Risk of subsequent in situ and invasive lesions after a primary diagnosis of ductal carcinoma in situ with follow-up time up to 28 years

Full text

Conclusions: The interim results of the MICRA trial demonstrate that 8
ultrasound-guided core-biopsies of the breast in patients with excellent
response on MRI after NST are not accurate enough in identifying patients
with pCR for omission of surgery.
Conflict of interest:
Other Substantive Relationships:
This research was funded by Pink Ribbon (NL) and The Innovatiefonds
Zorgverzekaars (NL).
CLINICAL SCIENCE SYMPOSIUM
Implants
13 Oral
Safety of pre-pectoral breast reconstruction followed by post
mastectomy radiotherapy
M. Bernini
1
, I. Meattini
2
, S. Sordi
1
, C. Tommasi
1
, L. Orzalesi
1
, V. Scotti
2
,
I. Desideri
2
, J. Nori Cucchiari
3
, V. Vezzosi
4
, S. Bianchi
4
, L. Livi
2
.
1
Azienda
Ospedaliero Universitaria Careggi, University of Florence, Breast Surgery,
Oncology Department, Florence, Italy;
2
Azienda Ospedaliero Universitaria
Careggi, University of Florence, Radiation Oncology, Breast Unit, Oncology
Department, Florence, Italy;
3
Azienda Ospedaliero Universitaria Careggi,
University of Florence, Breast Radiology, Radiology Department, Florence,
Italy;
4
Azienda Ospedaliero Universitaria Careggi, University of Florence,
Pathology Department, Florence, Italy
Background: Implant-based breast reconstruction (IBBR) after mastectomy
either with TE or DTI in pre-pectoral position has been widely accepted. The
pre-pec breast reconstruction, in fact, spares muscles, preserving the natural
anatomy and reduces post-operative pain. Moreover, the pre-pec approach is
associated to a decreased risk of capsular contracture and animation
deformities. An increasing number of women, who undergo IBBR, will require
post mastectomy radiotherapy (PMRT), since the meta-analysis of Early
Breast Cancer Trialists’Collaborative Group (EBCTCG) confirmed a
significant reduction of both local recurrence and breast cancer mortality in
patients with pathological nodal involvement and locally advanced cancer.
Methods: Between January 2013 and December 2018, 521 pre-pectoral
IBBR were performed and prospectively recorded at University of Florence
Careggi teaching hospital, Italy. Two hundred and eight were two-stage pre-
pectoral TE IBBR and 313 cases were DTI. In both cases, a titanium-coated
polypropylene synthetic mesh (Ti-LOOP Bra, pfm medical Cologne,
Germany) was used to cover the prosthesis and create a pre-pectoral
pocket in a subcutaneous plane. Seventy three cases underwent PMRT,
which was performed 10 to 20 weeks after surgery and in between first and
second surgical stage in case of TE reconstruction. In case of adjuvant
chemotherapy, PMRT was delivered at the end of medical treatment. We
analysed short term complications of PMRT and reconstruction failure rate in
pre-pectoral IBBR. In case of DTI we observed complications whithin 6
months after PMRT. In case of TE we considered complications both after
PMRT and 6 months after second stage procedure.
Results: The most frequent complication was seroma, which occurred in 8
cases (10.9%). Infection rate was 5.4% (4 cases) and in only two cases
(2.7%) the implant was removed and replaced with a retro-pectoral TE: in
both cases the patients were active smokers and with BMI > 30.
Patients
characteristics
Total 73 TE 40 DTI 33
Age, mean (range) 53.3 (28–75) 52.5 (28–70) 54.0 (29–75)
BMI, mean (range) 23.5 (18–36) 22.8 (18–35) 23.9(19–36)
Active smokers (%) 9 (12.3%) 5 (12.5%) 4 (12.1%)
Previous breast
surgery (%)
4 (5.4%) 3 (7.5%) 1 (3.0%)
Comorbidities (%) 6 (8.2%) 4 (10%) 2 (6.1%)
Surgical
complications
Total 73 TE 40 DTI 33
Infection (%) 4 (5.4%) 1 (2.5%) 3 (9.1%)
Seroma (%) 8 (10.9%) 3 (7.5%) 5 (15.1%)
Failure (%) 2 (2.7%) 1 (2.5%) 1 (3.0%)
Conclusions: This is the most numerous series of PMRT inpre-pec IBBR
and the only one with a synthetic mesh. Currently, there are few studies, only
with ADM, that analyzed pre-pectoral DTI and TE in the se tting of PMRT. Our
prospective series showed that PMRT in the setting of pre-pec IBBR with
synthetic mesh is surgically safe, except in not-fit patients and active
smokers, who shouldn’t be candidate for pre-pectoral reconstruction overall.
No conflict of interest.
PROFFERED PAPER SESSION
Are your breasts still at risk?
