Association between miRNA signatures in serum samples from epidermal growth factor inhibitor treated patients and skin toxicity

Objective: Epidermal growth factor receptor inhibitors (EGFRI) are used as targeted cancer therapy. On average 70% of patients treated with EGFRIs suffer from skin toxicity. Studies showed a correlation between overall survival and the appearance of a skin rash, which is used as a biomarker for therapy efficacy. Micro RNAs (miRNA) as tumor or resistance biomarkers for cancer therapy are also highly investigated. In our study, we searched for associations of miRNA expression profiles in serum, with the severity of skin rash, in order to identify tentative therapy predictive biomarkers.Materials and Methods: Five candidate miRNAs were selected, based on an earlier in vitro next-generation-sequencing-experiment and after literature search. MiR-21, miR-31, miR-17, miR-106b and miR-520e were investigated in serum samples from patients (n = 254) treated with EGFRI. The quantitative expression of miRNA was tested for association with the occurrence/severity of the rash.Results: In our cohort of patients treated with EGFR inhibiting monoclonal antibodies, miR-21 and miR-520e serum concentrations were negatively correlated with severity of skin rash (p-value 0.000582 and 1.53e-07 linear-trend-test) whereas for miR-31, a positive correlation was observed (p-value 9.01e-06 linear-trend-test).Conclusions: This suggests that miR-21, miR-31 and miR-520e expression might be a treatment dependent marker for EGFRI induced skin rash.     

Markers in the epidermal growth factor receptor pathway and skin toxicity during erlotinib treatment.

BACKGROUND: Skin toxicity is a common adverse effect of erlotinib and other anti-epidermal growth factor receptor (EGFR) agents. The aim of the study was to explore the relationship between markers in the EGFR pathway and skin rash. PATIENTS AND METHODS: Eighteen patients with metastatic breast cancer were treated with daily oral erlotinib at 150 mg. Skin biopsies were obtained at baseline and after 1 month of treatment in 15 patients. EGFR, phosphorylated EGFR (pEGFR), phosphorylated mitogen-activated protein kinase (pMAPK), and phosphorylated Akt (pAkt) or Ki67 were examined quantitatively by immunohistochemistry. RESULTS: 11 of 18 (61%, 95% confidence interval 35.7% to 82.7%) patients developed skin rash. pAkt at baseline was significantly higher in patients with no rash than those with a grade 1 or 2 rash (18.8 +/- 8.3 versus 2.4 +/- 1.2 versus 3.3 +/- 3.3; P = 0.0017 for trend). There was a trend towards a significant increase of pMAPK in skin posttreatment with increasing grade of rash (no rash versus grade 1 versus grade 2 rash: 4.5 +/- 2.3 versus 8.4 +/- 4.2 versus 19.4 +/- 4.6; P = 0.036). Other markers were not associated with rash. CONCLUSIONS: pAkt was significantly associated with not developing a rash and may have a predictive utility for skin toxicity in patients treated with erlotinib and possibly with other anti-EGFR agents.     

DNA methylation status as a biomarker of anti‐epidermal growth factor receptor treatment for metastatic colorectal cancer

Anti‐epidermal growth factor receptor (EGFR) treatment is an effective option for metastatic colorectal cancer (CRC) treatment. However, there are few reliable biomarkers to predict the clinical response to anti‐EGFR treatment. We investigated the genome‐wide DNA methylation status in metastatic colorectal cancer to identify associations between the methylation status and clinical response to anti‐EGFR antibody. We retrospectively reviewed the medical records of 97 patients (45 patients for the first cohort and 52 patients for the second cohort) who received anti‐EGFR treatment for KRAS wild‐type metastatic CRC. Then we analyzed the associations between genome‐wide DNA methylation status and clinical response to anti‐EGFR treatment, and evaluated the predictive power and value of the methylation status statistically. As a result, each cohort was classified into highly methylated CRC and low methylated CRC subgroups by unsupervised clustering analyses. In the first cohort, clinical outcomes were significantly better in the low methylated CRC subgroup than in the highly methylated CRC subgroup (response rate, 35.7% vs 6.3%, P = 0.03; disease control rate, 75% vs 31.3%, P = 0.005; hazard ratio for progression‐free survival, 0.27; 95% confidence interval, 0.13–0.57, P < 0.001; overall survival, 0.19; 95% confidence interval, 0.06–0.54, P < 0.001). These results were reproducible in the second cohort. The genome‐wide methylation status was a predictive factor of progression‐free survival and overall survival independently of RAS mutation status. In conclusion, we found that the genome‐wide DNA methylation status is a powerful epigenetic predictor of anti‐EGFR treatment in patients with KRAS wild‐type metastatic colorectal cancer (UMIN000005490).     

