Pre-emptive skin toxicity treatment for anti-EGFR drugs: evaluation of efficacy of skin moisturizers and lymecycline. A phase II study.

BACKGROUND: Anti-epidermal growth factor receptor (EGFR) target therapies like erlotinib for metastatic lung cancer and cetuximab or panitumumab for metastatic colorectal cancer (mCRC) cause skin reaction that seems to be related to treatment efficacy. Skin toxicity evaluation protocol with panitumumab study has shown that preemptive treatment reduces the incidence of ≥Grade 2 (G2) skin toxicity in mCRC treated with panitumumab. Aim of this study is to evaluate if preemptive skin toxicity treatment with different drugs has good efficacy in patients receiving anti-EGFR therapies, such as cetuximab, panitumumab, and erlotinib, for mCRC and metastatic lung cancer. METHODS: Treatment included skin moisturizers with sunscreen and lymecycline 300 mg/daily. Primary objective is to reduce the incidence of ≥G2 skin toxicity during the first 3 months of therapy. Toxicities are reported with confidence interval at 95%. Quality of life was assessed with Dermatology Life Quality Index every 2 weeks and evaluated with repeated measure ANOVA. RESULTS: Fifty-one patients with mCRC (60.8%) and metastatic lung cancer (39.2%) were enrolled. Anticancer drugs were erlotinib/cetuximab/panitumumab 20:30:1. At 3-month evaluation, 27.4% patients had =G2 skin toxicity. Skin toxicity was not related with age (p = 0.67), sex (p = 0.65), previous chemotherapy regimens (p = 0.41), and current anti-EGFR treatment (p = 0.22). No gastrointestinal or hematological toxicities related to lymecycline were observed. Only six patients required further drugs. Quality of life analysis did not show a significant difference from the beginning and the end of treatment. CONCLUSIONS: Data show efficacy of preemptive treatment with a well-tolerated profile. A reduction of severe skin toxicities is shown with an increase of grade 1 toxicities, not leading to anti-EGFR dose reduction and with better quality of life for patients.

Differential response of fast and slow myosin ATPase from skeletal muscle to F-actin and to phalloidin F-actin.

Fast muscle myosin responds in similar way to F-actin and to phalloidin F-actin. It is activated 7.5 fold at infinite F-actin concentration and 6.8 fold at infinite phalloidin F-actin. The actomyosin dissociation constants are 0.89 +/- 0.34 microM with F-actin and 0.90 +/- 0.71 microM with phalloidin F-actin. Slow muscle myosin responds differently to F-actin and to phalloidin F-actin. It is activated 3.76 fold at infinite F-actin concentration and only 2.27 fold at infinite phalloidin F-actin concentration. The actomyosin dissociation constants are 1.95 +/- 1.27 microM with F-actin and 0.27 +/- 0.16 microM with phalloidin F-actin. At first glance this means that substitution of F-actin with phalloidin F-actin magnifies the difference between fast muscle and slow muscle myosins. Furthermore the change of the dissociation constants may affect the contractile force of the attached crossbridge.

The transition of polymers into a network of polymers alters per se the water activity.

We have found that polyacrylamide gels cross-linked with bisacrylamide induce a larger macromolecular osmotic pressure than the non cross-linked gels. This means also that in the cross-linked gels hydration water is held more tightly to the polymer, i.e., more work is needed to remove water, than in the non cross-linked gel. Since the chemical nature of the two gels is extremely similar, we propose that the formation of the network alters per se the water activity.

On the stiffness of the natural actin filament decorated with alexa fluor tropomyosin.

Natural, phalloidin-free, actin filaments were decorated with tropomyosin made fluorescent by reaction with alexa fluor (R) 488 C(5) maleimide. The elastic modulus by stretching of these filaments was then determined and found to span between 38.2 MPa and 61.48 MPa. We tried also to determine the yield strength of the same filaments in the laser light trap operated at 920 mW, the maximum power of the apparatus. Only two out of the 10 filaments tested were broken under these conditions, yield strength being 50.5 and 55 pN, respectively.

Role and prognostic significance of CD44s expression in colorectal cancer.

