Characteristics And Prognosis Of Different Metastatic Organ Site And Proposal For The Revision Of M Descriptors Based On Genotype And Metastatic Tumor Burden In Advanced NSCLC

BackgroundLung cancer is the leading cause of cancer-related death in both men and women worldwide. Non-small-cell lung cancer (NSCLC) accounts for approximately80%of primary lung cancers. More than half (55%) of patients with NSCLC present with metastatic disease at diagnosis that is medically and surgically incurable and the main treatment is chemotherapy. Although the third generation drug of chemotherapy can improve the response rate,reduce the toxicity and prolong the survival, the overall survival is poor with a median survival of8-9months.So it is important to enhance the response rate and survival in NSCLC.The most common metastatic organ sites in NSCLC patients include lung,bone,brain,liver,adrenal grand and pleural dissemination. Study demonstrated that distant metastasis occurred non-randomly in lung cancer patients, and there may be specific patterns of distant metastasis. Doebele indicated that compared to the EGFR/ALK/KRAS triple negative patients,with EGFR mutation was predisposed to liver metastasis and ALK gene rearrangement was significantly associated with pericardial disease, pleural disease and liver metastasis,the dominant molecular oncogenes in NSCLC are associated with different biological behaviors regulate patterns of metastatic spread at the time of diagnosis. Non small cell lung cancer is heterogeneous with different clinicopathologic and molecular characteristics in their disease process. Nevertheless, few study performed individual analysis of clinicopathologic and molecular characteristics in NSCLC base on different distant metastases.The detection of driver alterations in the genes encoding epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and the increase in available targeted therapies have transformed the standard treatment of lung cancer. EGFR has a higher frequence in Asian ethnicity, female gender, never/light smoking history, and adenocarcinoma patients in previous reports. EGFR mutation always occur in the exon18to21,and exon19deletion mutation and exon21L858R insert mutation is sensitive to the TKIs.Several prospective clinical trials shown that EGFR mutant is a strong predictive factor for EGFR tyrosine kinase inhibitors (TKIs).Clinical trials have confirmed that EGFR TKIs (gefitinib,erlotinib or afatinib) provide a significant clinical benefit to patients with NSCLC with a median PFS of9.5-13.6months, a median overall survival of21.0-30.9months.Crizotinib is an oral small-molecule tyrosine kinase inhibitor targeting ALK gene and ALK fusion is a strong predictive factor for ALK TKIs. Several clinical trials shown that patients with ALK gene-rearranged advanced NSCLC received clinical benefits from crizotinib with high response rate,low toxicity,objective response rates of approximately65%and a median progression-free survival ranging from7.7to9.7months.The TNM staging system classifies disease base on its anatomic extent and remains the most important prognostic factors in NSCLC.It consider of the extent of primary tumor, the extent of involvement of regional lymph nodes, and the the extent of spread to distant sites and classify the lung cancer into4stage.lt is essential to regularly update the staging system as changes occur in tumor characteristics, diagnostic techniques and advances in treatment. In the7th TNM staging system, patients with stage IV NSCLC are divided into two subgroups according to their prognosis. Patients with either pleural dissemination or contralateral pulmonary nodules are defined as having M1a disease with a median overall survival (OS) of10months, while those with distant metastases are defined as having M1b disease with a median OS of only6months (p<0.001). Several studies have indicated that an increased number of metastatic organ sites is correlated with decreased survival in patients with stage IV NSCLC,an increasing number of metastatic organ sites is a poor prognostic factor.Gene alteration is a prognostic factor in NSCLC patients as targeting therapy significantly improve the survival.Advanced NSCLC patients is heterogeneous with different molecular biological characterization and different number of metastatic organ sites and metastatic sites. The7th edition of the NSCLC staging system was released in2009. The TNM classification system for lung cancer was built on a large database with67725cases of NSCLC treated by all modalities between1990and2000. At