ABSTRACTS

P15 Impact of pandemic Covid19 on Multidisciplinary Tumor Board in Breast Cancer around the world

Introduction: Pandemic Covid19 had an important impact on health care systems worldwide. Multidisciplinary tumour boards (MTB) are considered essential to provide the best care to cancer patients. The aim of this study is to evaluate the impact of Covid19 in Breast Cancer (BC) MTB worldwide.

P18 Retrospective analysis of the clinical presentation, treatment and outcome of angiosarcoma in a sarcoma referral center

Objective: Angiosarcoma (AS) is a rare, aggressive subtype of soft tissue sarcoma (STS). Treatment requires a multidisciplinary approach and should preferably be carried out in reference centers. We performed an in-depth analysis of patient characteristics, treatments and prognostic factors in patients (pts) with AS treated at the University Hospitals Leuven (Belgium).

P17 Efficacy of palliative metronomic chemotherapy: A retrospective analysis of the 15 years experience at CHU UCL Namur site Godinne

Background: Metronomic chemotherapy consists of low-dose oral chemotherapy given continuously. The antitumor activity is supposed to be due to antiangiogenic and immunomodulation effects. This retrospective analysis was done to evaluate the benefit-risk balance of this treatment in palliative setting for unselected metastatic cancer patients.

P09 Developing and evaluating a participatory arts programme for cancer patients and their caregivers

Introduction: Cancer patients, survivors and caregivers often encounter severe distress, having signifi cant consequences to wellbeing, functionality and physical health. This study developed and evaluated a participatory arts programme to determine if such could help to improve the wellbeing of cancer patients and their caregivers.

Treatment algorithm ER positive HER2 negative Advanced Breast Cancer

After the major advances seen in the field of HER2 positive disease, fortunately, we have now also much more treatment options available for estrogen receptor positive HER2 negative advanced breast cancer. The better understanding of the mechanisms of resistance to endocrine therapy has allowed a much more rational treatment approach. Chemotherapy is only the preferred treatment option for patients with extensive symptomatic visceral disease. Almost all of our patients receive now an endocrine therapy based approach for several lines of treatment for advanced breast cancer. As endocrine therapy alone is not highly effective most of our patients are good candidates for combined therapy approaches with targeted agents. In the frst-line setting for advanced disease, the CDK4/6 inhibitors are now the targeted agents of choice because of the excellent safety profle in addition to the rapid and pronounced antitumoral effect. Nevertheless, many questions remain unanswered today. How should we treat specific subgroups of patients such as older patients, patients with some co-morbidities, patients with visceral disease or patients presenting bone only disease? Are biomarkers available to select the most appropriate treatments? Is progression-free survival a valid endpoint of clinical trials or do we need overall survival data? What is the optimal sequence? Should we use the best drugs frst? What should be the next line therapy in this case? During my presentation I will summarize the data available today and give you my personal view concerning these questions.

Practice changing topics in breast cancer

The most important new paradigm in the field of systemic breast cancer treatment is the concept of treatment intensifcation with trastuzumab emtansine in case of poor response to neoadjuvant chemotherapy in HER2+ disease. In the phase 3 KATHERINE study, 1,486 patients who did not achieve pathological complete response after standard neoadjuvant chemotherapy in combination with trastuzumab +/- pertuzumab were randomly assigned to 14 cycles of trastuzumab or 14 cycles of trastuzumab emtansine. The patients treated with the latter treatment had a 50% reduction in the risk of invasive breast cancer recurrence or death, with a probability of being free of invasive cancer at 3 years of 88.3% in the trastuzumab emtansine arm and 77.0% in the trastuzumab arm. Neoadjuvant treatment is now de facto the standard of care for HER2+ disease, except for patients who are candidates for the Tolaney regimen. In hormone receptor positive metastatic disease, further studies have positioned the CDK4/6 inhibitors palbociclib, ribociclib and abemaciclib as the treatment of choice in first or second line. After PALOMA-3 showed a trend towards an improved OS of the same magnitude as the improvement shown for PFS, concerns about accelerated post-treatment progression are receding.

In the same disease setting, the SOLAR-1 study showed a PFS benefit of adding alpelisib (a PI3K inhibitor) to fulvestrant in patients with tumors harboring a PIK3CA mutation (median PFS of 11.0 vs 5.7 months). The identification of PIK3CA mutations on the tumor and/or cfDNA will soon become a standard in this context. Finally, the IMPASSION130 study, a phase 3 study in which 451 first line metastatic triple negative breast cancer patients were randomly assigned to nab-paclitaxel + atezolizumab or nab-paclitaxel + placebo, showed a modest PFS benefit in the ITT population, with a median PFS of 7.2 months in the immunotherapy arm and 5.5 months in the placebo arm. Although the statistical plan did not allow for the analysis of this endpoint, it was reported that in the subgroup of patients whose tumor was PD-L1 positive, the median OS in the atezolizumab arm reached 25.0 months, vs 15.5 months in the placebo arm (no p-value).

Practice changing topics in Sarcoma

“Soft tissue sarcomas represent 75% of all sarcomas and constitute a group of more than 50 different histological subtypes, with an even greater number of molecular subtypes.

Localized STSs are generally treated by surgery followed, or preceded, by radiotherapy and according to criteria linked with the risk of local recurrence.

Metastatic STSs are principally treated by systemic treatments such as chemotherapy and targeted drugs. The most important drugs used are doxorubicin, ifosfamide, dacarbazine, gemcitabine/docetaxel, eribulin and trabectedin; but also, pazopanib.

The place of localized treatments (surgery, radiotherapy, radiofrequency, …) in this setting is reserved for oligometastatic disease.

A multidisciplinary approach is mandatory, with centralization of all cases in reference centers, as early as at the time of the clinical diagnosis of a suspected sarcoma. This “centralized” approach, for this rare and complex 7