Gary M. Clark

Estrogen Receptor Status by Immunohistochemistry Is Superior to the Ligand-Binding Assay for Predicting Response to Adjuvant Endocrine Therapy in Breast Cancer

PURPOSE Immunohistochemistry (IHC) is a newer technique for assessing the estrogen receptor (ER) status of breast cancers, with the potential to overcome many of the shortcomings associated with the traditional ligand-binding assay (LBA). The purpose of this study was to evaluate the ability of ER status determination by IHC, compared with LBA, to predict clinical outcome-especially response to adjuvant endocrine therapy-in a large number of patients with long-term clinical follow-up. PATIENTS AND METHODS ER status was evaluated in 1,982 primary breast cancers by IHC on formalin-fixed paraffin-embedded tissue sections, using antibody 6F11 and standard methodology. Slides were scored on a scale representing the estimated proportion and intensity of positive-staining tumor cells (range, 0 to 8). Results were compared with ER values obtained by the LBA in the same tumors and to clinical outcome. RESULTS An IHC score of greater than 2 (corresponding to as few as 1% to 10% weakly positive cells) was used to define ER positivity on the basis of a univariate cut-point analysis of all possible scores and disease-free survival (DFS) in patients receiving any adjuvant endocrine therapy. Using this definition, 71% of all tumors were determined to be ER-positive by IHC, and the level of agreement with the LBA was 86%. In multivariate analyses of patients receiving adjuvant endocrine therapy alone, ER status determined by IHC was better than that determined by the LBA at predicting improved DFS (hazard ratios/P = 0.474/.0008 and 0.707/.3214, respectively) and equivalent at predicting overall survival (0.379/.0001 and 0.381/.0003, respectively). CONCLUSION IHC is superior to the LBA for assessing ER status in primary breast cancer because it is easier, safer, and less expensive, and has an equivalent or better ability to predict response to adjuvant endocrine therapy.

REporting recommendations for tumour MARKer prognostic studies (REMARK).

Despite years of research and hundreds of reports on tumour markers in oncology, the number of markers that have emerged as clinically useful is pitifully small. Often initially reported studies of a marker show great promise, but subsequent studies on the same or related markers yield inconsistent conclusions or stand in direct contradiction to the promising results. It is imperative that we attempt to understand the reasons that multiple studies of the same marker lead to differing conclusions. A variety of methodological problems have been cited to explain these discrepancies. Unfortunately, many tumour marker studies have not been reported in a rigorous fashion, and published articles often lack sufficient information to allow adequate assessment of the quality of the study or the generalisability of the study results. The development of guidelines for the reporting of tumour marker studies was a major recommendation of the US National Cancer Institute and the European Organisation for Research and Treatment of Cancer (NCI-EORTC) First International Meeting on Cancer Diagnostics in 2000. Similar to the successful CONSORT initiative for randomised trials and the STARD statement for diagnostic studies, we suggest guidelines to provide relevant information about the study design, preplanned hypotheses, patient and specimen characteristics, assay methods, and statistical analysis methods. In addition, the guidelines suggest helpful presentations of data and important elements to include in discussions. The goal of these guidelines is to encourage transparent and complete reporting so that the relevant information will be available to others to help them to judge the usefulness of the data and understand the context in which the conclusions apply.

HER-2/neu oncogene protein and prognosis in breast cancer.

Amplification of the HER-2/neu oncogene was recently reported to predict poor clinical outcome in node-positive breast cancer patients. Since expression of the oncogene as its protein product might be even more closely related than gene amplification to disease progression, we have now examined levels of the HER-2/neu oncogene protein for its prognostic potential in both node-positive and node-negative breast cancer. Using Western blot analysis, levels of this protein were determined in 728 primary human breast tumor specimens. We examined relationships between this protein and other established markers of prognosis, as well as clinical outcome. In node-negative patients (n = 378), the HER-2/neu protein failed to predict disease outcome. However, in node-positive patients (n = 350), those patients with higher HER-2/neu protein had statistically shorter disease-free (P = .0014) and overall survival (P less than .0001) than patients with lower levels of the protein. Higher HER-2/neu protein was found in tumors without estrogen receptor (ER) (P = .02) or progesterone receptor (PgR) (P = .0003), and in patients with more than three positive lymph nodes (P = .04). A significant correlation between levels of the HER-2/neu gene protein and amplification of the gene itself was also found (n = 48, P less than .001). Multivariate analyses in these patients showed that the HER-2/neu protein is a significant independent predictor of both the disease-free and the overall survival in node-positive breast cancer, even when other prognostic factors are considered.

