EGFR Mutation is a Prognostic Factor in Lung Cancer Patients with Pleural Dissemination Detected During or After Surgery.

BACKGROUND: Primary lung tumors are sometimes resected when either pleural dissemination (PD) or malignant pleural effusion (MPE) exists. This study clarified the prognostic factors for non-small cell lung cancer (NSCLC) with either PD and MPE, or both, detected during or after surgery. PATIENTS AND METHODS: We examined patients with NSCLC from a multicenter database who had either PD, MPE, or both, detected during or after surgery between 2005 and 2015. Hazard ratios and 95% confidence intervals were estimated using the Cox proportional hazards model adjusted for potential confounding factors. RESULTS: Among 9463 registered patients, PD, MPE, or both, were found in 114 patients with NSCLC during or after surgery. Primary tumor resection and exploratory thoracotomy were performed in 65 and 49 patients, respectively. In univariate analysis, adenocarcinoma, clinically undetected lymph node metastasis (c-N0 or unknown), EGFR mutation, and combination of chemotherapy or tyrosine kinase inhibitors after surgery were better prognostic factors for overall survival (OS), whereas in the multivariate analysis, adenocarcinoma, clinically undetected lymph node metastasis, and EGFR mutation were favorable independent prognostic factors in OS. Additionally, limited to patients with EGFR mutation, patients with primary lung tumor resection showed a significantly better 5-year OS than those with exploratory thoracotomy (86.4 vs. 44.8%; p < 0.001). CONCLUSION: Our findings show that surgical resection of primary tumors could improve the prognosis of patients with PD, MPE, or both, detected during or after surgery when the tumors harbor an EGFR mutation.

Adjuvant therapy of operable nonsmall cell lung cancer: an update.

PURPOSE OF REVIEW: The current status of postoperative adjuvant therapy for nonsmall cell lung cancer (NSCLC) is reviewed. RECENT FINDINGS: Cisplatin-based postoperative chemotherapy is a current standard of care for patients with stage II-III NSCLC who underwent complete resection. However, its benefit is limited. In these 20 years, the introduction of targeted therapies and immune checkpoint inhibitors has dramatically changed the treatment of metastatic lung cancer. The accumulated knowledge is now being applied in the adjuvant setting and many clinical trials are underway. Recently, postoperative osimertinib was shown to greatly prolong disease-free survival of patients with resected, stage II/IIIA NSCLC with EGFR mutation with an unprecedented hazard ratio of 0.17 in ADAURA study. Furthermore, initial results of adjuvant studies of immune checkpoint inhibitors are expected to be reported shortly. SUMMARY: As lung cancer is inherently prone to metastasize even though it looks in its earlier stage, it is essential to develop a newer generation of adjuvant therapies to improve patient outcomes. To this end, international and multidisciplinary collaboration is key to establish a new standard of care. It is anticipated that the treatment algorithm of early-stage lung cancer will be completely revised in 5 years using a more individualized approach.

A Simple Prognostic Benefit Scoring System for Sarcoma Patients with Pulmonary Metastases: Sarcoma Lung Metastasis Score.

BACKGROUND: Pulmonary metastasectomy could be considered one of the treatment options for disease control in sarcoma patients with pulmonary metastases; however, there is little consensus regarding the suitable criteria for predicting the likely outcomes in these patients. The aim of this study was to establish a prognostic benefit scoring system based on preoperatively examined prognostic factors for sarcoma patients with pulmonary metastases. METHODS: This was a single-center, retrospective cohort study conducted in a cohort of 135 sarcoma patients who underwent a first pulmonary metastasectomy at Okayama University Hospital between January 2006 and December 2015. Based on the results of a multivariable logistic regression analysis performed to determine the factors influencing 3-year mortality, a Sarcoma Lung Metastasis Score was created and its correlation with 3-year survival was analyzed. RESULTS: The results of the multivariate analysis revealed significant differences in the disease-free interval (< 2 years vs. ≥ 2 years; odds ratio (OR) 4.22, 95% confidence interval (CI) 1.67-10.70), maximum tumor diameter (≥ 15 mm vs. < 15 mm; OR 3.86, 95% CI 1.75-8.52), and number of pulmonary metastases (≥ 6 vs. < 6; OR 2.65, 95% CI 1.06-6.620). The Sarcoma Lung Metastasis Score, which was defined as the total score of these three factors, reliably predicted 3-year survival (score: 0, 89.5%; 1, 63.2%; 2, 39.0%; 3, 10.5%). CONCLUSIONS: Our newly proposed simple Sarcoma Lung Metastasis Score appears to be a useful prognostic predictor for sarcoma patients with pulmonary metastases, in that it could be helpful for the selection of appropriate treatments for these patients.

