Janakiraman Subramanian

GENOMIC LANDSCAPE OF NON-SMALL CELL LUNG CANCER IN SMOKERS AND NEVER SMOKERS

We report the results of whole-genome and transcriptome sequencing of tumor and adjacent normal tissue samples from 17 patients with non-small cell lung carcinoma (NSCLC). We identified 3,726 point mutations and more than 90 indels in the coding sequence, with an average mutation frequency more than 10-fold higher in smokers than in never-smokers. Novel alterations in genes involved in chromatin modification and DNA repair pathways were identified, along with DACH1, CFTR, RELN, ABCB5, and HGF. Deep digital sequencing revealed diverse clonality patterns in both never-smokers and smokers. All validated EFGR and KRAS mutations were present in the founder clones, suggesting possible roles in cancer initiation. Analysis revealed 14 fusions, including ROS1 and ALK, as well as novel metabolic enzymes. Cell-cycle and JAK-STAT pathways are significantly altered in lung cancer, along with perturbations in 54 genes that are potentially targetable with currently available drugs.

Lung Cancer in Never Smokers: A Review

Lung cancer is the leading cause of cancer-related death in the United States. Although tobacco smoking accounts for the majority of lung cancer, approximately 10% of patients with lung cancer in the United States are lifelong never smokers. Lung cancer in the never smokers (LCINS) affects women disproportionately more often than men. Only limited data are available on the etiopathogenesis, molecular abnormalities, and prognosis of LCINS. Several etiologic factors have been proposed for the development of LCINS, including exposure to radon, cooking fumes, asbestos, heavy metals, and environmental tobacco smoke, human papillomavirus infection, and inherited genetic susceptibility. However, the relative significance of these individual factors among different ethnic populations in the development of LCINS has not been well-characterized. Adenocarcinoma is the predominant histologic subtype reported with LCINS. Striking differences in response rates and outcomes are seen when patients with advanced non-small-cell lung cancer (NSCLC) who are lifelong never smokers are treated with epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors such as gefitinib or erlotinib compared with the outcomes with these agents in patients with tobacco-associated lung cancer. Interestingly, the activating mutations in the EGFR-TK inhibitors have been reported significantly more frequently in LCINS than in patients with tobacco-related NSCLC. This review will summarize available data on the epidemiology, risk factors, molecular genetics, management options, and outcomes of LCINS.

Molecular genetics of lung cancer in people who have never smoked

Lung cancer is a major cause of cancer-related mortality in the USA, and tobacco smoke is the major risk factor for this disease. However, many patients with lung cancer have never smoked (never smokers). Patients with lung cancer who have never smoked are more likely to have mutations in epidermal growth factor receptor (EGFR) tyrosine kinase and have better response to its inhibitors than do patients with tobacco-associated lung cancer. Furthermore, the prevalences of mutations in KRAS and P53 differ for patients with lung cancer who have never smoked and those with tobacco-associated lung cancer. Genetic mutations seem to be more common in patients with tobacco-associated lung cancer than in never smokers. Current evidence indicates that the two types of lung cancer are biologically distinct. Here, we review published studies of the molecular genetics of lung cancer in never smokers and identify the specific differences from tobacco-associated lung cancer.

Distinctive Characteristics of Non-small Cell Lung Cancer (NSCLC) in the Young: A Surveillance, Epidemiology, and End Results (SEER) Analysis

Background: The median age of patients with newly diagnosed non-small cell lung cancer (NSCLC) at presentation is 71 years. We conducted an analysis of Surveillance, Epidemiology, and End Results data to assess whether the presentation and outcomes of NSCLC in younger patients (age ≤40 years) are different from that in older patients (age >40 years). Methods: We obtained the demographic, clinical, and outcomes data for all patients diagnosed with NSCLC from 1988 to 2003 in the Surveillance, Epidemiology, and End Results registry. Patients were grouped by age at diagnosis into younger than or equal to 40 years (younger cohort) or older than 40 years (older cohort). Results: During the period analyzed, we identified 2775 patients with NSCLC in the younger cohort and 236,313 patients in the older cohort. Compared with the older group, the younger group had greater proportion of African Americans (19.2% versus 10.9%; p < 0.0001), Asian or Pacific Islander (10.3% versus 5.9%; p < 0.0001), women (48.7% versus 41.9%; p < 0.0001), and patients with stage IV disease (57.4% versus 43.0%; p < 0.0001). Adenocarcinoma was more common in younger patients than in the older patients (57.5% versus 45.2%; p < 0.0001). Squamous cell carcinoma was less prevalent in the younger cohort than in older cohort (12.5% versus 26.4%; p < 0.0001). Five-year overall survival and cancer specific survival were significantly better for younger patients than for older patients across all stages. Conclusions: There is a greater representation of African Americans, Asians or Pacific Islanders, women, and adenocarcinoma histology in the younger cohort of patients with NSCLC compared with the older cohort. Despite presenting with stage IV disease more often, the overall and cancer-specific survivals are better in younger cohort than in the older cohort.