Cytokine regulation by epidermal growth factor receptor inhibitors and epidermal growth factor receptor inhibitor associated skin toxicity in cancer patients

AimEpidermal growth factor receptor inhibitor (EGFRI) induced skin toxicity has a prognostic value suggesting skin toxicity can be a useful surrogate marker for successful epidermal growth factor receptor (EGFR) inhibition, improved response and survival. But the pathophysiology of EGFRI induced skin toxicity remains elusive. However the involvement of immunological mechanisms has been speculated. This study investigates the possible underlying mechanism of EGFR inhibition associated cytokine production in keratinocytes as well as in patients after treatment with epidermal growth factor receptor inhibitors (EGFRIs).MethodsNormal human epidermal keratinocytes (NHEK) were incubated for 2 and 24 h with different concentrations of EGFRI (erlotinib) for Western blot analysis and cytokine expression analysis, respectively. Inhibition of EGFR, extracellular-signal-regulated kinase 1/2 (Erk 1/2) and c-Jun was examined by Western blot analysis. Cytokine concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in the NHEK cell supernatant and also in the serum of 186 cancer patients who are followed up for EGFRI induced skin rash.ResultsA significant inhibitory effect of EGFRI was seen on EGFR (Y845), Erk 1/2 and c-Jun in a dose dependent manner. Further downstream, increased CC-chemokine ligand 2 (CCL2), CC-chemokine ligand 5 (CCL5) and decreased interleukin-8 (IL-8) or CXCL8 expression was observed in keratinocytes. In EGFRI treated patients, low levels of serum CXCL8 corresponding to stronger EGFR inhibition were associated with a higher grade of skin toxicity (p = 0.0016) and a prolonged overall survival (p = 0.018).ConclusionsThe results obtained in this study indicate that EGFRI can regulate cytokines by modulating EGFR signalling pathway in keratinocytes. Moreover, serum levels of CXCL8 in EGFRI treated patients may be important for individual EGFRI induced skin toxicity and patient’s survival.     

Promising biomarkers for predicting the outcomes of patients with KRAS wild‐type metastatic colorectal cancer treated with anti‐epidermal growth factor receptor monoclonal antibodies: A systematic review with meta‐analysis

KRAS mutations have been established as a major predictive biomarker for resistance to the treatment of metastatic colorectal cancer (mCRC) with anti‐epidermal growth factor receptor monoclonal antibodies (anti‐EGFR MoAbs). However, many patients with KRAS wild‐type tumors still do not respond to the treatment. We conducted a systematic review with meta‐analysis to assess whether BRAF mutations, PIK3CA mutations and PTEN loss can predict the outcomes of patients with KRAS wild‐type mCRC treated with anti‐EGFR MoAbs. Studies that explored the association of one or more of the three biomarkers with progression‐free survival (PFS), overall survival (OS) and/or objective response rate (ORR) were identified through August 2012. Summary hazard ratios (HRs) and rate differences (RDs) and corresponding 95% confidence intervals (CIs) were calculated by using the random‐effects model. BRAF mutations, PIK3CA exon 20 mutations and PTEN loss were all associated with shorter PFS (HR = 2.59, 95% CI 1.67–4.03; HR = 2.52, 95% CI 1.33–4.78 and HR = 1.75, 95% CI 1.19–2.56, respectively), shorter OS (HR = 2.74, 95% CI 1.79–4.19; HR = 3.29, 95% CI 1.60–6.75 and HR = 1.85, 95% CI 1.30–2.64, respectively) and lower ORR (RD = ?36%, 95% CI ?44 to ?28%; RD = ?38%, 95% CI ?51 to ?24% and RD = ?41%, 95% CI ?68 to ?14%, respectively). PIK3CA exon 9 mutations were associated with none of the outcomes. Studies with relevant data consistently demonstrated a stronger predictive power of combined multiple biomarkers as compared to one alteration alone. These results suggest that BRAF mutations, PIK3CA exon 20 mutations and PTEN loss are predictive of better outcomes in KRAS wild‐type mCRC treated with anti‐EGFR MoAbs. However, the quality of included studies varied, and some of the meta‐analyses were limited by significant between‐study heterogeneity. In the future, well‐designed large randomized controlled trials conducted in KRAS wild‐type mCRC patients with subgroup analysis according to BRAF, PIK3CA exon 20 and PTEN status are essential to fully assess the clinical relevance of these biomarkers.     

