, respectively. Toxicities of grade 3 or higher were observed in 6.5% of the patients. None of the patients experienced grade 4 or 5 acute adverse events; however, 2 patients possibly died of treatment-related late toxicity. CONCLUSIONS: SBRT with a BED 100 Gy in 4-10 fractions is effective and acceptable for treating patients with central early-stage NSCLC. Further studies are warranted.

The CT appearance pattern of radiation-induced lung injury and tumor recurrence after stereotactic body radiation therapy in early stage non-small cell lung cancer.

BACKGROUND: Radiographic changes after stereotactic body radiation therapy (SBRT) have not been well studied. The purpose of this study was to investigate the computed tomography (CT) appearance pattern of radiation-induced lung injury (RILI) and recurrence after SBRT in patients with early stage non-small cell lung cancer (NSCLC). METHODS: We retrospectively analyzed clinical data of inoperable early stage NSCLC patients undergoing SBRT treatment from February 2012 to June 2018. All patients had undergone serial CT scanning before SBRT and after completion of SBRT. An experienced radiation oncologist and radiologist reviewed all CT images, and identified the RILI and CT high-risk features (HRFs). RESULTS: A total of 60 patients were enrolled in this study; 55 patients had RILI (91.67%) and 7 patients had local failure. In the early CT findings of observers 1 and 2, there were diffuse ground glass opacities (GGOs) in 3 and 4 patients, diffuse consolidation in 10 and 12 patients, patchy consolidation in 22 and 15 patients, patchy GGOs in 19 and 24 patients, and no changes in 5 and 4 patients, respectively (kappa =0.706). In the late CT findings of observer 1 and 2, there were modified conventional patterns in 37 and 37 patients, mass-like patterns in 10 and 9 patients, scar-like patterns in 7 and 8 patients, and no changes in 5 and 5 patients, respectively (kappa =0.726). In the results of the CT-based HRFs of disease local failure, there were ≥1 HRFs in 7 patients, ≥2 HRFs in 7 patients, ≥3 HRFs in 6 patients, ≥4 HRFs in 5 patients, and ≥5 HRFs in 3 patients, respectively. Patients with only 1 HRF showed high sensitivity (100%) and low specificity (52.80%), with the specificity increasing and the sensitivity decreasing as the number of HRFs increased. CONCLUSIONS: The agreement of the CT appearance on RILI between 2 observers was good. Regular follow-up and attention to HRFs are vital for better identifying RILI and local disease failure.

Stereotactic body radiotherapy for early stage non-small cell lung cancer in patients with subclinical interstitial lung disease.

BACKGROUND: For lung cancer patients with subclinical (untreated and asymptomatic) interstitial lung disease (ILD), there is a lack of relatively safe and effective treatment. Stereotactic body radiation therapy (SBRT) can achieve a high level of tumor control with low toxicity in early-stage non-small cell lung cancer (NSCLC). This study aimed to evaluate the efficacy and toxicity of early stage NSCLC patients with subclinical ILD receiving SBRT. METHODS: A total of 109 early stage NSCLC patients receiving SBRT treatment between December 2011 and August 2016 were reviewed in our institutions; patients with clinical ILD were excluded. The median dose of SBRT was 50 Gy in 5 fractions. The median biologically effective dose (BED; α/ß=10) was 100 Gy (range, 72-119 Gy). An experienced radiation oncologist and an experienced radiologist reviewed the presence of subclinical ILD in the CT findings before SBRT. The relationships among the efficacy, radiation-induced lung injury (RILI) and subclinical ILD were explored. RESULTS: In all, 38 (34.9%) of 109 patients were recognized with subclinical ILD before SBRT, 48 (44.0%) of 109 patients were recognized with grade 2-5 RILI after SBRT, and 18 (47.4%) of 38 patients with subclinical ILD were observed with grade 2-5 RILI. Subclinical ILD was not a significant factor of grade 2-5 RILI (P=0.608); however, 3 patients had extensive RILI, and they all suffered from subclinical ILD. Dosimetric factor of the lungs, such as mean lung dose (MLD) was significantly related with Grade 2-5 RILI in patients with subclinical ILD (P=0.042). The progression-free survival (PFS) rates at 3 years in the subclinical ILD patients and those without ILD were 61.6% and 66.8%, respectively (P=0.266). CONCLUSIONS: Subclinical ILD was not a significant factor for RILI or PFS in early stage NSCLC patients receiving SBRT; however, patients with subclinical ILD receiving SBRT may experience uncommon extensive RILI.

