Modulation of DNA strand break induction and repair by tyrosine kinase inhibitors targeted against EGFR and HER2

Purpose: The human epidermal growth factor receptors EGFR (erbB1) and HER2 (erbB2/neu) are involved in mediating resistance to chemotherapy and ionising radiation (IR). In vitro studies demonstrate that small molecule tyrosine kinase inhibitors (TKIs) which target these receptors can increase the effectiveness of DNA damaging agents. However, these combinations have failed to produce the clinical results anticipated and one potential explanation is that the inhibition of EGFR and HER2 cell signalling pathways by TKIs is short lived, with cells able to switch to alternative mechanisms of signalling through HER3. The purpose of this study was to examine whether the duration of exposure to TKIs modulates the induction and repair of DNA damage produced by chemotherapy or IR and describes attempts to elucidate the role of HER2 in mediating resistance to chemotherapy. Experimental design: Two HER targeting TKIs, lapatinib and gefitinib were investigated. The effect of lapatinib in combination with cisplatin and doxorubicin on the inhibition of cell proliferation and the role of schedule were examined in drug combination assays. The influence of the duration of exposure to TKIs on the induction and repair of DNA lesions induced by cisplatin, IR, doxorubicin, etoposide and m-AMSA were investigated using the alkaline and neutral Comet assays and measurement of γH2AX and RAD51 foci. DNA expression arrays were used to identify the potential mechanisms through which HER2 produces resistance to cisplatin in cells transfected with HER2. Results: Lapatinib is able to synergistically inhibit cell proliferation in combination with cisplatin or doxorubicin in a schedule dependent manner. Duration of exposure to TKIs has no effect on the induction of DNA lesions by cisplatin or IR, but significantly reduces the production of DNA double strand breaks by doxorubicin, etoposide and m-AMSA in part through the down-regulation of the expression of topoisomerase IIα (Topo IIα), increasing resistance to these drugs. Conclusions: These results indicate the scheduling of small molecule TKIs targeted against EGFR and HER2 is important and continuous exposure to these drugs induces resistance to doxorubicin, etoposide and m-AMSA, through reduced expression of their target, Topo IIα. The importance of schedule should be considered when combining TKIs with chemotherapy in clinical practice

Quality of life in patients with psoriasis

Psoriasis is one of the prevalent skin conditions in the United States. This chronic condition has a significant negative impact on patients' quality of life. Psoriasis has been linked to the depression and suicidal tendencies in the patients. The costs associated with decrements in quality of life, lost productivity, and work absenteeism may be enormous, increasing overall costs associated with the disease management. This review attempts to outline different quality of life measures available for psoriasis and describes their use in studies examining patient reported outcomes associated with pharmacological interventions for psoriasis. Factors associated with quality of life in psoriasis patients are described. It further describes physician's role in the psoriasis management to improve patients' overall well-being

Ethnomedical Knowledge of Plants used by the Tribal people of Purandhar in Maharashtra, India

This study presents the results of a field survey of the plants used medically by the tribal people of Purandhar in Maharashtra, India. Tribes like Dhangars and Gowlis inhabit the dry deciduous forests of the region. This is an effort to record the valuable ethnomedical knowledge of these Purandhar tribes. A total of 77 species belonging to 30 families and 56 genera were included. These plants are used to treat various aliments, discomforts and diseases like whooping cough, asthma, diabetes, diphtheria, conjunctivitis, snake bite, scorpion bite, etc

An unblinded, randomised phase II study of platinum-based chemotherapy with vitamin B12 and folic acid supplementation in the treatment of lung cancer with plasma homocysteine blood levels as a biomarker of severe neutropenic toxicity

BACKGROUND: Vitamin B12 and folic acid (referred to as vitamin supplementation) improves the toxicity profile of pemetrexed containing regimens. Low baseline vitamin B12 and folate levels are reflected in a raised total homocysteine level (HC). Studies have suggested that pretreatment HC levels predict neutropenia toxicity. We have tested supplementation with vitamin B12 and folate in non-pemetrexed platinum-based regimens to decrease treatment-related toxicity and looked for a correlation between toxicity and change in homocysteine levels. PATIENT AND METHOD: Eighty-three patients with advanced lung cancer and malignant mesothelioma were randomly assigned to receive platinum-based chemotherapy with (arm A) or without (arm B) vitamin B12 and folic acid supplementation. The primary end point was grade 3/4 neutropenia and death within 30 days of treatment. Secondary end points included quality of life, overall survival (OS) and the relationship between baseline and post supplementation HC levels and toxicity. RESULTS: In the intention-to-treat population, no significant difference was seen between the two groups with respect to chemotherapy-induced grade 3/4 neutropenia and death within 30 days of chemotherapy (36% vs 37%; p=0.966, emesis (2% vs 6%; p=0.9) or OS (12.3 months vs 7 months; p=0.41). There was no significant difference in survival rates by baseline HC level (p=0.9). Decrease in HC with vitamin supplementation was less frequent than expected. High baseline HC levels decreased with vitamin supplementation in only 9/36 (25%) patients (successful supplementation). Post hoc analysis showed that patients in arm A who were successfully supplemented (9/36=25%) had less neutropenic toxicity (0% vs 69%; p=0.02) compared to unsupplemented patients. CONCLUSIONS: The addition of vitamin B12 and folic acid to platinum-containing regimens did not overall improve the toxicity, quality of life or OS. Rates of grade 3/4 neutropenia at 36/37% was as predicted. Further studies to increase the rate of successful supplementation and to further test the biomarker potential of post supplementation HC levels in predicting chemotherapy-induced neutropenia in platinum-based chemotherapy are warranted. TRIAL REGISTRATION NUMBER: EudracCT 2005-002736-10 ISRCTN8734355

