Comparison of gefitinib and erlotinib in advanced NSCLC and the effect of EGFR mutations

Introduction

Erlotinib and gefitinib are tyrosine kinase (TK) inhibitors of epidermal growth factor receptor (EGFR) that are effective in treating non-small cell lung cancer (NSCLC). This study aimed to compare their clinical uses and the influence of EGFR mutation.

Methods

The usages of erlotinib and gefitinib in advanced NSCLC were analyzed. Clinical data and EGFR mutational status of tumors were collected.

Results

Seven hundred and sixteen (716) patients received gefitinib (n = 440) or erlotinib (n = 276) for stage IIIb or IV NSCLC. Erlotinib was prescribed more frequently than gefitinib in males (58.2% vs. 41.8%, p < 0.001), smokers (60.5% vs. 39.5%, p < 0.001), and non-adenocarcinoma (70.6% vs. 29.4%, p < 0.001). Of the 716 study patients, 327 underwent testing for EGFR mutations (170 with mutant EGFR and 157 with wild-type EGFR). Adenocarcinoma in patients with mutant EGFR and non-smoker status in patients with wild-type EGFR were associated with better overall survival after TK inhibitor treatment. In both patient groups with mutant EGFR or wild-type EGFR, the effectiveness of gefitinib and erlotinib, including drug response or overall survival, were not different.

Conclusions

Our study revealed the obvious disparity in drug selection between erlotinib and gefitinib in clinical practice. Type of TK inhibitors did not influence treatment outcomes in patients with EGFR mutation or wild-type EGFR.     

Detection of EGFR mutations in plasma DNA from lung cancer patients by mass spectrometry genotyping is predictive of tumor EGFR status and response to EGFR inhibitors

Aims

EGFR mutations now guide the clinical use of EGFR-targeted therapy in lung cancer. However, standard EGFR mutation analysis requires a minimum amount of tumor tissue, which may not be available in certain situations. In this study, we combined a mass spectrometry genotyping assay (Sequenom) with a mutant-enriched PCR (ME-PCR) to detect EGFR mutations in free plasma DNA from patients with lung cancer.

Method

DNAs were extracted from 31 plasma samples from 31 patients and analyzed by both methods for EGFR Exon 19 deletion and EGFR L858R mutation. Results in plasma DNA samples were compared with EGFR mutation status obtained in tumor DNA (18/31 EGFR mutant). The relationship of EGFR mutation status in tumor and/or plasma samples to overall survival was assessed.

Results

The EGFR mutation status in plasma DNA was identical to the primary tumor in 61% of patients (19/31). By mass spectrometry genotyping, the plasma samples contained mutant DNA corresponding to 5/14 EGFR Exon 19 deletions and 3/4 EGFR L858R mutations previously diagnosed in the matched tumors. Two samples were positive in plasma DNA but negative in primary tumor tissue. Results were similar for samples studied by ME-PCR. For patients treated with erlotinib, overall survival was correlated with the presence of EGFR mutation in plasma and/or tumor tissue (p = 0.002), with the two patients positive only in plasma DNA showing responses and favorable outcomes.

Conclusion

The detection of EGFR mutations in plasma DNA samples by mass spectrometry genotyping and ME-PCR is feasible. A positive EGFR result in plasma DNA has a high predictive value for tumor EGFR status and for favorable clinical course on EGFR-targeted therapy and could therefore be useful in guiding clinical decisions in patients with insufficient or unavailable tumor specimens.     

Oncogenic mutations in gastric cancer with microsatellite instability

Aim

Mitogen-activated protein kinase (MAPK) cascade and phosphatidylinositol 3-kinase (PI3K) survival pathways are frequently activated in the progression of gastrointestinal malignancies. In this study, we aimed to determine the frequency of gene mutations in members of these pathways - Epithelial Growth Factor Receptor (EGFR), KRAS, BRAF, PIK3CA and MLK3 in a series of 63 gastric carcinomas with high levels of microsatellite instability (MSI).