Improving Survival for Stage IV Non-small Cell Lung Cancer: A Surveillance, Epidemiology, and End Results Survey from 1990 to 2005

Background: Although there has been a significant survival improvement for patients with metastatic NSCLC enrolled in randomized trials, it is not clear whether a similar benefit is seen in an unselected group of patients. Therefore, we conducted a study to evaluate for survival changes in a large national cancer registry database. Patients and Methods: The Surveillance, Epidemiology, and End Results (SEER) registry was queried for patients with NSCLC stage IV, aged 21 years or older, and diagnosed between 1990 and 2005. We analyzed four equally divided time periods between 1990 and 2005 (1990 to 1993 or period 1, 1994 to 1997 or period 2, 1998 to 2001 or period 3, and 2002 to 2005 or period 4) to determine changes in overall survival for all patients and according to histology. Results: We identified 129,337 patients meeting eligibility criteria. There was a significant improvement in overall survival since period 1. One-year and 2-year overall survival increased from 13.2 and 4.5%, respectively, in period 1 to 19.4% and 7.8%, respectively, in period 4. On multivariate analysis, survival for adenocarcinoma was increased compared with squamous cell carcinoma only in period 4 (p = 0.02). Conclusions: There has been a modest but statistically significant improvement in overall survival for stage IV NSCLC over the past 16 years. The recent differences in outcomes based on histology observed in period 4 may reflect the increased activity of epidermal growth factor receptor tyrosine kinase inhibitors in adenocarcinoma compared with squamous cell carcinoma.

Prognostic Impact of Malignant Pleural Effusion at Presentation in Patients with Metastatic Non–Small-Cell Lung Cancer

Background: Despite its common occurrence, the influence of malignant pleural effusion (MPE) on the outcomes of patients with advanced non–small-cell lung cancer (NSCLC) with distant metastasis (M1b) is unknown. We evaluated the clinical characteristics associated with MPE at presentation and the prognostic impact of MPE at presentation in patients with stage M1b NSCLC. Methods: We extracted data from the Surveillance Epidemiology and End Results (SEER) registry from patients with NSCLC diagnosed between 2004 and 2005. Odds-ratio estimates were calculated using logistic regression, and the Kaplan–Meier method was used to estimate the overall survival. Cox proportional hazard model was used to evaluate whether MPE was an independent risk for outcome. Results: Among the 57,685 patients, MPE was present in 9170 (15.9%), including 3944 out of 31,506 (12.5%) without distant metastases and 5226 (20.0%) out of 26,179 with M1b. The probability of MPE was higher in patients with larger tumors, mediastinal lymph node involvement, and adenocarcinoma, NSCLC not otherwise specified, or large-cell histology. In patients with stage M1b, median overall survival (3 months versus 5 months), estimated 1-year survival (12.6% versus 24.8%), and 2-year survival (5.4% versus 11.3%) were significantly lower in patients with MPE compared with those without MPE (hazards ratio 1.49, 95% confidence interval 1.44–1.54, p < 0.0001). MPE was also an independent factor for worse survival in multivariate analysis (hazards ratio 1.36, 95% confidence interval1.30–1.43, p < 0.001). Conclusions: MPE is a common complication in patients with NSCLC and is associated with decreased survival in patients with distant metastases. If these data are validated, subsequent studies in patients with advanced NSCLC may consider stratification according to the MPE status.

Risk of Recurrence of Resected Stage I Non-small Cell Lung Cancer in Elderly Patients as Compared with Younger Patients

Purpose: Half of all patients with non-small cell lung cancer (NSCLC) are 70 years or older at the time of diagnosis. Surgery is an option for fit elderly patients with early stage disease, but rates of disease recurrence after surgical resection are not well described. We report the outcomes in elderly patients (70 years or older) with stage I NSCLC after surgical resection. Patients and Methods: We conducted a retrospective study of patients diagnosed with stage I NSCLC after surgical resection at Washington University School of Medicine-Alvin J. Siteman Cancer Center from 1990 to 2000. Demographic, pathologic, treatment, and follow-up data were collected. Recurrence rates and overall survival were calculated by the Kaplan-Meier method. Multivariate Cox proportional hazards models were used to detect associations between potential prognostic factors and survival and recurrence. Results: Of the 715 patients with stage I NSCLC, 286 were 70 years or older at diagnosis. In this elderly cohort, the median age was 74 years (range, 70–89 years) and 140 of them were women (49%). Lobectomy was performed in 237 patients (83%) whereas 43 patients (15%) had a wedge or segmental resection, and six patients (2%) underwent pneumonectomy. Clinical and pathologic characteristics were not statistically different between the elderly and younger cohorts, with the exception that older patients were more likely to be white (90% versus 80%, p = 0.0003) and less likely to be smokers (88% versus 95%, p = 0.019) compared with the younger cohort. With a median follow-up of 4.6 years, the overall 5-year survival rate was 52% with a 5-year recurrence rate of 24%. In comparison, the patients younger than 70 years had a 5-year survival rate of 67% (p < 0.001) and a 5-year recurrence rate of 24%. Conclusions: Although overall survival was worse in elderly patients, estimated disease recurrence rates after resection were identical.

