Updated molecular analyses of exons 19 and 21 of the epidermal growth factor receptor (EGFR) gene and codons 12 and 13 of the KRAS gene in non-small cell lung cancer (NSCLC) patients treated with erlotinib in National Cancer Institute of Cancer

7571

Background: BR.21 demonstrated significant survival benefit from erlotinib for NSCLC patients (Shepherd, NEJM 2005). EGFR gene point mutations in exon 21 and deletions in exon 19 predict response to EGFR TKIs, but the predictive value of EGFR mutations (Mut) or high copy number (Amp) on survival remains unclear. Methods: The sensitivity of PCR-sequencing to detect EGFR mutations may be suboptimal. Thus, we re-analyzed all BR.21 samples with available material using a fluourescent-based PCR technique (Pan, JMD 2005;7:396) and ScorpionIM kits (DxS, Manchester, UK) as they may detect mutations in samples with only 5–10% tumor DNA. 204 samples were analyzed successfully for EGFR Mut, 206 for KRAS Mut and 159 by FISH for EGFR Amp. Results: Exon 19 deletion and/or exon 21 L858R Mut were identified in 34 patients (overall Mut rate 17%). EGFR high polysomy or true amplification was present in 61 patients (38%), and 30 patients (15%) had KRAS Mut. Overall response rates were EGFR wildtype (WT)/Mut: 7%/27%, p=0.03; KRAS WT/Mut: 10%/5%, p=0.69; No Amp/Amp: 5%/21%, p=0.02. Hazard ratios for survival benefit were EGFR WT: 0.74 (0.52–1.05, p=0.09), Mut: 0.55 (0.25–1.19, p=0.12); KRAS WT: 0.69 (0.9–0.97, p=0.03), Mut: 1.67 (0.62–4.50, p=0.31); no Amp: 0.80 (0.49–1.29, p=0.35), Amp: 0.43 0.23–0.78, p=0.004). The test for interaction was borderline for KRAS Mut (0.09) but was not significant for EGFR Mut (p=0.47) or EGFR Amp (0.12). It was significant only for non-smokers with EGFR Amp (p=0.04). In the multiple Cox regression model, including all markers, EGFR Amp was both prognostic for poorer survival (p=0.005) and predictive of a differential survival benefit from erlotinib (p=0.009). EGFR and KRAS Mut were not significant prognostic or predictive markers. Conclusion: EGFR genotype and copy number are predictive of objective response to erlotinib. In BR.21, EGFR gene copy number is the strongest molecular prognostic marker and the only significant molecular predictor of a differential survival benefit from treatment.

[Table: see text]

Randomized phase II study of maintenance vandetanib (ZD6474) in small cell lung cancer (SCLC) patients who have a complete or partial response to induction therapy: NCIC CTG BR.20

7522

Background: Vandetanib (V) is an inhibitor of vascular endothelial and epidermal growth factor receptors. This trial sought to determine whether maintenance V, given after standard chemotherapy (CT) and radiation (RT), prolonged progression-free survival (PFS) in responding patients with SCLC. Secondary endpoints: overall survival (OS) and toxicity. Methods: Phase II randomized, study of V 300 mg PO daily or placebo (P). Eligibility: complete (CR) or partial response (PR) to platinum-based CT, ECOG PS 0–2 and completion of RT (thoracic or prophylactic cranial). Statistics: 80% power to detect a 2.5 months improvement in median PFS (estimate for P of 4 months) using a 1-sided 10% level test (100 eligible patients; 77 events). Results: Between May 2003 and March 2006, 107 patients were accrued from 17 centres. Median follow up: 13.5 months. 46 had limited disease (LD); 61 extensive disease (ED). There were fewer PS 0 patients (11 vs. 20), and fewer had CR to initial CT (4 vs. 8) in the V arm. V patients were more likely to experience toxicity and require dose modification. The most frequent toxicities leading to dose modifications were gastrointestinal and rash. Clinically asymptomatic QTc prolongation was observed in 8 V patients. 83 of 107 patients developed progressive disease (43 on V; 40 on P). The median PFS for V was 2.7 months (80% C.I.: 1.1 –4.5) and 2.8 months for P (80% C.I.: 1.9 –5.6); estimated hazard ratio (HR) was 1.01 for V vs P (80% C.I.: 0.75 –1.36, 1-sided P-value = 0.51). Median OS for V was 10.6 months vs. 11.9 months for P; HR was 1.43 for V vs. P (80% C.I.: 1.00 –2.05, 1-sided P-value = 0.90). In a planned subgroup analysis, a significant interaction was noted (P-value = 0.01); with LD patients randomized to V having a longer OS (HR: 0.45, 1-sided P-value = 0.07), whereas ED patients randomized to V had a shorter OS compared to P (HR: 2.27, 1-sided P-value = 0.996). Conclusion: V failed to demonstrate efficacy as maintenance therapy for SCLC. Future targeted therapies should probably be explored concurrently with chemotherapy. This study was supported by the Canadian Cancer Society and AstraZeneca.