Methods

Gene mutation analysis was performed by PCR amplification followed by direct sequencing. In selected tumour cases, EGFR expression was evaluated by immunohistochemistry. Association studies between molecular data and clinicopathologic characteristics were performed.

Results

Mutations in EGFR (3′-untranslated region [UTR] polyA repeat), KRAS, PIK3CA and MLK3 genes occurred in 30 (47.6%), 11 (17.5%), 9 (14.3%) and 2 (3.2%) of the MSI gastric cancer (GC) cases, respectively. No BRAF or EGFR hotspot mutations were identified. Overall, mutations in at least one of these genes were found in 55.6% (35/63) of gastric carcinomas. From those mutant cases 40.0% (14/35) of them had concomitant gene mutations, always involving EGFR polyA deletions. Interestingly, we observed significant associations between oncogenic mutations and female gender (p = 0.046) old age of diagnosis (p = 0.001) and intestinal subtype (p = 0.043).

Conclusion

Our results show that MSI gastric carcinoma frequently shows activation of EGFR-MAPK and PI3K pathways. Within all alterations found, deletions of the A13 repeats of EGFR were common, suggesting this molecular event as an important biomarker for stratification of GC patients for treatment with EGFR inhibitors.     

AKT inhibition synergistically enhances growth-inhibitory effects of gefitinib and increases apoptosis in non-small cell lung cancer cell lines

Objectives

EGFR inhibitors are ineffective against most EGFR wild-type non-small cell lung cancer, for which novel treatment strategies are needed. AKT signalling is essential for mediating EGFR survival signals in NSCLC. We evaluated the combination of gefitinib and two different AKT inhibitors, the allosteric inhibitor AKTi-1/2 and the ATP-competitive pan-AKT inhibitor AZD5363, in EGFR-mutant (HCC-827 and PC-9) and -wild-type (NCI-H522, NCI-H1651), non-small cell lung cancer cell lines.

Materials and methods

Drug interaction was studied in two EGFR mutant and two EGFR wild-type non-small cell lung cancer cell lines by calculating combination index (CI) using median effect analysis. The effects on p-EGFR, p-ERK, p-AKT, p-S6 and apoptosis were studied by Western blot analysis.

Results

The combination of gefitinib and AKTi-1/2 or AZD5363 showed synergistic growth inhibition in all cell lines. CI values for the combination of gefitinib and AKTi-1/2 were 0.35 (p = 0.0048), 0.56 (p = 0.036), 0.75 (p = 0.13) and 0.64 (p = 0.0003) in NCI-H522, NCI-H1651, HCC-827 and PC-9 cell lines, respectively; CI values of 0.45 (p = 0.0087) and 0.22 (p < 0.0001) were observed in NCI-H522 and PC-9 cells, respectively, when gefitinib was combined with AZD5363. Additive inhibition of signalling output through AKT and key downstream proteins (S6) and increased apoptosis were demonstrated.

Conclusion

Dual inhibition of EGFR and AKT may be a useful up-front strategy for patients with EGFR-mutant and -wild-type non-small cell lung cancer.     

Spatial relationship of phosphorylated epidermal growth factor receptor and activated AKT in head and neck squamous cell carcinoma

Background

Overexpression of EGFR correlates with decreased survival after radiotherapy in head and neck squamous cell carcinoma (HNSCC). However, the contribution of the activated form, pEGFR, and its downstream signaling (PI3-K/AKT) pathway is not clear yet.

Methods

Fifty-eight patients with HNSCC were included in the study. pEGFR, pAKT, hypoxia, and vessels were visualized using immunohistochemistry. Fractions (defined as the tumor area positive for the respective markers relative to the total tumor area) were calculated by automated image analysis and related to clinical outcome.

Results

Both pEGFR (median 0.6%, range 0-34%) and pAKT (median 1.8%, range 0-16%) expression differed between tumors. Also, a large variation in hypoxia was found (median pimonidazole fraction 3.9% 0-20%). A significant correlation between pEGFR and pAKT (r_s 0.44, p = 0.004) was seen, however, analysis revealed that this was not always based on spatial coexpression. Low pAKT expression was associated with increased risk of regional recurrence (p < 0.05, log-rank) and distant metastasis (p = 0.04).

