PURPOSE: BMI affects breast cancer risk and prognosis. In contrast to cytotoxic chemotherapy, CDK4/6 inhibitors are given at a fixed dose, irrespective of BMI or weight. This preplanned analysis of the global randomized PALLAS trial investigates the impact of BMI on the side-effect profile, treatment adherence, and efficacy of palbociclib. METHODS: Patients were categorized at baseline according to WHO BMI categories. Neutropenia rates were assessed with univariable and multivariable logistic regression. Time to early discontinuation of palbociclib was analyzed with Fine and Gray competing risk models. Unstratified Cox models were used to investigate the association between BMI category and time to invasive disease-free survival (iDFS). 95% CIs were derived. RESULTS: Of 5,698 patients included in this analysis, 68 (1.2%) were underweight, 2,082 (36.5%) normal weight, 1,818 (31.9%) overweight, and 1,730 (30.4%) obese at baseline. In the palbociclib arm, higher BMI was associated with a significant decrease in neutropenia (unadjusted odds ratio for 1-unit change, 0.93; 95% CI, 0.91 to 0.94; adjusted for age, race ethnicity, region, chemotherapy use, and Eastern Cooperative Oncology Group at baseline, 0.93; 95% CI, 0.92 to 0.95). This translated into a significant decrease in treatment discontinuation rate with higher BMI (adjusted hazard ratio [HR] for 10-unit change, 0.75; 95% CI, 0.67 to 0.83). There was no significant improvement in iDFS with the addition of palbociclib to ET in any weight category (normal weight HR, 0.84; 95% CI, 0.63 to 1.12; overweight HR, 1.10; 95% CI, 0.82 to 1.49; and obese HR, 0.95; 95% CI, 0.69 to 1.30) in this analysis early in follow-up (31 months). CONCLUSION: This preplanned analysis of the PALLAS trial demonstrates a significant impact of BMI on side effects, dose reductions, early treatment discontinuation, and relative dose intensity. Additional long-term follow-up will further evaluate whether BMI ultimately affects outcome.

Background: Residual fibroglandular breast tissue (RFGT) following a mastectomy has been claimed to be associated with the occurrence of an in-breast local recurrence (IBLR) or new primary tumor (NP). Yet, scientific evidence proving this assumption is lacking. The primary aim of the study was to verify whether RFGT following a mastectomy is a risk factor for an IBLR or NP. Methods: This retrospective analysis included all patients that underwent a mastectomy and were followed up at the Department of Obstetrics and Gynecology of the Medical University of Vienna between 01.01.2015 and 26.02.2020. RFGT volume (assessed on magnetic resonance imaging) was correlated with the prevalence of an IBLR and a NP. Results: A total of 105 patients (126 breasts) following a therapeutic mastectomy were included. After a mean follow-up of 46.0 months an IBLR had occurred in 17 breasts and a NP in 1 breast. A significant difference in RFGT volume was observed between the disease-free cohort and the subgroup with an IBLR or NP (p = .017). A RFGT volume of ≥ 1153 mm³ increased the risk by the factor 3.57 [95%CI 1.27; 10.03]. Conclusions: RFGT volume is associated with an increased risk for an IBLR or NP.

Summary: Background: This study investigated the impact of curative breast cancer surgery on patient satisfaction concerning cosmetic results and quality of life (QoL).Methods: In this study 61 participants completed questionnaires to evaluate their QoL and patient satisfaction with cosmetic results following breast cancer surgery. Cosmetic outcomes were evaluated by the breast surgeon and an independent breast specialist using the Harris scale and the breast analyzing tool (BAT).Results: Of the participants 71% completed all 4 follow-up visits, 38 (62%) patients received breast-conserving therapy (BCT) and 23 (38%) received a mastectomy. Surgery-associated complications arose in 2.6% of the patients who received BCT and 17.4% of patients who received a mastectomy. No significant differences in QoL between BCT patients and mastectomy patients were observed immediately after surgery, or after 6 and 12 months. Breast asymmetry, measured using the BAT score, and QoL scores were worst immediately after surgery. The surgeon rated the cosmetic results as better compared to the independent breast expert (p = 0.001). Furthermore, patients aged over 60 years old were less satisfied with the cosmetic outcome compared to younger patients at the time of discharge (p = 0.024). Patients who received a mastectomy were less satisfied when the resected volume was higher.Conclusion: Patient satisfaction was lowest immediately after surgery but improved during the following months, despite continued breast asymmetry. For mastectomy patients, a lower resected volume led to a higher satisfaction with cosmetic results. Satisfaction is subjective and cannot be determined from the esthetic satisfaction of the surgeon or using an objective tool measuring breast asymmetry.

