Role of postoperative radiotherapy in resected non-small cell lung cancer: a reassessment based on new data

European Organization for Research and Treatment of Cancer (EORTC) recommendations for planning and delivery of high-dose, high precision radiotherapy for lung cancer

PURPOSE

To update literature-based recommendations for techniques used in high-precision thoracic radiotherapy for lung cancer, in both routine practice and clinical trials.

METHODS

A literature search was performed to identify published articles that were considered clinically relevant and practical to use. Recommendations were categorised under the following headings: patient positioning and immobilisation, Tumour and nodal changes, CT and FDG-PET imaging, target volumes definition, radiotherapy treatment planning and treatment delivery. An adapted grading of evidence from the Infectious Disease Society of America, and for models the TRIPOD criteria, were used.

RESULTS

Recommendations were identified for each of the above categories.

CONCLUSION

Recommendations for the clinical implementation of high-precision conformal radiotherapy and stereotactic body radiotherapy for lung tumours were identified from the literature. Techniques that were considered investigational at present are highlighted.

Propensity score-matching analysis of postoperative radiotherapy for stage IIIA-N2 non-small cell lung cancer using the Surveillance, Epidemiology, and End Results database

Background

To investigate the effects of postoperative radiotherapy (PORT) on the survival of patients with resected stage IIIA-N2 non-small cell lung cancer (NSCLC).

Methods

A total of 3,334 patients with resected stage IIIA-N2 NSCLC in 2004 to 2013 were identified in the Surveillance, Epidemiology, and End Results database and stratified according to use of PORT. Propensity score-matching (PSM) methods were used to balance the baseline characteristics of patients who did (n = 744) or did not (n = 744) undergo PORT. Overall survival (OS) and lung cancer-specific survival (LCSS) were compared between these two patient groups.

Results

After PSM, PORT increased OS (hazard ratio, 0.793; p = 0.001) and LCSS (hazard ratio, 0.837; p = 0.022) compared with no PORT. The OS benefit for PORT was mainly seen in patients aged <60 years (5-year OS, 35.4% versus 28.9% for PORT versus no PORT, respectively; p = 0.026) and in those who underwent lobectomy (5-year OS, 43.5% versus 34.5% for PORT versus no PORT, respectively; p = 0.001). The LCSS benefit for PORT was significant in patients undergoing lobectomy (5-year LCSS, 48.3% versus 42.3% for PORT versus no PORT, respectively; p = 0.036).

Conclusions

The survival benefits of PORT were primarily observed in patients with resected stage IIIA-N2 NSCLC who were <60 years of age or had undergone lobectomy.

Role of Adjuvant Thoracic Radiation Therapy and Full Dose Chemotherapy in pN2 Non-small Cell Lung Cancer: Elucidation Based on Single Institute Experience

Purpose

The optimal adjuvant therapy modality for treating pN2 non-small cell lung cancer patients has not yet been established. In this study, the authors investigated clinical outcomes following three different adjuvant therapy modalities.

Materials and Methods

From January 2006 to December 2012, 240 patients with cN0/1 disease were found to have pN2 disease following curative resection and received one of three adjuvant therapy modalities:thoracic radiation therapy (TRT) and concurrent chemotherapy (CTx) (CCRT) (group I), CCRT plus consolidation CTx (group II), and CTx alone (group III). TRT was delivered to 155 patients (groups I/II), and full dose CTx was delivered to 172 patients either as a consolidative or a sole modality (group II/III).

Results

During 30 months of median follow-up, 44 patients died and 141 developed recurrence. The 5-year overall survival (OS), locoregional control (LRC), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates of all patients were 76.2%, 80.7%, 36.4%, and 29.6%, respectively. There was no difference in OS among groups. TRT (groups I/II) significantly improved LRC, full dose CTx (groups II/III) did DMFS, and CCRT plus consolidation CTx (group II) did DFS, respectively.

Conclusion

The current study could support that TRT could improve LRC and full dose CTx could improve DMFS and that CCRT plus consolidation CTx could improve DFS.

Prognostic value of tumor-infiltrating lymphocytes for patients with completely resected stage IIIA(N2) non-small cell lung cancer

Background

The patient prognosis after complete resection for pathologic stage IIIA(N2) non-small cell lung cancer (NSCLC) remains a significant concern. The clinical relevance of the host immune response to NSCLC has yet to be established. We aimed to investigate the prognostic value of tumor-infiltrating lymphocytes (TILs) in a uniform cohort of patients with completely resected stage IIIA(N2) NSCLC.

Methods

From 2005 to 2012, consecutive patients with pathologic stage IIIA(N2) NSCLC who underwent complete resection at our institution were reviewed. For each case, full-face hematoxylin and eosin-stained sections from surgical specimens were evaluated for the TIL density. A published, recommended TIL scoring scale was followed. The patients were stratified into the TIL− or TIL+ group based on pathologic evaluation.

Results

Data from 320 patients were included in the analysis. Based on a median follow-up duration of 30.8 months, a higher density of TILs was associated with an improved postoperative survival time (P = 0.06). Subgroup analyses indicated that this positive effect was the greatest for patients with squamous cell carcinoma (SCC; P = 0.03). Among those with SCC, the TIL+ patients experienced a significantly increased 3-year distant metastasis-free survival (DMFS) compared to the TIL− patients (60.6% versus 42.7%, P = 0.02). Multivariate analyses of the 93 patients with SCC tumors confirmed that TIL+ was an independent prognostic factor for an increased DMFS (HR = 0.39, 95%CI 0.17–0.87, P = 0.02) and a prolonged overall survival (OS; HR = 0.47, 95%CI 0.22–1.00, P = 0.05).

Conclusions

Our data suggest a potential role of TILs in predicting the survival of patients with completely resected stage IIIA(N2) NSCLC. The beneficial effects of TILs were more pronounced in the prediction of the DMFS and the OS in patients with SCC. This parameter should be considered for prospective inclusion in clinical trials.

Chemoradiotherapy of locally advanced nonsmall cell lung cancer: state of the art and perspectives

PURPOSE OF REVIEW

The treatment of locally advanced nonsmall cell lung cancer (NSCLC) is becoming a significant challenge because of a growing proportion of patients with unresectable or potentially eligible for surgery after a multimodality treatment, stage II to III disease. Despite a multimodality approach consisting in concurrent chemoradiotherapy, the prognosis remains poor.

RECENT FINDINGS

Different strategies, including induction and consolidation chemotherapy, chemotherapy regimens, fractionation and radiation doses have been evaluated in phase II and III trials, as well as new therapeutic approaches such as immunotherapy. For patients with resectable stage III disease the optimal strategy remains unclear. The American Society for Radiation and Clinical Oncology and the European Society for Medical Oncology published recent guidelines in 2015.