A prospective observational study of on-treatment plasma homocysteine levels as a biomarker of toxicity, depression and vitamin supplementation lead-in time pre pemetrexed, in patients with non-small cell lung cancer and malignant mesothelioma

OBJECTIVES: Vitamin supplementation reduces pemetrexed toxicity. Raised plasma homocysteine reflects deficiency in vitamin B12 and folate, and is suppressed by supplementation. This observational study of 112 patients receiving pemetrexed-based chemotherapy assessed homocysteine levels after 3 weeks of vitamin supplementation, hypothesising high levels would correlate with ongoing deficiency, thus increased toxicity. MATERIAL AND METHODS: Primary endpoint was the composite of proportion of patients with treatment delay/ dose reduction/ drug change or hospitalisation during the first six weeks of chemotherapy, comparing those with normal plasma homocysteine (successfully supplemented, SS) and those with high homocysteine (unsuccessfully supplemented, USS). Secondary endpoints included toxicity and analyses for depression. Post-hoc analysis examined correlation between interval of vitamin and folate supplementation and pemetrexed on primary endpoint and grade 3-4 toxicities. RESULTS: Eighty-four patients (84%) were successfully supplemented (SS group). The proportion of patients undergoing a treatment delay/ dose reduction/ drug change or hospitalisation in SS group was 44.0% (95% confidence interval [CI] 33.2%-55.3%) and in USS group was 18.8% (95% CI 4.0%-45.6%) (p = 0.09). Twelve percent of patients gave a past history of depression however 66% of patients had an on study Hospital Anxiety and Depression (HAD) score of >7. Supplementation status was not associated with depression. The median overall survival (OS) was 11.8 months (95% CI 8.6-16.5) in the SS group and 8.8 months (95% CI 6.6-16.2) in the US group (p = 0.5). The number of days (<7 or ≥ 7 days) between vitamin B12 and folate initiation and pemetrexed administration, had no effect on the primary endpoint and grade 3-4 toxicities. CONCLUSION: On-treatment homocysteine levels were not a biomarker of toxicity or depression. Standard vitamin supplementation is adequate in the majority of patients receiving pemetrexed. High HAD score were noted in this population giving an opportunity for mental health intervention. The lead-in time for vitamin supplementation can be short

Real-world outcomes in thoracic cancer patients with severe Acute respiratory syndrome Coronavirus 2 (COVID-19): Single UK institution experience.

BACKGROUND: UK COVID-19 mortality rates are amongst the highest globally. Controversy exists on the vulnerability of thoracic cancer patients. We describe the characteristics and sequelae of patients with thoracic cancer treated at a UK cancer centre infected with COVID-19. METHODS: Patients undergoing care for thoracic cancer diagnosed with COVID-19 (RT-PCR/radiology/clinically) between March-June 2020 were included. Data were extracted from patient records. RESULTS: Thirty-two patients were included: 14 (43%) diagnosed by RT-PCR, 18 (57%) by radiology and/or convincing symptoms. 88% had advanced thoracic malignancies. Eleven of 14 (79%) patients diagnosed by RT-PCR and 12 of 18 (56%) patients diagnosed by radiology/clinically were hospitalised, of which four (29%) and 2 (11%) patients required high-dependency/intensive care respectively. Three (21%) patients diagnosed by RT-PCR and 2 (11%) patients diagnosed by radiology/clinically required non-invasive ventilation; none were intubated. Complications included pneumonia and sepsis (43% and 14% respectively in patients diagnosed by RT-PCR; 17% and 11% respectively in patients diagnosed by radiology/clinically). In patients receiving active cancer treatment, therapy was delayed/ceased in 10/12 (83%) and 7/11 (64%) patients diagnosed by RT-PCR and radiology/clinically respectively. Nine (28%) patients died; all were smokers. Median time from symptom onset to death was 7 days (range 3-37). CONCLUSIONS: The immediate morbidity from COVID-19 is high in thoracic cancer patients. Hospitalisation and treatment interruption rates were high. Improved risk-stratification models for UK cancer patients are urgently needed to guide safe cancer-care delivery without compromising efficacy