Conclusion

The correlation between expression of pEGFR and pAKT is indicative of activation of the PI3-K/AKT pathway through phosphorylation of EGFR. Since not all tumors show coexpression to the same extent, other factors must be involved in the activation of this pathway as well.     

Expression of estrogen receptor beta predicts a clinical response and longer progression-free survival after treatment with EGFR-TKI for adenocarcinoma of the lung

Purpose

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (EGFR-TKI) demonstrates a dramatic clinical response for the lung adenocarcinoma patients harboring a somatic mutation of EGFR. Such EGFR mutations are frequently found in adenocarcinoma with a strong expression of estrogen receptor (ER) beta, which has been shown to correlate with a favorable prognosis for the patients with EGFR mutations. The aim of this study is to elucidate the correlation between expression of ER beta and the therapeutic effect of EGFR-TKI in adenocarcinoma of the lung.

Patients and methods

Forty-three patients who were treated with EGFR-TKI for adenocarcinoma of the lung were evaluated. The expression of ER beta and the EGFR mutation were evaluated by immunohistochemistry and the polymerase chain reaction, respectively. Patients divided into two groups by the nuclear expression of ER beta. The clinical response and survival data were compared between the two groups.

Result

Strong (S) and weak (W) expression of ER beta was observed in 21 and 22 patients, respectively. EGFR mutations were detected in 30 (69.8%) cases. The S group had more frequent EGFR mutations than the W group (85.7%, 54.5%, p = 0.045). The S group had better response rate (p = 0.006) and longer progression-free survival (PFS; p = 0.001) than the W group. Even in a limited analysis in the patients with EGFR mutations, the S group had tended to have a better response rate (77.8%, 41.7%, p = 0.063), and significant longer PFS (p = 0.012) than the W group.

Conclusion

A strong expression of ER beta predicts a good clinical outcome for patients with adenocarcinoma of the lung after treatment with EGFR-TKI. This suggests that the expression status of ER beta can be a candidate surrogate marker for EGFR-TKI treatment of patients with adenocarcinoma of the lung. Further investigation will be necessary to identify biomarkers using a larger cohort of patients in a prospective study.     

CYP1A1*2A polymorphism as a predictor of clinical outcome in advanced lung cancer patients treated with EGFR-TKI and its combined effects with EGFR intron 1 (CA)n polymorphism

Background

Mutations in the epidermal growth factor receptor (EGFR) have been confirmed as predictors of efficacy for EGFR-tyrosine kinase inhibitors (TKIs). We investigated whether polymorphisms of the EGFR and cytochrome P450, family 1, member A1 (CYP1A1) genes were associated with clinical outcome in NSCLC patients treated with EGFR-TKI.

Methods

Genotypes for the intron 1 (CA)n repeat and R497K polymorphisms in the EGFR gene and the *2A (3801 T → C) and *2C (2455 A → G) polymorphisms in CYP1A1 gene were evaluated in 115 NSCLC patients by PCR-RFLP and DNA sequencing. Genetic polymorphisms were correlated with clinical outcomes of EGFR-TKIs. From a subgroup of patients whose tumour tissues were available, associations between somatic EGFR mutations, EGFR expression, and genomic polymorphisms were also analysed.

Results

EGFR intron 1 (CA)n and CYP1A1*2A polymorphisms were independent predictive factors (p = 0.046, p = 0.011, respectively) and the latter was also a prognostic factor (p = 0.001) for patients treated with EGFR-TKIs. We also observed a strong synergistic effect from two genotypes. Specifically, patients with both the T/T allele of the CYP1A1 gene and shorter intron 1 CA repeats (?16 CA) of the EGFR gene showed an improved response (p = 0.002) compared with patients with the T/C or C/C allele and longer intron 1 CA repeats (both alleles >16 CA). In contrast, for R497K and CYP1A1*2C, no relationship was observed with clinical outcome for patients treated with EGFR-TKIs (p = 0.573; p = 0.629, respectively). Both SNPs in the CYP1A1 gene showed a correlation with EGFR somatic mutations.