14 Oral
Risk of subsequent in situ and invasive lesions after a primary
diagnosis of ductal carcinoma in situ with follow-up time up to 28 years
M. Van Seijen
1
, E.H. Lips
1
, L.P. Fu
1
, E. Groen
1
, F. van Duijnhoven
2
,
A. Thompson
3
, P. Elkhuizen
4
, M.K. Schmidt
1,5
, J. Wesseling
6,7
,
M. Schaapveld
8
, Grand Challenge Precision Team.
1
Netherlands Cancer
Institute, Antoni van Leeuwenhoek Hospital, Molecular Pathology,
Amsterdam, Netherlands;
2
Netherlands Cancer Institute, Antoni van
Leeuwenhoek Hospital, Surgery, Amsterdam, Netherlands;
3
Baylor College
of Medicine, Dan L Duncan Comprehensive Cancer Centre, Houston, USA;
4
Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital,
Radiotherapy, Amsterdam, Netherlands;
5
Leiden University Medical Center,
Clinical Genetics, Leiden, Netherlands;
6
Netherlands Cancer Institute,
Antoni van Leeuwenhoek Hospital, Pathology, Amsterdam, Netherlands;
7
Leiden University Medical Center, Pathology, Leiden, Netherlands;
8
Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital,
Psychosocial research and epidemiology, Amsterdam, Netherlands
Background: Ductal Carcinoma in situ (DCIS) is considered a potential
precursor of invasive breast cancer (BC) and is treated by mastectomy or
breast conserving surgery (BCS) often supplemented with radiotherapy
(RT). This study aimed to assess the long-term risk of ipsilateral subsequent
in situ and invasive lesions after a diagnosis of primary DCIS and the
association with initial DCIS treatment.
Material and Methods: The study cohort comprised all women diagnosed
with DCIS between 1989 and 2004 in the Netherlands. Subsequent
ipsilateral in situ (iDCIS) and/or invasive breast (iBC) lesions, and death
were derived by linkage with the Netherlands Cancer Registry (NCR) and the
nationwide registry of histo- and cytopathology in the Netherlands (PALGA).
Information was complete until 2017. Cumulative incidence following
mastectomy, BCS only and BCS supplemented with RT were assessed,
with death as competing risk. Associations of DCIS treatment with risk of
subsequent ipsilateral invasive and in situ lesions were studied in uni- and
multivariable Cox models.
Results: Our study cohort comprised 10,051 women with a median follow-
up of 15.7 years. After 20 years of follow-up cumulative incidence of iBC was
2.0% after mastectomy, 11.6% after BCS+RTand 17.5% after BCS only; 20-
year cumulative incidence of iDCIS was 6.1% after BCS+RT and 12.3% after
BCS only. In the first five years of follow-up, patients treated with BCS had a
higher risk of developing subsequent iDCIS (HR 3.3; 95%CI 2.5–4.2) and
iBC (HR 4.1; 95%CI 3.0–5.7) compared to those who also received RT.
However, this risk difference between treatment with or without RT after BCS
stabilized after ten years of follow-up (HR > 10 years for BCS+RT versus
BCS only 0.7; (95%CI 0.3–1.3 for iDCIS and HR 1.1; 95%CI 0.9–1.4 for iBC,
respectively). Influence of age, grade and method of detection will be
available at EBCC.
Conclusions: In the first five years following diagnosis, patients treated
with BCSonly had a higher risk of developing a subsequent in situ or invasive
lesion than patients treated with BCS+RT. The favorable effect of
radiotherapy for prognosis of BCS treated patients disappeared after ten
years of follow-up.
Acknowledgement: This work is supported by Cancer Research UK and
by the Dutch Cancer Society (ref. C38317/A24043).
No conflict of interest.
European Journal of Cancer 138, Suppl. 1 (2020) S3–S17 S10
Abstracts, EBCC 12 Proffered Paper Session

15 Oral
Differences in breast cancer risk after a benign breast disease
according to the screening type
J. Louro
1,2
, M. Román
1,2
, M. Posso
1,2
, C. Vidal
3
, M. Prieto
4
, F. Saladié
5
,
M. Baré
6,7
,M.Sa
́nchez
8
, M.J. Quintana
9
, X. Bargalló
10
, J. Ferrer
11
,
L. Peñalva
12
, M. Sala
1,2
, X. Castells
1,2
.
