Faculty Bibliography

BACKGROUND:Little is known about recent trends in surveillance among the more than 1 million US colorectal cancer (CRC) survivors. Moreover, for stage I disease, which accounts for more than 30% of survivors, the guidelines are limited, and the use of surveillance has not been well studied. Guidelines were changed in 2005 to include recommendations for computed tomography (CT) surveillance in select patients, but the impact of these changes has not been explored. METHODS:A retrospective analysis of patients who were identified in the Survival, Epidemiology, and End Results-Medicare database and underwent resection of stage I to III CRC between 2001 and 2009 was performed. The receipt of guideline-determined sufficient surveillance, including office visits, colonoscopy, carcinoembryonic antigen (CEA) testing, and CT imaging, in the 3 years after resection was evaluated. RESULTS:The study included 23,990 colon cancer patients and 5665 rectal cancer patients. Rates of office visits and colonoscopy were high and stable over the study period. Rates of CEA surveillance increased over the study period but remained low, even for stage III disease. Rates of CT imaging increased gradually during the study period, but the 2005 guideline change had no effect. Stage II patients, including high-risk patients, received surveillance at significantly lower rates than stage III patients despite similar recommendations. Conversely, up to 30% of stage I patients received nonrecommended CEA testing and CT imaging. CONCLUSIONS:There continues to be substantial underuse of surveillance for CRC survivors and particularly for stage II patients, who constitute almost 40% of survivors. The 2005 guideline change had a negligible impact on CT surveillance. Conversely, although guidelines are limited, many stage I patients are receiving intensive surveillance.

BACKGROUND:Pulmonary nodules (PNs) are a common reason for referral to pulmonologists. The majority of data for the evaluation and management of PNs is derived from studies performed in academic medical centers. Little is known about the prevalence and diagnosis of PNs, the use of diagnostic testing, or the management of PNs by community pulmonologists. METHODS:This multicenter observational record review evaluated 377 patients aged 40 to 89 years referred to 18 geographically diverse community pulmonary practices for intermediate PNs (8-20 mm). Study measures included the prevalence of malignancy, procedure/test use, and nodule pretest probability of malignancy as calculated by two previously validated models. The relationship between calculated pretest probability and management decisions was evaluated. RESULTS:The prevalence of malignancy was 25% (n = 94). Nearly one-half of the patients (46%, n = 175) had surveillance alone. Biopsy was performed on 125 patients (33.2%). A total of 77 patients (20.4%) underwent surgery, of whom 35% (n = 27) had benign disease. PET scan was used in 141 patients (37%). The false-positive rate for PET scan was 39% (95% CI, 27.1%-52.1%). Pretest probability of malignancy calculations showed that 9.5% (n = 36) were at a low risk, 79.6% (n = 300) were at a moderate risk, and 10.8% (n = 41) were at a high risk of malignancy. The rate of surgical resection was similar among the three groups (17%, 21%, 17%, respectively; P = .69). CONCLUSIONS:A substantial fraction of intermediate-sized nodules referred to pulmonologists ultimately prove to be lung cancer. Despite advances in imaging and nonsurgical biopsy techniques, invasive sampling of low-risk nodules and surgical resection of benign nodules remain common, suggesting a lack of adherence to guidelines for the management of PNs.

RATIONALE/BACKGROUND:Annual low-radiation-dose computed tomography (LDCT) screening for lung cancer has been shown to reduce lung cancer mortality among high-risk individuals and is now recommended by multiple organizations. However, LDCT screening is complex, and implementation requires careful planning to ensure benefits outweigh harms. Little guidance has been provided for sites wishing to develop and implement lung cancer screening programs. OBJECTIVES/OBJECTIVE:To promote successful implementation of comprehensive LDCT screening programs that are safe, effective, and sustainable. METHODS:The American Thoracic Society (ATS) and American College of Chest Physicians (ACCP) convened a committee with expertise in lung cancer screening, pulmonary nodule evaluation, and implementation science. The committee reviewed the evidence from systematic reviews, clinical practice guidelines, surveys, and the experience of early-adopting LDCT screening programs and summarized potential strategies to implement LDCT screening programs successfully. MEASUREMENTS AND MAIN RESULTS/RESULTS:We address steps that sites should consider during the main three phases of developing an LDCT screening program: planning, implementation, and maintenance. We present multiple strategies to implement the nine core elements of comprehensive lung cancer screening programs enumerated in a recent ACCP/ATS statement, which will allow sites to select the strategy that best fits with their local context and workflow patterns. Although we do not comment on cost-effectiveness of LDCT screening, we outline the necessary costs associated with starting and sustaining a high-quality LDCT screening program. CONCLUSIONS:Following the strategies delineated in this policy statement may help sites to develop comprehensive LDCT screening programs that are safe and effective.

