Passive laser power stabilization via an optical spring.

Metrology experiments can be limited by the noise produced by the laser involved via small fluctuations in the laser's power or frequency. Typically, active power stabilization schemes consisting of an in-loop sensor and a feedback control loop are employed. Those schemes are fundamentally limited by shot noise coupling at the in-loop sensor. In this Letter, we propose to use the optical spring effect to passively stabilize the classical power fluctuations of a laser beam. In a proof of principle experiment, we show that the relative power noise of the laser is stabilized from approximately 2 × 10-5 Hz-1/2 to a minimum value of 1.6 × 10-7 Hz-1/2, corresponding to the power noise reduction by a factor of 125. The bandwidth at which stabilization occurs ranges from 400 Hz to 100 kHz. The work reported in this Letter further paves the way for high power laser stability techniques which could be implemented in optomechanical experiments and in gravitational wave detectors.

An observational study investigating failure of primary endocrine therapy for operable breast cancer in the elderly.

BACKGROUND: Elderly patients are more likely to have oestrogen receptor positive cancers that can be treated without surgery with primary endocrine therapy (PET). Few studies have sought to identify predictors of failure of PET and so the aim of this study was to evaluate treatment failures in elderly breast cancer patients treated with PET and to determine predictors of failure. METHODS: A retrospective observational study was performed on consecutive patients with ER-positive early stage breast cancer treated with PET between 2005 and 2015 in the three breast units in the North East of England. The primary outcome measure was treatment failure and secondary outcome measure was disease progression. RESULTS: 488 patients were included with mean follow-up 31 months (SD 23). Overall, 206 patients were still alive with their disease controlled at the end of follow-up, 219 had died with their disease controlled and 63 (12%) experienced treatment failure. Younger age [SHR 0.96 (95% CI 0.94-0.99) p 0.013], larger tumours [SHR 1.03 (1.01-1.06) p 0.015], grade 3 cancers [SHR 3.58 (1.93-6.63) p < 0.001] and axillary lymph node metastases [SHR 1.93 (1.06-3.52) p 0.030] were all independent predictors of treatment failure. Disease progression was reported in 86 (17.6%) of patients. CONCLUSIONS: This is the largest retrospective series evaluating PET treatment failure. Clear predictors of failure have been identified, which can be used to facilitate treatment decision making. These results support previous analyses, further validating our results.

Patients electing to have PET rather than surgery for operable breast cancer are a high risk of treatment failure.

BACKGROUND: Primary endocrine therapy (PET) is a treatment option for elderly patients with ER-positive breast cancer enabling frail patients to avoid surgery. As a long-term treatment option, it has been shown to be inferior to surgery in controlling local disease. Decision-making in these patients is crucial in avoiding treatment failure. We examined the influence of decision-making on outcomes of PET failure as a secondary analysis as part of a large observational study. METHODS: Consecutive patients treated with PET between 2005 and 2015 for operable breast cancers were included in a retrospective observational study in 3 breast centres in the North-East. Treatment decision processes were examined by case note review and outcomes of treatment success or failure recorded. RESULTS: 488 patients were included with mean follow-up of 31 months. Overall 63 (12%) experienced treatment failure. 227 (46.6%) were given a choice between surgery and PET at diagnosis. Logistic regression identified older age [OR 0.94 (0.91-0.96) p < 0.001] and reduced mobility [OR 0.6 (0.37-0.97) p 0.036] to be less likely offered surgery. Those offered surgery were more likely to experience treatment failure with PET [SHR 1.78 (1.05-3.02) p 0.033]. CONCLUSIONS: Despite a low failure rate in our series (literature failure rates vary between 12 and 85%), these results suggest that those actively offered a choice between surgery and PET are at greater risk of failure when choosing PET.

A randomised controlled trial of Pre-Operative Oncotype DX testing in early-stage breast cancer (PRE-DX study) - Study protocol.