A modified MethyLight assay predicts the clinical outcomes of anti‐epidermal growth factor receptor treatment in metastatic colorectal cancer

DNA methylation status correlates with clinical outcomes of anti‐epidermal growth factor receptor (EGFR) treatment. There is a strong need to develop a simple assay for measuring DNA methylation status for the clinical application of drug selection based on it. In this study, we collected data from 186 patients with metastatic colorectal cancer (mCRC) who had previously received anti‐EGFR treatment. We modified MethyLite to develop a novel assay to classify patients as having highly methylated colorectal cancer (HMCC) or low‐methylated colorectal cancer (LMCC) based on the methylation status of 16 CpG sites of tumor‐derived genomic DNA in the development cohort (n = 30). Clinical outcomes were then compared between the HMCC and LMCC groups in the validation cohort (n = 156). The results showed that HMCC had a significantly worse response rate (4.2% vs 33.3%; P = .004), progression‐free survival (median: 2.5 vs 6.6 mo, P < .001, hazard ratio [HR] = 0.22), and overall survival (median: 5.6 vs 15.5 mo, P < .001, HR = 0.23) than did LMCC in patients with RAS wild‐type mCRC who were refractory or intolerable to oxaliplatin‐ and irinotecan‐based chemotherapy (n = 101). The DNA methylation status was an independent predictive factor and a more accurate biomarker than was the primary site of anti‐EGFR treatment. In conclusion, our novel DNA methylation measurement assay based on MethyLight was simple and useful, suggesting its implementation as a complementary diagnostic tool in a clinical setting.     

Prognostic value of cetuximab‐related skin toxicity in metastatic colorectal cancer patients and its correlation with parameters of the epidermal growth factor receptor signal transduction pathway: Results from a randomized trial of the GERMAN AIO CRC Study Group

Skin toxicity is a frequent adverse event of epidermal growth factor receptor (EGFR) targeting agents. Occurrence of cetuximab‐induced skin toxicity (Cet‐ST) correlates with better treatment response and longer survival times. Molecular markers predicting Cet‐ST are still missing. This investigation analyzed the value of Cet‐ST for treatment efficacy in a randomized trial comparing cetuximab plus capecitabine/irinotecan to cetuximab plus capecitabine/oxaliplatin as first‐line treatment of metastatic colorectal cancer. Patient characteristics and molecular parameters (KRAS mutation, EGFR‐FISH, EGFR‐IHC and EGFR intron‐1 polymorphism) of the tumour were correlated with response and Cet‐ST. Cet‐ST grade 0–1 was observed in 31%, grade 2–3 in 69% of patients. Outcome favoured patients with grade 2–3 Cet‐ST with regard to overall response rate (62 vs. 41%), PFS (7.8 vs. 5.2 months) and overall survival (OS) (30.3 vs. 18.0 months). First‐cycle rash was observed in 66% of patients and corresponded with longer survival (30.7 vs. 20.2 months, p = 0.007). Patients without Cet‐ST had a poor outcome (PFS, 1.9 months; OS, 11 months). The correlation of Cet‐ST with survival was specifically evident in patients with KRAS codon‐12‐mutated tumours assumed to be cetuximab resistant. In multivariate analysis of patient characteristics, male gender and younger age were significantly correlated with Cet‐ST. Among molecular parameters, no significant correlation with Cet‐ST was found. Cet‐ST is an early predictor of treatment efficacy in cetuximab‐treated patients. This effect of Cet‐ST is independent of the KRAS mutation status, suggesting that Cet‐ST rather relates to constitutional factors of the patient than alterations of the EGFR pathway in the tumour.     

Serum levels of hepatocyte growth factor and epiregulin are associated with the prognosis on anti-EGFR antibody treatment in KRAS wild-type metastatic colorectal cancer

Background:

Ligands of transmembrane receptor tyrosine kinases have important roles in cell proliferation, survival, migration and differentiation in solid tumours. We conducted this study to evaluate the relationship between concentration of serum ligands and prognosis of patients with metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) antibodies.

