Women Commencing Anastrozole, Letrozole or Tamoxifen for Early Breast Cancer: The Impact of Comorbidity and Demographics on Initial Choice

Abstract

BackgroundAustralian clinical guidelines recommend endocrine therapy for all women with hormone-dependent early breast cancer. Guidelines specify tamoxifen as first-line therapy for pre-menopausal women, and tamoxifen or an aromatase inhibitor (AI) for post-menopausal women depending on the risk of recurrence based on tumour characteristics including size. Therapies have different side effect profiles; therefore comorbidity may also influence choice. We examined comorbidity, and the clinical and demographic characteristics of women commencing different therapies.Patients and MethodsWe identified the first dispensing of tamoxifen, anastrozole or letrozole for women diagnosed with invasive breast cancer in the 45 and Up Study from 2004–2009 (N = 1266). Unit-level pharmacy and medical service claims, hospital, Cancer Registry, and self-reported data were linked to determine menopause status at diagnosis, tumour size, age, comorbidities, and change in subsidy restrictions. Chi-square tests and generalised regression models were used to compare the characteristics of women commencing different therapies.ResultsMost pre-menopausal women commenced therapy with tamoxifen (91%). Anastrozole was the predominant therapy for post-menopausal women (57%), followed by tamoxifen (28%). Women with osteoporosis were less likely to commence anastrozole compared with tamoxifen (anastrozole RR = 0.7, 95% CI = 0.5–0.9). Women with arthritis were 1.6-times more likely to commence letrozole than anastrozole (95% CI = 1.1–2.1). Tamoxifen was more often initiated in women with tumours >1 cm, who were also ≥75 years. Subsidy restriction changes were associated with substantial increases in the proportion of women commencing AIs (anastrozole RR = 4.3, letrozole RR = 8.3).ConclusionsThe findings indicate interplay of comorbidity and therapy choice for women with invasive breast cancer. Most post-menopausal women commenced therapy with anastrozole; however, letrozole and tamoxifen were more often initiated for women with comorbid arthritis and osteoporosis, respectively. Tamoxifen was also more common for women with tumours >1 cm and aged ≥75 years. Subsidy restrictions appear to have strongly influenced therapy choice.

Cloud-Based Service Information System for Evaluating Quality of Life after Breast Cancer Surgery

“…Cloud computing technologies offer many advantages over conventional information technology infrastructure, including support for on-demand access to massive computational resources and massively reduced costs to the user. Therefore, implementing the CSIS-BCP in a cloud environment enhances its flexibility, accessibility and usability [ 9 – 12 ], and our experimental results confirmed that the CSIS-BCP indeed enables researchers to integrate and analyze questionnaire data for breast-cancer patients easily and efficiently.…”

“…Many co-morbidities are found to be linked with low QOL subscale scores, and previous reports have found that many co-morbidities are strongly associated with poor post-operative functional status [ 12 , 13 ].…”

Dry eyes and AIs: If you don't ask you won't find out

“…The only statistically significant difference was a slightly higher proportion of Caucasian participants in the exposure group (89%) compared with the control group (78%) (p ¼ 0.04). Anastrozole was the most common AI used (n ¼ 45), followed by letrazole (n ¼ 39) and exemestane (n ¼ 9), in keeping with data from Australian population studies [29]. Duration of treatment ranged from 1 month to 8 years, with 2.5 years the average.…”

Switching between endocrine therapies for primary breast cancer: Frequency and timing in Australian clinical practice

“…The sample was also restricted to women who were postmenopausal at the time of diagnosis. Menopause status was derived from information contained in the Cancer Registry and the 45 and Up Study baseline survey, and has been described previously . The final study sample composed 645 women.…”

“…Median follow‐up time prior to censoring for switching, discontinuation or recurrence was 4.3 years (interquartile range 3.6–5.0), and after censoring was 3.5 years (interquartile range 2.2–4.4). Previous work by our group examined the factors associated with choice of first‐line therapy . Switching was defined as a dispensing of a different endocrine therapy to the one previously dispensed.…”