BACKGROUND: The Oncotype DX® Breast Recurrence Score assay can guide recommendations made to patients with oestrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) breast cancer regarding post-surgery adjuvant therapy. Standard practice is to order the test in the post-operative setting on a specimen from the excised invasive carcinoma. However, it has been shown to be technically possible to perform the test on the diagnostic core biopsy. By testing the diagnostic core biopsy in the pre-operative setting, the wait for excised invasive carcinoma Recurrence Score results could be reduced allowing patients to be more accurately counselled regarding their treatment pathway sooner with any adjuvant treatment recommendations expedited. This would allow for more efficient streaming of follow up appointments. The aim of this study is to compare the impact on the patient treatment pathway of performing the Oncotype DX® test on the diagnostic core biopsy pre-operatively (intervention) as opposed to the excised invasive carcinoma (control). METHODS AND ANALYSIS: This parallel group randomised controlled trial aims to recruit 330 newly diagnosed patients with grade 2 or grade 3, ER+, HER2-, invasive intermediate risk early-stage breast cancer. Participants will be randomised 2:1 to the preoperative testing of the diagnostic core biopsy compared to the post-operative testing of the excision specimen. The primary endpoint is number of clinical touchpoints between treating team and patient from initial approach until offer and prescription of the first adjuvant treatment. Secondary endpoints include time from diagnosis to offer and prescription of the first adjuvant treatment, patient-reported anxiety scores and health cost impact analysis collected at baseline, following the post-operative clinic and following the offer of adjuvant treatment, and number of alterations in treatment sequence from original planned surgical treatment to neoadjuvant therapy. TRIAL REGISTRATION: The study was registered on ISRCTN (ISRCTN14337451) on the 16th August 2022.

Development of the HT&Me intervention to support women with breast cancer to adhere to adjuvant endocrine therapy and improve quality of life.

BACKGROUND: Breast cancer is the most common cancer in women worldwide. Approximately 80% of breast cancers are oestrogen receptor positive (ER+). Patients treated surgically are usually recommended adjuvant endocrine therapy (AET) for 5-10 years. AET significantly reduces recurrence, but up to 50% of women do not take it as prescribed. OBJECTIVE: To co-design and develop an intervention to support AET adherence and improve health-related quality-of-life (QoL) in women with breast cancer. METHODS: Design and development of the HT&Me intervention took a person-based approach and was guided by the Medical Research Council framework for complex interventions, based on evidence and underpinned by theory. Literature reviews, behavioural analysis, and extensive key stakeholder involvement informed 'guiding principles' and the intervention logic model. Using co-design principles, a prototype intervention was developed and refined. RESULTS: The blended tailored HT&Me intervention supports women to self-manage their AET. It comprises initial and follow-up consultations with a trained nurse, supported with an animation video, a web-app and ongoing motivational 'nudge' messages. It addresses perceptual (e.g. doubts about necessity, treatment concerns) and practical (e.g. forgetting) barriers to adherence and provides information, support and behaviour change techniques to improve QoL. Iterative patient feedback maximised feasibility, acceptability, and likelihood of maintaining adherence; health professional feedback maximised likelihood of scalability. CONCLUSIONS: HT&Me has been systematically and rigorously developed to promote AET adherence and improve QoL, and is complemented with a logic model documenting hypothesized mechanisms of action. An ongoing feasibility trial will inform a future randomised control trial of effectiveness and cost-effectiveness.

Radioactive seed localization compared with wire-guided localization of non-palpable breast carcinoma in breast conservation surgery- the first experience in the United Kingdom.

OBJECTIVE: In the UK, guidewires have traditionally been used for localization of non-palpable breast lesions in patients undergoing breast conservation surgery (BCS). Radioactive seed localization (RSL) using Iodine-125 seeds is an alternative localization method and involves inserting a titanium capsule, containing radioactive Iodine-125, into the breast lesion. We aim to demonstrate feasibility of RSL compared with guidewire-localization (GWL) for BCS in the UK. METHODS: Data were collected on 100 patients with non-palpable unifocal invasive carcinoma of the breast undergoing GWL WLE prior to the introduction of RSL and the first 100 patients treated with RSL WLE. Statistical comparisons were made using Χ2-squared analysis or unpaired two-sample t-test. Significance was determined to be at p ≤ 0.05. RESULTS: Mean total tumour size was 19.44 mm (range: 5-55) in the GWL group and 18.61 mm (range: 3.8-59) in the RSL group (p = 0.548), while mean total specimen excision weight was significantly lower in the RSL group; 31.55 g (range: 4.5-112) vs 37.42 g (range: 7.8-157.1) (p = 0.018). Although 15 patients had inadequate surgical resection margins in the GWL group compared the 13 in the RSL group (15 vs 13%, respectively, p = 0.684), 10 of the patients in the GWL group had invasive carcinoma present resulting in at least one positive margin compared with only 3 patients in the RSL group (10 vs 3%, respectively, p = 0.045). CONCLUSION: In this study, RSL is shown to be non-inferior to the use of GWL for non-palpable carcinoma in patients undergoing BCS and we suggest that it could be introduced successfully in other breast units. Advances in knowledge: Here we have demonstrated the use of RSL localization results in significant lower weight resection specimens of breast carcinoma when compared with a matched group using GWL, without any significant differences in oncological outcome between the groups.