Methods:

Between August 2008 and August 2011, serum samples were obtained from KRAS wild-type patients who met the inclusion criteria and received an anti-EGFR antibody treatment. Serum concentration of ligands was measured by an enzyme-linked immunosorbent assay, and somatic mutations of KRAS, BRAF, PIK3CA and BRAF were analysed by direct sequencing.

Results:

A total of 103 patients were enrolled in the present study. At the pretreatment serum levels, patients with high levels of hepatocyte growth factor (HGF) had shorter progression-free survival (PFS) and overall survival (OS) compared with those with low levels of HGF (median PFS: 6.4 months vs 4.4 months; P<0.001, median OS: 15.3 months vs 8.0 months; P<0.001, respectively). Patients with high levels of epiregulin (EREG) also had shorter PFS and OS compared with those with low levels of EREG (median PFS: 6.6 months vs 4.9 months; P=0.016, median OS: 13.8 months vs 7.4 months; P=0.048, respectively). In addition, patients whose serum levels of ligands were elevated at progressive disease had shorter PFS and OS compared with other patients.

Conclusions:

Our study indicated that high levels of HGF and EREG were associated with resistance to treatment with anti-EGFR antibodies in KRAS wild-type patients with mCRC. Our findings will contribute to the newly combination therapy on the treatment of anti-EGFR antibodies.     

Controversies in antiepidermal growth factor receptor therapy in metastatic colorectal cancer

The randomized first‐line trials, including the CRYSTAL trial, the OPUS trial, and the PRIME trial, have demonstrated the significant efficacy of cetuximab or panitumumab in patients with v‐Ki‐ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) wild‐type tumors. The addition of an antiepidermal growth factor receptor (anti‐EGFR)‐directed monoclonal antibody to chemotherapy for these patients significantly improved progression‐free survival, response rates, and R0 resection rates to a greater extent than overall survival compared with patients who received chemotherapy alone. However, 2 recent randomized phase 3 trials, the MRC COIN trial and the Nordic VII trial, reported an unexpected lack of benefit from the addition of cetuximab to chemotherapy in the first‐line setting. In addition, recent retrospective analyses performed on a pooled data set from major clinical trials added more complexity, reporting an unexpected association of KRAS G13D mutation with a better clinical outcome compared with patients who had other KRAS mutations in the first‐line and salvage settings, whereas the other independent analysis failed to demonstrate a benefit from panitumumab in patients with the same KRAS G13D mutation. The anti‐EGFR monoclonal antibody‐associated skin toxicity and the controversial strategies of management also are discussed. In this review, the authors analyze the previous randomized clinical trials and more critically re‐evaluate recent trials and subgroup analyses to derive 3 factors that need to be taken into consideration regarding the addition of EGFR‐directed monoclonal antibodies to chemotherapy: the preclinical data on mechanisms of action between chemotherapy and anti‐EGFR antibodies along with mechanisms of resistance to anti‐EGFR antibodies, the role of cross‐over events in overall survival data, and the significant dose reductions of chemotherapeutic agents when combined with anti‐EGFR agents. Cancer 2013;119:1941–1950. © 2013 American Cancer Society.     

EGFR在结直肠癌组织中的表达及其临床意义

目的：检测表皮生长因子受体（epidermal growth factor receptor,EGFR）在结直肠癌组织中的表达情况,分析其表达水平与各种主要临床病理学预后因子及长期生存的关系。方法：选取解放军307医院和301医院第二附属医院64例结直肠癌患者的石腊包埋肿瘤标本,以免疫组化方法检测结直肠癌肿瘤标本中EGFR的表达。通过单因素分析和多因素分析判断EGFR表达与临床病理学指标之间的关系;通过多因素分析（COX模型）判断EGFR表达水平与患者总生存期的关系。结果：所有患者肿瘤组织EGFR的阳性表达率为69%。T3期肿瘤EGFR阳性表达明显多于T1和T2期（P〈0.05）,淋巴结转移阳性者EGFR阳性表达明显多于无转移者（P〈0.05）,有远处转移者EGFR阳性表达明显多于无远处转移者（P〈0.05）;EGFR表达与患者性别、年龄、肿瘤原发部位、肿瘤大小、肿瘤分化程度等均无明显相关性。EGFR表达水平与患者总生存期无明显相关。结论：结直肠癌组织EGFR的表达与肿瘤TNM分期相关,与患者总生存期无明显相关。     

