Tumori Journal Abstract Book - October 2020 - 119

E - Breast Cancer

119

With the rising trend in delaying pregnancy later in life, the
topics of pregnancy and lactation following BC diagnosis
become increasingly more current. Oncological pregnancy
is beset with specific worries about recurrence and women
may believe that their milk transfers oncologic disease to
the baby. BC women might face a unique set of emotional
and physical factors during the perinatal period that might
also have an impact on their decision and ability to breastfeed. Breastfeeding after BC diagnosis and treatments
could also be difficult because of the lack of specific support and guidelines. Our study aimedto explore feeding
practices in mothers with a history of BC. Specifically, we
explored the relationship between different feeding methods and mood states of BC survivors compared to women
without a past cancer diagnosis.
Material and methods: At three months after childbirth,
28 women with a history of BC (clinical sample) and 30

Clinical sample
Control sample
Total

Count
% within sample
% within feeding methods
% of Total
Count
% within sample
% within feeding methods
% of Total
Count
% within sample
% within feeding methods
% of Total

without a past oncological diagnosis (control sample) were
asked for socio-demographics and clinical data, information about feeding practices and to complete the Profile of
Mood States (POMS) questionnaire.
Results: Feeding practices of both samples are illustrated in Table 1. Women with past BC breastfeed significantly less than women of control sample (χ2=13.39;
p<.001) and tend to feel more confused (F=3.01;
p=.06). Instead, breastfeeding women without a cancer
diagnosis feel more vigorous (F=5.91; p<.05) than BC
mothers.
Conclusions: Puerperae with a BC history are faced with
unique challenges when they attempt breastfeeding.
These findings may have a wide range of clinical implications which could be useful in order to develop tailored
treatment, interventions and specific guidelines for this
population.

Breastfeeding

Formula

Mixed method

Total

4
14,3%
21,1%
6,9%
15
50,0%
78,9%
25,9%
19
32,8%
100,0%
32,8%

17
60,7%
77,3%
29,3%
5
16,7%
22,7%
8,6%
22
37,9%
100,0%
37,9%

7
25,0%
41,2%
12,1%
10
33,3%
58,8%
17,2%
17
29,3%
100,0%
29,3%

28
100,0%
48,3%
48,3%
30
100,0%
51,7%
51,7%
58
100,0%
100,0%
100,0%

Crosstab samples*feeding methods

E38
Ki67 expression and CDK4/6i
activity: an emerging role for
PIK3CA mutations in metastatic
breast cancer patients
Del Re M.1, Lorenzini G.2, Crucitta S.2, De Angelis C.2, Cucchiara
F.2, Diodati L.2, Cavallero D.2, Bargagna I.2, Cinacchi P.2, Fratini B.2,
Salvadori B.2, Fontana A.2, Danesi R.2
1
Azienda Ospedaliero Universitaria Pisana, Pisa; 2Azienda Ospedaliero
Universitaria di Pisa, Pisa

Background: Preclinical studies indicate that alterations
of PIK3/AKT/mTOR pathway may be correlated with
resistance to CDK4/6 inhibitors (CDK4/6i) in breast cancer (BC) cells and that PI3K inhibitors could prevent
resistance to CDK4/6i [Abreu H MT, et al. Cancer Res
2016;76:2301]. For these compelling evidences the present study evaluated the impact of PI3K mutations on
treatment outcome in metastatic BC (mBC) patients (pts)

receiving CDK4/6i in association with hormonal therapy
as per approved indication.
Methods: Thirty pts treated with palbociclib (n=26) or
ribociclib (n=4) plus hormonal therapy were enrolled.
Plasma samples were obtained prior to CDK4/6i treatment
and circulating free DNA (cfDNA) extraction was performed using the QIAamp Circulating Nucleic Acid Kit
(Qiagen). PI3K mutations (C420R, E542K, E545A,
E545D, E545G, E545K, Q546E, Q546R, H1047L,
H1047R, H1047Y) were analysed on cfDNA using a
QX100 ddPCR (Bio-Rad).
Results: In pts with (n=12) vs. without (n=18) PI3K mutations, PFS was significantly shorter (5.9 vs 11.6 months,
p=0.01, respectively). The univariate and multivariate
analysis comparing PFS and clinically relevant data (i.e.,
age, metastasis, previous lines of hormonal or chemotherapy), confirmed PI3K as the only biomarker significantly
associated to PFS (p=0.01). A significant correlation was
observed between Ki67 expression in primary lesions and
PI3Kstatus. Higher Ki67 levels were associated with PI3K

Tumori Journal Abstract Book - October 2020

Table of Contents for the Digital Edition of Tumori Journal Abstract Book - October 2020