SUMMARY

Concurrent chemoradiotherapy improves overall survival compared with sequential chemotherapy followed by radiation. Adding induction or consolidation chemotherapy to chemoradiotherapy does not appear to improve the outcome. Chemotherapy based on cisplatin combined with radiation is recommended in stage III NSCLC. The standard dose and fractionation of radiotherapy are 60 Gy, one daily fraction of 2 Gy over 6 weeks. Targeted therapies and immunotherapy may improve the management of locally advanced NSCLC in the future.

Downregulation of AATK mediates microRNA-558-induced resistance of A549 cells to radiotherapy

The deregulation of microRNAs (miRNAs) is often implicated in the control of sensitivity to radiotherapy. The objective of the present study was to identify the association between miR‑558 and apoptosis‑associated tyrosine kinase (AATK), and their importance in regulating the development of resistance to radiotherapy. The current study demonstrated that AATK, a radiosensitization-associated gene, is a target of miR‑558 in lung cancer cells, using in silico analysis and a luciferase reporter system. Furthermore, it was determined that transfection of 30 or 50 nM miR‑558 mimics and AATK specific siRNA markedly suppressed the mRNA and protein expression of AATK. To determine whether miR‑558 was required for lung cancer cell radioresistance, A549 cells were treated with different doses of ionizing radiation, from 0 to 10 Gy, following transfection with miR‑558 mimics or AATK specific siRNA. It was determined that the administration of miR‑558 mimics or AATK specific siRNA alone did not significantly alter the survival rate of the cells. By contrast, in the cells exposed to 4, 6 or 8 Gy, the administration of miR‑558 mimics or AATK specific siRNA significantly promoted cell survival rate and overexpression of AATK reversed this effect. In conclusion, these data demonstrate that the miR‑558/AATK cascade is important for the radiosensitization of lung cancer cells and may be a potential radiotherapy target.

miRNA-148b regulates radioresistance in non-small lung cancer cells via regulation of MutL homologue 1

miR-148b regulates radioresistance of lung cancer cells by modulating MLH1 expression level.

Radioresistance represents a major obstacle in cancer treatment, the underlying mechanism of which is complex and not well understood. miR-148b has been reported to be implicated regulating radioresistance in lymphoma cells. However, this function has not been investigated in lung cancer cells. Microarray analysis was performed in A549 cells 48 h after exposure to 8 Gy of γ-irradiation or sham irradiation to identify differentially expressed miRNAs. miR-148b mimic and inhibitor were transfected, followed by clonogenic survival assay to examine response to irradiation in A549 cells. Western Blot and luciferase assay were performed to investigate the direct target of miR-148b. Xenograft mouse models were used to examine in vivo function of miR-148b. Our data showed that expression of miR-148b was significantly down-regulated in both serum and cancerous tissues of radioresistant lung cancer patients compared with radiosensitive patients. Overexpression of miR-148b reversed radioresistance in A549 cells. MutL homologue 1 (MLH1) is the direct target of miR-148b which is required for the regulatory role of miR-148b in radioresistance. miR-148b mimic sensitized A549 xenografts to irradiation in vivo. Our study demonstrated that miR-148b regulates radioresistance of lung cancer cells by modulating MLH1 expression level. miR-148b may represent a new therapeutic target for the intervention of lung cancer.

Gelsolin Promotes Radioresistance in Non-Small Cell Lung Cancer Cells Through Activation of Phosphoinositide 3-Kinase/Akt Signaling

Gelsolin is an actin-binding protein and acts as an important regulator of cell survival. This study aimed to determine the function of gelsolin in the radioresistance of non-small cell lung cancer cells. We examined the expression of gelsolin in radioresistant A549 and H460 cells and their parental cells. The effects of gelsolin overexpression and knockdown on the clonogenic survival and apoptosis of non-small cell lung cancer cells after irradiation were studied. The involvement of phosphoinositide 3-kinase/Akt signaling in the action of gelsolin was checked. We found that gelsolin was significantly upregulated in radioresistant A549 and H460 cells. Overexpression of gelsolin significantly ( P < .05) increased the number of colonies from irradiated A549 and H460 cells compared to transfection of empty vector. In contrast, knockdown of gelsolin significantly ( P < .05) suppressed colony formation after irradiation. Gelsolin-overexpressing cells displayed reduced apoptosis in response to irradiation, which was coupled with decreased levels of cleaved caspase-3 and poly adenosine diphosphate-ribose polymerase. Ectopic expression of gelsolin significantly ( P < .05) enhanced the phosphorylation of Akt compared to nontransfected cells. Pretreatment with the phosphoinositide 3-kinase inhibitor LY294002 (20 μmol/L) significantly decreased clonogenic survival and enhanced apoptosis in gelsolin-overexpressing A549 and H460 cells after irradiation. Taken together, gelsolin upregulation promotes radioresistance in non-small cell lung cancer cells, at least partially, through activation of phosphoinositide 3-kinase/Akt signaling.

MicroRNA-126 Targeting PIK3R2 Inhibits NSCLC A549 Cell Proliferation, Migration, and Invasion by Regulation of PTEN/PI3K/AKT Pathway

BACKGROUND

Our study explored whether the microRNA-126 (miR-126)-mediated PTEN/PI3K/AKT (phosphatase and tensin homology deleted on chromosome 10/phosphatidylinositol 3-kinase regulatory subunit-β/AKT) signaling pathway by targeting PIK3R2 affects the proliferation, migration, and invasion of non-small-cell lung cancer (NSCLC) A549 cells.

MATERIALS AND METHODS

Quantitative real-time polymerase chain reaction was used to measure the expression of miR-126 in A549 cells. The MTT (methyl thiazolyl tetrazolium) assay, cell scratch test, Transwell assay, and Western blot were used to detect the proliferation, migration, and invasion of A549 cells and protein expression in A549 cells, respectively.

RESULTS

The expression of miR-126 decreased and the expression of PIK3R2 increased in A549 cells (P < .05, for both). Upregulation of miR-126 resulted in the decrease of the proliferation, migration, and invasive abilities of A549 cells, the downregulation of the expression of PIK3R2, PI3K, and phosphorylated Akt (p-Akt) protein, and the upregulation of PTEN expression (P < .05 for all). Also, these abilities of A549 cells increased, and the expression of these 3 proteins was upregulated with downregulation of miR-126 (P < .05 for all). The results of the dual luciferase reporter gene assay showed that PIK3R2 was the target gene of miR-126. PIK3R2, PI3K, and p-Akt proteins were downregulated, but PTEN protein was upregulated as PIK3R2 was silenced or the inhibitor of the PTEN/PI3K/AKT signaling pathway increased. Also, downregulation of miR-126 with silencing of PIK3R2 or increasing the inhibitor of the pathway caused increased PI3K and p-Akt protein expression and increased active proliferation, migration, and invasive abilities of A549 cells (P < .05 for all).