Randomized phase II study of daily and alternate-day administration of S-1 for adjuvant chemotherapy in completely-resected stage I non-small cell lung cancer: results of the Setouchi Lung Cancer Group Study 1301.

BACKGROUND: The aim of this multicenter, randomized phase II study was to analyze the feasibility and safety of alternate-day S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in patients with completely resected pathological stage I (tumor diameter > 2 cm) non-small cell lung cancer (NSCLC). METHODS: Patients were randomly assigned to receive adjuvant chemotherapy for 1 year comprising either alternate-day oral administration of S-1 (80 mg/m2/day) for 4 days a week (Group A) or a 2-week oral administration of S-1 (80 mg/m2/day) followed by 1 week of rest (Group B). The primary endpoint was feasibility, which was defined as the proportion of patients who completed the allocated intervention for 6 months with a relative dose intensity (RDI) of 70% or more. RESULTS: Ninety-three patients were enrolled of whom 90 patients received S-1 treatment. Median follow-up was 66.9 months. The treatment completion rate based on an RDI of 70% or more for 6 months was 84.4% (95%CI; 70.5-93.5%) in group A and 64.4% (95%CI; 48.8-78.1%) in group B. There were no grade 4 adverse events in either group. Moderate or severe adverse events (grade 2 or grade 3) were significantly more frequent in group B (67%) compared with group A (29%, P = 0.001). The 5-year relapse-free survival rate was 87.0 and 80.9% for group A and B, respectively (P = 0.451). The 5-year overall survival rate for all patients (n = 93) was 100 and 89.4% for group A and B, respectively (P = 0.136). CONCLUSION: Alternate-day oral administration of S-1 for 1 year as adjuvant chemotherapy was demonstrated to be feasible with low toxicity in completely resected stage I (tumor diameter > 2 cm) NSCLC. TRIAL REGISTRATION: Trial registration number: UMIN000011994 . Date of registration: 10/8/2013.

Pulmonary Enteric Adenocarcinoma Harboring a BRAF G469V Mutation.

Pulmonary enteric adenocarcinoma (PEAC) is a rare subtype of lung cancer that should be differentiated from colorectal cancer metastasis. Little is known about its genetic background. An 84-year-old male with adenocarcinoma of the lung underwent left upper lobectomy. The histology of the surgical specimen was suggestive of PEAC. Gastrointestinal and colorectal fiberscopy revealed no evidence of colorectal cancer. Next-generation sequencing of the tumor identified a G469V substitution in serine/threonine-protein kinase B-raf (BRAF). Based on the higher prevalence of the G469 substitution in BRAF-mutant lung adenocarcinoma than in BRAFmutant colorectal cancer, the tumor likely originated from the lung. Identification of mutational genotype may be of some help in distinguishing PEAC from the lung metastasis of colorectal cancer.

Successful Bronchoscopic Treatment for Postoperative Bronchopleural Fistula Using N-butyl-2-cyanoacrylate (NBCA): Report of a Post-completion Pneumonectomy Case with a History of Induction Chemoradiotherapy Followed by Bilobectomy for Advanced Lung Cancer.

Bronchopleural fistula (BPF) is a severe complication following lung resection. We present the case of a patient with a history of advanced lung cancer, who had undergone induction chemoradiotherapy followed by right middle and lower lobectomy, and who developed BPF after completion right pneumonectomy. Although we had covered the bronchial stump with an omental pedicled flap, BPF was found on postoperative day 19. We covered the fistula with n-butyl-2-cyanoacrylate (NBCA) using bronchoscopy. Although we had to repeat the NBCA treatment, we ultimately cured the patient's BPF and no recurrence was observed up to 15.2 months after surgery.

The prognostic nutritional index is correlated negatively with the lung allocation score and predicts survival after both cadaveric and living-donor lobar lung transplantation.