Conclusions

The findings of this study suggest that the CYP1A1*2A polymorphism is a predictor for clinical outcome in NSCLC patients treated with EGFR-TKI therapy, and combining analysis of both CYP1A1*2A and EGFR intron 1 (CA)n polymorphisms may be useful for predicting treatment outcome in NSCLC patients treated with EGFR-TKIs.     

Impact of cigarette smoking on response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations

Objectives

The aim of this study is to evaluate the predictive impact of cigarette smoking on treatment outcomes of EGFR-tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma patients with activating EGFR mutations.

Methods

We retrospectively analyzed 222 consecutive recurrent or unresectable lung adenocarcinoma patients who harbored activating EGFR mutations (exon 19 deletion or exon 21 L858R) and had received gefitinib or erlotinib. Detailed smoking histories were obtained from all patients according to a standard protocol.

Results

Of 222 EGFR-mutated patients, 65.3% were never-smokers, 19.8% were smokers with <30 pack-years, and 14.9% were smokers with ≥30 pack-years smoking dosage. The disease control rate (DCR) and objective response rate (ORR) of smokers with ≥30 pack-years were significantly lower than never-smokers and smokers with <30 pack-years (DCR, 78.8% vs. 93.1%, p = 0.016; ORR, 45.5% vs. 62.4%, p = 0.020). Smokers with ≥30 pack-years showed significantly shorter PFS than never-smokers (6.4 vs. 11.8 months, p = 0.001) and smokers with <30 pack-years (6.4 vs. 11.4 months, p = 0.033), as well as shorter overall survival from the time of metastatic diagnosis than never-smokers (33.6 vs. 46.2 months, p = 0.003). There was no survival difference between smokers with <30 pack-year and never smokers. In the multivariate analysis adjusted for age, sex, performance status, initial stage, and line of EGFR-TKI, the presence of smoking dosage ≥30 pack-years was an independent predictive factor for the disease progression to EGFR-TKIs (hazard ratio, 1.87; 95% confidence interval, 1.15–3.05; p = 0.012).

Conclusions

Cigarette smoking dosage of ≥30 pack-years is an independent negative predictive factor of EGFR-TKI treatment outcome in lung adenocarcinoma patients with activating EGFR mutations.     

The usefulness of mutation-specific antibodies in detecting epidermal growth factor receptor mutations and in predicting response to tyrosine kinase inhibitor therapy in lung adenocarcinoma

Introduction

Among the mutations of epidermal growth factor receptor (EGFR), deletions in exon 19 (DEL), and point mutations in exon 21 (L858R) predict the response to EGFR-tyrosine kinase inhibitors (TKIs) in primary lung adenocarcinoma. The ability to detecting such mutations using immunohistochemistry (IHC) would be advantageous.

Methods

The molecular-based and IHC-based EGFR mutations were analyzed in 577 lung adenocarcinomas using high resolution melting analysis (HRMA) and 2 mutation-specific antibodies, respectively.

Results

In the molecular-based analyses, DEL was detected in 135 cases (23%), and L858R was detected in 172 cases (30%). In the IHC-based analyses, a positive reaction was detected in 59 cases (10%) for the DEL-specific antibody, and in 139 cases (24%) for the L858R-specific antibody. With the molecular-based results set as the gold standard, the sensitivity and specificity of the DEL-specific antibody were 42.2% and 99.5%, respectively, while the sensitivity and specificity of the L858R-specific antibody were 75.6% and 97.8%, respectively. The antibody specificities improved when the threshold for the mutation-positive reactions was set as >50% of immunopositive tumor cells. The significant predictors of the clinical response to EGFR-TKI were molecular-based EGFR mutations (p < 0.001) and IHC-based EGFR mutations (p = 0.001). However, a multivariate analysis revealed that only molecular-based EGFR mutations were significantly correlated with the clinical response (p < 0.001).

Conclusions

Mutation-specific antibodies demonstrated extremely high specificities, but their sensitivities were not higher than those of molecular-based analyses. However, IHC should be performed before a molecular-based analysis, because it is more cost-effective and can effectively select candidates for EGFR-TKI therapy.     

