Survival improvements for advanced stage nonbronchioloalveolar carcinoma-type nonsmall cell lung cancer cases with ipsilateral intrapulmonary nodules

Prognostic factors and survival prediction of resected non-small cell lung cancer with ipsilateral pulmonary metastases: a study based on the Surveillance, Epidemiology, and End Results (SEER) database

BACKGROUND

Prognostic factors and survival outcomes of non-small cell lung cancer (NSCLC) with Ipsilateral pulmonary metastasis (IPM) are not well-defined. Thus, this study intended to identify the prognostic factors for these patients and construct a predictive nomogram model.

METHODS

One thousand, seven hundred thirty-two patients with IPM identified between 2000 to 2019 were from the Surveillance, Epidemiology, and End Results (SEER) database. Independent prognostic factors were identified using multivariate Cox regression analyses. Nomograms were constructed to predict the overall survival (OS), C-index, the area under the curve (AUC), and the calibration curve to determine the predictive accuracy and discrimination; the decision curve analysis was used to confirm the clinical utility.

RESULTS

Patients were randomly divided into training (n = 1213) and validation (n = 519) cohorts. In the training cohort, the multivariable analysis demonstrated that age, sex, primary tumor size, N status, number of regional lymph nodes removed, tumor grade, and chemotherapy were independent prognostic factors for IPM. We constructed a 1-year, 3-year, and 5-year OS prediction nomogram model using independent prognostic factors. The C-index of this model for OS prediction was 0.714 (95% confidence interval [CI], 0.692 to 0.773) in the training cohort and 0.695 (95% CI, 0.660 to 0.730) in the validation cohort. Based on the AUC of the receiver operating characteristic analysis, calibration plots, and decision curve analysis, we concluded that the prognosis model of IPM exhibited excellent performance. Patients with total nomogram points greater than 96 were considered high-risk.

CONCLUSION

We constructed and internally validated a nomogram to predict 1-year, 3-year, and 5-year OS for NSCLC patients with IPM according to independent prognostic factors. This nomogram demonstrated good calibration, discrimination, clinical utility, and practical decision-making effects for the prognosis of NSCLC patients with IPM.

Ethnic Differences in Survival Among Lung Cancer Patients: A Systematic Review

Background

Despite a substantially worse risk factor profile, Hispanics in the United States experience lower incidence of many diseases and longer survival than non-Hispanic Whites (NHWs), an epidemiological phenomenon known as the Hispanic Health Paradox (HHP). This systematic review evaluated the published longitudinal literature to address whether this pattern extends to lung cancer survival.

Methods

Searches of Medline, PubMed, Embase, Web of Science, and the Cochrane Library were conducted for publications dated from January 1, 2000, to July 18, 2018. Records were restricted to articles written in English, employing a longitudinal design, and reporting a direct survival comparison (overall survival [OS], cancer-specific survival [CSS]) between NHW and Hispanic lung cancer patients.

Results

A final sample of 29 full-text articles were included, with 28 fully adjusted models of OS and 21 of CSS included. Overall, 26 (92.9%) OS models and 20 (95.2%) CSS models documented either no difference (OS = 16, CSS = 11) or a Hispanic survival advantage (OS = 10, CSS = 9). Both larger studies and those including foreign-born Hispanics were more likely to show a Hispanic survival advantage, and 2 studies of exclusively no-smokers showed a survival disadvantage. A number of reporting gaps were identified including Hispanic background and sociodemographic characteristics.

Conclusions

Hispanics exhibit similar or better survival in the context of lung cancer relative to NHWs despite a considerably worse risk factor profile. These findings support the HHP in the context of lung cancer. Further research is needed to understand the potential mechanisms of the HHP as it relates to lung cancer.

Chelerythrine suppresses proliferation and metastasis of human prostate cancer cells via modulating MMP/TIMP/NF-κB system

