Breast and Prostate Cancer: Lessons to Be Shared

Applications of T1 and T2 relaxation time calculation in tissue differentiation and cancer diagnostics-a systematic literature review

INTRODUCTION

The purpose of this review was to summarize current applications of non-contrast-enhanced quantitative magnetic resonance imaging (qMRI) in tissue differentiation, considering healthy tissues as well as comparisons of malignant and benign samples. The analysis concentrates mainly on the epithelium and epithelial breast tissue, especially breast cancer.

METHODS

A systematic review has been performed based on current recommendations by publishers and foundations. An exhaustive overview of currently used techniques and their potential in medical sciences was obtained by creating a search strategy and explicit inclusion and exclusion criteria.

RESULTS AND DISCUSSION

PubMed and Elsevier (Scopus & Science Direct) search was narrowed down to studies reporting T1 or T2 values of human tissues, resulting in 404 initial candidates, out of which roughly 20% were found relevant and fitting the review criteria. The nervous system, especially the brain, and connective tissue such as cartilage were the most frequently analyzed, while the breast remained one of the most uncommon subjects of studies. There was little agreement between published T1 or T2 values, and methodologies and experimental setups differed strongly. Few contemporary (after 2000) resources have been identified that were dedicated to studying the relaxation times of tissues and their diagnostic applications. Most publications concentrate on recommended diagnostic standards, for example, breast acquisition of T1- or T2-weighted images using gadolinium-based contrast agents. Not enough data is available yet to decide how repeatable or reliable analysis of relaxation times is in diagnostics, so it remains mainly a research topic. So far, qMRI might be recommended as a diagnostic help providing general insight into the nature of lesions (benign vs. malignant). However, additional means are generally necessary to differentiate between specific lesion types.

Patient views and correlates of radiotherapy omission in a population-based sample of older women with favorable-prognosis breast cancer

BACKGROUND

The omission of radiotherapy (RT) after lumpectomy is a reasonable option for many older women with favorable-prognosis breast cancer. In the current study, we sought to evaluate patient perspectives regarding decision making about RT.

METHODS

Women aged 65 to 79 years with AJCC 7th edition stage I and II breast cancer who were reported to the Georgia and Los Angeles County Surveillance, Epidemiology, and End Results registries were surveyed (response rate, 70%) regarding RT decisions, the rationale for omitting RT, decision-making values, and understanding of disease recurrence risk. We also surveyed their corresponding surgeons (response rate, 77%). Patient characteristics associated with the omission of RT were evaluated using multilevel, multivariable logistic regression, accounting for patient clustering within surgeons.

RESULTS

Of 999 patients, 135 omitted RT (14%). Older age, lower tumor grade, and having estrogen receptor-positive disease each were found to be strongly associated with omission of RT in multivariable analyses, whereas the number of comorbidities was not. Non-English speakers were more likely to omit RT (adjusted odds ratio, 5.9; 95% confidence interval, 1.4-24.5). The most commonly reported reasons for RT omission were that a physician advised the patient that it was not needed (54% of patients who omitted RT) and patient choice (41%). Risk of local disease recurrence was overestimated by all patients: by approximately 2-fold among those who omitted RT and by approximately 8-fold among those who received RT. The risk of distant disease recurrence was overestimated by approximately 3-fold on average.

CONCLUSIONS

To some extent, decisions regarding RT omission are appropriately influenced by patient age, tumor grade, and estrogen receptor status, but do not appear to be optimally tailored according to competing comorbidities. Many women who are candidates for RT omission overestimate their risk of disease recurrence. Cancer 2018;124:2714-2723. © 2018 American Cancer Society.