PURPOSE: The prognostic nutritional index (PNI), calculated based on the serum albumin levels and the total lymphocyte count, has been identified as a predictor of clinical outcomes in various fields of surgery. In this study, we investigated the relationship between the PNI and the lung allocation score (LAS) as well as the impact of the PNI on the outcomes of both cadaveric lung transplantation (CLT) and living-donor lobar lung transplantation (LDLLT). METHODS: We reviewed retrospective data for 127 recipients of lung transplantation (LT), including 71 recipients of CLT and 56 recipients of LDLLT. RESULTS: The PNI was correlated significantly and negatively with the LAS (r = - 0.40, P = 0.0000037). Multivariate analysis revealed that age (P = 0.00093), BMI (P = 0.00087), and PNI (P = 0.0046) were independent prognostic factors of a worse outcome after LT. In a subgroup analysis, survival after both CLT (P = 0.015) and LDLLT (P = 0.041) was significantly worse in the low PNI group than in the high PNI group. CONCLUSION: Preoperative nutritional evaluations using the PNI can assist with the assessment of disease severity in LT recipients and may predict survival after both CLT and LDLLT.

The prevalence and risk factors associated with preoperative deep venous thrombosis in lung cancer surgery.

PURPOSE: Few studies have so far focused on the preoperative presence of venous thromboembolism (VTE) in lung cancer patients undergoing surgery. In this study, we investigated the prevalence and risk factors for preoperative deep venous thrombosis (DVT) in patients scheduled to undergo lung cancer surgery. METHODS: Between June 2013 and December 2018, 948 consecutive patients underwent lung cancer surgery in Kindai University Hospital. Four patients did not undergo screening for DVT; thus, 944 patients were enrolled in this study. Preoperatively, venous ultrasonography of the lower extremities was performed in patients deemed at risk for DVT, and the prevalence and risk factors for preoperative DVT were examined. RESULTS: Ninety-one patients (9.6%) were diagnosed with preoperative DVT, and postoperative symptomatic pulmonary thromboembolism occurred in one patient (0.11%). A multivariable logistic regression analysis demonstrated that female sex, age ≥ 72 years, history of VTE, a Wells score ≥ 2 points, chronic obstructive pulmonary disease (COPD), and lower hemoglobin levels were significantly associated with preoperative DVT. CONCLUSION: Female sex, age ≥ 72 years, history of VTE, Wells score ≥ 2 points, COPD, and lower hemoglobin levels were identified to be independent risk factors for preoperative DVT. Monitoring for these risk factors and management considering them should help improve the outcomes after lung cancer surgery.

The neutrophil-to-lymphocyte ratio as a novel independent prognostic factor for multiple metastatic lung tumors from various sarcomas.

PURPOSE: Sarcomas are among the most refractory malignant tumors and often recur as pulmonary metastasis. Although the presence of a high neutrophil-to-lymphocyte ratio (NLR) has been associated with the prognosis of several malignancies, the relationship between the NLR and sarcoma with pulmonary metastasis is unclear. We investigated the impact of the NLR in patients who underwent surgical resection for metastatic lung tumors from various sarcomas. METHODS: The subjects of this retrospective study were 158 patients with metastatic lung tumors from various sarcomas, who underwent initial pulmonary metastasectomy between 2006 and 2015. We examined the clinicopathological variables, including the NLR and the characteristics of surgical procedures. Survival was estimated by the Kaplan-Meier method and prognostic factors were evaluated by multivariate analysis. RESULTS: Multivariate analysis revealed significantly better survival of the group with an NLR < 2.26 immediately before the most recent pulmonary metastasectomy, in addition to such factors as the largest resected lesion being < 22 mm, a disease-free interval of > 2 years, and 3 or more pulmonary metastasectomies. CONCLUSION: The NLR immediately before the most recent pulmonary metastasectomy is a novel independent prognostic factor, which may be helpful when considering repeated pulmonary metastasectomy.

Effectiveness of scheduled intravenous acetaminophen in the postoperative pain management of video-assisted thoracic surgery.

PURPOSE: The scheduled administration of intravenous acetaminophen (scheduled-IV-AcA) is one of the more effective multimodal analgesic approaches for postoperative pain in abdominal/orthopedic surgeries. However, there is little evidence concerning scheduled-IV-AcA after general thoracic surgery, especially when limited to video-assisted thoracoscopic surgery (VATS). We investigated the efficacy of scheduled-IV-AcA administration in patients after undergoing VATS. METHODS: Ninety-nine patients who underwent VATS lobectomy or segmentectomy via an 8-cm access window and 1 camera port were retrospectively reviewed by categorizing them into groups either with scheduled-IV-AcA (Group AcA: n = 29) or without it (Group non-AcA: n = 70). Group AcA received 1 g of IV-AcA every 6 h from the end of the operation until the end of POD2. Postoperative pain was measured using a numeric rating scale (NRS) three times per day until discharge. RESULTS: NRS scores were significantly lower in Group AcA with motion (on POD1 to the first point of POD2) than in Group non-AcA. Group non-AcA was also more likely to use additional analgesics than Group AcA (39% vs. 17%, p = 0.058). CONCLUSIONS: Scheduled-IV-AcA administration is a safe and effective multimodal analgesic approach in patients undergoing VATS pulmonary resection via an 8-cm access window.