Association between plasma hepatocyte growth factor and gefitinib resistance in patients with advanced non-small cell lung cancer

Purpose

It has been suggested that hepatocyte growth factor (HGF) and insulin-like growth factor binding protein (IGFBP)-3 are associated with gefitinib resistance in non-small cell lung cancer (NSCLC). We investigated the predictive and prognostic roles of these proteins in NSCLC patients treated with gefitinib.

Patients and methods

Of 106 patients enrolled in a randomized phase II study of gefitinib, 97 had plasma samples available for ELISA testing. Of these samples, seven and eight, respectively, had HGF and IGFBP-3 values that could not be measured. Therefore, the correlations between clinical outcomes and plasma levels of HGF and IGFBP-3 were evaluated in 90 and 89 patients, respectively.

Results

Plasma HGF levels were significantly higher in older patients, male patients, patients with squamous cell carcinoma, current smokers, and patients with epidermal growth factor receptor (EGFR) wild-type tumors. Low HGF levels were significantly associated with higher response rate, and longer progression-free survival (PFS) and overall survival (OS) irrespective of EGFR mutation status. In a multivariate analysis, the presence of EGFR mutations (P = 0.002) and low HGF levels (P = 0.031) were independently predictive of longer PFS, and an ECOG PS of 0 (P = 0.001) and low HGF levels (P = 0.002) were independently predictive of longer OS. No statistically significant differences were found for IGFBP-3.

Conclusion

High HGF levels are significantly associated with resistance to gefitinib and can be used as a predictive marker for the differential outcome of gefitinib treatment in NSCLC irrespective of EGFR mutation status.     

Reduced chemotherapy sensitivity in EGFR-mutant lung cancer patient with frontline EGFR tyrosine kinase inhibitor

Objectives

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are a standard first-line treatment for EGFR-mutant patients with non-small cell lung cancer (NSCLC). However, it remains unclear whether frontline EGFR TKIs affect subsequent chemo-sensitivity in EGFR-mutant patients. This study compared chemo-sensitivity in patients treated with post-TKI chemotherapy and first-line chemotherapy controls.

Materials and methods

This study included 203 EGFR-mutant patients. The study group contained 68 patients treated with chemotherapy after first-line EGFR-TKI and the control group contained 135 patients who received first-line chemotherapy. The response rate (RR), progression-free survival (PFS) and overall survival (OS) were assessed.

Results

In study group, the RR of chemotherapy was 13.2% compared with 34.1% in the control group (P = 0.002). The median PFS of chemotherapy in the control group was significantly longer than in the study group (6.9 vs. 3.9 months, P < 0.001), while the RR (76.5% vs. 68.9%, P = 0.259) and PFS (11.0 vs. 10.2 months) of EGFR-TKI were similar between first- and second-line treatment. Cox regression analyses indicated that prior EGFR-TKI treatment had a higher risk for disease progression during chemotherapy treatment [hazard ratio (HR) = 3.06; 95% CI = 2.12–4.42, P < 0.001]. Median overall survival was 31.7 months in the control group and 23.5 months in the study group (P < 0.001). The adjusted HR for death in the study group was 1.91 (95% CI = 1.33–2.76; P < 0.001).

Conclusion

In EGFR-mutant patients, frontline EGFR-TKI significantly reduced the sensitivity of subsequent chemotherapy compared with that of TKI-naïve frontline chemotherapy. These findings need to be validated in further randomized trials.     

Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: Re-analysis of the SATURN study

Introduction

The phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p = 0.63) or OS (p = 0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN.

Methods

The H-score method assigned a score of 0–300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score < 200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications.

Results

In the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53–0.86] and 0.76 [95% CI 0.62–0.93], respectively) and OS (HR 0.80 [95% CI 0.62–1.05] and 0.80 [95% CI 0.64–1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51–0.95] and 0.84 [95% CI 0.63–1.12], respectively) and OS (HR 0.78 [95% CI 0.55–1.10] and 0.76 [95% CI 0.55–1.05], respectively).

