Tumori Journal Abstract Book - October 2020 - 103

E - Breast Cancer

103

in all subgroup of low-risk luminal MBC pts. Moreover,
ET after ET-CDKi represents a viable option. However,
prospective randomized trials are needed to investigate
optimal sequence strategy.

Table 1. First-line therapy - PFS1 (p<0.001).
Treatment

95%CI

ET vs. ET-CDKi
CT vs. ET-CDKi

1.74
1.89

0.001
<0.001

1.28-2.42
1.35-2.67

Table 2. First-line therapy - OS (p= 0.133).
Treatment

95%CI

ET vs. ET-CDKi
CT vs. ET-CDKi

1.23
1.51

0.486
0.169

0.68-2.22
0.83-2.75

E09
Sarcopenic obesity phenotype
is associated with vertebral
fracture prevalence in women
with early breast cancer
undergoing adjuvant aromatase
inhibitor therapy
Monteverdi S.1, Pedersini R.1, Gallo F.2, Maffezzoni F.3, Dalla Volta
A.1, Di Mauro P.1, Turla A.1, Vassalli L.1, Ardine M.1, Formenti A.M.4,
Simoncini E.L.1, Giustina A.4, Maroldi R.3, Amoroso V.1, Berruti A.1
1

Università degli studi di Brescia, ASST-Spedali Civili di Brescia, Oncologia
Medica, Brescia; 2Università di Genova, Section of Biostatistics, Department
of Health Sciences, Genova; 3Università degli studi di Brescia, ASST-Spedali
Civili di Brescia, Radiologia, Brescia; 4Università San Raffaele Vita e Salute,
Ospedale San Raffaele, Endocrinologia, Milano

Background Aromatase inhibitors (AIs) are widely used
as adjuvant therapy in postmenopausal women with endocrine-sensitive early breast cancer (BC). AIs induce bone
mineral density (BMD) loss and increased fracture risk.
Our group previously showed that high fat body mass
(FBM), as measured by dual-energy X-ray absorptiometry
(DXA), is an independent factor associated with a higher
proportion of morphometric vertebral fractures (VFs) in
BC patients undergoing AI therapy. In the present study,
we explored the role of lean body mass (LBM) as well as
the interaction of LBM with FBM in predicting the occurrence of VFs in BC patients who were either AI-naïve or
AI-treated in the adjuvant setting.
Patients and methods Six hundred eighty-four early BC
patients were selected to take part to this cross-sectional
study. This initial number was restricted to 480 women,
240 AI-naïve and 240 AI-treated, after propensity score
adjustment, applied to control for potential confounders.
Each patient underwent a DXA scan at baseline, assessing

BMD, FBM, and LBM. VFs were assessed independently
by two of the authors using a quantitative morphometric
analysis of DXA images. We used logistic regression analyses to explore the associations between baseline characteristics and the VF prevalence and the interaction between
LBM, FBM and AI therapy on the VF prevalence.
Results The proportion of VFs was significantly higher
in AI-treated than in AI-naïve patients, 26% and 16%
respectively (OR, 1.90; 95% CI, 1.29 to 2.78; p=0.0196).
No association was found between BMD and VFs in
AI-treated patients. LBM alone was not associated with
bone fragility fractures. Conversely, in patients having a
sarcopenic obesity phenotype (FBM > and LBM < the
median value), we observed 4.8 times increased chance
of having a prevalent VF in AI-treated (prevalence,
48%;OR, 4.81; 95% CI, 1.82 to 13.21) as compared with
AI-naïve women (prevalence, 16%). The highest proportion of VFs in the AI-naïve population was observed in
the subgroup with both LBM and FBM < the median
value (prevalence, 27%).
Conclusions: These data favour the notion that bone fragility in women under AI therapy has different pathophysiology than postmenopausal osteoporosis. Our data suggest
that the assessment of the body composition parameters
LBM and FBM using DXA may add valuable information
when analyzing fracture risk in early BC patients undergoing AI therapy. This observation is new and deserves further investigation.

E10
First- and second-line treatment
strategies for hormone-receptor
(HR)-positive HER2-negative
metastatic breast cancer: the
PLBC study
Basile D.1, Gerratana L.2, Pelizzari G.2, Franceschin G.2, Buriolla
S.2, Corvaja C.2, Bertoli E.2, Palmero L.2, Zara D.2, Alberti M.2, Da
Ros L.3, Mansutti M.4, Spazzapan S.3, Bolzonello S.3, Bonotto M.4,
Minisini A.M.4, Cinausero M.4, Fasola G.4
1
Università degli Studi di Udine, Dipartimento di Area Medica; Dipartimento
di Oncologia Medica a Prevenzione Oncologica, CRO, IRCCS, Aviano, Udine;
2
Dipartimento di Area Medica, Università degli Studi di Udine, Udine;
3
Dipartimento di Oncologia Medica e Prevenzione Oncologica, Centro di
Riferimento Oncologico, IRCCS, Aviano, Udine; 4Dipartimento di Oncologia
Medica, Azienda Sanitaria Universitaria Friuli Centrale di Udine, Udine

Background: Endocrine therapy (ET) plus cyclin-dependent kinases 4/6 inhibitors (CDK4/6i) represents the standard treatment for HR-positive HER2-negative metastatic
breast cancer (MBC). However, prospective head-to-head
comparisons are still lacking for many 1° line (L) options,
and it is still crucial to define the best treatment strategy
for both 1° and 2°L. This study aims to describe real-world
treatment outcomes for luminal MBC.

Tumori Journal Abstract Book - October 2020

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