YES1 activation induces acquired resistance to neratinib in HER2-amplified breast and lung cancers.

Molecular-targeted therapies directed against human epidermal growth factor receptor 2 (HER2) are evolving for various cancers. Neratinib is an irreversible pan-HER tyrosine kinase inhibitor and has been approved by the FDA as an effective drug for HER2-positive breast cancer. However, acquired resistance of various cancers to molecular-targeted drugs is an issue of clinical concern, and emergence of resistance to neratinib is also considered inevitable. In this study, we established various types of neratinib-resistant cell lines from HER2-amplified breast and lung cancer cell lines using several drug exposure conditions. We analyzed the mechanisms of emergence of the resistance in these cell lines and explored effective strategies to overcome the resistance. Our results revealed that amplification of YES1, which is a member of the SRC family, was amplified in two neratinib-resistant breast cancer cell lines and one lung cancer cell line. Knockdown of YES1 by siRNA and pharmacological inhibition of YES1 by dasatinib restored the sensitivity of the YES1-amplified cell lines to neratinib in vitro. Combined treatment with dasatinib and neratinib inhibited tumor growth in vivo. This combination also induced downregulation of signaling molecules such as HER2, AKT and MAPK. Our current results indicate that YES1 plays an important role in the emergence of resistance to HER2-targeted drugs, and that dasatinib enables such acquired resistance to neratinib to be overcome.

Survival Outcomes of Treatment with Radiofrequency Ablation, Stereotactic Body Radiotherapy, or Sublobar Resection for Patients with Clinical Stage I Non-Small-Cell Lung Cancer: A Single-Center Evaluation.

PURPOSE: To retrospectively compare the outcomes of radiofrequency (RF) ablation, stereotactic body radiotherapy (SBRT), and sublobar resection (SLR) in patients with stage I non-small-cell lung cancer (NSCLC) at a single center. MATERIALS AND METHODS: Overall, 289 patients (38 RF ablation, 58 SBRT, and 193 SLR) were included. Kaplan-Meier curves were generated, multiple propensity score was estimated using a multinomial logistic regression model, and relationships between treatments and outcomes were assessed using a Cox proportional hazard model. Hazard ratios (HRs) for death from any cause and disease progression or death from any cause were examined by a crude model, an inverse probability of treatment weighting (IPTW) model, and an IPTW model adjusted for missing variables. RESULTS: The 5-year overall and progression-free survival rates were 58.9% and 39.9%, respectively, for RF ablation; 42.0% and 34.9%, respectively, for SBRT; and 85.5% and 75.9%, respectively, for SLR. Significantly longer survival time and lower HR were observed for SLR than other treatments. However, after statistical adjustment, these relationships were not significant except for reduced HR of disease progression or death from any cause of SLR compared to RF ablation in the IPTW model. The median hospital stays for RF ablation, SBRT, and SLR were 6.5, 6, and 16 days, respectively. Adverse events of grade 3 or higher occurred only in 11 SLR cases. CONCLUSIONS: SLR achieved the longest survival. However, after statistical adjustment, there were no significant outcome differences among RF ablation, SBRT, and SLR, except for 1 model. RF ablation or SBRT may be alternative treatments for selected patients with early-stage NSCLC.

Chemoradiation therapy for non-small cell lung cancer exacerbates thoracic aortic calcification determined by computed tomography.

Preoperative chemoradiation therapy (CRT) has been considered as an effective treatment for non-small cell lung cancer. However, there is concern that CRT progresses atherosclerosis in cancer survivors. This study sought to determine if preoperative CRT exacerbated thoracic aortic calcification (TAC) detected by computed tomography (CT) in patients with lung cancer. Among 473 patients who underwent surgery for lung cancer at Okayama University Hospital between 2011 and 2015, 34 patients undergoing preoperative CRT and surgery (CRT group) and 33 matched patients undergoing initial surgery (non-CRT group) were analyzed and compared. The volume of TAC between the 2nd and 12th thoracic vertebrae was quantitatively measured by CT at baseline and 1-year follow-up. Patients in the CRT group (62 ± 7 years old, 74% male) received cisplatin chemotherapy with docetaxel or vinorelbine and radiation therapy (mean 47.3 ± 4.0 Gy). The percent change in TAC volume was significantly greater in the CRT compared with the non-CRT group (58.7%, 95% confidence interval [CI] 41.7-75.7% vs. 27.2%, 95% CI 9.9-44.4%; p = 0.01). Multivariate logistic regression analysis identified CRT as an independent factor associated with greater TAC progression (> the median value) (odds ratio 3.63, 95% CI 1.19-11.08; p = 0.02). In conclusion, preoperative CRT for lung cancer exacerbates TAC. Follow-up of such patients should thus include careful longitudinal assessment for cardiovascular disease.

