This study retrospectively analyzed exclusive radiotherapy (ERT), surgery, and both as local regional therapies (LRT) for denovo metastatic breast cancer patients. It found that both ERT and surgery plus radiotherapy (BMT) were associated with improved overall survival compared to no LRT or surgery alone. ERT showed similar overall survival as BMT and could be an acceptable alternative to avoid invasive surgeries. However, the study had limitations as a retrospective analysis and larger prospective studies are still needed to provide stronger evidence and guidelines on the role of LRT like ERT for metastatic breast cancer.

1. DR. ADITYA SINGLA

2. RATIONALE
• In the past decade, there has been improvement in the OS of
Metastatic breast cancer(MBC).
• Denovo metastatic breast cancer patients have better survival
than the ones who metastasize after therapy.
• Concept of MBC as a chronic disease is gradually emerging
• Techniques of EBRT has improved a lot in the last few decades
and has proved to be as effective as Surgery
• RT could be an alternative to patients who are medically
inoperable or those who are unwilling for surgery

3. INTRODUCTION
• Patients presenting with upfront metastatic disease are
labeled as denovo metastatic breast cancer(dnMBC).
• In the past, several meta analysis have confirmed that surgical
resection may offer an survival advantage of 30-40% in MBC
• Retrospective and bias was extensive.
• Only 3 prospective trials have assessed LRT in MBC and
evaluated only surgery± RT.
• Though they failed to give any concrete guidelines and also
Exclusive RT(ERT) arm was not studied
• In this study ERT has been analyzed retrospectively as an
alternative to surgery by studying the impact of ERT/Sx/both
on OS and PFS

4. INCLUSION CRITERIA
• All patients were enrolled after minimum 1 yr of controlled
systemic disease
• All patients received systemic chemotherapy
• Majority patients received RT to chest wall and nodes
• 30-50Gy (at least 4 weeks)
• Hypo fractionation/conventional fractionation
• 60% had tumor boost
• Surgery - TMAC/BCS

5. EXCLUSION CRITERIA
• Those who progress within 1 year of receiving systemic
chemotherapy
• Patients receiving LRT at the time of diagnosis or before the
diagnosis of MBC
• Male breast cancer

6. DESIGN
• Retrospective and comparative study was done on the
database from Epidemiological Strategy and Medical
Economics(ESME).
• MBC patients were included from18 cancer centers between
Jan 2008 to Dec 2014
• Data base was gathered from medical records, hospital data
and pharmacy records
• Data base was built in compliance with French and European
guidelines
• Analysis was approved by independent ethics committee

7. DESIGN

8. ENDPOINTS
• PRIMARY OBJECTIVE-
 Study impact on OS of each LRT
 Comparing ERT, exclusive surgery, both
• SECONDARY OBJECTIVE-
 Impact of each LRT on PFS defined as the time from initial
diagnosis to first local recurrence/distant mets/death

9. VARIABLES
• Hormone receptor positive if ER/PR + if ≥ 10%
• HER 2neu status as per ASCO guidelines
• Visceral metastasis include CNS
• Non visceral include LN, skin, bone, pleura
• No. of metastatic sites ≤ 2 or > 2
• LRT include ERT/ only surgery(Bcs/Mastectomy)/ BMT

10. STATISTICAL ANALYSIS
• Qualitative variables were expressed as numbers and
percentage
• Quantitative variables were expressed as median and range
• Chi-Square and Fischer’s exact tests were used for qualitative
variables
• Kruskal –Wallis test for quantitative analysis
• All survival times were calculated from diagnosis and
estimated by Kaplan-Meier method with 95%CI
• Univariable analysis performed by log-rank test
• Multivariable analysis using Cox’s proportional hazards model
• PSM was done to avoid treatment selection bias

11. BASELINE CHARACTERISTICS

12. RESULTS

13. RESULTS

14. RESULTS

15. RESULTS

16. RESULTS
• UNIVARIATE ANALYSIS= ERT (46%)and BMT(44%) – reduction
in HR for death compared with no LRT (OS)
• MULTIVARIATE ANALYSIS= ERT(37%) and BMT(39%)reduction
in HR for death compared with no LRT (OS)
• Only surgery was not a/w significant reduction
• On PSM, OS was better with ERT/BMT rather than no LRT
• LRT was a/w better PFS compared with no LRT

17. RESULTS
• Median OS was 65months
• Median PFS was 25.5 months

18. DISCUSSION
• Largest multicenter study to have evaluated impact of ERT vs
surgery based LRT or no LRT
• After adjustments for confounding factors,both ERT(HR=0.63)
and BMT(HR= 0.61) had better OS than only surgery(HR=0.87)
• Though surgery cohort was 1/3rd of ERT/BMT cohort
• All patients received systemic chemotherapy.
• Controlled systemic disease at 1 yr is the inclusion criteria to
do away with treatment selection bias.

19. DISCUSSION
• Further to limit selection bias PSM was done
• No difference in OS and PFS in ERT/BMT after adjustments for
prognostic factors
• All three LRT modalities had better PFS than no LRT
• RT was well tolerated by patients with no acute or late grade 4
toxicities
• The main clinical benefit of ERT was to avoid the mutilating
and invasive surgeries

20. LIMITATIONS
• Retrospective
• Much of patient data was missing
• Data on Radiotherapy like doses, fractionation, fields,
techniques was not mentioned
• Surgery details were not shared
• No availability of HPR report
• No assessment just before starting any LRT modality
• No accurate data on LRT toxicities

24. TAKE AWAY
• ERT was associated with same OS as with BMT
• Hence, RT can be an acceptable alternative to surgery based
LRT
• These results cannot be taken as evidence to support ERT
• But these findings definitely made us aware about exploring
options of LRT in dnMBC
• Though above all is patient choice

25. THANK YOU