that time, there was no data of driver alteration and targeting therapy, molecular characteristics were not taken into consideration. A new, rational classification of stage IV NSCLC is imperative to consider the potential for inclusion of these new prognostic factors in the staging system.Therefore, we designed this retrospective study to evaluated the clinicopathologic and molecular characteristics of different localization of metastatic organ site;and evaluate the survival outcome of patients with stage IV NSCLC based on their gene alteration status and number of metastatic organ sites.Chapter1Clinicopathologic and molecular characteristics of different localization of metastatic organ site in NSCLC Objectivewe designed this retrospective study to evaluated the clinicopathologic and molecular characteristics of different localization of metastatic organ site in Chinese patients with advanced non-small-cell lung cancer andMethodsA consecutive cohort of patients newly diagnosed with the TNM stage IV non small cell lung cancer at Guangdong Lung Cancer Institute (GLCI) between January2005and July2012were enrolled in this retrospective analyses.All the patients had provided consent for the use of their tumor samples for molecular and pathological analyses.EGFR and KRAS mutation were identified by the reverse transcription polymerase chain reaction (RT-PCR) followed by direct sequencing.The ALK gene fusion was identified by rapid-amplification of cDNA ends (RACE) PCR sequential DNA sequencing and fluorescent in situ hybridization (FISH). All analyses were performed using SPSS13.0software.The chi-square test was used to compare qualitative variables, and those with an expected frequency of <5were analyzed by Fisher’s exact test. A two-sided p-value of <0.05was defined as statistically significant.ResultsFrom January2005to July2012,a total of1904evaluable stage Ⅳ NSCLC patients were elvaluated for this study.The most common metastatic organ sites were bone (804,44.3%),lung (657,36.5%),pleural dissemination (546,30.3%),followed by brain (418,23.4%), liver (232,13.1%),adrenal grand (223,12.5%), pericardial dissemination (52,2.9%) and other metastatic organ sites extramediastinal lymph node and other uncommon metastatic organ sites,a total of259. A total of528patients had EGFR mutations (528of1370,38.5%),66had ALK rearrangements (66of630,10.5%) and60had KRAS mutation (60/1035,6.0%). In the comparision of characteristics of subgroups with different metastatic organ sites,there were statistically significant differences in terms of variables of gender (p<0.001), age (p=0.006), smoking status (p<0.001), PS (p=0.003), pathology (p<0.001) and EGFR status (p<0.001).There were no difference in KRAS (p=0.266) or ALK status (p=0.194).Patients with pleural dissemination (42.1%),lung (43.4%) metastasis were more likely to be females than liver (33.2%),adrenal grand (28.7%) and other metastatic organ site (28.6%). Lung (57.4%)、pleural dissemination (61.8%),Pericardia dissemination (58.8%),bone (57.3%) metastasis were more non smoker,but adrenal grand (58.7%) and other metastatic organ site (53.7%) metastasis were more smoker.The patients with lung (82.3%),pleural dissemination (89.2%),pericardial dissemination (92.3%),bone (87.1%),brain (87.1%) metastasis had a higher rate of adenocarcinoma than liver (74.1%),adrenal grand (82.3%) and other metastatic organ site (80.3%).Patients with lung (43.7%), pleural dissemination (41.8%) and brain(46.6%) metastasis had a higher rate of EGFR mutation than liver (29.0%), adrenal grand (31.3%) and other metastatic organ sites (26.3%).Conclusion1. The frequencies of EGFR mutant, ALK rearrangement and KRAS mutant were38.5%,110.5%,6.0%respectively in Chinese patients with advanced non-small-cell lung cancer.2. In the comparision of characteristics of subgroups with different metastatic organ sites,there were statistically significant differences in terms of variables of gender age, smoking status, PS, pathology and EGFR status. Patients with lung (43.7%), pleural dissemination (41.8%) and brain (46.6%) metastasis had a higher rate of EGFR mutation than liver (29.0%), adrenal grand (31.3%) and other metastatic organ sites (26.3%).Chapter2Survival outcome of patients with different tumor burden in advanced NSCLCObjectiveWe aims to analyze the survival outcome of patients with different number of metastatic organ sites and those with different localization in single metastatic organ in stage IV non-small cell lung cancerMethodsA consecutive cohort of patients newly diagnosed with the TNM