ADC correlation with Sirtuin1 to assess early chemoradiotherapy response of locally advanced esophageal carcinoma patients.

AIMS: To determine the biological correlation between apparent diffusion coefficient (ADC) values and Sirtuin1 (SIRT1) levels of tumour tissues in patients with esophageal carcinoma (EC), and to ascertain the treatment biomarker of ADC in predicting the early response of patients undergoing definitive chemoradiotherapy (CRT). METHODS: A total of 66 patients were enrolled, and the specimens of tumour tissues were collected before treatment to perform immunohistochemical (IHC) examinations and quantify the levels of SIRT1. Then all patients were given two esophageal magnetic resonance imaging (MRI) examinations with diffused weighed imaging (DWI) including pretreatment and intra-treatment (1~2 weeks after the start of radiotherapy). The regions of interest (ROIs) were contoured according to the stipulated rules in advance using off-line software, and the values of the ADC in the ROIs were generated automatically. Then, the values of the ADC at baseline and intra-treatment were labeled as pre-ADC and intra-ADC respectively, and ΔADC, ADCratio were calculated. Pearson's correlation coefficients were acquired to estimate the correlation between each of ADC values and SIRT1 levels. Spearman's rank correlation coefficients were acquired to estimate the correlation between early response and the values of each ADC. Receptor operation characteristics (ROC) curves were constructed to estimate the accuracy of the ADC in predicting the early response of CRT. RESULTS: The findings of this study showed different correlations between ADC values and the levels of SIRT1 (ΔADC: r = - 0.943, P = 0.002; ADCratio: r = - 0.911, P = 0.000; intra-ADC: r = - 0.748, P = 0.002; pre-ADC: r = 0.109, P = 0.558). There was a positive correlation between ΔADC and early response to treatment (ρ = 0.615, P = 0.023), and multivariable logistic regression revealed that ΔADC was significantly associated with short-term response of CRT in esophageal carcinoma patients. CONCLUSIONS: In summary, early increases in ADC may facilitate the predication of early CRT response in patients with esophageal squamous cell carcinoma (ESCC), which may be attributed to the different correlation between ADC changes and SIRT1 expression.

Outcomes of stereotactic body radiotherapy versus lobectomy for stage I non-small cell lung cancer: a propensity score matching analysis.

BACKGROUND: Lobectomy is the standard treatment for patients with stage I non-small cell lung cancer (NSCLC). Recent studies have shown promising results of stereotactic body radiation therapy (SBRT) in these patients. We retrospectively compared the outcomes of lobectomy and SBRT in these patients from our therapeutic center. METHODS: Patients who underwent lobectomy or SBRT for clinical T1-2a (T size≤5 cm), N0 M0, NSCLC between December 2011 and August 2016 were reviewed. Patient characteristics, treatment-related outcomes and toxicities were analyzed. Propensity score matching (PSM) was performed to improve comparability between the two groups. RESULTS: Median follow-up period in the lobectomy (n = 246) and SBRT (n = 70) group was 31.4 months and 24.9 months, respectively. Three-year local recurrence-free survival (LRFS) was comparable in the two groups (97% vs. 91.7%, respectively; P = 0.768). Recurrence-free survival (RFS) at 3-year in the lobectomy and SBRT groups was 85.4 and 69.5%, respectively (P = 0.014). Three-year overall survival (OS) after lobectomy and SBRT was 88.2 and 79.7%, respectively (P = 0.027), while 3-year cancer-specific survival (CSS) was 91.3 and 82.5% (P = 0.022). After PSM (45 matched patients in each group), there was no significant between-group difference with respect to 3-year LRFS (89.6% vs. 87.5%, P = 0.635), RFS (77.6% vs. 67.3%, P = 0.446), OS (78.5% vs. 79.5%, P = 0.915) or CSS (86.4 and 79.5%, P = 0.551). In matched subgroup, 30-day mortality after lobectomy was 2.2%, and no treatment-related death occurred after SBRT. CONCLUSIONS: Treatment-related outcomes of SBRT and lobectomy were comparable. SBRT was well tolerated and had a very low toxicity profile in our study. SBRT is a promising alternative treatment option for stage I NSCLC patients. This study indicates that matching these disparate cohorts of patients is challenging. Clinical trials are essential to define the indications and relative efficacy of lobectomy and SBRT in a selected population.

