Abstract 3608
Background
High BMI has been repeatedly identified as a risk factor for breast cancer (BC), but also as an adverse prognostic factor in women with early-stage BC. Little is known about its impact on outcome in patients with metastatic BC (MBC).
Methods
We used the National ESME-MBC cohort, which includes all consecutive patients (pts) newly diagnosed with MBC between Jan 2008 and Dec 2016 in 18 French comprehensive cancer centres. Women with available BMI at the diagnosis of MBC were selected. Four groups were defined according to WHO classification: underweight (BMI < 18.5 kg/m2), normal weight (18.5-24.9), overweight (25.0-29.9) and obese (≥30.0). Multivariate Cox analyses for OS were conducted in the whole population (primary objective). OS and 1st line progression-free survival (PFS) in subtypes (HER2+, Triple negative BC (TNBC) and HR+ HER2-) were secondary objectives.
Results
Of 22 463 patients in the ESME cohort, 12 999 women had BMI data available. Med BMI was 24.9 kg/m2 (range 12.1-66.5). Pts characteristics are reported in Table. Obesity was associated with more de novo MBC, while underweight pts had more aggressive features. Median follow-up was 48.6 months. Median OS was 47.4 months (95% CI [46.2-48.5]). By multivariate analysis, age, visceral metastases, time to MBC, number of metastatic sites, tumor subtype and BMI were independent predictors for OS. Underweight (but not overweight or obesity) was associated with a worse prognosis (HR 1.29, 95%CI [1.16-1.44]), and this was true in each tumour subtype. Median 1st line PFS was 12.2 months, with similar multivariate results.Table:
367P
Underweight | Normal weight | Overweight | Obese | p | |
---|---|---|---|---|---|
N | 637 (5%) | 6020 (46%) | 3708 (29%) | 2634 (20%) | |
Age at MBC diagnosis (med) | 58 | 58 | 61 | 60 | <0.001 |
De novo MBC | 228 (36%) | 1939 (32%) | 1389 (37%) | 1132 (43%) | 0.000 |
Time to MBC (med, months) | 24 | 33 | 27 | 18 | <0.001 |
Visceral metastases | 400 (63%) | 3543 (59%) | 2148 (58%) | 1484 (56%) | 0.012 |
Subtype HR+HER2- | 354 (56%) | 3566 (59%) | 2311 (62%) | 1633 (62%) | 0.000 |
HER2+ | 131 (21%) | 1295 (21%) | 725 (20%) | 545 (21%) | |
TNBC | 105 (16%) | 860 (14%) | 499 (13%) | 345 (13%) | |
>3 metastatic sites | 180 (28%) | 1306 (22%) | 753 (20%) | 553 (21%) | 0.000 |
Median OS (95% CI) | 33 (29-40) | 47 (45-49) | 49 (47-51) | 48 (45-51) |
Conclusions
Unlike in early-stage BC, overweight and obesity do not seem associated with poorer OS in MBC women, whatever the subtype, on the opposite of underweight.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
M. Robain: Research grant / Funding (institution), ESME plateform support: Roche; Research grant / Funding (institution), ESME plateform support: AstraZeneca; Research grant / Funding (institution), ESME plateform support: Pfizer; Research grant / Funding (institution), ESME plateform support: BMS; Research grant / Funding (institution), ESME plateform support: DAIICHI Sankyo. All other authors have declared no conflicts of interest.
Resources from the same session
3330 - Tumour-infiltrating lymphocytes and BRCA-like status in stage III breast cancer patients treated with intensified carboplatin-based chemotherapy
Presenter: Leonora De Boo
Session: Poster Display session 2
Resources:
Abstract
3971 - Unravelling the biological characteristics of MammaPrint extreme risk subgroups
Presenter: Rajith Bhaskaran
Session: Poster Display session 2
Resources:
Abstract
5871 - Residual Cancer burden as a prognostic factor in a large series of Neoadjuvant chemotherapy. Subgroup analysis per molecular surrogated subtypes
Presenter: Catalina Falo
Session: Poster Display session 2
Resources:
Abstract
5014 - Clinical validation of CanAssist Breast in a Spanish cohort
Presenter: Manjiri Bakre
Session: Poster Display session 2
Resources:
Abstract
2787 - Meta-analysis on association of pathological complete response with long-term survival outcomes in triple-negative breast cancer
Presenter: Peter A. Fasching
Session: Poster Display session 2
Resources:
Abstract
4301 - Immune infiltrate composition across intrinsic subtypes in hormone receptor (HR)+/HER2- early breast cancer (BC) enrolled in the prospective LETLOB trial
Presenter: Gaia Griguolo
Session: Poster Display session 2
Resources:
Abstract
3205 - Frequency of germline mutations in women's cancer susceptibility genes in a large cohort of Chinese breast cancer patients
Presenter: Ning Liao
Session: Poster Display session 2
Resources:
Abstract
4091 - Triple blinded Prospective Study assessing the Impact of Genomics & Artificial Intelligence Watson For Oncology (WFO) on MDT’s Decision of Adjuvant Systemic Therapy for Hormone Receptor Positive Early Breast Carcinoma-
Presenter: Somashekhar Sampige Prasannakumar
Session: Poster Display session 2
Resources:
Abstract
4359 - Prognostic significance of Progesterone Receptor levels in luminal-like Her2- early Breast Cancer patients. A retrospective single Cancer Center analysis.
Presenter: Anna Diana
Session: Poster Display session 2
Resources:
Abstract
1369 - PAM50 HER2-enriched subtype and pathological complete response in HER2-positive early breast cancer: a meta-analysis
Presenter: Francesco Schettini
Session: Poster Display session 2
Resources:
Abstract