Comparison of Mammographic Changes Across Three Different Fractionation Schedules for Early-Stage Breast Cancer

Fixed and random effect selections in generalized linear mixed models

Generalized linear mixed models are commonly used to describe relationships between correlated responses and covariates in medical research. In this paper, we propose a simple and easily implementable regularized estimation approach to select both fixed and random effects in generalized linear mixed model. Specifically, we propose to construct and optimize the objective functions using the confidence distributions of model parameters, as opposed to using the observed data likelihood functions, to perform effect selections. Two estimation methods are developed. The first one is to use the joint confidence distribution of model parameters to perform simultaneous fixed and random effect selections. The second method is to use the marginal confidence distributions of model parameters to perform the selections of fixed and random effects separately. With a proper choice of regularization parameters in the adaptive LASSO framework, we show the consistency and oracle properties of the proposed regularized estimators. Simulation studies have been conducted to assess the performance of the proposed estimators and demonstrate computational efficiency. Our method has also been applied to two longitudinal cancer studies to identify demographic and clinical factors associated with patient health outcomes after cancer therapies.

Quantification of breast lymphoedema following conservative breast cancer treatment: a systematic review

PURPOSE

Breast lymphoedema is a possible side effect of breast conserving surgery, but it is poorly understood. This is due, in part, to difficulty assessing the breast. This systematic review described outcome measures that quantify breast lymphoedema signs and symptoms and evaluated the measurement properties for these outcome measures.

METHOD

Seven databases were searched using terms in four categories: breast cancer, lymphoedema and oedema, clinician reported (ClinROM) and patient reported outcome measures (PROM) and psychometric and measurement properties. Two reviewers independently reviewed studies and completed quality assessments. The Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) methodology was used for studies including measurement property evidence.

RESULTS

Fifty-six papers were included with thirteen questionnaires, eight patient-reported rating scales, seven physical measures, seven clinician-rating scales and four imaging techniques used to quantify breast lymphoedema. Based on COSMIN methodology, one ClinROM had sufficient reliability, ultrasound measuring dermal thickness. Tissue dielectric constant (TDC) measuring local tissue water had promising reliability. Four questionnaires had sufficient content validity (BLYSS, BLSQ, BrEQ and LYMQOL-Breast).

CONCLUSIONS

Ultrasound is recommended to reliably assess breast lymphoedema signs. No PROM can be recommended with confidence, but BLYSS, BLSQ, BrEQ and LYMQOL-Breast are promising. Further research is recommended to improve evidence of measurement properties for outcome measures.

IMPLICATIONS FOR CANCER SURVIVORS

There are many approaches to assess breast lymphoedema, but currently, only ultrasound can be recommended for use, with others, such as TDC and questionnaires, showing promise. Further research is required for all approaches to improve evidence of measurement properties.

Time to development and imaging features of new calcifications in the treated breast after breast-conserving therapy

OBJECTIVE

The purpose of our study was to analyze the time to development, malignancy rate, location, and mammographic features of new calcifications in the treated breast after breast-conserving therapy (BCT).

MATERIALS AND METHODS

In this HIPAA-complaint, IRB-approved retrospective study, we reviewed the records of patients treated with BCT at our institution with breast-conserving surgery performed between January 1, 2009 and December 31, 2010. A total of 735 breasts in 732 women were included in our study cohort. Factors analyzed included rate of development of new calcifications, malignancy rate of new calcifications, the time between completion of radiation therapy and development of new calcifications, imaging features of new calcifications, and location of the new calcifications in relation to the primary malignancy.

RESULTS

During follow-up, new calcifications developed in 155 of the 735 treated breasts (21.1%) and 155 of the 732 women (21.2%). After excluding two cases that were lost to follow-up, the malignancy rate of new calcifications was 5.2% (8/153; 95% CI: 2.3% to 10.0%). The median time to development of the benign calcifications was 27 months (range, 2 to 91 months) and of the malignant calcifications was 41 months (range, 11 to 57 months). Of the 20 (13.1%) cases of new calcifications categorized as BI-RADS 3 (probably benign), all were benign on follow-up (19 cases) or on biopsy (1 case). Of the 51 BI-RADS 4 (suspicious) cases, 8 (16%) were biopsy-proven malignant. The malignancy rate was the highest in fine pleomorphic 100% (1/1), followed by amorphous 17%, (5/29), coarse heterogeneous 8% (2/26) and typically benign 0 (0/97) calcifications (p < 0.0001). The malignancy rate was 1.5% (2/137) for new calcifications within the lumpectomy site vs. 37.5% (6/16) for new calcifications outside the lumpectomy site (p < 0.0001) and was 3.4% (5/147) for new calcifications at or within the same quadrant as the lumpectomy site vs. 50.0% (3/6) for new calcifications in a different quadrant from the lumpectomy site (p=0.002).

CONCLUSION

Most new calcifications that developed in the treated breast after BCT were benign. Evaluation of morphology and distribution of those calcifications is imperative. New calcifications in the treated breast outside the lumpectomy site are more likely to be malignant and should be viewed with greater suspicion. Benign calcifications developed earlier than malignant calcifications, but the time courses overlapped.

Modern radiation techniques in early stage breast cancer for the breast radiologist

Partial breast irradiation (PBI) and ultra-hypofractionated whole breast irradiation (uWBI) are contemporary alternatives to conventional and standard hypofractionated whole breast irradiation (WBI), which shorten treatment from 3 to 6 weeks to 1-2 weeks for select patients. PBI and accelerated PBI (APBI) can be delivered with external beam radiation (3D conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT)), intraoperative radiation (IORT), or brachytherapy. These new radiation techniques offer the advantage of convenience and lower cost, which ultimately improves access to care. Globally, the COVID 19 pandemic has accelerated APBI/PBI and ultra-hypofractionated regimens into routine practice for carefully selected patients. Recent long-term data from randomized controlled trials (RCTs) have demonstrated these techniques are safe and effective in suitable patients demonstrating equivalent or improved local recurrence, acute/late toxicity, and cosmesis. PBI and APBI should be limited to low risk unifocal invasive ductal carcinoma and ductal carcinoma in situ with tumor size < 2 cm, clear margins (≥2 mm), ER+, and negative nodes. Based on the results from UK Fast-Forward and UK FAST ultra-hypofractionated breast radiation can be safely employed for early stage node negative patients, but is not yet considered an international standard of care. In this review, authors will appraise recent data for these shorter course radiation treatment regimens, as well as, considerations for breast radiologists including surveillance imaging and radiographic findings.