Chelerythrine is a natural benzo[c]phenanthridine alkaloid found in many herbs and displays a wide range of antitumor activities. Here, the present study tested their effects on prostate cancer cells. The addition of chelerythrine can significantly inhibit the proliferation of androgen-independent prostate cancer DU145 and PC-3 cells at the concentration of 5 and 10 μM, but not on androgen-dependent prostate cancer LNCaP cells as well as normal prostate epithelial cell line PrEC cells. Wound migration and transwell invasion assay showed the similar inhibitory effect of chelerythrine on the migration and invasion of DU145 and PC-3 cells in the same condition. Western blot analysis further confirmed that chelerythrine not only dramatically decreased MMP-2, MMP-9, and uPA protein expression, but also augmented the expression of their endogenous inhibitors (TIMP-1 and TIMP-2) and plasminogen activator inhibitors (PAI-1 and PAI-2) in both cancer cells. Meanwhile, NF-κB and AP-1 transcription factors were all suppressed as evidenced by the decline of p-p65, c-Fos, and c-Jun protein expression in both cells. Taken together, these findings suggested that chelerythrine could reduce the metastasis of androgen-independent prostate cancer cells via modulation of MMP/TIMP system and inactivation of NF-κB pathway.

Sub-solid lung adenocarcinoma in Asian versus Caucasian patients: different biology but similar outcomes

Background

Asian and Caucasian patients with lung cancer have been compared in several database studies, with conflicting findings regarding survival. However, these studies did not include proportion of ground-glass opacity or mutational status in their analyses. Asian patients commonly develop sub-solid lung adenocarcinomas that harbor EGFR mutations, which have a better prognosis. We hypothesized that among patients undergoing surgery for sub-solid lung adenocarcinomas, Asian patients have better survival compared to Caucasian patients.

Methods

We identified Asian and Caucasian patients who underwent surgical resection for a sub-solid lung adenocarcinoma from 2002 to 2015 at our institution. Sub-solid was defined as ≥10% ground-glass opacity on preoperative CT scan or ≥10% lepidic component on surgical pathology. Time-to-event multivariable analysis was performed to determine which characteristics were associated with recurrence and survival.

Results

Two hundred twenty-four patients were included with median follow up 48 months. Asian patients were more likely to be never smokers (76.3% vs. 29.0%, P<0.01) and have an EGFR mutation (69.4% vs. 25.6% of those tested, P<0.01), while Caucasian patients were more likely to have a KRAS mutation (23.5% vs. 4.9% of those tested, P<0.01). There was a trend towards Asian patients having a higher proportion of ground-glass opacity (38.8% vs. 30.5%, P=0.11). Time-to-event multivariable analysis showed that higher proportion of ground-glass opacity was significantly associated with better recurrence-free survival (HR 0.76 per 20% increase, P=0.02). However, mutational status and race did not have a significant impact on recurrence-free or overall survival.

Conclusions

Asian and Caucasian patients with sub-solid lung adenocarcinoma have different tumor biology, but recurrence-free and overall survival after surgical resection is similar.

Racial and Ethnic Disparities in Cancer Survival: The Contribution of Tumor, Sociodemographic, Institutional, and Neighborhood Characteristics

Purpose Racial/ethnic disparities in cancer survival in the United States are well documented, but the underlying causes are not well understood. We quantified the contribution of tumor, treatment, hospital, sociodemographic, and neighborhood factors to racial/ethnic survival disparities in California. Materials and Methods California Cancer Registry data were used to estimate population-based cancer-specific survival for patients diagnosed with breast, prostate, colorectal, or lung cancer between 2000 and 2013 for each racial/ethnic group (non-Hispanic black, Hispanic, Asian American and Pacific Islander, and separately each for Chinese, Japanese, and Filipino) compared with non-Hispanic whites. The percentage contribution of factors to overall racial/ethnic survival disparities was estimated from a sequence of multivariable Cox proportional hazards models. Results In baseline models, black patients had the lowest survival for all cancer sites, and Asian American and Pacific Islander patients had the highest, compared with whites. Mediation analyses suggested that stage at diagnosis had the greatest influence on overall racial/ethnic survival disparities accounting for 24% of disparities in breast cancer, 24% in prostate cancer, and 16% to 30% in colorectal cancer. Neighborhood socioeconomic status was an important factor in all cancers, but only for black and Hispanic patients. The influence of marital status on racial/ethnic disparities was stronger in men than in women. Adjustment for all covariables explained approximately half of the overall survival disparities in breast, prostate, and colorectal cancer, but it explained only 15% to 40% of disparities in lung cancer. Conclusion Overall reductions in racial/ethnic survival disparities were driven largely by reductions for black compared with white patients. Stage at diagnosis had the largest effect on racial/ethnic survival disparities, but earlier detection would not entirely eliminate them. The influences of neighborhood socioeconomic status and marital status suggest that social determinants, support mechanisms, and access to health care are important contributing factors.