Infiltrating inflammatory cells are highly prevalent within the tumor microenvironment and mediate many processes associated with tumor progression; however, the contribution of specific populations remains unclear. For example, the nature and function of tumor-associated neutrophils (TANs) in the cancer microenvironment is largely unknown. The goal of this study was to provide a phenotypic and functional characterization of TANs in surgically resected lung cancer patients. We found that TANs constituted 5%-25% of cells isolated from the digested human lung tumors. Compared with blood neutrophils, TANs displayed an activated phenotype (CD62L(lo)CD54(hi)) with a distinct repertoire of chemokine receptors that included CCR5, CCR7, CXCR3, and CXCR4. TANs produced substantial quantities of the proinflammatory factors MCP-1, IL-8, MIP-1α, and IL-6, as well as the antiinflammatory IL-1R antagonist. Functionally, both TANs and neutrophils isolated from distant nonmalignant lung tissue were able to stimulate T cell proliferation and IFN-γ release. Cross-talk between TANs and activated T cells led to substantial upregulation of CD54, CD86, OX40L, and 4-1BBL costimulatory molecules on the neutrophil surface, which bolstered T cell proliferation in a positive-feedback loop. Together our results demonstrate that in the earliest stages of lung cancer, TANs are not immunosuppressive, but rather stimulate T cell responses.

BACKGROUND:Ideally, quality indicators are developed with the input of professional groups involved in the care of patients. This project, led by the Thoracic Oncology Network and Quality Improvement Committee of the American College of Chest Physicians (CHEST), had the goal of developing quality indicators related to the evaluation and staging of patients with lung cancer. METHODS:Evidence-based guidelines were used to generate a list of process-of-care quality indicators, and project members revised the content and wording of this list. A survey of the Steering Committee of the Thoracic Oncology Network was performed to rate the validity, feasibility, and relevance of the indicators. Predefined thresholds were used to select indicators from the list. This process was repeated for the selected indicators through a survey available to all members of the Thoracic Oncology Network. Three academic medical centers determined if the surviving indicators were feasible and relevant within their practices. RESULTS:Eighteen quality indicators were drafted. Eleven survived the first round of voting, and seven survived the second round of voting. One was related to tissue acquisition for molecular testing, four were related to staging and stage documentation, one was related to smoking cessation counseling, and one was related to documentation of a performance status measure. The indicators were feasible and relevant within the practices assessed. CONCLUSIONS:We have defined seven process-of-care quality indicators related to the evaluation and staging of patients with lung cancer, which are felt to be valid, feasible, and relevant by lung cancer specialists.

RATIONALE/BACKGROUND:Pulmonologists frequently encounter indeterminate pulmonary nodules in practice, but it is unclear what clinical factors they rely on to guide the diagnostic evaluation. OBJECTIVES/OBJECTIVE:To assess the current approach to the management of indeterminate pulmonary nodules and to determine the extent to which the addition of a hypothetical diagnostic blood test will influence clinical decision making. METHODS:Selected pulmonologists practicing in the United States were invited to participate in a conjoint exercise based on 20 randomly generated cases of varying age, smoking history, and nodule size. Some cases included the result of a hypothetical blood test. Each respondent chose from among three diagnostic options for a patient: noninvasive monitoring (i.e., serial CT or positron emission tomography scan), a minor procedure (i.e., biopsy or bronchoscopy), or a major procedure (i.e., video-assisted thorascopic surgery or thoracotomy). Multivariate logistic regression was used to assess the impact of the three risk factors and the diagnostic blood test on decision making. MEASUREMENTS AND MAIN RESULTS/RESULTS:Four hundred nineteen physicians participated (response rate, 10%). One hundred fifty-three physician surveys met predetermined criteria and were analyzed (4% of all invitees). A diagnostic procedure was recommended for 23% of 6-mm nodules, versus 54, 66, 77, and 84% of nodules 10, 14, 18, and 22 mm, respectively (P < 0.001). Older age limited recommendations for invasive testing: 54% of 80-year-olds versus 61, 64, 63, and 61% of patients 71, 62, 53, and 44 years of age, respectively (P < 0.001). In multivariate analyses, nodule size, smoking history, age, and the blood test each influenced decision making (P < 0.001). CONCLUSIONS:The pulmonologists who participated in this survey were more likely to proceed with invasive testing, instead of observation or additional imaging, as the size of the nodule increased. The use of a hypothetical blood test resulted in significant alterations in the decision to pursue invasive testing.

Rac1b, an alternative splice form of Rac1, has been previously shown to be upregulated in colon and breast cancer cells, suggesting an oncogenic role for Rac1b in these cancers. Our analysis of NSCLC tumor and matched normal tissue samples indicates Rac1b is upregulated in a significant fraction of lung tumors in correlation with mutational status of K-ras. To directly assess the oncogenic potential of Rac1b in vivo, we employed a mouse model of lung adenocarcinoma, in which the expression of Rac1b can be conditionally activated specifically in the lung. Although expression of Rac1b alone is insufficient to drive tumor initiation, the expression of Rac1b synergizes with an oncogenic allele of K-ras resulting in increased cellular proliferation and accelerated tumor growth. Finally, we show that in contrast to our previous findings demonstrating a requirement for Rac1 in K-ras-driven cell proliferation, Rac1b is not required in this context. Given the partially overlapping spectrum of downstream effectors regulated by Rac1 and Rac1b, our findings further delineate the signaling pathways downstream of Rac1 that are required for K-ras driven tumorigenesis.