UNLABELLED: The purpose of this study was to clarify the role and the predictive strength of the adhesion molecule CD44s (standard isoform) in colorectal carcinogenesis. MATERIALS AND METHODS: CD44s immunohistochemical expression was evaluated in 100 patients with colon adenoma and 100 patients with colon adenocarcinoma and adjacent non-neoplastic mucosa (ANNM). The patients were followed-up for five years. RESULTS: CD44s immunoreactivity was expressed in low-moderate-high-grade dysplasia adenomas and associated with adenocarcinoma (p = 0.01), ANNM (p = 0.05) and pTNM stage (p = 0.00001). Univariate analysis revealed that CD44s expression was associated with overall survival (OS) in carcinomas (p = 0.01) and ANNM (p = 0.05). Bivariate analysis revealed that CD44s was associated with OS in stages I and II patients (p = 0.03). Multivariate analysis revealed that stage (p = 0.0001) and CD44s expression (p = 0.05) were independent predictors of OS. CONCLUSION: CD44s is involved in colon carcinogenesis and is associated with aggressive carcinomas. The immunohistochemical expression of CD44s may reveal cells that have lost their adhesion ability and therefore detect carcinomas with high metastatic power.

Changing monoclonal antibody keeping unaltered the chemotherapy regimen in metastatic colorectal cancer patients: is efficacy maintained?

UNLABELLED: Monoclonal antibodies bevacizumab and cetuximab both improve overall survival (OS), progression free survival (PFS) and overall response rate (ORR) when combined with irinotecan-containing regimens. The optimal sequence of these monoclonal antibodies in combination with chemotherapy is controversial. This study analysed the efficacy of cetuximab plus Folfiri after progression with the same regimen plus bevacizumab in patients with metastatic colorectal cancer (mCRC). Patients are eligible if progressive disease (PD) after Folfiri-bevacizumab; ECOG PS 0-1. Primary endpoint is the disease control rate (DCR:ORR plus stable disease > 6 months); secondary endpoints: ORR, PFS, duration of response, OS and toxicity. ORR and DCR were reported with their confidence interval at 95%. Kaplan-Meier method was used for PFS and OS evaluation. RESULTS: 54 patients were enrolled to receive Folfiri-cetuximab after PD to Folfiri-bevacizumab treatment. Median age was 65 (43-80), M/F 31/23, ECOG PS 0/1 was 36/ 18, WT Kras 33(61%). The DCR was 64.8% (CI 95% 52.1-77.5). Among the group of patients with stable or progressive disease at first line treatment, 13.3% of them obtained a response at second line. For second line treatment median duration of response was 6 months and clinical benefit 7 months. The ORR was 22.2% (CI 95% 11.1-33.3). The median progression-free survival was 7 months (CI 95% 6-8). The median overall survival for second line treatment was 14 months (CI 95% 11-17). No grade 4 toxicity was observed. Data suggest that this sequential combination therapy is active and well tolerated. At disease progression to first line chemotherapy treatment the maintenance of the same chemotherapy regimen and the change of the monoclonal antibody showed efficacy in response and survival in patients with mCRC.

On the mechanics of the actin filament: the linear relationship between stiffness and yield strength allows estimation of the yield strength of thin filament in vivo.

Comparison of the behaviour of actin filaments either modified with tetramethylrhodamine iodoacetamide or decorated with tetramethylrhodamine-phalloidin or with tropomyosin or with myosin subfragment 1 shows that, in all the cases, yield strength is linearly related to stiffness.

Effects of chemical modification, tropomyosin, and myosin subfragment 1 on the yield strength and critical concentration of F-actin.

The effects of coupling with tetramethylrhodamine-5-iodoacetamide and of the decoration with tropomyosin and with myosin subfragment 1 on the elastic properties of F-actin filament are investigated. At 22 degrees C, in 15 mM orthophosphate and 3 mM MgCl2, tetramethylrhodamine F-actin displays a yield strength of 3.69 +/- 0.213 pN and an elastic modulus by stretching of 0.91 MPa. Decoration with tropomyosin increases the yield strength of tetramethylrhodamine F-actin to 10.51 +/- 0.24 pN and the elastic modulus by stretching to 23-75 MPa. Mixtures of myosin subfragment 1 and tetramethylrhodamine F-actin at the 0.2:1, 0.4:1, 0.6:1, 0.8:1, and 1:1 molar ratios are also studied. Both yield strength and the elastic modulus by stretching are found to increase progressively with the ratio. At the 1:1 molar ratio, the yield strength is 15.81 +/- 0.26 pN and the elastic modulus by stretching is 13.45 to 40 MPa. Decoration of tetramethylrhodamine F-actin with both tropomyosin and myosin subfragment 1, at the 1:1 molar ratio with the actin monomer, produces filaments with an yield strength of 22.3 +/- 0.48 pN.

An Unusual Case of Neurofibroma of the Thyroid Capsule.

A solitary neurofibroma arising from the thyroid capsule in a 64 year-old woman is reported. The tumor was adherent to the lower margin of the thyroid gland and extended into the anterior mediastinum. The unusual nature of the lesion, both its relationship to the thyroid gland and to the occurrence of a neural tumor in the anterior mediastinum is discussed.