stage IV non small cell lung cancer at Guangdong Lung Cancer Institute (GLCI) between January2005and July2012were enrolled in this retrospective analyses. Survival data were collected from the Guangdong Lung Cancer Institute medical record system or by telephone follow-up. OS was defined as the time from initial diagnosis to death or the last follow-up. OS from initial diagnosis to the last follow-up for being alive or loss to follow-up were censored data.All patients were divided into three groups based on the number of metastatic organs:1)1metastatic organ:patients only have1metastatic organ site;2)2metastatic organs:patients have2metastatic organ sites;3)>3metastatic organs: patients have more than2metastatic organ sites.The single metastatic organ site patients were divided into lung, pleural, pericardium, bone, brain, liver, adrenal grand and other metastasis group.The chi-square test was used to compare qualitative variables, and those with an expected frequency of<5were analyzed by Fisher’s exact test. A nonparametric test was used to analyze quantitative data.A survival analysis was performed by the Kaplan-Meier method and log-rank test. A two-sided p-value of<0.05was defined as statistically significant. All analyses were performed using SPSS13.0software.ResultsA total of1053patients (1053/1904,55.3%) had one metastatic organ site,530(530/1904,27.8%) had2metastatic organ sites and321(321/1904,16.9%) had>3metastatic organ sites.In the single metastatic organ site patient,there were255(24.2%) with bone metastasis,231(21.9%) lung,269(25.5%) pleural dissemination. 148(14.1%) brain,42(4.0%) liver,45(4.3%) adrenal grand,12(1.2%) pericardica dissemination and51(4.8%) other metastasis。The median OS of all the patients was14.4months.The median OS of patients with1,2or>3matastatic organ sites was16.9months,13.4months,8.5months respectively. There were statistically significant differences among patients with different numbers of metastatic organ sites (p<0.001).In the patients with antitumor therapy,the median OS was20.3months,16.2months and11.6months (p<0.001).In the M1a patients,the median OS of the single metastatic organ was19.8months, multiple metastatic organs was16.6months (p=0.052).In the Mlb patients,the median OS of1,2or>3matastatic organ sites was14.5months,12.7months and8.3months (p<0.001).In the adenocarcinoma,the median OS of these three groups were18.9months,14.4months and8.6months (p<0.001); In the non-adenocarcinoma,the median OS of these three groups were12.6months,10.2months and8.5months (p=0.049).In the patients with single metastatic organ, pericardial disease metastasis (21.9months), pleural disease metastasis (21.0months), lung metastasis (19.3months) had a better prognosis,followed by brain metastasis(16.8months), liver metastasis (16months),bone metastasis (14.9months), adrenal grant metastasis (8.9months) and other metastatic organ sites (10.9months) had a worse survival.Conclusion1A high number of metastatic sites was predictive of inferior survival in patients with stage IV NSCLC2In the patients with single metastatic organ,intrathoracic metastasis had a better survival outcome,followed by the brain and liver metastasis,adrenal grand and other organ sites prognosis worse.Chapter3Proposal for the revision of M descriptors based on genotype and the number of metastatic organ sites and metastatic sitesObjectivewe designed this retrospective study to evaluate the survival outcome of patients with stage IV NSCLC based on their gene alteration status and number of metastatic organ sites.MethodsPatients enrolled in section one were screened for the survival analysis. The inclusion criteria were as following:1) diagnosis between January2009and July2012;2) provided consent for the use of their tumor samples for EGFR and ALK gene detection.Exclusion criteria were as following:1) did not have the tumor samples for EGFR/ALK gene detection;2) with other concomitant malignant disease.We reviewed the patients’medical records to collect clinical data, including age, sex, smoking status, Eastern Cooperative Oncology Group performance status (PS), EGFR and ALK gene status, histologic type of lung cancer, localization of metastatic organ sites, treatment regimens, and dates of diagnosis and death or the last follow-up. Survival data were collected from the Guangdong Lung Cancer Institute medical record system or by telephone follow-up. OS was defined as the time from initial diagnosis to death or the last follow-up. OS from initial diagnosis to the last follow-up for being alive or loss to