[Table: see text]

Adjuvant chemotherapy in elderly patients: An analysis of National Cancer Institute of Canada Clinical Trials Group and Intergroup BR.10

7009

Background: Recent trials have shown significant survival benefit from adjuvant chemotherapy after resection of NSCLC. Whether elderly patients tolerate platinum-based adjuvant chemotherapy and derive the same survival advantage is unknown. This retrospective study evaluated the influence of age on survival, chemotherapy delivery and toxicity in NCIC CTG BR.10. Methods: Pretreatment characteristics and survival benefit from treatment were compared for patients ≤65 & >65. Chemotherapy delivery and toxicity were compared for 213 treated patients. Results: There were 327 young and 155 elderly patients. Baseline prognostic factors by age were similar with the exception of histology (adeno 58% young, 43% elderly; squamous 32% young, 49% elderly; p=0.001) and PS (PS 0 53% young, 41% elderly; p=0.01). Overall survival by age showed a trend favoring the young in univariate (HR 0.77, CI 0.58–1.04, p=0.084) and multivariate analyses (HR 0.75, CI 0.56–1.01, p=0.059). Patients >75 years had significantly shorter survival than those aged 66–74 (HR 1.95, CI 1.11–3.41, p=0.02). Overall survival for patients >65 was significantly better with chemotherapy v observation (HR 0.61, CI 0.38–0.98, p=0.04). Chemotherapy administration and toxicity were evaluated in 63 elderly and 150 young patients. Mean dose intensities of vinorelbine (V) and cisplatin (C) were 13.2 and 18.0 in the young and 9.9 and 14.1 in the elderly (V p=0.0004; C p=0.001). The elderly received significantly fewer doses of V (p=0.014) and C (p=0.006). Fewer elderly patients completed treatment and more refused treatment compared to the young (p=0.03). There were no significant differences in toxicities, G-CSF use or hospitalization by age group, except for myalgias and mood alteration (more frequent among the young). Six of 126 deaths (4.8%) in the young were from non-malignant causes v 12 of 71 (16.9%) in the elderly (p=0.008). Conclusions: In spite of receiving less chemotherapy than young patients, adjuvant chemotherapy improves overall survival in patients aged >65 with acceptable toxicity. Adjuvant chemotherapy should not be withheld from elderly patients, although patients >75 years of age require further study.

No significant financial relationships to disclose.

Class III beta tubulin expression and benefit from adjuvant cisplatin/vinorelbine chemotherapy in operable non-small cell lung cancer: Analysis of the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) study JBR.10

7051

Background: Biomarkers may be useful to select patients who will benefit from a particular chemotherapy regimen. High class III beta tubulin (bTubIII) expression in advanced NSCLC is known to correlate with reduced response rates and inferior survival with the anti-microtubule agents vinorelbine or paclitaxel. JBR.10 demonstrated a 12% and 15% improvement in 5-year recurrence-free (RFS) and overall survival (OS) respectively with the addition of cisplatin and vinorelbine following resection of stage IB-II NSCLC. We sought to determine the impact of bTubIII on patient outcome and benefit from adjuvant chemotherapy in the JBR.10 trial. Methods: We performed an immunohistochemical assay for bTubIII on primary tumor tissue available from 265 of the 482 patients in JBR.10. A validated, numerical bTubIII score was assigned by two observers based on the intensity and frequency of tumour cell staining. Tumours were classified as bTubIII “low” or “high” based on the median score. We examined the prognostic impact of bTubIII in patients treated with or without chemotherapy, and the survival benefit from chemotherapy in low versus high bTubIII subgroups. Results: High bTubIII expression was associated with poorer RFS (HR = 1.9, p = 0.01) in patients treated with surgery alone, but not in patients treated with adjuvant chemotherapy (HR = 1.1, p = .75). In the low bTubIII subgroup, the improvement in RFS with chemotherapy was non-significant (HR = 0.78, p = 0.4), while the improvement in RFS with chemotherapy was significant in the high bTubIII subgroup (HR = 0.45, p = 0.002). With Cox regression, the interaction between bTubIII status and chemotherapy treatment in predicting RFS did not reach statistical significance (p = 0.15). Results for OS were similar. Conclusions: Chemotherapy appeared to overcome the negative prognostic impact of high bTubIII expression. Greater benefit from adjuvant chemotherapy was seen in patients with high bTubIII expression. This is contrary to what has been seen in the setting of advanced disease; possible reasons for this difference are being explored.