Comparative Analysis of Clinicopathologic Features of, Treatment in, and Survival of Americans with Lung or Bronchial Cancer

Ethnic disparities in lung and bronchial cancer diagnoses and disease-specific survival (DSS) rates in the United States are well known. However, few studies have specifically assessed these differences in Asian subgroups. The primary objectives of the retrospective analysis described herein were to identify any significant differences in clinicopathologic features, treatment, and survival rate between Asian lung cancer patients and lung cancer patients in other broad ethnic groups in the United States and to determine the reasons for these differences among subgroups of Asian patients with lung or bronchial cancer. We searched the Surveillance, Epidemiology, and End Results Program database to identify patients diagnosed with lung or bronchial cancer from 1990 to 2012. Differences in clinicopathologic features, treatment, and DSS rate in four broad ethnic groups and eight Asian subgroups were compared. The study population consisted of 849,088 patients, 5.2% of whom were of Asian descent. Female Asian patients had the lowest lung and bronchial cancer incidence rates, whereas male black patients had the highest rates. Asian patients had the best 5-year DSS rate. In our Asian subgroup analysis, Indian/Pakistani patients had the best 5-year DSS rate, whereas Hawaiian/Pacific Islander patients had the worst 5-year DSS rates. We found the differences in DSS rate among the four broad ethnic groups and eight Asian subgroups when we grouped patients by age and disease stage, as well. Asian patients had better DSS rates than those in the other three broad ethnic groups in almost every age and disease-stage group, especially in older patients and those with advanced-stage disease. In conclusion, we found that clinicopathologic features and treatment of lung and bronchial cancer differ by ethnicity in the United States, and the differences impact survival in each ethnic group.

The Clinical Use of Genomic Profiling to Distinguish Intrapulmonary Metastases From Synchronous Primaries in Non-Small-Cell Lung Cancer: A Mini-Review

The ability to reliably distinguish synchronous primary non-small-cell lung cancer (NSCLC) from intrapulmonary metastatic spread affects staging and treatment decisions in resected NSCLC. Adjuvant therapy for early-stage NSCLC is complicated and recommendations are primarily based on older data from trials that used now-outdated staging systems. Patients found to have 2 tumors with similar morphology in the same lobe are currently staged as pathologic T3 (pT3) but such cases represent a minority of patients in adjuvant lung cancer trials. Potentially more precise than tumor morphology alone, comprehensive genomic profiling technologies have the power to discriminate whether tumors in the same lobe represent 2 separate primary lesions or localized spread of a single lesion. In addition to lineage insights, tumor profiling simultaneously provides information on actionable genomic alterations. In this review we discuss the data that support the ability of molecular technologies to distinguish synchronous primary tumors from intrapulmonary metastases and discuss the use of molecular assays as an adjunct to current staging systems. Two cases are presented to highlight the potential immediate clinical implications of comprehensive genomic profiling.

Huaier polysaccharides suppresses hepatocarcinoma MHCC97-H cell metastasis via inactivation of EMT and AEG-1 pathway

We have recently reported that astrocyte elevated gene-1 (AEG-1) might be an epithelial-mesenchymal transition (EMT) associated biomarker in human hepatocellular carcinoma (HCC), and play an important role in the progression of hepatocellular carcinoma. To extend our study, we examined here the anti-invasive and metastatic effects of Huaier polysaccharide (HP) on human HCC cell line MHCC97-H and explored its possible mechanism of action. Treatment with HP dose-dependently inhibited the proliferation, adhesion, migration and invasion of MHCC97-H cells in vitro. This was achieved not only by reducing the expression of AEG-1 and N-cadherin, but also by enhancing E-cadherin expression. Therefore, these data suggested that HP can inhibit the growth and metastatic potential of MHCC97-H cells through modulation of the AEG-1/EMT pathway.

Special treatment issues in non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

This guideline updates the second edition and addresses patients with particular forms of non-small cell lung cancer that require special considerations, including Pancoast tumors, T4 N0,1 M0 tumors, additional nodules in the same lobe (T3), ipsilateral different lobe (T4) or contralateral lung (M1a), synchronous and metachronous second primary lung cancers, solitary brain and adrenal metastases, and chest wall involvement.