CONCLUSION

The upregulation of miR-126 in NSCLC A549 cells can reduce the expression of the target gene PIK3R2 and influence the PTEN/PI3K/AKT signaling pathway, suppressing the proliferation, migration, and invasive abilities of A549 cells.

[Postoperative radiotherapy for non-small cell lung cancer: Efficacy, target volume, dose]

The rate of local failure of stage IIIA-N2 non-small cell lung cancer is 20 to 40%, even if they are managed with surgery and adjuvant chemotherapy. Postoperative radiotherapy improves local control, but its benefit on global survival remains to be demonstrated. Considered for many years as an adjuvant treatment option for pN2 cancers, it continues nevertheless to be deemed too toxic. What is the current status of postoperative radiotherapy? The Lung Adjuvant Radiotherapy Trial (Lung ART) phase III trial should give us a definitive, objective response on global survival, but inclusion of patients is difficult. The results are consequently delayed. The aim of this review is to show all the results about efficacy and tolerance of postoperative radiotherapy and to define the target volume and dose to prescribe.

Personalized treatment of early-stage non-small-cell lung cancer: the challenging role of EGFR inhibitors

Adjuvant cisplatin-based chemotherapy significantly improves outcomes of completely resected early-stage non-small-cell lung cancer (NSCLC) patients. However, its effect on overall survival is limited and may be unsuitable for many patients due to toxicity. Targeted therapies and individualization of adjuvant treatment offer the potential to improve curability and extend survival of these patients while decreasing toxicity. Here we review Phase II and III studies examining the role of EGF receptor inhibitors, including tyrosine kinase inhibitors and the monoclonal antibody cetuximab, as adjuvant therapy in resected patients or as part of multimodality treatment for stage III NSCLC. Recent results from genotype-directed adjuvant tyrosine kinase inhibitors trials including early-stage NSCLC patients with EGFR mutations are promising, but more data are needed to support their use in this setting.

Adjuvant therapy following surgery in non-small cell lung cancer (NSCLC)

Non-small cell lung cancer (NSCLC) accounts for 80-90 % of cases of primary lung cancer. Although surgery is recommended as the primary treatment for early-stage NSCLC, the prognosis is unsatisfactory even when complete resection is achieved. Recent clinical trials have shown that postoperative adjuvant chemotherapy with cytotoxic agents, namely uracil-tegafur (UFT) for stage IA (>2 cm in diameter)-IB patients or cisplatin-based regimens for stage II-IIIA patients, improves the prognosis, and adjuvant chemotherapy is recommended as the "standard treatment of care." However, adjuvant chemotherapy provides only a modest 5-year survival benefit of 4 % and may sometimes be fatal. To improve the risk-benefit balance of adjuvant chemotherapy, targeting agents such as antibodies against vascular endothelial growth factor (VEGF) and tyrosine-kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are being evaluated in ongoing adjuvant trials. Another promising approach may be the individualization of adjuvant chemotherapy based on biomarkers that may predict the prognosis or benefits associated with adjuvant chemotherapy. The current status and future perspectives of adjuvant chemotherapy for NSCLC are reviewed and discussed.

Tangeretin derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone induces G2/M arrest, apoptosis and autophagy in human non-small cell lung cancer cells in vitro and in vivo

Tangeretin, a major phytochemicals in tangerine peels--an important Chinese herb, has been found to have anti-carcinogenic properties. To improve bioavailability and increase potency of tangeretin, its derivative, 5-acetyloxy-6,7,8,4'-tetramethoxyflavone (5-AcTMF), has been synthesized and shown potent inhibition of proliferation activity against human breast and leukemia cancer cell lines. In this study, we have further investigated the anticancer effects of 5-AcTMF on CL1-5 non-small cell lung cancer cells (NSCLC) both in vitro and in vivo and demonstrated that 5-AcTMF effectively inhibited cancer cell proliferation, induced G2/M-phase arrest associated with cdc2 and CDC25c and increased in the apoptotic cells associated with caspase activation, down regulation of Bcl-2, XIAP and Survivn, inducing release of cytochrome c into the cytosol and disruption of mitochondrial membrane potential. We also found that 5-AcTMF treatment of CL1-5 activated autophagy, indicated by triggered autophagosome formation and increased LC3-II levels and formation of LC3 puncta. Moreover, we also found that 5-AcTMF lowered phophoatidylinositol 3-kinase/AKT/mTOR signaling pathway. Over-expression of AKT by AKT cDNA transfection decreased 5-AcTMF mediated apoptosis and autophagy, supporting the induction of apoptosis and autophagy by inhibition of AKT pathway. In an animal study, 5-AcTMF effectively delayed tumor growth in a nude mouse model of CL1-5 xenografts without observed adverse effect. Immunohistochemistry Analysis indicated that 5-AcTMF induced CL1-5 cell apoptosis and autophagy in vivo. Taken together, these data demonstrate that 5-AcTMF is a novel small molecule agent that can inhibit NSCLC cell proliferation, and induce G(2)/M phase arrest and via the mitochondrial apoptotic pathway and autophagy.

Outcome and prognostic factors of postoperative radiation therapy (PORT) after incomplete resection of non-small cell lung cancer (NSCLC)

PURPOSE

Current guidelines recommend postoperative radiation therapy (PORT) for incompletely resected non-small cell lung cancer (NSCLC). However, there is still a paucity of evidence for this approach. Hence, we analyzed survival in 78 patients following radiotherapy for incompletely resected NSCLC (R1) and investigated prognostic factors.

PATIENTS AND METHODS

All 78 patients with incompletely resected NSCLC (R1) received PORT between December 2001 and September 2014. The median total dose for PORT was 60 Gy (range 44-68 Gy). The majority of patients had locally advanced tumor stages (stage IIA (2.6%), stage IIB (19.2%), stage IIIA (57.7%) and stage IIIB (20.5%)). 21 patients (25%) received postoperative chemotherapy.

RESULTS

Median follow-up after radiotherapy was 17.7 months. Three-year overall (OS), progression-free (PFS), local (LPFS) and distant progression-free survival (DPFS) rates were 34.1, 29.1, 44.9 and 51.9%, respectively. OS was significantly prolonged at lower nodal status (pN0/1) and following dose-escalated PORT with total radiation doses >54 Gy (p=0.012, p=0.013). Furthermore, radiation doses >54 Gy significantly improved PFS, LPFS and DPFS (p=0.005; p=0.050, p=0.022). Interestingly, survival was neither significantly influenced by R1 localization nor by extent (localized vs. diffuse). Multivariate analyses revealed lower nodal status and radiation doses >54.0 Gy as the only independent prognostic factors for OS (p=0.021, p=0.036).

CONCLUSION

For incompletely resected NSCLC, PORT is used for improving local tumor control. Local progression is still the major pattern of failure. Radiation doses >54 Gy seem to support improved local control and were associated with better OS in this retrospective study.

