voluntary-breath-hold-technique-for-reducing-heart-dose-left-breast

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these ...

Royal Marsden NHS Foundation Trust

Chemotherapy for lung cancer.

The ductal approach to breast cancer, encompassing nipple aspiration, ductal lavage and duct endoscopy, allows assessment of breast ductal epithelial cells and their local microenvironment in a graded process of increasing invasiveness. Samples of ductal epithelial cells sufficient for cytological diagnosis may be safely collected, titres of individual proteins showing variation with breast cancer status may be measured, and abnormal pathology within the breast ducts may be directly visualized. Identification of surrogate molecular markers may facilitate early breast cancer detection, in conjunction with cytological assessment, and be useful for individual prediction of breast cancer risk and assessment of treatment response. However, the sensitivity and specificity of the ductal approach require further evaluation. The small quantities of nipple aspiration fluid available for analysis, and difficulties identifying and cannulating ducts remain important limitations of these techniques.

Ductal approaches to assessment and management of women at high risk for developing breast cancer.

In this study, the differential gene expression changes following radiation-induced DNA damage in healthy cells from BRCA1/BRCA1 mutation carriers have been compared with controls using high-density microarray technology. We aimed to establish if BRCA1/BRCA2 mutation carriers could be distinguished from noncarriers based on expression profiling of normal cells.

Accurate prediction of BRCA1 and BRCA2 heterozygous genotype using expression profiling after induced DNA damage.

Female BRCA gene mutation carriers are at increased risk for developing breast cancer. Ductal lavage is a novel method for sampling breast ductal fluid, providing epithelial cells for cytologic assessment and a source of free DNA for molecular analyses. Loss of heterozygosity (LOH) at the BRCA loci in ductal lavage fluid is a potential biomarker of breast cancer risk. The LOH rate was measured at the BRCA1/2 loci and compared with that at a control locus (APC) using free DNA from the ductal lavage fluid of BRCA carriers and predictive test negative controls. We evaluated the reproducibility of these analyses. Free DNA sufficient for PCR amplification was obtained from 33 ductal lavage samples of 17 healthy women of known BRCA status (14 BRCA carriers and 3 controls). LOH rates of 36.4% to 56.3% at the BRCA1 locus and 45% to 61.5% at the BRCA2 locus were found among BRCA carriers. The LOH rate at the APC locus was lower (18.5%). The interaliquot reproducibility for the D17S855 marker of the BRCA1 locus was 66.7%. Intraaliquot reproducibility was 90%. Although we successfully isolated sufficient free DNA from ductal lavage fluid for PCR amplification, the degree of reproducibility of these LOH studies raises questions about the robustness of this technique as a risk assessment tool in the evaluation of high-risk women. Further studies are required to evaluate the specificity and predictive value of LOH in ductal lavage fluid for breast cancer development.

Loss of heterozygosity at the BRCA1 and BRCA2 loci detected in ductal lavage fluid from BRCA gene mutation carriers and controls.

A proteomic approach to nipple aspiration fluid (NAF) has been used in a number of studies comparing women with breast cancer and healthy women. However, to make useful comparisons between women with breast cancer and healthy women it is necessary to establish whether there is physiological variation in the proteomic profiles of NAF. The purpose of this study was, for the first time, to examine how the proteomic profile of NAF using surface-enhanced laser desorption ionisation time-of-flight mass spectrometry varies across the menstrual cycle in healthy pre-menopausal women. Twelve women were recruited and nipple aspiration was carried out weekly from both breasts of each subject for two menstrual cycles. Matching serum samples for luteinising hormone, follicle stimulating hormone and oestradiol were obtained at each aspiration attempt. Statistically significant peaks were found for three healthy volunteers (p < 0.05). However, the peaks that varied across the menstrual cycle were different from one healthy volunteer to another and the differences were small compared with the large variation in proteomic profiles between healthy volunteers. This study provides proof of concept that the NAF proteomic profile does not vary substantially during the menstrual cycle and that therefore it is valid to compare NAF profiles from pre-menopausal women that have been taken at different stages in the menstrual cycle.

Proteomic analysis of nipple aspirate fluid throughout the menstrual cycle in healthy pre-menopausal women.

Female germline BRCA gene mutation carriers are at increased risk for developing breast cancer. The purpose of our study was to establish whether healthy BRCA mutation carriers demonstrate an increased frequency of aberrant gene promoter hypermethylation in ductal lavage (DL) fluid, compared with predictive genetic test negative controls, that might serve as a surrogate marker of BRCA1/2 mutation status and/or breast cancer risk.

Gene promoter hypermethylation in ductal lavage fluid from healthy BRCA gene mutation carriers and mutation-negative controls.

There is conflicting evidence as to whether individuals who are heterozygous for germ-line BRCA1 or BRCA2 mutations have an altered phenotypic cellular response to irradiation. To investigate this, chromosome breakage and apoptotic response were measured after irradiation in peripheral blood lymphocytes from 26 BRCA1 and 18 BRCA2 mutation carriers without diagnosed breast cancer, and 38 unaffected age, ethnically and sex-matched controls. To assess the role of BRCA1 and BRCA2 in homologous recombination, an S phase enrichment chromosome breakage assay was used. BrdUrd incorporation studies allowed verification of the correct experimental settings. We found that BRCA1 mutation carriers without cancer had increased chromosome breaks as well as breaks and gaps per cell post irradiation using the classical G2 assay (p = 0.01 and 0.004, respectively) and the S phase enrichment assay (p = 0.01 and 0.01, respectively) compared to age-matched unaffected controls. BRCA2 mutation carriers without cancer had increased breaks as well as breaks and gaps per cell post irradiation using the S phase enrichment assay (p = 0.045 and 0.012, respectively). No difference was detected using the G2 assay (p = 0.88 and 0.40 respectively). BRCA1 and BRCA2 mutation carriers had normal cell cycle kinetics and apoptotic response to irradiation compared to age-matched controls. Our results show a demonstrable impairment in irradiation induced DNA repair in women with heterozygous germline BRCA1 and BRCA2 mutations prior to being diagnosed with breast cancer.

Lymphocyte radiosensitivity in BRCA1 and BRCA2 mutation carriers and implications for breast cancer susceptibility.

To determine whether voluntary deep-inspiratory breath-hold (v_DIBH) and deep-inspiratory breath-hold with the active breathing coordinator™ (ABC_DIBH) in patients undergoing left breast radiotherapy are comparable in terms of normal-tissue sparing, positional reproducibility and feasibility of delivery.

The UK HeartSpare Study: randomised evaluation of voluntary deep-inspiratory breath-hold in women undergoing breast radiotherapy.

To document the apparent diffusion coefficient (ADC) of fibroglandular breast tissue in women at high-risk of developing breast cancer and investigate the relationship between ADC and breast density.

Imogen Locke

Department of Radiotherapy

Royal Marsden NHS Foundation Trust

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Imogen Locke

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Royal Marsden NHS Foundation Trust

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Department of Radiotherapy