METHODS

The nature of these special clinical cases is such that in most cases, meta-analyses or large prospective studies of patients are not available. To ensure that these guidelines were supported by the most current data available, publications appropriate to the topics covered in this article were obtained by performing a literature search of the MEDLINE computerized database. Where possible, we also reference other consensus opinion statements. Recommendations were developed by the writing committee, graded by a standardized method, and reviewed by all members of the Lung Cancer Guidelines panel prior to approval by the Thoracic Oncology NetWork, Guidelines Oversight Committee, and the Board of Regents of the American College of Chest Physicians.

RESULTS

In patients with a Pancoast tumor, a multimodality approach appears to be optimal, involving chemoradiotherapy and surgical resection, provided that appropriate staging has been carried out. Carefully selected patients with central T4 tumors that do not have mediastinal node involvement are uncommon, but surgical resection appears to be beneficial as part of their treatment rather than definitive chemoradiotherapy alone. Patients with lung cancer and an additional malignant nodule are difficult to categorize, and the current stage classification rules are ambiguous. Such patients should be evaluated by an experienced multidisciplinary team to determine whether the additional lesion represents a second primary lung cancer or an additional tumor nodule corresponding to the dominant cancer. Highly selected patients with a solitary focus of metastatic disease in the brain or adrenal gland appear to benefit from resection or stereotactic radiosurgery. This is particularly true in patients with a long disease-free interval. Finally, in patients with chest wall involvement, provided that the tumor can be completely resected and N2 nodal disease is absent, primary surgical resection should be considered.

CONCLUSIONS

Carefully selected patients with more uncommon presentations of lung cancer may benefit from an aggressive surgical approach.

[The conceptual oligometastatic non-small cell lung cancer and therapeutic strategies]

非小细胞肺癌是发病率及致死率最高的恶性肿瘤之一。约20%-50%会发生远处转移，最常见的转移部位为脑、骨、肝及肾上腺。寡转移状态是一段肿瘤生物侵袭性较温和的时期，存在于局限性原发灶与广泛性转移之间的过渡阶段，转移瘤数目有限并且转移器官具有特异性。“寡转移”来源于微转移，肿瘤细胞已具有器官特异性，但尚不具备全身播散的遗传倾向。治疗寡转移状态的关键是局部控制，需要兼顾预防远处转移、治疗隐匿性转移灶、治疗寡转移灶和全身治疗结束后清除残留癌灶四个方面。本文旨在对“寡转移”概念在非小细胞肺癌常见转移脏器治疗中的应用作一综述。

Stereotactic body radiotherapy (SBRT) for oligometastatic lung tumors from colorectal cancer and other primary cancers in comparison with primary lung cancer

PURPOSE

To analyze local control of oligometastatic lung tumors (OLTs) compared with that of primary lung cancer after stereotactic body radiotherapy (SBRT).

MATERIALS AND METHODS

Retrospective record review of patients with OLTs who received SBRT with 50Gy in 5 fractions. Local control rates (LCRs), toxicities, and factors of prognostic significance were assessed.

RESULTS

Twenty-one colorectal OLTs, 23 OLTs from other origins, and 188 primary lung cancers were included. Multivariate analysis revealed only tumor origin was prognostically significant (p<0.05). The 1-year/2-year LCRs in colorectal OLTs and OLTs from other origins were 80%/72% and 94%/94%, respectively. The LCR in colorectal OLTs was significantly worse than that in OLTs from the other origins and primary lung cancers with pathological and clinical diagnosis (p<0.05, p<0.0001 and p<0.005). Among 44 OLT patients, Grades 2 and 3 radiation pneumonitis were identified in 2 and 1 patients, respectively. No other toxicities of more than Grade 3 occurred.

CONCLUSION

SBRT for OLTs is tolerable. The LCR for OLTs from origins other than colorectal cancer is excellent. However, LCR for colorectal OLTs is worse than that from other origins. Therefore dose escalation should be considered to achieve good local control for colorectal OLTs.

High p27 expression is associated with a better prognosis in East Asian non-small cell lung cancer patients

BACKGROUND

The role of the anti-apoptotic protein p27 in non-small cell lung cancer (NSCLC) remains controversial. To clarify its association with survival in NSCLC, we performed a systematic review of the literature with meta-analysis.

METHODS

Trials were selected for further analysis if they provided an independent assessment of p27 in NSCLC and reported the analysis of survival data based on p27 status. A total of 11 trials, which comprised 1646 patients, provided sufficient information for the meta-analysis. Sensitivity analyses were conducted using histology, disease stage and ethnicity.