Simultaneously modulated accelerated radiation therapy reduces severe oesophageal toxicity in concomitant chemoradiotherapy of locally advanced non-small-cell lung cancer

OBJECTIVE

The aim of this study was to evaluate the potential of simultaneously modulated accelerated radiation therapy (SMART) to reduce the incidence of severe acute oesophagitis in the treatment of unresectable locally advanced non-small-cell lung cancer (LANSCLC).

METHODS

21 patients were treated with SMART and concomitant platinum-based chemotherapy. The prescribed doses were limited to 54 Gy at 1.8 Gy per day to the zones of presumed microscopic extent while simultaneously maintaining doses of 66 Gy at 2.2 Gy per day to the macroscopic disease. The whole treatment was delivered over 30 fractions and 6 weeks. Dosimetric parameters of SMART and the standard technique of irradiation [intensity-modulated radiation therapy (IMRT)] were compared. Acute toxicity was prospectively recorded.

RESULTS

The highest grade of oesophagitis was 62% (13 patients) grade 1, 33% (7 patients) grade 2 and 5% (1 patient) grade 3. Three (14%) patients experienced acute grade 2 pneumonitis. There was no grade 4 oesophageal or pulmonary toxicity. Doses to the organs at risk were significantly reduced in SMART compared with IMRT [oesophagus: V50Gy, 28.5 Gy vs 39.9 Gy (p = 0.003); V60Gy, 7.1 Gy vs 30.7 Gy (p = 0.003); lung: V20Gy, 27.4 Gy vs 30.1 Gy (p = 0,002); heart: V40Gy, 7.3 Gy vs 10.7 Gy (p = 0.006); spine: Dmax, 42.4 Gy vs 46.4 Gy (p = 0.003)]. With a median follow-up of 18 months (6-33 months), the 1-year local control rate was 70% and the disease-free survival rate was 47%.

CONCLUSION

SMART reduces the incidence of severe oesophagitis and improves the whole dosimetric predictors of toxicity for the lung, heart and spine.

ADVANCES IN KNOWLEDGE

Our study shows that SMART optimizes the therapeutic ratio in the treatment of LANSCLC, opening a window for dose intensification.

Extracapsular extension is a powerful prognostic factor in stage IIA-IIIA non-small cell lung cancer patients with completely resection

The purpose of this study is to evaluate the relationship between extracapsular extension (ECE) and clinicopathology, and its influence on the prognosis in non-small cell lung cancer (NSCLC) patients. Clinical data from 388 stage IIA-IIIA NSCLC patients who underwent curative resection and confirmed ECE positive were reviewed. The Fisher's exact or Chi-square test was used to analyze the associations between ECE and the clinical pathology. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). ECE was detected in 85 (21.9%) patients, and it had a significant correlation with advanced T stage, pathological stage and histologic type of adenocarcinoma. For the whole population, the median OS was 39.0 months, and the 5-year OS rate was 33.9%. In multivariate analysis, both ECE status and postoperative chemotherapy were significant factors for OS. The median DFS for all patients was 26.0 months, and the 5-year DFS rate was 21.7%. In multivariate analysis, pathologic stage, ECE, and postoperative chemotherapy were the independent predictor factors for DFS. Further analysis found that the locoregional recurrence-free survival and the distant recurrence-free survival rates in ECE negative group were also significantly higher than in the ECE positive group. For NSCLC patients with lymph node metastasis, the presence of ECE occurs more frequently in advanced stage and histologic type of adenocarcinoma and it may be a powerful prognostic factor which reflects the aggressive biological behavior.

Evidence-based recommendations of postoperative radiotherapy in lung cancer from Oncologic Group for the Study of Lung Cancer (Spanish Radiation Oncology Society)

Locally advanced non-small cell lung cancer (NSCLC) is a diversified illness in which postoperative radiation therapy (PORT) for complete resection with positive hiliar (pN1) and/or mediastinal (pN2) lymph nodes is controversial. Although several studies have shown that PORT has beneficial effects, randomized trials are needed to demonstrate its impact on overall survival. In this review, the Spanish Radiation Oncology Group for Lung Cancer describes the most relevant literature on PORT in NSCLC patients stage pN1-2. In addition, we have outlined the current recommendations of different national and international clinical guidelines and have also specified practical issues regarding treatment volume definition, doses and fractionation.

2nd ESMO Consensus Conference in Lung Cancer: locally advanced stage III non-small-cell lung cancer

To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The 2nd ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, first-line/second and further lines of treatment in advanced disease, early-stage disease and locally advanced disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on locally advanced disease.

ACR Appropriateness Criteria(®) induction and adjuvant therapy for N2 non-small-cell lung cancer

The integration of chemotherapy, radiation therapy (RT), and surgery in the management of patients with stage IIIA (N2) non-small-cell lung carcinoma is challenging. The American College of Radiology (ACR) Appropriateness Criteria Lung Cancer Panel was charged to update management recommendations for this clinical scenario. The Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. There is limited level I evidence to guide patient selection for induction, postoperative RT (PORT), or definitive RT. Literature interpretation is complicated by inconsistent diagnostic procedures for N2 disease, disease heterogeneity, and pooled analysis with other stages. PORT is an appropriate therapy following adjuvant chemotherapy in patients with incidental pN2 disease. In patients with clinical N2 disease who are potential candidates for a lobectomy, both definitive and induction concurrent chemotherapy/RT are appropriate treatments. In N2 patients who require a pneumonectomy, definitive concurrent chemotherapy/RT is most appropriate although induction concurrent chemotherapy/RT may be considered in expert hands. Induction chemotherapy followed by surgery +/- PORT may also be an option in N2 patients. For preoperative RT and PORT, 3-dimensional conformal techniques and intensity-modulated RT are most appropriate.

Selection of proper candidates with resected pathological stage IIIA-N2 non-small cell lung cancer for postoperative radiotherapy

BACKGROUND

To establish a prediction model in selecting fit patients with resected pIIIA-N2 non-small cell lung cancer (NSCLC) for postoperative radiotherapy (PORT), and evaluate the model in clinical practice.

METHODS

Between January 2003 and December 2005, 221 patients with resected pIIIA-N2 NSCLC were retrospectively analyzed. The effect of PORT on overall survival (OS) of patients with different clinicopathological factors was evaluated and the results were used to establish a prediction model to select patients fit for PORT.

RESULTS

Compared with the control, PORT significantly improved the OS of patients with a smoking index ≤400 (P = 0.033), cN2 (P = 0.003), pT3 (P = 0.014), squamous cell carcinoma (SCC) (P = 0.013), or ≥4 positive nodes (P = 0.025). Patients were divided from zero to all five factors into low, middle, and high PORT index (PORT-I) groups (scored 0-1, 2, and 3-5, respectively). PORT did not improve OS (3-year, P = 0.531), disease free survival (DFS) (P = 0.358), or loco-regional recurrence free survival (LRFS) (P = 0.412) in the low PORT-I group. PORT significantly improved OS (P = 0.033), and tended to improve DFS (P = 0.064), but not LRFS (P = 0.287) in the middle PORT-I group. PORT could significantly improve OS (P = 0.000), DFS (P = 0.000), and LRFS (P = 0.006) in the high PORT-I group.