Presentation and Stage-Specific Outcomes of Lifelong Never-smokers with Non-small Cell Lung Cancer (NSCLC)

Background: Tobacco smoking leads to lung cancer. Approximately 10% of patients with lung cancer are life long never-smokers. There are only limited data available on the clinical characteristics and outcomes of lung cancer in never-smokers from the Western hemisphere. Methods: Demographic and survival information was collected on 254 never-smokers with a confirmed pathologic diagnosis of non-small cell lung cancer (NSCLC) by reviewing their medical records and the Social Security database. Results: The study population consisted of 182 (71.6%) women and 72 (28.3%) men. The median age was 70 years (range: 31–91 years). Adenocarcinoma was the most common histology accounting for 60.8% of all patients, followed by NSCLC not otherwise specified (14.4%), bronchoalveolar carcinoma (13.6%), squamous cell carcinoma (8.8%), and large-cell type (2.4%). Majority of patients presented with stage III or IV disease (62.5%). We compared survival between never-smokers and smokers with NSCLC matched for gender, histology, tumor stage, and years of diagnosis. No significant difference in 5-year survival was seen between never-smokers (27.2%) and smokers with NSCLC (31.3%; p = 0.73). Conclusions: Two thirds of patients with lung cancer who report no history of tobacco smoking are women. In the matched case–control analysis, we report no significant survival difference between lung cancer in never-smokers and those with history of tobacco smoking and lung cancer.

Phase II study of docetaxel in combination with everolimus for second- or third-line therapy of advanced non-small-cell lung cancer.

We conducted a phase II study of docetaxel in combination with everolimus, a mammalian target of rapamycin (mTOR) inhibitor, for salvage therapy of advanced non–small-cell lung cancer (NSCLC) based on promising preclinical and early-phase clinical data. Patients with advanced-stage NSCLC treated with one or two previous systemic therapy regimens were given docetaxel (60 mg/m2) and everolimus (5 mg orally once daily on days 1–19) every 3 weeks. Archived tumor specimens were evaluated for markers of mTOR pathway activation (total and phosphorylated mTOR, Akt, S6, eIF4e, and 4EBP1). Twenty-eight patients were enrolled (median age: 62 years; male: 13; Caucasians: 19; adenocarcinoma: 20; performance status 0, 3; performance status 1, 23; 1 previous regimen, 16). A median of 3.5 cycles of therapy was administered. Two patients experienced partial response and 15 had stable disease (clinical benefit rate, 70%). The 6-month progression-free survival rate was 5%, and the median overall survival was 9.6 months. Low pAkt expression correlated with clinical benefit rate (p = 0.01) but not with progression-free survival or overall survival. The combination of everolimus and docetaxel was tolerated well, but the efficacy was relatively modest in an unselected population of patients with NSCLC.

Review of Ongoing Clinical Trials in Non–Small-Cell Lung Cancer: A Status Report for 2012 from the ClinicalTrials.gov Web Site

Introduction: Clinical research in non–small-cell lung cancer (NSCLC) is a rapidly evolving field. In an effort to identify the current trends in lung cancer clinical research, we reviewed ongoing clinical trials in NSCLC listed in the ClinicalTrials.gov registry in 2012, and we also compared this data to a similar survey conducted by us in 2009. Methods: The Web site’s advanced search function was used to search for the term “non-small cell lung cancer.” The search was further refined by using the following options from the search page drop-down menu, “open studies” and “interventional.” Studies with non-NSCLC tumor histologies and pediatric studies were excluded. Results: Of the 477 trials included in the analysis, 105 (22.0%) were phase I, 223 phase II (46.8%), and 63 phase III trials (13.2%). When compared with data from 2009, university-sponsored trials decreased in number (45.4%–34.2%; p < 0.001) whereas industry-sponsored trials remained almost the same. There was a significant increase in trials conducted exclusively outside of the United States (35.9%–48.8%; p = 0.001). The number of studies with locations in China (61, 12.8%) was second only to that in the United States (244, 51.2%). Studies reporting biomarker analysis increased significantly from 37.5% to 49.1% in 2012 (p < 0.001). Biomarker-based patient selection also increased significantly from 7.9% to 25.8% (p < 0.001). Targeted therapies were evaluated in 70.6% of phase I/II and II trials, and the most common class of targeted agent studied was epidermal growth factor receptor tyrosine kinase inhibitors (38.0%). Prespecified accrual times were observed to increase when compared with data reported in 2009, especially among industry-sponsored studies. Conclusions: Our survey identified major changes in lung cancer clinical research since 2009. Almost half of all studies registered at the ClinicalTrials.gov Web site are being conducted outside the United States, and several novel molecularly targeted agents are being evaluated in the treatment of patients with NSCLC. More importantly, we identified a threefold increase in the number of studies that perform biomarker testing to determine patient selection over the last 3 years.