Efficient Genotyping of KRAS Mutant Non-Small Cell Lung Cancer Using a Multiplexed Droplet Digital PCR Approach

© 2015 Pender et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Droplet digital PCR (ddPCR) can be used to detect low frequency mutations in oncogenedriven lung cancer. The range of KRAS point mutations observed in NSCLC necessitates a multiplex approach to efficient mutation detection in circulating DNA. Here we report the design and optimisation of three discriminatory ddPCR multiplex assays investigating nine different KRAS mutations using PrimePCRddPCRMutation Assays and the Bio-Rad QX100 system. Together these mutations account for 95% of the nucleotide changes found in KRAS in human cancer. Multiplex reactions were optimised on genomic DNA extracted from KRAS mutant cell lines and tested on DNA extracted from fixed tumour tissue from a cohort of lung cancer patients without prior knowledge of the specific KRAS genotype. The multiplex ddPCR assays had a limit of detection of better than 1 mutant KRAS molecule in 2,000 wild-type KRAS molecules, which compared favourably with a limit of detection of 1 in 50 for next generation sequencing and 1 in 10 for Sanger sequencing. Multiplex ddPCR assays thus provide a highly efficient methodology to identify KRAS mutations in lung adenocarcinoma

Development of molecularly targeted agents and immunotherapies in small cell lung cancer.

Small cell lung cancer (SCLC) is a smoking-induced malignancy with multiple toxin-associated mutations, which accounts for 15% of all lung cancers. It remains a clinical challenge with a rapid doubling time, early dissemination and poor prognosis. Despite multiple clinical trials in SCLC, platinum-based chemotherapy remains the mainstay of treatment in the first line advanced disease setting; good initial responses are nevertheless inevitably followed by disease relapse and survival ultimately remains poor. There are currently no molecularly targeted agents licenced for use in SCLC. Advances in sequencing the cancer genome and other high-throughput profiling technologies have identified aberrant pathways and mechanisms implicated in SCLC development and progression. Novel anti-tumour therapeutics that impact these putative targets are now being developed and investigated in SCLC. In this review, we discuss novel anti-tumour agents assessed in SCLC with reference to the complex molecular mechanisms implicated in SCLC development and progression. We focus on novel DNA damage response inhibitors, immune checkpoint modulators and antibody-drug conjugates that have shown promise in SCLC, and which may potentially transform treatment strategies in this disease. Finally, we envision the future management of SCLC and propose a biomarker-driven translational treatment paradigm for SCLC that incorporates next generation sequencing studies with patient tumours, circulating plasma DNA and functional imaging. Such modern strategies have the potential to transform the management and improve patient outcomes in SCLC

Focused molecular analysis of small cell lung cancer: feasibility in routine clinical practice

© 2015 Abdelraouf et al.Background: There is an urgent need to identify molecular signatures in small cell lung cancer (SCLC) that may select patients who are likely to respond to molecularly targeted therapies. In this study, we investigate the feasibility of undertaking focused molecular analyses on routine diagnostic biopsies in patients with SCLC. Methods: A series of histopathologically confirmed formalin-fixed, paraffin-embedded SCLC specimens were analysed for epidermal growth factor receptors (EGFR), KRAS, NRAS and BRAF mutations, ALK gene rearrangements and MET amplification. EGFR and KRAS mutation testing was evaluated using real time polymerase chain reaction (RT-PCR cobas®), BRAF and NRAS mutations using multiplex PCR and capillary electrophoresis-single strand conformation analysis, and ALK and MET aberrations with fluorescent in situ hybridization. All genetic aberrations detected were validated independently. Results: A total of 105 patients diagnosed with SCLC between July 1990 and September 2006 were included. 60 (57 %) patients had suitable tumour tissue for molecular testing. 25 patients were successfully evaluated for all six pre-defined molecular aberrations. Eleven patients failed all molecular analysis. No mutations in EGFR, KRAS and NRAS were detected, and no ALK gene rearrangements or MET gene amplifications were identified. A V600E substitution in BRAF was detected in a Caucasian male smoker diagnosed with SCLC with squamoid and glandular features. Conclusion: The paucity of patients with sufficient tumour tissue, quality of DNA extracted and low frequency of aberrations detected indicate that alternative molecular characterisation approaches are necessary, such as the use of circulating plasma DNA in patients with SCLC