CONCLUSION

The prediction model is valuable in selecting patients with resected pIIIA-N2 NSCLC fit for PORT. PORT is strongly recommended for patients with three or more of the five factors of smoking index ≤400, cN2, pT3, SCC, and ≥4 positive nodes.

Comparison of single-agent chemotherapy and targeted therapy to first-line treatment in patients aged 80 years and older with advanced non-small-cell lung cancer

Purpose

The aim of this study was to compare single-agent chemotherapy with targeted therapy in initial treatment and to explore a better choice of treatment for patients aged 80 years and older with advanced non-small-cell lung cancer (NSCLC).

Patients and methods

A retrospective chart review was conducted for 136 patients aged 80 years and older who were cytopathologically diagnosed and staged as advanced (stage IIIB or IV) NSCLC. The patient population was divided into two treatment groups: 78 patients were allocated to the chemotherapy group (group A, pemetrexed or gemcitabine or docetaxel as a single agent), and 60 patients were allocated to another group and received epidermal growth factor-receptor tyrosine-kinase inhibitors (group B, erlotinib or gefitinib as a single agent). The primary end points were overall survival (OS) and progression-free survival (PFS), and the secondary end points were response rate, disease-control rate, safety, and quality of life.

Results

In group A and group B, respectively, the median PFS was 2 versus 4 months (P=0.013), and the median OS was 8 versus 16 months (P=0.025). The 1- and 2-year survival rates of the two groups were 23.7% (group A, 18 of 76) versus 76.7% (group B, 46 of 60) and 13.2% (group A, ten of 76) versus 10% (group B, six of 60), respectively. The response rate and disease-control rate were 28.9% versus 36.7% (P=0.39) and 57.9% versus 76.7% (P=0.022) in group A and group B, respectively.

Conclusion

Elders aged 80 years and over with advanced NSCLC in group B had longer PFS and OS compared with group A. It was well tolerated in group B because of the mild adverse effects. Targeted therapy can be considered primarily for patients aged 80 years and older with advanced NSCLC who cannot tolerate chemotherapy or radiotherapy.

Postoperative radiotherapy for pathologic N2 non-small-cell lung cancer treated with adjuvant chemotherapy: a review of the National Cancer Data Base

PURPOSE

To investigate the impact of modern postoperative radiotherapy (PORT) on overall survival (OS) for patients with N2 non-small-cell lung cancer (NSCLC) treated nationally with surgery and adjuvant chemotherapy.

PATIENTS AND METHODS

Patients with pathologic N2 NSCLC who underwent complete resection and adjuvant chemotherapy from 2006 to 2010 were identified from the National Cancer Data Base and stratified by use of PORT (≥ 45 Gy). A total of 4,483 patients were identified (PORT, n = 1,850; no PORT, n = 2,633). The impact of patient and treatment variables on OS was explored using Cox regression.

RESULTS

Median follow-up time was 22 months. On univariable analysis, improved OS correlated with younger age, treatment at an academic facility, female sex, urban population, higher income, lower Charlson comorbidity score, smaller tumor size, multiagent chemotherapy, resection with at least a lobectomy, and PORT. On multivariable analysis, improved OS remained independently predicted by younger age, female sex, urban population, lower Charlson score, smaller tumor size, multiagent chemotherapy, resection with at least a lobectomy, and PORT (hazard ratio, 0.886; 95% CI, 0.798 to 0.988). Use of PORT was associated with an increase in median and 5-year OS compared with no PORT (median OS, 45.2 v 40.7 months, respectively; 5-year OS, 39.3% [95% CI, 35.4% to 43.5%] v 34.8% [95% CI, 31.6% to 38.3%], respectively; P = .014).

CONCLUSION

For patients with N2 NSCLC after complete resection and adjuvant chemotherapy, modern PORT seems to confer an additional OS advantage beyond that achieved with adjuvant chemotherapy alone.

miR-25 modulates NSCLC cell radio-sensitivity through directly inhibiting BTG2 expression

A large proportion of the NSCLC patients were insensitive to radiotherapy, but the exact mechanism is still unclear. This study explored the role of miR-25 in regulating sensitivity of NSCLC cells to ionizing radiation (IR) and its downstream targets. Based on measurement in tumor samples from NSCLC patients, this study found that miR-25 expression is upregulated in both NSCLC and radio-resistant NSCLC patients compared the healthy and radio-sensitive controls. In addition, BTG expression was found negatively correlated with miR-25a expression in the both tissues and cells. By applying luciferase reporter assay, we verified two putative binding sites between miR-25 and BTG2. Therefore, BTG2 is a directly target of miR-25 in NSCLC cancer. By applying loss-and-gain function analysis in NSCLC cell lines, we demonstrated that miR-25-BTG2 axis could directly regulated BTG2 expression and affect radiotherapy sensitivity of NSCLC cells.

Radical-intent hypofractionated radiotherapy for locally advanced non-small-cell lung cancer: a systematic review of the literature

PURPOSE

To identify survival and toxicity characteristics associated with radical-intent hypofractionated radiotherapy for the treatment of stage III non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Relevant studies were identified from a systematic PubMed search of articles published between January 1990 and January 2014. All studies were peer reviewed and included both retrospective and prospective studies of NSCLC patients being treated with radical hypofractionated radiotherapy. Data on overall survival (OS) and toxicity were extracted from each of the studies where available.

RESULTS

Of 685 studies initially identified by the search, a total of 33 studies were found to be relevant and were included in this systematic review. The number of fractions ranged from 15 to 35, the dose per fraction ranged from 2.3 to 3.5 Gy, and the delivered dose ranged from 45.0 to 85.5 Gy. Fifteen of the studies included concurrent chemotherapy, while 18 did not. OS was found to be associated with tumor biological effective dose, with the Pearson correlation coefficient ranging from 0.34 to 0.48. For both concurrent and nonconcurrent chemoradiotherapy acute pulmonary, late esophageal and late pulmonary incidences of toxicity ranged from 1.2% to 12.2%, but had 95% confidence intervals that included zero. The greatest incidence of toxicity was acute esophageal toxicity at 14.9% (95% confidence interval, 0.7%, 29.1%).

CONCLUSIONS

There is a moderate linear relationship between biological effective dose and OS, and greater acute esophageal toxicity with concurrent chemotherapy. Improving outcomes in stage III NSCLC may involve some form of hypofractionation in the context of systemic concurrent therapy.