Conclusions

These data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC.     

Radiation-induced lipid peroxidation activates src kinase and triggers nuclear EGFR transport

Purpose

Elucidation of the molecular mechanism of radiation-induced activation of src kinase, which initiates EGFR internalization and nuclear transport.

Material and methods

Radiation-induced src activation was investigated in the bronchial carcinoma cell line A549. Proteins were Western blotted and quantified by the help of specific antibodies. Residual DNA-damage was quantified with γH₂AX-foci analysis. Radiation-induced lipid peroxidation was prevented by acetyl-cysteine.

Results

The radiation-induced src activation and EGFR stabilization could be mimicked by addition of hydroxy-nonenal (HNE), one of the major lipid peroxidation products. Radiation-generated HNE is bound to EGFR and src and correlated with complex formation between both following radiation. Treatment with HNE activated src and stimulated radiation-associated EGFR and caveolin 1 phosphorylations resulting in increased nuclear transport of EGFR. Consequently, radiation-induced phosphorylation and activation of DNA-PK were increased. This phosphorylation was associated with improved removal of residual damage 24 h after irradiation. Inhibition of radiation-induced HNE generation by acetyl-cysteine blocked radiation-induced src activation and EGFR phosphorylation.

Conclusions

HNE generated in response to radiation exposure activates src kinase and is involved in regulation of radiation-stimulated DNA-repair processes.     

Gefitinib vs. chemotherapy as first-line therapy in advanced non-small cell lung cancer: meta-analysis of phase III trials

Background

Gefitinib is an oral tyrosine kinase inhibitor against the epidermal growth factor receptor (EGFR). It has been shown to be active in patients with advanced non-small cell lung cancer (NSCLC) whose tumors contain EGFR mutations.

Methods

We performed a meta-analysis of four randomized studies that compared gefitinib with chemotherapy in the first-line treatment of patients with advanced NSCLC: IPASS, North-East Japan, West Japan and first-SIGNAL studies. Patients were selected either on the basis of known EGFR mutations or based on clinicopathologic criteria - non-smokers with adenocarcinomas - associated with increased likelihood of EGFR mutations.

Results

Nearly 2000 patients were enrolled on these four trials. Median ages ranged from 57 to 64 years. Seventy-six percent were women and 86% were non-smokers. Overall, gefitinib was associated with significantly less toxicity than chemotherapy and improved quality-of-life. Gefitinib also produced higher response rates in the EGFR mutation-positive patients (72% vs. 38%, odds ratio 4.04, p < 10⁻¹⁵), as well as improved progression-free survival (PFS; hazard ratio 0.45, p < 10⁻¹⁶). Overall survival (OS) was not significantly different between treatment groups (p = 0.35).

Conclusions

This meta-analysis confirms the results of each individual study and narrows the confidence intervals of these results. In patients with known EGFR mutations or whose tumors are likely to harbor a mutation, upfront gefitinib or chemotherapy are associated with similar OS. Gefitinib is associated with less fatigue, myelosuppression and nausea than chemotherapy (but produces more skin rash, diarrhea and pneumonitis). Patients receiving gefitinib have improved quality-of-life compared to those receiving chemotherapy, making it an appropriate first-line choice.     

Poorer outcome in Polynesian patients with prostate cancer treated with definitive conformational radiation therapy

Purpose

To compare freedom from biochemical failure (FFBF) of French Polynesian (FP) and Native European (NE) prostate cancer patients after definitive conformal radiotherapy (RT).

Patients and methods

Data were reviewed from medical records of 152 consecutive patients (46 FP and 106 NE) with clinically localised prostate cancer treated with definitive RT. Neoadjuvant androgen deprivation therapy (ADT) was used in 22% of cases. Definition for biochemical failure was a rise by 2 ng/mL or more above the nadir prostate-specific antigen (PSA) level. The median follow-up was 34 months.