Correlation between Development of Rash and Efficacy in Patients Treated with the Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Erlotinib in Two Large Phase III Studies

Purpose: Data from two large phase III studies were analyzed to characterize the correlation between the occurrence of rash during treatment with the epidermal growth factor receptor inhibitor erlotinib and improved clinical outcomes. Experimental Design: Overall survival, progression-free survival (PFS), and tumor response were compared between patients in a rash-evaluable subset who did or did not develop rash in National Cancer Institute of Canada Clinical Trials Group Studies BR.21 (single agent in non–small-cell lung cancer, n = 444 in erlotinib group and n = 229 in placebo group) and PA.3 (combination with gemcitabine in pancreatic cancer, n = 254 in erlotinib plus gemcitabine group and n = 245 in placebo plus gemcitabine group). Results: Presence of rash strongly correlated with overall survival in both studies. In Study BR.21, these correlations increased with rash severity grade: grade 1 versus no rash [hazard ratio (HR), 0.41, P < 0.001] and grade ≥2 versus no rash (HR, 0.29, P < 0.001). Similar results were observed for PFS. Disease control (complete response + partial response + stable disease) seemed to increase with the presence and severity of rash. In Study PA.3, grade ≥2 rash (but not grade 1) strongly correlated with overall survival improvement: grade ≥2 versus no rash (HR, 0.47, P < 0.001). Similarly, grade ≥2 rash was strongly correlated with improvements in PFS and disease control. Conclusions: Physicians and patients should view rash development as a positive event indicative of greater likelihood of clinical benefit. Further studies are required to identify patients most likely to develop rash and to determine if dose escalation to induce rash can improve efficacy.

Symptom improvement in lung cancer patients treated with erlotinib: quality of life analysis of the National Cancer Institute of Canada Clinical Trials Group Study BR.21.

PURPOSE This report describes the quality of life (QOL) findings of a randomized placebo controlled study of erlotinib, an epidermal growth factor receptor inhibitor, in patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS This double-blind phase III trial randomly assigned 731 patients with NSCLC who had progressed after prior chemotherapy to erlotinib 150 mg daily or placebo, with survival as the primary study outcome. QOL was assessed by European Organisation for Research and Treatment of Cancer QLQ-C30 and the lung cancer module QLQ-LC13. The primary end points for QOL analysis were time to deterioration of three common lung cancer symptoms: cough, dyspnea, and pain. RESULTS Survival was significantly longer (hazard ratio, 0.70; P < .0001) in the erlotinib arm. Compliance with QOL was 87% at baseline and more than 70% during treatment. Patients receiving erlotinib had significantly longer median time to deterioration for all three symptoms (4.9 v 3.7 months for cough [P = .04]; 4.7 v 2.9 months for dyspnea [P = .04], and 2.8 v 1.9 months for pain [P = .03]). QOL response analyses showed that 44%, 34%, and 42% of patients receiving erlotinib had improvement in these three symptoms, respectively. This was accompanied by a significant improvement in the physical function (31% erlotinib v 19% placebo, P = .01), and global QOL (35% v 26%, P < .0001). Patients with complete or partial response were more likely to have improvement in the QOL response than patients with stable or progressive disease (P < .01). CONCLUSION Erlotinib not only improves survival in previously treated patients with NSCLC, but also improves tumor-related symptoms and important aspects of QOL.

Effects of smoking on the pharmacokinetics of erlotinib.

Purpose: To compare the pharmacokinetic variables of erlotinib in current smokers with nonsmokers after receiving a single oral 150 or 300 mg dose of erlotinib. Experimental Design: This was a single-center, open-label pharmacokinetic study in healthy male subjects. Subjects were enrolled into two treatment cohorts based on smoking status (current smokers and nonsmokers). The pharmacokinetic profile for erlotinib and its metabolite, OSI-420, was determined for each subject following each treatment. Results: Current smokers achieved significantly less erlotinib exposure following a single 150 or 300 mg dose than nonsmokers. Following the 150 mg dose, the geometric mean erlotinib AUC0-∞ in smokers was 2.8-fold lower than in nonsmokers and similar to that of nonsmokers at the 300 mg dose. Cmax in smokers was two-thirds of that in nonsmokers, and C24h in smokers was 8.3-fold lower than in nonsmokers. The median C24h of smokers at the 300 mg dose was slightly less than the C24h of smokers at the 150 mg dose. The median Cmax was greater in smokers at the 300 mg dose than in nonsmokers at the 150 mg dose. Conclusion: This study confirms that the pharmacokinetics of erlotinib is different in current smokers and nonsmokers. The observation that AUC0-∞ and C24h were significantly decreased in smokers compared with nonsmokers, and a smaller decrease in Cmax was observed, is consistent with increased metabolic clearance of erlotinib in current smokers.