EGFR mutations as a prognostic and predictive marker in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) has entered the age of individual treatment, and increasing point mutations of specific oncogenes and rearrangement of some chromosomes are biomarkers used to predict the therapeutic effect of targeted therapy. At present, there is a consensus among clinicians that epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown favorable efficacy in NSCLC patients with EGFR mutation, and some relevant research has suggested that the presence of EGFR mutations is a favorable prognostic marker. However, the association of EGFR mutation status with the responsiveness to conventional chemotherapy agents and survival in NSCLC patients is still unclear. This review provides an overview of and assesses the role of EGFR as a prognostic marker for postoperative patients and as a predictive marker for response to cytotoxic chemotherapy. In addition, we review the comparison of response to chemotherapy between EGFR mutations in exon 19 and in exon 21 and the predictive role of p.T790M mutation.

Correlation between EGFR mutation status and response to first-line platinum-based chemotherapy in patients with advanced non-small cell lung cancer

Background

The purpose of this research was to investigate the relationship between epidermal growth factor receptor (EGFR) mutations and the response to first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

Methods

A total of 266 patients with stage IIIB or IV NSCLC who received platinum-based doublet therapies as first-line chemotherapy were investigated retrospectively, and their clinical data were assessed according to EGFR mutation.

Results

EGFR mutations were identified in 45.5% of patients. There was no significant difference in response rate between EGFR mutation carriers and EGFR wild-type carriers (P=0.484). Among the patients with Kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type, however, those with EGFR mutations responded better to treatment than EGFR wild-type patients (46.2% versus 20.8%, P=0.043). The disease control rate associated with pemetrexed-based treatments was higher than for vinorelbine-based therapies in EGFR mutation patients (P=0.001). EGFR mutation was found in patients with longer progression-free survival and median survival time, and improved 1-year and 2-year overall survival when compared with EGFR wild-type patients (6.1 versus 5.0 months, P=0.004; 18.9 versus 13.8 months, P=0.001; 81.0% versus 63.4%, P=0.002; and 33.9% versus 22.8% P=0.044, respectively). Patients with the EGFR exon 19 mutation had longer progression-free survival than those with EGFR exon 21 mutation (P=0.007). Multivariate analysis showed that the response to first-line chemotherapy and the presence of EGFR mutations were independent prognostic factors in patients with advanced NSCLC.

Conclusion

Our data showed that the presence of EGFR mutations meant longer survival times for patients with advanced NSCLC who received platinum-based doublet first-line chemotherapy, especially in those with the exon 19 deletion mutation. Among KRAS wild-type patients, those with EGFR mutation responded better to first-line chemotherapy than EGFR wild-type patients.

Adjuvant chemotherapy and radiotherapy in the treatment of non-small cell lung cancer (NSCLC)

Lung cancer is one of the most common human malignancies and remains the leading cause of cancer related deaths worldwide. Many recent technological advances led to improved diagnostics and staging of lung cancer. With development of new treatment options such as targeted therapies there might be improvement in progression free survival of patients with advanced stage non-small cell lung cancer (NSCLC). Improvement in overall survival is still reserved for selected patients and selected treatments. One of the mostly investigated therapeutic options is adjuvant treatment. There are many open issues in selection of patients and administration of appropriate adjuvant treatment.

Silencing miR-21 sensitizes non-small cell lung cancer A549 cells to ionizing radiation through inhibition of PI3K/Akt

We investigated the role of microRNA-21 (miR-21) in radiotherapy resistance of non-small cell lung cancers (NSCLC) and the underlying molecular mechanism. A549 cells were transfected with anti-miR-21 or the negative control oligonucleotides and real-time PCR was applied to detect miR-21 expression level. After ionizing radiation (IR), the survival fractions, proliferation, apoptosis, and expression of phosphorylated-Akt of A549 cells were determined by clonogenic survival analysis, MTT assay, flow cytometry, and Western blotting. Downregulation of miR-21 in radioresistant NSCLC A549 cells inhibited the colony-forming ability and proliferation of A549 cells after IR. Moreover, silencing miR-21 enhanced apoptosis of A549 cells induced by IR accompanied by decreased phosphorylated-Akt protein level. However, PI3K activator IGF-1 reversed suppression of phosphorylated-Akt protein level and promotion of apoptosis of A549 cells after IR caused by miR-21 knockdown. Silencing miR-21 in radioresistant NSCLC A549 cells sensitized them to IR by inhibiting cell proliferation and enhancing cell apoptosis through inhibition of PI3K/Akt signaling pathway. This might help in sensitization of NSCLC to radiotherapy.

Potential clinical predictors of outcome after postoperative radiotherapy of non-small cell lung cancer

AIM

The aim of this analysis was to investigate the impact of tumour-, treatment- and patient-related cofactors on local control and survival after postoperative adjuvant radiotherapy in patients with non-small cell lung cancer (NSCLC), with special focus on waiting and overall treatment times.

PATIENTS AND METHODS

For 100 NSCLC patients who had received postoperative radiotherapy, overall, relapse-free and metastases-free survival was retrospectively analysed using Kaplan-Meier methods. The impact of tumour-, treatment- and patient-related cofactors on treatment outcome was evaluated in uni- and multivariate Cox regression analysis.

RESULTS

No statistically significant difference between the survival curves of the groups with a short versus a long time interval between surgery and radiotherapy could be shown in uni- or multivariate analysis. Multivariate analysis revealed a significant decrease in overall survival times for patients with prolonged overall radiotherapy treatment times exceeding 42 days (16 vs. 36 months) and for patients with radiation-induced pneumonitis (8 vs. 29 months).

CONCLUSION

Radiation-induced pneumonitis and prolonged radiation treatment times significantly reduced overall survival after adjuvant radiotherapy in NSCLC patients. The negative impact of a longer radiotherapy treatment time could be shown for the first time in an adjuvant setting. The hypothesis of a negative impact of longer waiting times prior to commencement of adjuvant radiotherapy could not be confirmed.

Prognostic value of epidermal growth factor receptor mutations in resected lung adenocarcinomas

The purpose of this study was to evaluate the association between epidermal growth factor receptor (EGFR) mutations and prognosis in patients with completely resected lung adenocarcinoma. A total of 131 patients were included in this study. EGFR mutation status in exons 18-21 of the tyrosine kinase-binding domain was detected using nested PCR amplification of individual exon. The χ (2) test was used to analyze the associations between EGFR mutations and the different variables. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). EGFR mutations in 18-21 exons were detected in 58 of the 131 patients (44.3 %). Smoking status (P = 0.029), N stage (P = 0.021), and pathologic stage (P = 0.048) were significantly associated with EGFR mutations. The median DFS in mutant EGFR and wild-type EGFR groups was 36.6 and 25.7 months, respectively (P = 0.533). No significant correlation was observed between EGFR mutations and OS (P = 0.564). However, patients with exon 19 mutation tended to have longer DFS than those with exon 21 mutation (46.2 vs. 21.9 months, P = 0.056), and the 1-, 2-, and 3-year OS rates were significantly higher in patients with exon 19 mutation compared to patients with exon 21 mutation (100, 96.7, 93.3 vs. 91.3, 82.6, 60.9 %, respectively, P = 0.01). Our data demonstrated that EGFR mutations do not have significant prognostic value in primary resected lung adenocarcinomas, but patients with exon 19 mutation tended to have better prognostic value compared to patients with exon 21 mutation.