表皮生长因子受体抑制剂在大肠癌治疗中的应用

结直肠癌的发病率和死亡率均较高各种生长因子、生长因子抑制剂、生长因子受体在结直肠癌细胞的增殖、发展中起着重要的作用.65%～70%的结直肠癌中存在表皮生长因子受体邋(EGFR)的表达.多个研究显示,EGFR在细胞内信号传导过程中具有重要作用,EGFR的表达与结直肠癌的病情进展、预后密切相关,针对EGFR信号传导通路的治疗药物可抑制细胞的增殖,这些药物包括抗EGFR单克隆抗体、酪氨酸激酶抑制剂等,本文综述了这些表皮生长因子受体抑制剂在大肠癌治疗中的应用.     

Increased epidermal growth factor receptor expression at the invasive margin is a negative prognostic factor in colorectal cancer

The receptor tyrosine kinase epidermal growth factor receptor (EGFR) is often expressed in solid malignant tumours, and the expression has been correlated to disease progression. Multiple new agents targeted against the EGFR have been developed during the last decade, but treatment selecting criteria are still not clear. This immunohistochemical study includes 386 colorectal cancer patients and focuses on EGFR expression variations within the tumour, comparing central parts to the invasive margin. Positive immunostaining for EGFR was evident in the central part in 176/386 (46%) of analyzed primary tumours. The invasive margin was positive in 222/386 (58%). A similar expression in both the central part and the invasive front was evident in 286/386 (74%). An increased score at the invasive margin compared to central parts (EGFRⁱ) was evident in 97/386 (25%) of the tumours. Moreover, the results show a significant survival disadvantage for the EGFRⁱ group, both in potentially curatively resected colon cancer patients (n = 170, p = 0.01) and in potentially curatively resected colon and rectal cancer patients combined (n = 273, p = 0.013). Multivariate survival analysis adjusted for age, gender, bowel localisation, grade, stage and tumour type showed an increased risk of cancer death for EGFRⁱ tumours (HR, 1.53; 95% CI, 1.04–2.23; p = 0.029). A significant correlation between EGFR expression at the invasive margin and the presence of budding was seen (p = 0.0001). This investigation of a large patient material implies that EGFR immunohistochemical analysis still has a role in risk evaluation of colorectal cancer patients.     

Somatic mutations of epidermal growth factor receptor signaling pathway in lung cancers

Somatic mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in lung cancers have generated enormous interest, because they predict for sensitivity to TK inhibitors (TKIs). While mutational status is of great importance in determining response to TKIs, it is not the sole factor, and evidence is accumulating that EGFR gene amplification, other members of the EGFR family (HER2, HER3) and genes downstream of EGFR signaling (KRAS, BRAF), may be involved in cancer pathogenesis and the response of TKIs. EGFR mutations occur in highly selected subpopulations of lung cancer patients: adenocarcinoma histology, never-smoker status, East Asian ethnicity and female gender. The recent finding of "a resistance associated" mutation for TKIs also provides new insights into this complicated mechanism. Thus, molecular-based studies to analyze the biological functions and to assess TKI sensitivity depending on the type of mutations are required. Epidemiological studies to identify possible carcinogenic factor(s) affecting different subpopulations are also of interest. In addition, for optimal therapeutic approach a comprehensive understanding of the genes related to EGFR signaling pathway, including RAS/RAF/MAPK and PI3K-AKT pathways, are required.     