High PD-L1 expression is associated with a favorable prognosis in patients with esophageal squamous cell carcinoma undergoing postoperative adjuvant radiotherapy.

Previous results on the prognostic value of programmed death-ligand (PD-L)1 expression in patients with esophageal squamous cell carcinoma (ESCC) remain limited and conflicting. The present study aimed to determine whether PD-L1 expression status predicts prognosis in patients with ESCC, particularly in those undergoing different postoperative treatments. Immunohistochemical staining for PD-L1 was performed on surgical specimens that were obtained from 246 patients with ESCC, who underwent surgical treatment but did not undergo preoperative chemotherapy, radiotherapy, targeted therapy or immune therapy. The association of PD-L1 expression with the clinicopathological factors and the association of PD-L1 expression with survival of patients with ESCC, including subgroups of patients undergoing different postoperative treatments (surgery alone, surgery with adjuvant chemotherapy, surgery with adjuvant radiotherapy and surgery with adjuvant chemo-radiotherapy groups), were statistically analyzed. Positive PD-L1 expression was significantly associated with advanced tumor-node metastasis stage (P=0.022). Median overall survival (OS) time was compared between patients with positive PD-L1 expression and those with negative PD-L1 expression in the overall patient population. In patients who were treated with postoperative adjuvant radiotherapy, the prognosis was significantly improved in patients who were PD-L1-positive compared with those who were PD-L1-negative (P=0.046). In patients treated with adjuvant chemotherapy, median OS was poorer in patients with positive PD-L1 expression compared with those with negative PD-L1 expression. However, the difference was not significant. Multivariate Cox regression analysis demonstrated that PD-L1 expression status was not an independent prognostic factor in patients with ESCC. High PD-L1 expression was associated with a favorable prognosis in patients with ESCC undergoing postoperative adjuvant radiotherapy, and it was concluded that patients with positive PD-L1 expression might benefit from postoperative adjuvant radiotherapy.

DUSP1 enhances the chemoresistance of gallbladder cancer via the modulation of the p38 pathway and DNA damage/repair system.

Cisplatin (CDDP) is a commonly used drug for gallbladder cancer (GBC) chemotherapy. However, resistance to CDDP treatment results in relapse. Therefore, there is a need for the development of more effective treatment strategies to overcome chemoresistance. Dual-specificity phosphatase 1 (DUSP1) was reported to be involved in the resistance of a number of chemotherapeutic agents and was revealed to be highly expressed in CDDP-resistant GBC cells and CDDP-treated tumor types compared with normal cells or tissues in the present study. DUSP1 was revealed to inhibit the cytotoxicity of CDDP in two GBC cell lines, SGC996 and GBC-SD. P38 mitogen-activated protein kinases may be involved in the mechanism of chemoresistance. Furthermore, the number of DNA double-strand breaks in SGC996 OE cells was reduced compared with SGC996 vector cells indicating DUSP1 may attenuate the chemotherapeutic efficiency. Due to its potency against CDDP treatment, DUSP1 may be a promising target to overcome chemoresistance in GBC therapy.

Analysis of Clinical and Dosimetric Factors Influencing Radiation-Induced Lung Injury in Patients with Lung Cancer.