Modern post-operative radiotherapy for stage III non-small cell lung cancer may improve local control and survival: a meta-analysis

BACKGROUND

We hypothesized that modern postoperative radiotherapy (PORT) could decrease local recurrence (LR) and improve overall survival (OS) in patients with stage IIIA-N2 non-small-cell lung cancer (NSCLC).

METHODS

To investigate the effect of modern PORT on LR and OS, we identified published phase III trials for PORT and stratified them according to use or non-use of linear accelerators. Non-individual patient data were used to model the potential benefit of modern PORT in stage IIIA-N2 NSCLC treated with induction chemotherapy and resection.

RESULTS

Of the PORT phase III studies, eleven trials (2387 patients) were included for OS analysis and eight (1677 patients) for LR. PORT decreased LR, whether given with cobalt, cobalt and linear accelerators, or with linear accelerators only. An increase in OS was only seen when PORT was given with linear accelerators, along with the most significant effect on LR (relative risk for LR and OS 0.31 (p=0.01) and 0.76 (p=0.02) for PORT vs. controls, respectively). Four trials (357 patients) were suitable to assess LR rates in stage III NSCLC treated with surgery, in most cases after induction chemotherapy. LR as first relapse was 30% (105/357) after 5 years. In the modeling part, PORT with linear accelerators was estimated to reduce LR rates to 10% as first relapse and to increase the absolute 5-year OS by 13%.

CONCLUSIONS

This modeling study generates the hypothesis that modern PORT may increase both LR and OS in stage IIIA-N2 NSCLC even in patients being treated with induction chemotherapy and surgery.

Surgery for nonsmall cell lung cancer

Surgery remains the best curative option in patients with early stage lung cancer (stage I and II). Developments in minimally invasive techniques now allow surgeons to perform lung resections on elderly patients, patients with poor pulmonary function or significant cardiopulmonary comorbidities. New techniques, such as stereotactic radiotherapy and ablative procedures, are being evaluated in early-stage lung cancer and may represent an alternative to surgery in patients unfit for lung resection. Perioperative mortality rates have dropped significantly at most institutions in the past two decades and complications are managed more efficiently. Progress in imaging and staging techniques have helped cut futile thoracotomy rates and offer patients the most adequate treatment options. Large randomised trials have helped clarify the role of neoadjuvant, induction and adjuvant chemotherapy, as well as radiotherapy. Surgery remains an essential step in the multimodality therapy of selected patients with advanced-stage lung cancer (stage III and IV). Interventional and endoscopic techniques have reduced the role of surgery in the diagnosis and staging of nonsmall cell lung cancer, but surgery remains an important tool in the palliation of advanced-stage lung cancer. Large national/international surgical databases have been developed and predictive risk-models for surgical mortality/morbidity published by learned surgical societies. Nonetheless, lung cancer overall survival rates remain deceptively low and it is hoped that early detection/screening, better understanding of tumour biology and development of biomarkers, and development of efficient targeted therapies will help improve the prognosis of lung cancer patients in the next decade.

Management of non-small-cell lung cancer: recent developments

Non-small-cell lung cancer is one of the leading causes of deaths from cancer worldwide. Therefore, improvements in diagnostics and treatments are urgently needed. In this review, we will discuss the evolution of lung cancer staging towards more non-invasive, endoscopy-based, and image-based methods, and the development of stage-adapted treatment. A special focus will be placed on the role of novel surgical approaches and modern radiotherapy strategies for early stages of disease, the effect of multimodal treatment in locally advanced disease, and ongoing developments in the treatment of patients with metastatic disease. In particular, we will include an emphasis on targeted therapies, which are based on the assumption that a treatable driver mutation or gene rearrangement is present within the tumour. Finally, the position of lung cancer treatment on the pathway to personalised therapy will be discussed.

SHP1-mediated cell cycle redistribution inhibits radiosensitivity of non-small cell lung cancer

Background

Radioresistance is the common cause for radiotherapy failure in non-small cell lung cancer (NSCLC), and the degree of radiosensitivity of tumor cells is different during different cell cycle phases. The objective of the present study was to investigate the effects of cell cycle redistribution in the establishment of radioresistance in NSCLC, as well as the signaling pathway of SH2 containing Tyrosine Phosphatase (SHP1).

Methods

A NSCLC subtype cell line, radioresistant A549 (A549S1), was induced by high-dose hypofractionated ionizing radiations. Radiosensitivity-related parameters, cell cycle distribution and expression of cell cycle-related proteins and SHP1 were investigated. siRNA was designed to down-regulate SHP1expression.

Results

Compared with native A549 cells, the proportion of cells in the S phase was increased, and cells in the G0/G1 phase were consequently decreased, however, the proportion of cells in the G2/M phase did not change in A549S1 cells. Moreover, the expression of SHP1, CDK4 and CylinD1 were significantly increased, while p16 was significantly down-regulated in A549S1 cells compared with native A549 cells. Furthermore, inhibition of SHP1 by siRNA increased the radiosensitivity of A549S1 cells, induced a G0/G1 phase arrest, down-regulated CDK4 and CylinD1expressions, and up-regulated p16 expression.

Conclusions

SHP1 decreases the radiosensitivity of NSCLC cells through affecting cell cycle distribution. This finding could unravel the molecular mechanism involved in NSCLC radioresistance.

Adjuvant treatment in resected non-small cell lung cancer: current and future issues

The cornerstone of treatment for early-stage non-small cell lung cancer (NSCLC) has been surgical resection. In the last five years two phase III trials have provided evidence of adjuvant platinum-based chemotherapy for completely resected stage II-IIIA patients. We review the evidence supporting adjuvant therapy in early-stage NSCLC; we discuss new issues surrounding adjuvant therapy such as treatment in the elderly-unfit population, treatment toxicity and its influence on outcomes, the importance of histology and gender in adjuvant treatment; and we discuss the future landscape of early-stage NSCLC research, namely, therapeutic strategies exploiting pharmacogenomic and gene-expression profiling, in an attempt to customize the treatment.

Target volume for postoperative radiotherapy in non-small cell lung cancer: results from a prospective trial

BACKGROUND AND PURPOSE

A previous prospective trial reported that three-dimensional conformal postoperative radiotherapy (PORT) for pN2 NSCLC patients using a limited clinical target volume (CTV) had a late morbidity rate and pulmonary function that did not differ from those observed in pN1 patients treated with surgery without PORT. The aim of this study was to assess locoregional control and localization of failure in patients treated with PORT.