No significant financial relationships to disclose.

Are age and comorbidity independent prognostic factors in the treatment of metastatic NSCLC? A review of prospectively randomized national cancer institute of Canada Clinical Trials Group (NCIC CTG) trials

7117

Background: This study analyzed all patients enrolled in two large prospectively randomized trials of systemic chemotherapy to determine whether age and/or co-morbidity are independent predictors of outcome. Methods: Baseline information was recorded, including ongoing medical problems and current medications. This information was extracted and scored using the validated Charlson co-morbidity scale. Scores were then correlated with other clinical data, which included age, gender, race, performance status, histology, stage, weight, LDH, chemotherapy (type, total dose, dose intensity), response and survival. Results: A total of 1,255 patients (481 in BR10 and 774 in BR18) were included in this analysis, the median age was 61.2 years (range 34.2 to 88.7), 827 were less than 65yrs, and 428 65yrs or older. 391 had other medical conditions besides the primary disease of lung cancer, 310 with a Charlson co-morbidity score of 1, and 81 with a cumulative score of 2 or higher. There were more male patients with co-morbidity (35% vs. 21%, p < 0.0001); fewer patients with histologic subtype of adeno with co-morbidity (26% vs. 35%, p = 0.001); and more older patients with co-morbidity (42% vs. 26%, p < 0.001). There was no difference in overall survival in the elderly (≥65) as compared to the younger patients (<65). In contrast, patients with co-morbidity were associated with a shorter survival (p = 0.01). A cumulative Charlson score of 1 was associated with a hazard ratio of 1.28 (95% CI 1.09–1.5; p =0.003), and a cumulative score of 2+ was associated with a hazard ratio of 1.09 (95% C.I. 0.83 -1.44, p = 0.52). Conclusions: From these two large randomized NCIC CTG trials, one observes that age over 65 is not associated with a worse outcome. However, the presence of co-morbidity does appear to be a negative prognostic factor and co-morbity is more common in older patients.

No significant financial relationships to disclose.

Identifying patients with non-small cell lung cancer (NSCLC) unlikely to benefit from erlotinib: An exploratory analysis of National Cancer of Institute of Canada Clinical Trials Group BR.21

7161

Background: Despite a 9% response rate, BR.21 demonstrated significant survival benefit for patients receiving erlotinib as 2nd/3rd line therapy for NSCLC. We undertook to characterize, by exploratory subset analysis, patients less likely to benefit from erlotinib. To identify factors for consideration, we first identified baseline characteristics associated with early progression by eight wks and early death by 3 mos. Methods: Using stratification factors and potential prognostic factors from BR.21, the Cox regression model with stepwise selection was used to establish a prognostic model to separate erlotinib patients into 4 risk categories based on the 10th, 50th & 90th percentiles of prognostic index scores. 7 variables (smoking history, PS, weight loss, anemia, high LDH, response to prior chemo and time from diagnosis to randomization) were used in the final model. The hypothesis was that the characteristics of the treated patients in the highest risk group would also be predictive of lack of benefit from erlotinib when erlotinib and placebo patients with the same characteristics were compared. Results: Factors associated with PD by 8 wks were: PS2–3 (p = 0.009), weight loss (p = 0.0004), anemia (p = 0.008), PD to prior chemo (p = 0.006), non-Asian (p = 0.047), EGFR IHC-negative (p = 0.005), Factors associated with survival < 3 mos were: PS2–3 (p < 0.0001), weight loss (p < 0.0001), anemia (p < 0.0001), PD to prior chemo (p < 0.0001), non-Asian (p = 0.008), high LDH (p < 0.0001), time to randomization <12 mos (p = 0.0003). Comparison of overall survival for the 4 risk groups derived from prognostic index score as follows: high benefit (HR = 0.41, p = 0.007), 2 intermediate benefit (HR 0.79, p = 0.09; HR 0.80; p = 0.09); no benefit (HR 1.23; p = 0.42). Median survivals for erlotinib (placebo) patients in each group were 17.3 (8.3), 9.7 (7.5), 4.1 (3.7), 1.9 (2.7) mos. Conclusions: By establishing a prognostic model, we identified a small group of patients who are unlikely to benefit from 2nd/3rd line erlotinib therapy. This model requires prospective validation to confirm that it is both prognostic and predictive of outcome from treatment.