Controversial evaluation of EGFR protein and gene status in predicting response to anti-EGFR monoclonal antibodies in metastatic colorectal cancer: a case report and review of the literature

Clinical studies showed that only 10% of patients with metastatic colorectal cancer (mCRC) respond to treatment with the anti-epidermal growth factor receptor (EGFR) monoclonal antibodies panitumumab or cetuximab, regardless of the line of treatment. The current tool used to select patients, i.e. immunohistochemistry (IHC) evaluation of EGFR expression by EGFR pharmDx™ Kit, is not reliable in predicting response. Retrospective analyses of factors such as increased EGFR gene copy number and KRAS and/or BRAF mutations showed that such molecular changes could affect clinical benefit from anti-EGFR monoclonal antibodies. We report here the case of a 66-year-old man with chemorefractory mCRC, considered not eligible to salvage treatment with the anti-EGFR monoclonal antibody cetuximab and irinotecan because the primary adenocarcinoma of the rectum was found not expressing EGFR protein by IHC. However, FISH analysis of EGFR gene copy number and evaluation of KRAS and/or BRAF specific mutations by gene sequencing showed characteristics associated with favourable clinical outcome to anti-EGFR therapy. Based on the EGFR protein expression by IHC in a liver metastasis, the patient was then treated with cetuximab plus irinotecan, obtaining symptoms improvement and a dramatic objective tumor response in all sites of disease, lasting 4.2 months. We also discuss literature findings about the role of different biological characteristics in predicting clinical benefit from anti-EGFR therapy in patients with mCRC. Supported by research grants from Associazione Italiana Ricerca Cancro (AIRC) and Oncologia Ca’ Granda ONLUS Fondazione.     

Mutant p53 protein in the serum of patients with colorectal cancer: Correlation with the level of carcinoembryonic antigen and serum epidermal growth factor receptor

Introduction: Enzyme-linked immunosorbent assay (ELISA) was used for analysis of serum mutant p53 protein, carcinoembryonic antigen (CEA), and epidermal growth factor receptor (EGFR). Serum samples were obtained from 48 patients with colorectal cancer (CRC) and a control group of twenty healthy individuals. Results: The results demonstrated a significant increase of serum mutant p53, EGFR, and CEA levels in CRC patients compared to the control group (P < 0.001 for each). Mutant p53 protein was significantly different in the different CRC grades (P = 0.028). p53, CEA, and EGFR can differentiate successfully between different CRC grades and normal control (P < 0.001 for each). Sensitivities of p53, CEA, and EGFR were 39.6, 31, and 71%, respectively. There was no correlation between CEA, EGFR, and p53 indicating that these variables were independent. Positive status of serum CEA and (or) p53 was found in 29 out of 48 (60%) patients. Also, positive status of serum CEA and (or) EGFR was found in 39 out of 48 (81%) patients. Conclusion: Thus, the simultaneous determination of p53 or EGFR combined with the CEA may increase the sensitivity to diagnose CRC patients and may aid in disease prognosis.     

Novel cancer‐specific epidermal growth factor receptor antibody obtained from the serum of esophageal cancer patients with long‐term survival

Although esophageal cancer has a poor prognosis after recurrence, some patients have shown long‐term survival despite recurrence. We hypothesized that induction of either antitumor Abs or antitumor‐specific CTLs could play a role in long‐term survival (5 years or longer) in patients with recurrence and/or distant metastases. Therefore, we aimed to obtain Abs that specifically bind to cancer cells by using serum samples from patients with a good prognosis. A phage library was prepared using PBMC mRNA of the patients, and cell panning was carried out using an esophageal cancer cell line. Results showed the presence of an epidermal growth factor receptor (EGFR) Ab, KT112, that specifically bound to the cancer cell line. Notably, KT112 bound to only EGFR‐positive cancer cells but failed to bind to normal esophageal cells. Furthermore, KT112 was characterized by responses to EGFR expressed on cancer cells but not to the recombinant extracellular domain of EGFR. Immunohistochemical analysis showed that KT112 reacted with 17.4% of esophageal squamous cell carcinoma tissue but not with any other cancer or normal tissue, suggesting that the Ab recognizes cancer‐specific forms of EGFR and might have contributed to tumor suppression in patients with esophageal cancer. Furthermore, because of its high cancer specificity, KT112 could be a promising therapeutic option (e.g., in Ab‐drug conjugates) for esophageal cancer.     

Clinical efficacy and drug resistance of anti-epidermal growth factor receptor therapy in colorectal cancer

Colorectal cancer (CRC) ranked third in cancer related death and its incidence has been increasing worldwide. In recent decades important therapeutic advances have been developed in treatment of metastatic CRC (mCRC), such as monoclonal antibodies against epidermal growth factor receptor (anti-EGFR), which provided additional clinical benefits in mCRC. However, anti-EGFR therapies have limited usage due to approximately 95% of patients with KRAS mutated mCRC do not response to anti-EGFR treatment. Thus, KRAS mutation is predictive of nonresponse to anti-EGFR therapies but it alone is not a sufficient basis to decide who should not be received such therapies because; approximately fifty percent (40%-60%) of CRC patients with wild-type KRAS mutation also have poor response to anti-EGFR based treatment. This fact leads us to suspect that there must be other molecular determinants of response to anti-EGFR therapies which have not been identified yet. Current article summarizes the clinical efficacy of anti-EGFR therapies and also evaluates its resistance mechanisms.     