PURPOSE: Dose escalation of thoracic radiation can improve the local tumor control and surivival, and is in the meantime limited by the occurrence of radiation-induced lung injury (RILI). This study investigated the clinical and dosimetric factors influencing RILI in lung-cancer patients receiving chemoradiotherapy for better radiation planning. METHODS AND MATERIALS: A retrospective analysis was carried out on 161 patients with non-small-cell or small-cell lung cancer (NSCLC and SCLC, respectively), who underwent chemoradiotherapy between April 2010 and May 2011 with a median follow-up time of 545 days (range: 39-1453). Chemotherapy regimens were based on the histological type (squamous cell carcinoma, adenocarcinoma, or SCLC), and radiotherapy was delivered in 1.8-3.0 Gy (median, 2.0 Gy) fractions, once daily, to a total of 39-66 Gy (median, 60 Gy). Univariate analysis was performed to analyze clinical and dosimetric factors associated with RILI. Multivariate analysis using logistic regression identified independent risk factors correlated to RILI. RESULTS: The incidence of symptomatic RILI (≥grade 2) was 31.7%. Univariate analysis showed that V5, V20, and mean lung dose (MLD) were significantly associated with RILI incidence (P=0.029, 0.048, and 0.041, respectively). The association was not statistically significant for histological type (NSCLC vs. SCLC, P = 0.092) or radiation technology (IMRT vs. 3D-CRT, P = 0.095). Multivariate analysis identified MLD as an independent risk factor for symptomatic RILI (OR=1.249, 95%CI=1.055-1.48, P= 0.01). The incidence of bilateral RILI in cases where the tumor was located unilaterally was 22.7% (32/141) and all dosimetric-parameter values were not significantly different (P>0.05) for bilateral versus ipsilateral injury, except grade-1 (low) RILI (P < 0.05). The RILI grade was higher in cases of ipsilateral lung injury than in bilateral cases (Mann-Whitney U test, z=8.216, P< 0.001). CONCLUSION: The dosimetric parameter, MLD, was found to be an independent predictive factor for RILI. Additional contralateral injury does not seem to be correlated with increased RILI grade under the condition of conventional radiotherapy treatment planning.

Clinical significance of gefitinib antitumor activity in patients with lung adenocarcinoma.

Non-small cell lung cancer is a subtype of adenocarcinoma, which has previously shown positive responses to gefitinib. The aim of the current study was to determine a clinical profile of gefitinib-induced disease controls for patients with lung adenocarcinoma. Retrospective evaluation of the clinical characteristics of 52 lung adenocarcinoma patients, enrolled at the Zhejiang Cancer Hospital (Hangzhou, China) between October 2004 and August 2008, was undertaken. All patients received gefitinib (250 mg/day orally) until disease progression or until an unacceptable toxicity was observed. Of the 52 patients, complete response (CR) and partial response (PR) rates were 23.1% (12/52) and 57.7% (30/52), respectively. An additional 19.2% (10/52) of patients demonstrated stable disease (SD) after three months of treatment with gefitinib. Disease control was observed in the primary lesion, and tumor metastasis to the lungs, brain, adrenal glands, pleura, peritoneum, pericardium, bone and lymph nodes was identified. The one-year progression-free survival (PFS) and overall survival (OS) rates were 74.8 and 78.0%, respectively. Multivariate analysis revealed that female patients were associated with significantly longer survival times when compared with males (hazard ratio, 0.077; 95% confidence interval [CI], 0.007-0.083; P=0.035). One-year PFS and OS rates in CR, PR and SD patients were 77.8, 73.9 and 33.3%, and 89.2, 79.8 and 33.7%, respectively, although neither difference was identified to be statistically significant. In addition, the median OS of SD patients was 12 months (95% CI, 7.2-16.8 months). Brain metastasis was the major site of disease progression (23.1%). Gefitinib treatment for patients with lung adenocarcinoma showed a marked long-term survival benefit, even in SD patients. However, further studies are required to analyze the efficacy of gefitinib in penetrating the blood-brain barrier in order to prolong PFS in patients with lung adenocarcinoma.