A Giant Thymic Cyst Accompanied by Acute Mediastinitis.

We encountered a rare case of thymic cyst accompanied by mediastinitis. A 39-year-old Japanese male presented with fever and chest pain. The chest CT revealed a mass composed of a lobular cystic lesion with inflammation, suggesting the onset of mediastinitis. A definitive histological diagnosis was not obtained, and we performed a thymectomy. Pathologically, the thymic cyst was accompanied by multiple cavities, mimicking thymic cysts, caused by the inflammatory abscess. The surrounding adipose tissue showed inflammatory cell infiltrations with chronic fibrosis. These findings indicate that clinicians should be aware that thymic cysts may cause severe mediastinitis.

Association between Histological Types and Enhancement of Dynamic CT for Primary Lung Cancer.

The aim of this study was to explore enhancement patterns of different types of primary lung cancers on 2-phase dynamic computed tomography (CT). This study included 217 primary lung cancer patients (141 adenocarcinomas [ADs], 48 squamous cell carcinomas [SCCs], 20 small cell lung carcinomas [SCLCs], and 8 others) who were examined using a 2-phase dynamic scan. Regions of interest were identified and mean enhancement values were calculated. After excluding the 20 SCLCs because these lesions had different clinical stages from the other cancer types, the mean attenuation values and subtractions between phases were compared between types of non-small cell lung carcinomas (NSCLCs) using the Kruskal-Wallis test. Late phase attenuation and attenuation of the late minus unenhanced phase (LMU) of SCCs were significantly higher than those of ADs (p<0.05). To differentiate SCC and AD in the late phase, a threshold of 80.21 Hounsfield units (HU) gave 52.9% accuracy. In LMU, a threshold of 52.16 HU gave 59.3% accuracy. Dynamic lung CT has the potential to aid in differentiating among NSCLC types.

Prognostic nutrition index affects the prognosis of patients undergoing trimodality therapy for locally advanced non-small cell lung cancer.

PURPOSE: Trimodality therapy, comprised of induction chemoradiotherapy (iCRT) followed by surgery, is a highly invasive treatment option for locally advanced non-small cell lung cancers (LA-NSCLCs; defined as a heterogenous disease). We conducted this study to investigate the prognostic nutritional index (PNI) of LA-NSCLC patients undergoing trimodality therapy, which has not been studied in detail before. METHODS: The subjects of this retrospective study were 127 patients who underwent trimodality therapy between 1999 and 2016. We measured the PNI at three points: before iCRT (pre-iCRT), before the operation, and after the operation. RESULTS: PNIs decreased significantly as treatment progressed. Patients with clinical T3/4 (cT3/4) disease had a significantly lower PNI than those with cT1/2 disease, but the extent of lymph-node metastasis did not affect the PNI at any point. Using the cut-off values of receiver-operating curve analyses, multivariable analyses revealed that a high PNI pre-iCRT correlated significantly with a better survival of LA-NSCLC patients, especially those with cT3/4 disease (hazard ratio 3.84; 95% confidential interval 1.34-12.5, P = 0.012). CONCLUSIONS: Measuring the PNI before trimodality therapy is important for predicting the clinical outcome of patients with LA-NSCLC, with differing predictive ability according to the disease extent. Perioperative intensive nutritional intervention must be considered for patients who undergo trimodality therapy for LA-NSCLC.

Prognostic value of plasma fibrinogen and D-dimer levels in patients with surgically resected non-small cell lung cancer.