Correlation of capecitabine-induced skin toxicity with treatment efficacy in patients with metastatic colorectal cancer: results from the German AIO KRK-0104 trial

Background:

The AIO KRK-0104 randomised phase II trial investigated the efficacy and safety of two capecitabine-based regimens: combination of capecitabine and irinotecan (CAPIRI) plus cetuximab (CAPIRI-C) and combination of capecitabine with oxaliplatin (CAPOX) plus cetuximab (CAPOX-C) in the first-line treatment of metastatic colorectal cancer (mCRC). Treatment-related skin toxicity (ST) was evaluated separately for capecitabine and cetuximab. The present analysis investigates the correlation of capecitabine-attributed ST (Cape-ST) and parameters of treatment efficacy.

Methods:

Patients with mCRC were randomised to cetuximab (400 mg m⁻², day 1, followed by 250 mg m⁻² weekly) plus CAPIRI (irinotecan 200 mg m⁻², day 1; capecitabine 800 mg m⁻², twice daily, days 1–14, every 3 weeks), or cetuximab plus CAPOX (oxaliplatin 130 mg m⁻², day 1; capecitabine 1000 mg m⁻², twice daily, days 1–14, every 3 weeks).

Results:

Of 185 recruited patients, 149 (CAPIRI-C, n=78; CAPOX-C, n=71) received study treatment beyond the first tumour assessment and were evaluable for efficacy. Capecitabine-attributed ST, predominantly hand–foot syndrome, was observed in 32.2% of patients. Capecitabine-attributed ST grade 1–3 was associated with a significantly higher disease control rate (DCR) (97.9 vs 86.1%, P=0.038) compared with grade 0 toxicity. Moreover, Cape-ST grade 1–3 related to a markedly longer progression-free survival (PFS) (9.9 vs 5.6 months, P<0.001) and overall survival (OS) (32.8 vs 22.4 months, P=0.008). Separate analyses of treatment arms indicated that the effect of Cape-ST on PFS remained significant for both arms, whereas the effect on OS remained apparent as a strong trend.

Conclusion:

This analysis supports the hypothesis that for the evaluated regimens, a correlation exists between Cape-ST and treatment efficacy regarding DCR, PFS, and OS.     

IgG1 anti‐epidermal growth factor receptor antibodies induce CD8‐dependent antitumor activity

Anti‐EGFR monoclonal antibodies (mAb) like Cetuximab are commonly used for treatment of EGFR⁺ solid tumors mainly by exerting their therapeutic effect through inhibition of signal transduction. Additionally, IgG1 is a potent mediator of antibody‐dependent cytotoxicity (ADCC). In case of the IgG1, Cetuximab induction of ADCC in vivo is controversially discussed. In our study, we investigated the efficiency of Cetuximab‐mediated ADCC in a humanized mouse tumor model in vivo and analyzed the contribution of immunologic processes toward antitumor activity. Therefore, we used immunodeficient NOD/Scid mice transgenic for human MHC class I molecule HLA‐A2 and adoptively transferred human HLA‐A2⁺ PBMC after engraftment of human epidermoid cell carcinoma A431. Here, we show that high doses of anti‐EGFR mAb induced strong tumor regression independent of the immune system. However, tumor regression by low doses of anti‐EGFR mAb treatment was ADCC dependent and mediated by tumor infiltrating CD8⁺ T effector cells. This novel mechanism of ADCC conducted by CD8⁺ T effector cells was restricted to IgG1 anti‐EGFR mAb, dependent of binding to CD16 on T cells and could be inhibited after EGFR blockade on tumor cells. Furthermore, CD8⁺ T effector cell‐mediated ADCC was enhanced in the presence of IL‐15 and strongly improved after glycosylation of anti‐EGFR mAb indicating the potential of glycoengineered therapeutic mAb as efficient biologicals in cancer therapy.