[Table: see text]

An analysis of the prognostic and predictive importance of K-ras mutation status in the National Cancer Institute of Canada Clinical Trials Group BR.21 study of erlotinib versus placebo in the treatment of non-small cell lung cancer

7005

Background: BR.21 demonstrated a significant survival benefit for patients with advanced non-small cell lung cancer (NSCLC) who received erlotinib vs. placebo (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.58–0.85, p<0.001). Tyrosine kinase (TK) domain mutations and high EGFR gene copy number by fluorescent in situ hybridization (FISH) have been associated with significantly higher response rates to erlotinib, while high gene copy number is a better predictor of survival benefit than mutations. K-ras mutation has been associated with non-responsiveness to EGFR TK inhibitors and poorer outcome for patients treated with erlotinib and chemotherapy. The survival impact of K-ras mutation on single agent erlotinib therapy in NSCLC patients remains unknown. Methods: 731 patients were randomized to BR.21 (488 erlotinib, 243 placebo). K-ras mutation analysis was conducted by sequencing in 246 patient samples. Results: K-ras analysis was successful in 206 patients; 30 (14.6%) demonstrated oncogenic mis-sense mutations on codon 12 or 13 (22 on the erlotinib arm and 8 on the placebo arm). For all 206 patients with known K-ras genotype, the HR for erlotinib was 0.77 (95% CI 0.57–1.06, p=0.06). For the 176 K-ras wild type patients, the univariate HR for erlotinib was 0.69 (95% CI 0.49–0.97, p=0.03). In contrast, the HR for the thirty K-ras mutant patients was 1.67 (95% CI 0.62–4.5, p=0.31), with an interaction p value of 0.09. Overall response rates were 5% (1/20) in K-ras mutant patients, and 10.2% (10/98) in K-ras wild type patients. In patients with K-ras genotype known, the multivariate Cox regression model showed that K-ras mutation was significantly associated with shorter survival (HR 1.63, 95% CI 1.06–2.51, p=0.03). Conclusion: In BR.21, patients with K-ras mutation do not appear to derive any survival benefit from erlotinib therapy. However, the numbers of patients are small and results need to be confirmed in other studies. (Supported by the Canadian Cancer Society, Ontario Cancer Research Network, the Jacqueline Seroussi Memorial Foundation for Cancer Research and OSI Pharmaceuticals).

[Table: see text]

Reducing the expression of glutathione transferase D mRNA in Drosophila melanogaster exposed to phenol and aniline

Phenol and aniline are toxic to animals. The purpose of the present study was to examine the expression of glutathione transferase D mRNA in fruit flies altered by long-term exposure to phenol and aniline. Changes in the amount of mRNA were measured by a semiquantitative reverse-transcription polymerase chain reaction assay. The level of each glutathione transferase D mRNA expressed in the phenol-treated and aniline-treated strains of adult fruit flies differed after chemical treatment. Aniline was more potent than phenol in suppressing the expression of cytosolic glutathione transferase D mRNA. Aniline reduced the level of glutathione transferase mRNA expressed in the aniline-treated strain to less than a 0.5 fraction as compared to that measured in the wild-type strain. But phenol was only able to suppress the GstD7 and GstD4 mRNAs expressed in the phenol-treated strain. Neither aniline nor phenol reduced the expression of microsomal glutathione transferase mRNA in fruit flies.