Significance of Axillary Lymph Node Metastasis in Primary Breast Cancer

PURPOSE Axillary lymph node status is the single most important prognostic variable in the management of patients with primary breast cancer. Yet, it is not known whether metastasis to the axillary nodes is simply a time-dependent variable or also a marker for a more aggressive tumor phenotype. The purpose of this study was to determine whether nodal status at initial diagnosis predicts outcome after relapse and therefore also serves as a marker of breast cancer phenotype. PATIENTS AND METHODS Survival experience after first relapse in 1,696 primary breast cancer cases was analyzed using Cox proportional hazards regression. The following explanatory variables and their first-order interactions were considered: number of axillary lymph nodes involved (zero v one to three v four or more), hormone receptor status (any estrogen receptor [ER] negativity v ER negativity/progesterone receptor positivity v other ER positivity), primary tumor size (< 2 cm v 2 to 5 cm v > 5 cm), site of relapse (locoregional v distant), disease-free interval (< 1.5 years v 1.5 to 3 years v > 3 years), adjuvant endocrine therapy (none v any), adjuvant chemotherapy (none v any), and menopausal status (pre-, peri-, or postmenopausal). RESULTS Axillary lymph node status, site of relapse, and hormone receptor status were all highly significant as main effects in the model. After adjustment for other variables, disease-free interval alone was only modestly significant but interacted with nodal status. After disease-free interval, hormone receptor status, and site of relapse were accounted for, survival after relapse was poorer in node-positive cases, when compared with node-negative cases. The hazard ratios for patients with one to three and four or more involved nodes were 1.2 (95% confidence interval [CI], 0.8 to 1.9) and 2.5 (95% CI, 1.8 to 3.4), respectively. CONCLUSION Patients with four or more involved nodes at initial diagnosis have a significantly worse outcome after relapse than node-negative cases, regardless of the duration of the disease-free interval. We conclude that nodal metastasis is not only a marker of diagnosis at a later point in the natural history of breast cancer but also a marker of an aggressive phenotype.

Erlotinib for Advanced Non-Small-Cell Lung Cancer in the Elderly: An Analysis of the National Cancer Institute of Canada Clinical Trials Group Study BR.21

PURPOSE National Cancer Institute of Canada Clinical Trials Group Study BR.21 established erlotinib as a standard of care in patients with non-small-cell lung cancer (NSCLC) after failure of first- or second-line chemotherapy. The current study analyzes the influence of age on outcomes in BR.21. PATIENTS AND METHODS BR.21 was a double-blind phase III trial that randomly assigned 731 patients to erlotinib 150 mg daily or placebo. End points included progression-free survival and overall survival (OS), response, quality of life (QOL), drug exposure, and toxicity, which are analyzed in this retrospective study by the following two age groups: >or= 70 years (elderly) or less than 70 years (young). RESULTS There were 163 elderly patients (112 on erlotinib, 51 on placebo) and 568 young patients (376 on erlotinib, 192 on placebo). There was no significant difference between age groups randomly assigned to erlotinib or placebo in progression-free survival (elderly: 3.0 v 2.1 months; hazard ratio [HR] = 0.63; 95% CI, 0.44 to 0.90; P = .009; young: 2.1 v 1.8 months; HR = 0.64; 95% CI, 0.53 to 0.76; P < .0001; interaction, P = .77) or OS (elderly: 7.6 v 5.0 months; HR = 0.92; 95% CI, 0.64 to 1.34; P = .67; young: 6.4 v 4.7 months; HR = 0.73; 95% CI, 0.61 to 0.89; P = .0014; interaction, P = .31). Response rates were similar between age groups. Elderly patients, compared with young patients, had significantly more overall and severe (grade 3 and 4) toxicity (35% v 18%; P < .001), were more likely to discontinue treatment as a result of treatment-related toxicity (12% v 3%; P < .0001), and had lower relative dose-intensity (64% v 82% received > 90% planned dose; P < .001). CONCLUSION Elderly patients treated with erlotinib gain similar survival and QOL benefits as younger patients but experience greater toxicity.

A Perspective on Challenges and Issues in Biomarker Development and Drug and Biomarker Codevelopment

A workshop sponsored by the National Cancer Institute and the US Food and Drug Administration addressed past lessons learned and ongoing challenges faced in biomarker development and drug and biomarker codevelopment. Participants agreed that critical decision points in the product life cycle depend on the level of understanding of the biology of the target and its interaction with the drug, the preanalytical and analytical factors affecting biomarker assay performance, and the clinical disease process. The more known about the biology and the greater the strength of association between an analytical signal and clinical result, the more efficient and less risky the development process will be. Rapid entry into clinical practice will only be achieved by using a rigorous scientific approach, including careful specimen collection and standardized and quality-controlled data collection. Early interaction with appropriate regulatory bodies will ensure studies are appropriately designed and biomarker test performance is well characterized.

Teacher retention of stereotypes of exceptionality.

Before an experimentally induced stereotype of a child can be passed by a teacher to a child in the form of an expectancy, the teacher must attend to, comprehend, and retain the expectancy (see Barber, Forgione, Chaves, Claverly, McPeake, & Bowen, 1969). In actual classroom settings, the teachers expectancy for the child and the childs performance and characteristics are interactive; the childs behavior can create teacher expectancy or modify existing teacher expectancies. This study sought to determine what happens to stereotypes of exceptionality in the face of normal behavior. When teachers in training are faced with an intellectually normal child who is improperly labeled, do they retain the stereotype by rating the behavior of children labeled gifted more positively than when the same child is labeled normal and by rating the behavior of a child labeled retarded more negatively than when the same child is labeled normal?