RESULTS

The combined hazard ratio (HR) of 1.50 (95% CI=1.15-1.97; P<0.001 for heterogeneity) suggested that high p27 expression has a favorable impact on survival. When the studies were restricted to those of East Asian populations, patients that expressed high levels of p27 showed a better survival rate (HR 1.73, 95% CI=1.36-2.21; P=0.169 for heterogeneity) than those that did not express high levels of p27. In addition, the heterogeneity and publication bias disappeared.

CONCLUSION

In NSCLC, high p27 expression is associated with a better prognosis among East Asians.

Surgical treatment of oligometastatic non-small cell lung cancer

Patients with stage IV metastatic non-small cell lung cancer (NSCLC) are generally believed to have an incurable disease. Patients with oligometastatic disease represent a distinct subset of patients among those with metastatic disease. There is evidence that these patients have synchronous or metachronous satellite nodules in different pulmonary lobes or have solitary extrapulmonary metastases. In these cases, evidence has shown that surgical resection may provide patients with survival benefit. This article discusses the biology of the oligometastatic state in patients with lung cancer and the selection of patients for surgery, as well as the prognostic factors that influence survival of the patient. To properly select patients for an aggressive local treatment regime, accurate clinical staging is of prime importance. The use of FDG-PET should be considered for restaging if oligometastatic disease is suspected based on a patient's CT scan. A limitation of retrospective clinical studies for oligometastatic disease is that it is difficult to summarize and evaluate the available evidence for the effectiveness of surgical resection due to selection bias, and to a high degree of variability among different clinical studies. Nevertheless, we can certainly learn from the clinical experience acquired from retrospective case series to identify prognostic factors. Following surgical resection, the overall 5-year actuarial survival rate is about 28% for patients with satellite nodules and 21% for patients with ipsilateral nodules. Patients with resected brain metastasis achieve 5-year survival rates between 11% and 30%, and those with adrenalectomy for adrenal metastasis achieve 5-year survival rates of 26%.

Survival following non-small cell lung cancer among Asian/Pacific Islander, Latina, and Non-Hispanic white women who have never smoked

BACKGROUND

Lung cancer is the leading cause of cancer death among U.S. Asian/Pacific Islander (API) and Latina women despite low smoking prevalence. This study examined survival patterns following non-small cell lung cancer in a population-based sample of lung cancer cases from the San Francisco Bay Area Lung Cancer Study (SFBALCS).

METHODS

Women diagnosed with lung cancer from 1998 to 2003 and 2005 to 2008 and identified through the Greater Bay Area Cancer Registry were telephone-screened for eligibility for the SFBALCS. The screener data were linked to the cancer registry data to determine follow-up. This analysis included 187 non-Hispanic (NH) white, 23 U.S.-born Latina, 32 foreign-born Latina, 30 U.S.-born API, and 190 foreign-born API never-smokers diagnosed with lung cancer and followed through 2008.

RESULTS

All-cause survival was poorer among APIs [HR=1.7 (95% CI: 1.0-2.8) among U.S.-born APIs and HR=1.2 (95% CI: 0.9-1.5) among foreign-born APIs] and Latinas [HR=2.1 (95% CI: 1.2-3.6) among U.S.-born Latinas; HR=1.4 (95% CI: 0.9-2.3) among foreign-born Latinas] relative to NH whites. These survival differences were not explained by differences in selected sociodemographic or clinical factors.

CONCLUSIONS

Further research should focus on factors such as cultural behaviors, access to or attitudes toward health care, and genetic variations as possible explanations for these striking racial/ethnic differences.

IMPACT

Latina and API female never-smokers diagnosed with lung cancer were up to two times more likely to die than NH whites, highlighting the need for additional research to identify the underlying reasons for the disparities and heightened clinical awareness.

