Abstract 1534
Background
Adjuvant endocrine therapy (AET) is an important treatment for post-menopausal hormone receptor positive breast cancer. We used health administrative data to explore factors associated with AET adherence and survival.
Methods
We used health administrative databases to investigate adherence of post-menopausal women (aged ≥ 66 years) who started endocrine therapy from 2005-2010. Adherence was measured by medical possession ratio (MPR) and characterized as low (<40% MPR), intermediate (40-79% MPR) or high (≥80% MPR) over a five-year period. We investigated factors influencing AET adherence using a multinomial logistic regression model and the association with all-cause death (5-years after starting AET) using a multivariable cox-proportional hazards model.
Results
We identified 5,692 eligible patients with a median age of 73 years (IQR: 69-78), 67% received lumpectomy, 33% mastectomy, 26% adjuvant radiation, 13% adjuvant chemotherapy and 70% of patient originally started on an aromatase inhibitor versus tamoxifen. AET adherence was low in 13% (n = 749), intermediate in 13% (n = 733) and high in 74% (n = 4,210) of patients. Lower levels of adherence were observed among older patients [low vs. high adherence: odds ratio (OR)=1.03, 95% CI: 1.02-1.05 (per year); intermediate vs. high adherence: OR = 1.02, 95% CI: 1.01-1.04 (per year)]. High adherence was associated with use of adjuvant chemotherapy (low versus high adherence OR = 0.42 95% CI: 0.30-0.59) and short-term follow-up with a medical oncologist within 4 months of starting AET (low vs. high adherence OR = 0.83, 95% CI: 0.69-0.99). Unadjusted analysis showed an increased risk of death among patients with lower AET adherence [low vs. high adherence: hazard ratio (HR)=1.31, 95% CI: 1.12-1.53 and intermediate vs. high adherence: HR = 1.40, 95% CI: 1.21-1.62]. However, a significant association could no longer be detected after multivariable adjustment.
Conclusions
Non-adherence to endocrine therapy appears to be more common among older breast cancer patients. Short-term follow-up visit by a patient’s medical oncologist after starting AET may help to improve adherence. Developing strategies to optimize endocrine therapy adherence are warranted.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Academic Medical Association of South Western Ontario (AMOSO).
Disclosure
T. Vandenberg: Advisory / Consultancy: Novartis; Advisory / Consultancy: Roche. K. Pritchard: Advisory / Consultancy: Pfizer; Advisory / Consultancy: Roche; Advisory / Consultancy: Amgen; Advisory / Consultancy: Novartis; Advisory / Consultancy: Eisai; Advisory / Consultancy: Genomic Health; Advisory / Consultancy: Myriad Genetics. A. Louie: Advisory / Consultancy: AstraZeneca; Honoraria (self): Varian Medical Systems Inc. J. Raphael: Honoraria (self): Hoffmann La Roche. All other authors have declared no conflicts of interest.
Resources from the same session
3716 - Prognostic factors for predicting early recurrence within the first year of surgery in pancreatic ductal adenocarcinoma
Presenter: Naru Kim
Session: Poster Display session 2
Resources:
Abstract
3947 - Integrated population pharmacokinetic modelling of liposomal irinotecan in patients with various tumour types, including untreated metastatic pancreatic cancer (mPC)
Presenter: Teresa Macarulla
Session: Poster Display session 2
Resources:
Abstract
2880 - Expression of long noncoding RNA and clinical outcomes of pancreatic cancer patients who received adjuvant chemotherapy by S-1 or GEM after curative resection.
Presenter: Mariko Kamiya
Session: Poster Display session 2
Resources:
Abstract
5029 - POLO: Time to treatment discontinuation and subsequent therapies following maintenance olaparib for patients (pts) with a germline BRCA mutation and metastatic pancreatic cancer (mPC)
Presenter: Eric Van Cutsem
Session: Poster Display session 2
Resources:
Abstract
4730 - Diagnostic Value of Digital Multiplexed Detection of Single Nucleotide Variants in Pancreatic Cancer Specimens Collected by Endoscopic Ultrasound Fine-Needle Aspiration
Presenter: Irina Cazacu
Session: Poster Display session 2
Resources:
Abstract
3303 - Phase I/II study of LDE225 in combination with gemcitabine and nab-paclitaxel in patients with metastatic pancreatic cancer
Presenter: Esther Pijnappel
Session: Poster Display session 2
Resources:
Abstract
2009 - Efficacy of platinum-containing chemotherapy and prognosis of pancreatic cancer patients with homologous recombination deficiency: meta-analysis of published clinical studies
Presenter: Elizeveta Polyanskaya
Session: Poster Display session 2
Resources:
Abstract
2164 - Plasmatic CXCL8 is a marker for TGFß-activated kinase 1 (TAK1) activation which may predict resistance to nanoliposomal irinotecan (nal-IRI) in gemcitabine-refractory pancreatic cancer (PC) patients
Presenter: Valeria Merz
Session: Poster Display session 2
Resources:
Abstract
2529 - A protein level signature of four selected genes associated with survival outcomes of patients with pancreatic ductal adenocarcinoma
Presenter: Jie Hua
Session: Poster Display session 2
Resources:
Abstract
4947 - Pre-treatment serum 25-hydroxyvitamin D levels and survival in a Danish cohort of patients with pancreatic cancer
Presenter: Louise Rasmussen
Session: Poster Display session 2
Resources:
Abstract