Background/Objectives: Genetic testing in Human Epidermal Growth Factor Receptor 2-negative (HER2−) metastatic breast cancer (mBC) is necessary to enable optimal treatment choices including poly(ADP-ribose)polymerase inhibitors (PARPis). The present study evaluated the implementation of genetic testing in a real-world setting to reveal and subsequently allow targeting of potential inadequacies and risk factors for low testing frequency. Methods: We performed a retrospective analysis including HER2− mBC patients treated at a single academic center starting from 10 April 2019 (date of European Medicines Agency (EMA) approval of Olaparib for germline breast cancer gene mutant (gBRCAm) HER2− mBC) to 7 September 2021. The primary objective of the study was to evaluate the rate of HER2− mBC patients that were recommended to undergo genetic testing by the multidisciplinary tumor board (MTB). The secondary objective was to identify factors that were associated with a higher likelihood of having undergone genetic testing. Results: In total, 47.6% (109 of 229) of HER2− mBC patients had been recommended to undergo genetic testing by the MTB. Of these informed patients, 89.0% (97 of 109) underwent genetic testing, of which 11.6% (11 of 95) had a germline BRCA mutation (gBRCAmut) and were eligible for PARPi treatment. In multivariate analysis, younger age (p-value: 0.0007), hormone receptor positive (HR+)/HER2− subtype (p-value < 0.0001) and positive family history for breast and ovarian cancer (p-value: 0.0001) were significantly associated with the performance of genetic counseling. Conclusions: The present study demonstrated low genetic counseling rates of HER2− mBC patients, especially in individuals without specific risk factors for hereditary breast cancer. Informed patients showed a high willingness to undergo genetic testing. Genetic testing revealed targetable mutations in over 10% of tested patients.

Background/Objectives: The optimal management of bone-only progressive disease (PD) in metastatic breast cancer remains unclear for several reasons. Radiologic diagnosis of bone PD is complicated by the lack of standardized response assessment criteria, unspecific morphologic changes of the bone, and flare-up phenomena. Furthermore, bone-only disease and oligoprogression have been associated with favorable prognosis challenging a change of systemic treatment with the consequence of limited treatment options in the future. Additionally, bone-only metastatic disease is frequently excluded from clinical trials resulting in scarce data. This study aimed to assess the therapeutic management and outcome of bone-only PD in metastatic breast cancer patients in a real-world academic setting. Methods: A retrospective analysis of all breast cancer patients with bone metastases (BMs) and at least one event of radiologic evidence of bone-only PD and/or the occurrence of a skeletal-related event (SRE) who were treated at the Department of Obstetrics and Gynecology of the Medical University of Vienna, Austria, between 1 January 2015 and 14 December 2021 was performed. In cases of multiple bone-only PD events in one patient only the first event was considered for analysis. All cases with PD in organs other than the bone were excluded. The primary outcome of the study was to assess therapeutic measures of bone-only PD. Secondary outcomes were the time from bone-only PD to next bone PD (TTF BD) and overall survival (OS; time from bone-only PD to death). Predictors of TTF BD and OS were assessed as exploratory outcomes. Results: Out of a total of 308 breast cancer patients with BMs, 57 had at least one event of bone-only PD. In 59.3% of bone-only PD cases the systemic treatment was continued with a numerically higher rate if multiple metastatic sites were present (71.4% vs. 46.4%). In most bone-only PD events the bone-targeted agent (BTA) was continued (94.5%), independent of the total number of metastatic sites. In 24.1% radiotherapy (RT) was administered with similar rates between patients with bone-only and multiple metastatic sites. The median TTF BD was 6.3 months. In multivariate analysis no predictor for TTF BD could be identified including change of systemic treatment, RT, previous BTA treatment duration, number of previous treatment lines for the metastatic disease, number of metastatic sites and previous or current SRE. Median OS was 21.8 months. Number of previous treatment lines for the metastatic setting was significantly associated with OS with shorter OS in the more advanced disease stage (p-value = 0.0208). Conclusions: Systemic and BTA treatment were continued in the majority of bone-only PD cases. In 24.1% RT was administered. No association between change of systemic therapy and improved oncologic outcome was found. The study’s results are hypothesis-generating in terms of whether change of systemic treatment should be performed restrictively to avoid limited treatment options in the future. Similarly, radiotherapy did not ameliorate prognosis.

Background/Objectives: Prepectoral implant positioning has become an established option for implant-based breast reconstruction (IBBR) following a mastectomy. The impact of the implant position on the selected implant pocket thickness and the presence of residual fibroglandular breast tissue (RFGT) has yet to be determined. Methods: Patients following an IBBR between 2013 and 2017 at the Department of Obstetrics and Gynecology, Medical University of Vienna, Austria, and with an available archived breast MRI were identified through a retrospective chart review. Breast MRIs were reevaluated using Osirix. Results: A total of 14 patients (23 breasts) with prepectoral and 30 patients (45 breasts) with retropectoral breast implants were included. A reduction in the postoperative skin and subcutaneous tissue thickness compared to preoperative measurements was found in both cohorts, reaching statistical significance in the prepectoral subgroup (medially p = 0.001, laterally p = 0.044). Significantly higher RFGT volumes were present in the prepectoral compared to the retropectoral cohort (p = 0.026). This difference remained significant after accounting for unevenly distributed subgroup characteristics. In the retropectoral cohort, a significant reduction in the postoperative compared to preoperative thickness of the pectoralis major muscle (PMM) was observed (p < 0.001). The PMM only accounted for 30% of the implant pocket covering the breast implant. Conclusions: Prepectoral IBBR was associated with higher volumes of RFGT and a significant reduction in postoperative skin and subcutaneous tissue thickness compared with retropectoral reconstruction. These findings suggest that implant position may influence the quality of the implant pocket and underscore the importance of careful surgical planning and meticulous dissection. Further studies are warranted to determine the clinical significance of these findings with regard to oncologic and reconstructive outcomes. In retropectoral reconstruction, marked postoperative atrophy of the PMM was observed, raising questions about the long-term advantages of this reconstructive approach.