1
Hospital del Mar Medical Research
Institute, Epidemiology, Barcelona, Spain;
2
Research Network on Health
Services in Chronic Diseases REDISSEC, Catalonia Node, Barcelona,
Spain;
3
Catalan Institute of Oncology ICO, Cancer Prevention and Control,
Barcelona, Spain;
4
Direction General of Public Health, Breast Cancer
Screening Program, Principalty of Asturias, Spain;
5
Breast Cancer
Screening Program of Tarragona, Research and Prevention of Cancer,
Tarragona, Spain;
6
Parc Taulı́University Hospital, Clinical Epidemiology and
Cancer Screening, Sabadell, Spain;
7
Research Network on Health Services
in Chronic Diseases REDISSEC, Catalonia Node, Sabadell, Spain;
8
Direction General of Public Health, Breast Cancer Screening Program,
Cantabria, Spain;
9
Hospital de la Santa Creu i Sant Pau, Epidemiology,
Barcelona, Spain;
10
Hospital Clinic, Preventive Medicine and Epidemiology,
Barcelona, Spain;
11
Hospital de Santa Caterina, Radiology, Girona, Spain;
12
Vallés Oriental Breast Cancer Early Detection Program, Breast Cancer
Early Detection Program, Granollers, Spain
Background: Benign breast diseases (BBD) are related with an increased
risk of developing breast cancer and have been proposed as a risk factor to
personalize breast cancer screening strategies. This risk varies significantly
depending on the pathological characteristics of the BBD. Our aim was to
explore the differences in the risk of breast cancer across BBD types
diagnosed at prevalent or incident screen in a population-based mammog-
raphy program.
Materials and Methods: We conducted a retrospective cohort study with
data from 629,087 women who underwent 2,327,384 mammographic
examinations at the long-standing population-based screening program in
Spain between 1995 and 2015, and followed up until 2017. Each BBD was
classified according to the screening type as prevalent and incident, and
according to the BBD type as non-proliferative and proliferative. We used
partly conditional Cox hazard regression to estimate the adjusted hazard
ratios (aHR) and we plotted the adjusted survival curves.
Results: During a mean 7.8 years of follow-up, 9,431 breast cancers and
9,184 benign breast diseases were diagnosed in the study population. There
was a strong association between presence of a BBD and the risk of
subsequent breast cancer. Compared with those without a BBD, women with
incident BBD (aHR: 2.67) had a higher risk than those with prevalent BBD
(aHR: 1.87). In addition, women with proliferative BBD had an increased risk
than with those with non-proliferative BBD (aHR: 3.28 vs 1.96). The highest
risk was found in women with an incident proliferative BBD (aHR: 3.92).
There was no interaction between screening type and BBD type (p-value
0.83).
Conclusion: We found that classifying benign breast diseases according
to screening type predicts the risk of subsequent breast cancer independ-
ently to the type of BBD. This information could be useful to design
personalized breast cancer screening strategies aimed at improving the
effectiveness of breast cancer screening.
No conflict of interest.
Table 1 (abstract 14): Cumulative incidence, assessed by competing risk analysis, and cox regression analysis in women treated for DCIS
Event Treatment
Cumulative
incidence
(%)
Hazard ratio
(95%CI)
5 year 10 year 20 year 0–5 year 5–10 year
>10 year - end
follow-up
iBC +
iDCIS
BCS RT+ 4.7 9.2 17.4 1.0
BCS only 15.4 23.0 28.7 3.6 (3.0–4.5) 2.1(1.7–2.6) 1.0 (0.8–1.3)
iDCIS BCS RT+ 3.0 4.3 6.1 1.0
BCS only 9.0 11.5 12.3 3.3 (2.5–4.2) 2.2 (1.5–3.3) 0.7 (0.3–1.3)
iBC BCS RT+ 1.8 5.1 11.6 1.0
BCS only 6.7 12.2 17.5 4.1 (3.0–5.7) 2.0 (1.6–2.6) 1.1 (0.9–1.4)
Mastectomy 0.7 1.2 2.0 0.4 (0.2–0.6) 0.1 (0.1–0.2) 0.1 (0.1–0.2)
Table (abstract 15): Age and year adjusted hazard ratio for each classification and for the combined effect
Women –year
Breast Cancer
cases
Crude rate (×1000
wy)* aHR (95%CI)**
Screening type
No benign breast disease 4,847,709 9,184 1.89 Ref
Prevalent 34,040 121 3.55 1.87 (1.57–2.24)
Incident 21,691 126 5.81 2.67 (2.24–3.19)
BBD type
No benign breast disease 4,847,709 9,184 1.89 Ref
Nonproliferative 44,528 177 3.98 1.96 (1.68–2.27)
Proliferative 11,203 70 6.25 3.28 (2.60–4.15)
Combined effect between
screening and BBD type
No benign breast disease 4,847,709 9,184 1.89 Ref
Prevalent nonproliferative 27,053 85 3.14 1.63 (1.32–2.02)
Prevalent proliferative 6,987 36 5.15 2.85 (2.06–3.94)
Incident nonproliferative 17,475 92 5.26 2.39 (1.95–2.94)
Incident proliferative 4,216 34 8.06 3.92 (2.80–5.48)
aHR: adjusted Hazard Ratio, 95%CI: 95% confidence interval.
*Crude rate per 1000 women year.
**Adjusted by age and year of screening.
European Journal of Cancer 138, Suppl. 1 (2020) S3–S17 S11
Abstracts, EBCC 12Proffered Paper Session