[Anatomy, biology and concepts, pertaining to lung cancer stage classification]

尽管用于此修订本的大样本量患者数据库已极大地拓宽了我们的知识面，但最新提出的肺癌分期系统仍以解剖学特征为基础。可以预见，由于所鉴定出的患者亚群数目不断增加，肺癌分期系统变得愈加复杂。表述这些亚组的临床特征有可能为我们提供肿瘤亚组特殊的生物学行为特性的线索。本文探索了可用于以解剖学为基础的新分期系统的肿瘤生物学相关观念。

Uncovering disparities in survival after non-small-cell lung cancer among Asian/Pacific Islander ethnic populations in California

Asians may have better survival after non-small-cell lung cancer (NSCLC) than non-Asians. However, it is unknown whether survival varies among the heterogeneous U.S. Asian/Pacific Islander (API) populations. Therefore, this study aimed to quantify survival differences among APIs with NSCLC. Differences in overall and disease-specific survival were analyzed in the California Cancer Registry among 16,577 API patients diagnosed with incident NSCLC between 1988 and 2007. Adjusted hazard ratios (HR) with 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression models with separate baseline hazards by disease stage. Despite better overall and disease-specific survival among APIs compared with non-Hispanic Whites, differences were evident across API populations. Among women, Japanese (overall survival HR, 1.16; 95% CI, 1.06-1.27) and APIs other than those in the six largest ethnic groups (other APIs; HR, 1.19; 95% CI, 1.07-1.33) had significantly poorer overall and disease-specific survival than Chinese. By contrast, South Asian women had significantly better survival than Chinese (HR, 0.79; 95% CI, 0.63-0.97). Among men, Japanese (HR, 1.15; 95% CI, 1.07-1.24), Vietnamese (HR, 1.07; 95% CI, 1.00-1.16), and other APIs (HR, 1.18; 95% CI, 1.08-1.28) had significantly poorer overall and disease-specific survival than Chinese. Other factors independently associated with poorer survival were lower neighborhood socioeconomic status, involvement with a non-university hospital, unmarried status, older age, and earlier year of diagnosis. APIs have significant ethnic differences in NSCLC survival that may be related to disparate lifestyles, biology, and especially health care access or use. To reduce the nationwide burden of lung cancer mortality, it is critical to identify and ameliorate hidden survival disparities such as those among APIs.

The applicability of the proposed IASLC staging revisions to small cell lung cancer (SCLC) with comparison to the current UICC 6th TNM Edition

BACKGROUND

We examined the impact of the proposed Internal Association for the Study of Lung Cancer (IASLC) tumor, node, metastasis (TNM) and stage grouping revisions on staging and survival outcome of small cell lung cancer (SCLC).

METHODS

A total of 10,660 SCLC patients from the California Cancer Registry between 1991 to 2005 with complete TNM staging were identified and reclassified according to the IASLC proposed TNM revisions and new stage groupings. Surveillance Epidemiology and End Results extent of disease codes were used to identify various T4 and M descriptors. Cox proportional hazards regression was used to identify prognostic factors.

RESULTS

Survival was correlated with the current UICC6 and IASLC proposed T descriptors. Patients without mediastinal lymph node involvement (N 0-1) had superior survival compared to patients with mediastinal lymph node involvement (N 2-3). The IASLC proposed stage grouping results in better separation of survival curves among early stage SCLC than the current Union Internationale Centre le Cancer (UICC) 6 stage groupings by both univariate and multivariate analyses. Pleural effusion (IASLC M1a) in SCLC had survival similar to other IASLC M1a categories (pericardial effusion, contralateral intrapulmonary metastasis) by pairwise hazard ratio comparisons.

CONCLUSIONS

The IASLC proposed TNM staging changes result in better separation of stage-specific SCLC survival curves than the current UICC6 staging system. The new IASLC M1a descriptors (pleural effusion, pericardial effusion, and contralateral/bilateral intrapulmonary metastasis) adequately prognosticate SCLC patients as having metastatic disease.

Anti-metastatic potential of ginsenoside Rp1, a novel ginsenoside derivative

Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin with a chemopreventive action. In this study, we examined the anti-metastatic activities of G-Rp1 using relevant in vitro assays and in vivo metastasis models. Using a U937 cell-cell adhesion assay, we found that exogenously added G-Rp1 down-regulates beta1-integrin (CD29) activation at concentrations between 10 to 40 microM and suppresses the in vitro tube formation of human umbilical vein endothelial cells (HUVECs). Furthermore, this compound directly blocked cell viability of cancer cells such as A549 and HCT15 cells. In agreement with in vitro findings, G-Rp1 strongly inhibited the metastatic lung transfer of B16-F10 melanoma cells, which have a high surface level of beta1-integrins, without altering body weight. Therefore, these results suggest that G-Rp1 may act as an anti-cancer agent by strongly inhibiting cell viability and metastatic processes, presumably by inhibiting the adhesion of tumor cells and vessel formation.