Results

In comparison to NE patients, FP patients were younger (p = 0.002) with a higher low-risk proportion (p = 0.06). Probability of 5-year FFBF was 77% in the NE cohort and 58.0% in the FP cohort (p = 0.017). Univariate analysis showed that FP ethnicity was associated with worse prognosis in high-risk tumours (p = 0.004). Cox multivariate analysis showed that factors associated with FFBF were risk category (p < 0.017), and FP origin (p = 0.03), independently of ADT and radiation dose.

Conclusion

FP ethnicity was an independent prognostic factor for biochemical relapse after definitive conformal RT for prostate cancer.     

Frequency of EGFR and KRAS mutations in patients with non small cell lung cancer by racial background: Do disparities exist?

Introduction

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.     

Prognostic significance of CD24 protein expression in patients treated with adjuvant radiotherapy after radical hysterectomy for cervical squamous cell carcinoma

Background and purpose

The CD24 marker is expressed in various carcinomas and is associated with shorter survival rates. We evaluated the prognostic significance of CD24 protein overexpression in patients treated with post-operative radiotherapy (RT) after surgery, and its prognostic significance and specific role stratified by adjuvant treatment modalities.

Materials and methods

We determined the CD24 expression status of 140 patients with cervical squamous cell carcinoma treated with RT alone or with chemoradiotherapy (CRT) after radical hysterectomy procedures.

Results

CD24 expression was detected in 59 patients (42%) and was significantly associated with locoregional failure-free survival (LRFFS) (p = 0.0218), distant metastasis-free survival (DMFS) (p = 0.0001), and overall survival (OS) (p = 0.0053). In the multivariate analysis, CD24 positivity was also significantly associated with DMFS (p = 0.025) and OS (p = 0.045). CD24 expression stratified by post-operative treatments (CRT or RT alone) was associated with DMFS (p = 0.0001) but not with LRFFS (p = 0.4423) in the CRT group. However, CD24 expression was associated with LRFFS (p = 0.0198) but not with DMFS (p = 0.5269) in the RT alone group.

Conclusions

CD24 expression is an independent prognostic marker in patients with cervical squamous cell carcinoma, even adjuvant treatment after surgery. And this study reveals different prognostic role of CD24 expression in two subgroups treated differently after surgery. Therefore, new therapeutic strategies targeting CD24 expression stratified by subgroups might have important clinical implications.     

Tubulin, BRCA1, ERCC1, Abraxas, RAP80 mRNA expression, p53/p21 immunohistochemistry and clinical outcome in patients with advanced non small-cell lung cancer receiving first-line platinum-gemcitabine chemotherapy

Background

The aim of this study was to assess the predictive value of tumor expression of nine genes on clinical outcome in patients with advanced NSCLC receiving platinum-gemcitabine chemotherapy.

Methods

Quantitative PCR or immunohistochemistry were used to analyze the expression of β-tubuline IIA (TUBB2A), β-tubuline III (TUBB3), BRCA1, ERCC1, Abraxas (ABRX) and RAP80 in mRNA isolated from paraffin-embedded tumor biopsies of 45 NSCLC patients treated as part of a larger observational trial. All patients received first-line platinum-gemcitabine chemotherapy for stage IIIB or IV NSCLC.

Results

Median progression-free survival (PFS) was 7 months, overall survival (OS) 12 months. A partial treatment response was found in 14 patients (33%). Patients with low ERCC1 or ABRX expression had a significantly better response to chemotherapy (R = −0.45, p < 0.01 for ERCC1; R = −0.40, p = 0.016 for ABRX). A significant correlation was found between the individual time for PFS and the expression of both ERCC1 (R = −0.36, p = 0.015) and ABRX (R = −0.46, p = 0.001). Patients with low ERCC1 expression had a longer OS as compared to patients with high ERCC1 expression (HR = 0.26, log-rank p = 0.02).

Conclusions

The study confirms tumor expression of ERCC1 as a predictor for clinical outcome in patients with advanced NSCLC receiving platinum-based chemotherapy, and found ABRX expression to be similarly predictive of clinical outcome. Prospective validation is warranted and - if confirmed - non platinum-containing chemotherapy should be explored as the preferred treatment in patients with high ERCC1 or ABRX expression and no activating mutations of EGFR.