MATERIALS AND METHODS

The pattern of locoregional failure was evaluated retrospectively in 151 of 171 patients included in the PORT arm. The CTV included the involved lymph node stations and those with a risk of invasion >10%. Competing risk analysis was used to assess the incidence of locoregional failure and its location outside the CTV.

RESULTS

Overall survival at 5years was 27.1% with a median follow-up of 67months for 40 living patients. The 5-year cumulative incidence of locoregional failure was 19.4% (95% CI: 18.2-20.5%) including a failure rate of 2% (95% CI: 0-17%) in locations outside or at the border of the CTV.

CONCLUSIONS

The use of limited CTV was associated with acceptable risk of geographic miss. Overall locoregional control was similar to that reported by other studies using PORT for pN2 patients.

Developments in the treatment of early NSCLC: when to use chemotherapy

approximately 30% of lung carcinomas are resected and these cases are candidates for adjuvant treatments. The PORT meta-analysis reported in 1999 that postoperative radiotherapy had a detrimental effect for pathological N0 and N1 patients, and a debatable effect for N2 patients. Following the results of the 1995 meta-analysis on the role of chemotherapy (CT) in non-small-cell lung cancer (NSCLC), many randomized, controlled trials were launched to evaluate the effect of adjuvant cisplatin-based CT after the complete resection of NSCLC. The Lung adjuvant Ciplatin Evaluation pooled analysis included a total of 4584 patients recruited in five recent cisplatin-based adjuvant trials. It confirmed that adjuvant CT was associated with an absolute 5-year survival benefit of 5.3% (P = 0.0043). In addition, it showed that adjuvant cisplatin-based CT is detrimental in cases of stage Ia resected NSCLC; it also suggested that the combination of vinorelbine and cisplatin was of more benefit than older two and three drug combinations. The individual data-based meta-analysis was also updated with a total of over 10 000 patients. It confirmed the substantial effect of postoperative CT, with or without postoperative radiotherapy, with a substantial overall benefit of 4% at 5 years. Recent results of biological programs suggest that evaluating the expression of various tumor markers, including excision repair cross-complementation group 1, may allow the identification of patients most likely to benefit from CT. If these results are confirmed, tailored therapy might be the next step forward for resected NSCLC.

Improving image-guided radiation therapy of lung cancer by reconstructing 4D-CT from a single free-breathing 3D-CT on the treatment day

PURPOSE

One of the major challenges of lung cancer radiation therapy is how to reduce the margin of treatment field but also manage geometric uncertainty from respiratory motion. To this end, 4D-CT imaging has been widely used for treatment planning by providing a full range of respiratory motion for both tumor and normal structures. However, due to the considerable radiation dose and the limit of resource and time, typically only a free-breathing 3D-CT image is acquired on the treatment day for image-guided patient setup, which is often determined by the image fusion of the free-breathing treatment and planning day 3D-CT images. Since individual slices of two free breathing 3D-CTs are possibly acquired at different phases, two 3D-CTs often look different, which makes the image registration very challenging. This uncertainty of pretreatment patient setup requires a generous margin of radiation field in order to cover the tumor sufficiently during the treatment. In order to solve this problem, our main idea is to reconstruct the 4D-CT (with full range of tumor motion) from a single free-breathing 3D-CT acquired on the treatment day.

METHODS

We first build a super-resolution 4D-CT model from a low-resolution 4D-CT on the planning day, with the temporal correspondences also established across respiratory phases. Next, we propose a 4D-to-3D image registration method to warp the 4D-CT model to the treatment day 3D-CT while also accommodating the new motion detected on the treatment day 3D-CT. In this way, we can more precisely localize the moving tumor on the treatment day. Specifically, since the free-breathing 3D-CT is actually the mixed-phase image where different slices are often acquired at different respiratory phases, we first determine the optimal phase for each local image patch in the free-breathing 3D-CT to obtain a sequence of partial 3D-CT images (with incomplete image data at each phase) for the treatment day. Then we reconstruct a new 4D-CT for the treatment day by registering the 4D-CT of the planning day (with complete information) to the sequence of partial 3D-CT images of the treatment day, under the guidance of the 4D-CT model built on the planning day.

RESULTS

We first evaluated the accuracy of our 4D-CT model on a set of lung 4D-CT images with manually labeled landmarks, where the maximum error in respiratory motion estimation can be reduced from 6.08 mm by diffeomorphic Demons to 3.67 mm by our method. Next, we evaluated our proposed 4D-CT reconstruction algorithm on both simulated and real free-breathing images. The reconstructed 4D-CT using our algorithm shows clinically acceptable accuracy and could be used to guide a more accurate patient setup than the conventional method.

CONCLUSIONS

We have proposed a novel two-step method to reconstruct a new 4D-CT from a single free-breathing 3D-CT on the treatment day. Promising reconstruction results imply the possible application of this new algorithm in the image guided radiation therapy of lung cancer.

Image guided hypofractionated 3-dimensional radiation therapy in patients with inoperable advanced stage non-small cell lung cancer

PURPOSE

Hypofractionated radiation therapy (HypoRT) can potentially improve local control with a higher biological effect and shorter overall treatment time. Response, local control, toxicity rates, and survival rates were evaluated in patients affected by inoperable advanced stage non-small cell lung cancer (NSCLC) who received HypoRT.

METHODS AND MATERIALS

Thirty patients with advanced NSCLC were enrolled; 27% had stage IIIA, 50% had stage IIIB, and 23% had stage IV disease. All patients underwent HypoRT with a prescribed total dose of 60 Gy in 20 fractions of 3 Gy each. Radiation treatment was delivered using an image guided radiation therapy technique to verify correct position. Toxicities were graded according to Radiation Therapy Oncology Group morbidity score. Survival rates were estimated using the Kaplan-Meier method.

RESULTS

The median follow-up was 13 months (range, 4-56 months). All patients completed radiation therapy and received the total dose of 60 Gy to the primary tumor and positive lymph nodes. The overall response rate after radiation therapy was 83% (3 patients with complete response and 22 patients with partial response). The 2-year overall survival and progression-free survival rates were 38.1% and 36%, respectively. Locoregional recurrence/persistence occurred in 11 (37%) patients. Distant metastasis occurred in 17 (57%) patients. Acute toxicities occurred consisting of grade 1 to 2 hematological toxicity in 5 patients (17%) and grade 3 in 1 patient; grade 1 to 2 esophagitis in 12 patients (40%) and grade 3 in 1 patient; and grade 1 to 2 pneumonitis in 6 patients (20%) and grade 3 in 2 patients (7%). Thirty-three percent of patients developed grade 1 to 2 late toxicities. Only 3 patients developed grade 3 late adverse effects: esophagitis in 1 patient and pneumonitis in 2 patients.

CONCLUSIONS

Hypofractionated curative radiation therapy is a feasible and well-tolerated treatment for patients with locally advanced NSCLC. Randomized studies are needed to compare HypoRT to conventional treatment.