PURPOSE: A high plasma level of either fibrinogen or D-dimer has been shown to correlate with a poor prognosis in patients with surgically resected non-small-cell lung cancer (NSCLC). The present study aimed to identify whether or not both markers combined had a superior prognostic value to either alone. METHODS: Of the 1344 patients who underwent surgical resection for NSCLC at our institution between January 2007 and December 2016, 1065 had preoperative plasma fibrinogen and D-dimer data available and were included in the analysis. RESULTS: The recurrence-free survival (RFS) and overall survival (OS) rates were similar for patients with high plasma levels of either or both fibrinogen (> 4.0 g/L) or D-dimer (> 1.0 µg/mL); therefore, these three groups were combined for a further analysis into a single group with high plasma levels of either or both proteins. The high-level group had significantly lower 5-year RFS (53% vs. 68%, p < 0.001) and 5-year OS (65% vs. 80%, p < 0.001) rates than patients with normal plasma levels of fibrinogen and D-dimer (control group). CONCLUSIONS: Our results suggest that preoperative tests for both plasma fibrinogen and D-dimer are necessary to identify patients with surgically resected NSCLC likely to have a poor RFS and OS.

Pulmonary aspergillosis as a late complication after surgery for locally advanced non-small cell lung cancer treated with induction chemoradiotherapy.

PURPOSE: Some long-term survivors after surgery for locally advanced non-small cell lung cancer (NSCLC) treated with induction chemoradiotherapy (trimodality treatment) develop chronic pulmonary aspergillosis (CPA). The aim of our study was to assess the characteristics and outcomes of CPA that develops after trimodality treatment. METHODS: We retrospectively reviewed the data of 187 NSCLC patients who underwent trimodality treatment between 1999 and 2018. RESULTS: Six male ever-smoker patients developed CPA. All 6 patients had undergone extended resection for NSCLC and had a history of either adjuvant chemotherapy (n = 3) or radiation pneumonitis (n = 4). Among the 4 patients with CPA localized in a single lung, 3 patients were treated surgically (completion pneumonectomy or cavernostomy) and 1 patient was treated with antifungal therapy alone. Both treatments led to the improved control of CPA. In contrast, patients with CPA in both lungs were not candidates for surgery, and died of CPA. The survival rates after trimodality treatment in the CPA group and the group without CPA were comparable (10-year survival rate, 50.0% vs. 57.6%, P = 0.59). CONCLUSION: The early diagnosis of CPA localized in a single lung after NSCLC surgery is critical to improving control and survival in patients with CPA.

exSSSRs (extracellular S100 soil sensor receptors)-Fc fusion proteins work as prominent decoys to S100A8/A9-induced lung tropic cancer metastasis.

Within the "seed and soil" theory of organ tropic cancer metastasis is a growing compilation of evidence that S100A8/A9 functions as a soil signal that attracts cancer cells to certain organs, which prove beneficial to their growth. S100A8/A9-sensing receptors including Toll-like receptor 4 (TLR4), advanced glycation end products (RAGE), and also important receptors we recently succeeded in identifying (EMMPRIN, NPTNß, MCAM, and ALCAM) have the potential to become promising therapeutic targets. In our study, we prepared extracellular regions of these novel molecules and fused them to human IgG2-Fc to extend half-life expectancy, and we evaluated the anti-metastatic effects of the purified decoy proteins on metastatic cancer cells. The purified proteins markedly suppressed S100A8/A9-mediated lung tropic cancer metastasis. We hence expect that our novel biologics may become a prominent medicine to prevent cancer metastasis in clinical settings through cutting the linkage between "seed and soil".

Newly developed anti-S100A8/A9 monoclonal antibody efficiently prevents lung tropic cancer metastasis.

The metastatic dissemination of cancer cells to remote areas of the body is the most problematic aspect in cancer patients. Among cancers, melanomas are notoriously difficult to treat due to their significantly high metastatic potential even during early stages. Hence, the establishment of advanced therapeutic approaches to regulate metastasis is required to overcome the melanoma disease. An accumulating mass of evidence has indicated a critical role of extracellular S100A8/A9 in melanoma distant metastasis. Lung S100A8/A9 is induced by melanoma cells from distant organs and it attracts these cells to its enriched lung environment since melanoma cells possess several receptors that sense the S100A8/A9 ligand. We hence aimed to develop a neutralizing antibody against S100A8/A9 that would efficiently block melanoma lung metastasis. Our protocol provided us with one prominent antibody, Ab45 that efficiently suppressed not only S100A8/A9-mediated melanoma mobility but also lung tropic melanoma metastasis in a mouse model. This prompted us to make chimeric Ab45, a chimera antibody consisting of mouse Ab45-Fab and human IgG2-Fc. Chimeric Ab45 also showed significant inhibition of the lung metastasis of melanoma. From these results, we have high hopes that the newly produced antibody will become a potential biological tool to block melanoma metastasis in future clinical settings.