follow-up were censored data.All patients who underwent EGFR and/or ALK gene analysis were divided into three groups based on M descriptors: the M1-Ⅰ group comprised EGFR/ALK-positive patients, the M1-Ⅱ group comprised wild-type EGFR and ALK patients with intrathoracic metastasis or1distant metastatic organ site and<3metastasis, and the M1-III group comprised wild-type EGFR and ALK patients with1distant metastatic organ site and>3metastasis or multiple metastatic organ sites. The chi-square test was used to compare qualitative variables, and those with an expected frequency of<5were analyzed by Fisher’s exact test. A nonparametric test was used to analyze quantitative data. A survival analysis was performed by the Kaplan-Meier method and log-rank test. Maximally selected statistics19was used to comparison the maximum of the absolute values and p value of the M1category of our study and the M1category of the7th TNM staging system.Univariate and multivariate analyses were performed by the Cox proportional hazards method to identify factors associated with survival outcome. A two-sided p-value of<0.05was defined as statistically significant. All analyses were performed using SPSS13.0software.ResultsA total of627patients were evaluated for the analysis.301patients with genetic alterations in either EGFR or ALK were defined as M1-I,158wild-type EGFR and ALK patients with intrathoracic metastasis or1distant metastatic organ site<3metastasis were defined as M1-II, and168wild-type EGFR and ALK patients with1distant metastatic organ site>3metastasis or multiple metastatic organ sites were defined as M1c.Compare with the2wild type groups, patients with genetic alterations in either EGFR or ALK were more likely to be females (50.5%vs.26.6%vs.29.8%), nonsmokers (69.3%vs.49.4%vs.44.6%),and adenocarcinoma (97.0%vs.78.5%vs.79.8%)The median OS of all patients was17.6months. The median OS of the Ml-I, M1-Ⅱ, and M1-Ⅲ groups was23.3,16.0and10.6months, respectively. There were statistically significant differences among these three groups (p<0.001). The median OS of these3group who underwent antitumor therapy were25.0,21.1and14.4months, respectively (p<0.001).The median OS of the M1a, M1b groups according to the7th edition TNM cancer staging system was22.8and15.1months, respectively (p<0.001). In the M1a patients,EGFR/ALK gene positive patients had a median OS of27.3months,longer than those with EGFR/ALK wild type (16.2months, p=0.031).In the M1b patients, according to our grouping, the median OS of the Ml-I group was20.6months,longer than M1-Ⅱ group of13.5months (p=0.007) and M1-Ⅲ groups of10.0months (p<0.001).In the adenocarcinoma,the median OS of the M1-Ⅰ, Ml-II, and M1-III groups was23.4months,15.5months and10.6months, respectively (p<0.001). In the non-smoker,the median OS of the M1-Ⅰ, M1-Ⅱ, and M1-III groups was24.9months,16.8months and16.6months, respectively (p<0.001).In the smoker,the median OS of these three groups was19.1months,15.5months and7.7months, respectively (p<0.001).204EGFR/ALK-positive patients with TKIs,the median OS was26.0months,31EGFR/ALK-positive patients with chemotherapy but without TKIs was11.9months,,196EGFR and ALK gene wild type patients with chemotherapy was16.0months,there were significant different among these groups (p=0.001).In the category of our study and the M1category of the7th TNM staging system the maximum of the absolute values of these two grouping were5.532and4.335,respectively(p<0.001). So the grouping of our study can predicting prognosis better than the M1a/M1b grouping. Based on our study results we propose that M descriptors could be considered as M1a, M1b and M1c in coming the8th TNM staging system.Conclusion1. Patients with advanced NSCLC and EGFR/ALK gene alterations prognostic better,follow by the wild-type EGFR and ALK patients with intrathoracic metastasis or1distant metastatic organ site and≤3metastasis, wild-type EGFR and ALK patients with1distant metastatic organ site and>3metastasis or multiple metastatic organ sites prognostic worse. 2. Patients with EGFR/ALK gene alterations may be treated with TKIs; wild-type EGFR and ALK patients with1metastatic organ site<3metastasis could be treated by systemic therapy combined with local intervention,and those with1distant metastatic organ site>3metastasis or multiple metastatic organ sites could be treated by systemic chemotherapy.3.We propose that the M1descriptor should be divided into M1a, M1b, and M1c base on the gene alteration,number of the metastatic organ sites and metastatic lesions in the next NSCLC staging system.