Gemcitabine, dexamethasone and cisplatin is an active and non-toxic chemotherapy regimen in relapsed or refractory Hodgkin's disease: a phase II study by the National Cancer Institute of Canada Clinical Trials Group

BACKGROUND

Gemcitabine (difluorodeoxycytidine) is active as a single agent in Hodgkin's disease and has been used successfully in combination with cisplatin to treat a variety of solid tumors.

PATIENTS AND METHODS

We evaluated the combination of gemcitabine/dexamethasone/cisplatin (GDP) as salvage chemotherapy in 23 patients with relapsed or refractory Hodgkin's disease (median age 36 years, range 19-57). Treatment consisted of gemcitabine 1000 mg/m(2) intravenously on days 1 and 8, dexamethasone 40 mg orally days 1-4 and cisplatin 75 mg/m(2) on day 1, every 21 days as an outpatient. Response was assessed following two cycles of treatment.

RESULTS

There were four complete responses and 12 partial responses for a response rate of 69.5% (95% confidence interval 52% to 87%); the remaining seven patients had stable disease and no patient progressed on treatment. All patients had successful stem cell mobilization and underwent transplantation with a median 10.6 x 10(6) CD34+ cells/kg. Hematological toxicity from GDP was mild (grade 3 neutropenia 8.6%, grade 3 thrombocytopenia 13%).

CONCLUSIONS

In summary, GDP is an active regimen for patients with relapsed or refractory Hodgkin's disease. The response rate is similar to the rates of other current salvage regimens, it can be given to outpatients with tolerable toxicity and it does not inhibit the mobilization of autologous stem cells.

Randomized, double-blind, controlled trial of mitoxantrone/prednisone and clodronate versus mitoxantrone/prednisone and placebo in patients with hormone-refractory prostate cancer and pain

PURPOSE

To compare the incidence of palliative response in patients with hormone-resistant prostate cancer (HRPC) treated with mitoxantrone and prednisone (MP) plus clodronate with that of patients treated with MP plus placebo.

MATERIALS AND METHODS

Men with HRPC, bone metastases, and bone pain were randomly assigned to receive clodronate 1,500 mg administered intravenously (IV) or placebo every 3 weeks, in combination with mitoxantrone 12 mg/m2 IV every 3 weeks and prednisone 5 mg orally bid. Patients completed the present pain intensity (PPI) index and Prostate Cancer-Specific Quality-of-Life Instrument at each treatment visit and used a diary to record analgesic use on a daily basis. The primary end point was a reduction to zero or of two points in the PPI or a decrease of 50% in analgesic intake, without increase in either.

RESULTS

The study accrued 209 eligible patients over 44 months. One hundred sixty patients (77%) had mild PPI scores (1 or 2), and 49 (24%) had moderate PPI scores (3 or 4). The primary end point of palliative response was achieved in 46 (46%) of 104 patients on the clodronate arm and in 41 (39%) of 105 patients on the placebo arm (P =.54). The median duration of response, symptomatic disease progression-free survival, overall survival, and overall quality of life were similar between the arms. Subgroup analysis suggested possible benefit in patients with more severe pain.

CONCLUSION

MP provides useful palliation in symptomatic men with HRPC. Clodronate does not increase the rate of palliative response or overall quality of life. Clodronate may be beneficial to patients who have moderate pain, but this requires further confirmation.

[Detection of platelet fibronectin from congenital fibrinogenopenic patients and its clinical significance]

OBJECTIVE

To assess the platelet and plasma concentrations of fibronectin (Fn) and fibrinogen (Fg) in congenital fibrinogenopenic (FgP) patients and explore their role in inducing platelet adhesion and aggregation.

METHODS

A FgP family was selected as study group and the platelets isolated and purified to assess concentrations of Fn and Fg in platelets, alpha-granules and plasma with Western blotting, immuofluoresence staining and flow cytometry (FACS), respectively, the expression of platelets GP II b/III a by FACS.

RESULTS

The concentration of platelets Fn in FgP patients is higher than that in controls, and is higher in homozygote than in heterozygote. In contrast, plasma Fn levels were identical in all samples. The amount of platelet Fg from FgP patients is lower than that from the controls and positively correlated with the concentration of their plasma Fg. No difference in the expression of platelet GP II b/III a had been found.

CONCLUSION

It suggested that increased platelet Fn could partially compensate the lack of Fg and lead the platelet adhesion and aggregation.