PURPOSE/OBJECTIVE:Thymidylate synthase (TS) is a potential predictor of outcome after pemetrexed (Pem) in patients with malignant pleural mesothelioma (MPM), and assays measuring TS levels are commercially marketed. The goal of this study was to further evaluate the value of TS and to study another potential biomarker of response, the enzyme, folyl-polyglutamate synthase (FPGS), which activates Pem intracellularly. METHODS:Levels of TS and FPGS were semi-quantitatively determined immunohistochemically using H-scores on tissue samples from 85 MPM patients receiving Pem as primary therapy. H-score was correlated with radiographic disease control rate (DCR), time to progression (TTP) and overall survival (OS). In addition, expression levels of TS and FPGS in MPM cell lines were determined using immunoblotting and correlated with their sensitivity to Pem-induced cell death. RESULTS:H-scores from patients with disease control versus progressive disease showed extensive overlap. There were no significant correlations of DCR, TTP, or OS to either TS levels (p = 0.73, 0.93, and 0.59, respectively), FPGS levels (p = 0.95, 0.77, and 0.43, respectively) or the ratio of FPGS/TS using the median scores of each test as cutoffs. There was no correlation between TS or FPGS expression and chemosensitivity of mesothelioma cells to Pem in vitro. CONCLUSIONS:Although previous retrospective data suggest that TS and FPGS expression might be potential markers of Pem efficacy in MPM, our data indicate these markers lack sufficient predictive value in individual patients and should not be used to guide therapeutic decisions in the absence of prospective studies.

INTRODUCTION/BACKGROUND:Mutations in EGFR and KRAS can impact treatment decisions for patients with NSCLC. The incidence of these mutations varies, and it is unclear whether there is a decreased frequency among African Americans (AfAs). METHODS:We performed a retrospective chart review of 513 NSCLC patients undergoing EGFR and KRAS mutational analysis at the Hospital of the University of Pennsylvania between May 2008 and November 2011. Clinical and pathologic data were abstracted from the patients' electronic medical record. RESULTS:Of 497 patients with informative EGFR mutation analyses, the frequency of EGFR mutation was 13.9%. The frequency of EGFR mutations was associated with race (p < 0.001) and was lower in AfA patients compared to Caucasian (C) patients but did not reach statistical significance (4.8% vs. 13.7%, p = 0.06). Mean Charlson Comorbidity Index and number of cigarette pack years were significantly lower in patients with EGFR mutations (p = 0.01 and p < 0.001, respectively). Multivariable logistic regression analysis showed a significant association between race and EGFR mutation (p = 0.01), even after adjusting for smoking status (p < 0.001) and gender (p = 0.03). KRAS mutation (study frequency 28.1%) was not associated with race (p = 0.08; p=0.51 for Afa vs. C patients), but was more common among smokers (p < 0.001) and females (p = 0.01). CONCLUSIONS:Based on multivariable analysis, even after adjusting for smoking status and gender, we found that race was statistically significantly associated with EGFR mutation, but not KRAS mutational status. To the best of our knowledge, this is the largest single institution series to date evaluating racial differences in EGFR and KRAS mutational status among patients with NSCLC.

BACKGROUND:Molecular profiling of non-small-cell lung cancer (NSCLC) samples has a profound impact on choice of therapy. However, it is less clear whether EGFR and KRAS mutations are prognostic outside of a trial-based treatment paradigm. METHODS:We performed a retrospective chart review of 513 patients with NSCLC undergoing EGFR and KRAS mutational analysis at the Hospital of the University of Pennsylvania between May 2008 and November 2011. Survival analysis was based on the 376 patients who received systemic treatment, and their survival was determined from the date of initiation of systemic therapy. RESULTS:The median overall survival (OS) was 30.8 months (95% confidence interval [CI], 24.7-36.9). Neither EGFR mutational status (P = .09) nor KRAS mutational status (0.69) was associated with OS. Female sex (P < .001), never smoker status (P = .01), better performance status (PS) (P < .001), lower Charlson Comorbidity Index (P < .001), and lower age-weighted index (P < .001) were associated with prolonged survival. The presence of bone metastases (P = .001) and liver metastases (P = .004) was also associated with a shortened survival. In a multivariable regression that adjusted for stage, we demonstrated that male gender (P = .002), worse Eastern Cooperative Oncology Group PS (P = .01), metastases to bone (P = .03), and higher age-weighted comorbidity index (P = .001) were independent prognostic factors for shorter survival. EGFR mutation status was not prognostic (P = .85). CONCLUSION/CONCLUSIONS:In our series, EGFR and KRAS do not function as prognostic determinants for NSCLC.