Table 1.
Characteristics of the included cohort studies.
| Study | Country | Design | Patient characteristics | Sample size | Mean age | Timing of statin use | Follow-up duration | Outcomes reported (n) | Outcome validation | Variables adjusted |
|---|---|---|---|---|---|---|---|---|---|---|
| Years | Years | |||||||||
| Kwan et al. (18) | the US | PC | Stage I-IIIa BC women after completed treatment | 1,811 | 58.4 | Any statin use of >100 cDDD after BC diagnosis | 5.0 | Recurrence (210) | Medical record | Age at diagnosis, race, BMI, stage of BC, and TMX treatment |
| Chae et al. (13) | the US | RC | Stage II-III BC women after curative treatment | 703 | 59.1 | Any statin use of >180 cDDD after BC diagnosis | 4.6 | Recurrence (149) | Medical record | Age, race, menopausal status, family history, smoking history, DM, HR status, and hormonal therapy |
| Ahern et al. (12) | Denmark | PC | Stage I-III BC women after surgery | 18,769 | NR | Any statin use after BC diagnosis | 6.8 | Recurrence (3,419) | Medical record | Age, menopausal status, histological grade, ER status, hormonal therapy, cancer treatment, and concurrent use of other medications |
| Nielsen et al. (14) | Denmark | PC | BC women after treatment | 45,652 | NR | Any statin use within 2 years before the diagnosis of BC | 3.6 | BC-mortality (11,960) | Medical record | Age, education, study area, stage of BC, cancer treatments, and comorbidities |
| Botteri et al. (19) | Italy | RC | Postmenopausal stage I-III TNBC women after treatments | 800 | 59.8 | Any statin use at the diagnosis of BC | 5.7 | Recurrence (212) and BC-mortality (147) | Medical record | Age, BMI, stage of BC, cancer treatments, comorbidities, and concurrent medications |
| Brewer et al. (15) | the US | RC | Women with stage III IBC | 723 | 49.6 | Any statin use at the diagnosis of BC | 2.9 | Recurrence (433) and BC-mortality (366) | Medical record | Age, BMI, stage of IBC, HR status, comorbidities, cancer treatment and concurrent medications |
| Boudreau et al. (20) | the US | RC | Women with stage I-II BC | 4,216 | 63.0 | Any statin use after the diagnosis of BC | 6.3 | Recurrence (415) | Medical record | Age, BMI, BC stage, HR status, menopausal status, CCI, DM, cancer treatments and concurrent medications |
| Murtola et al. (16) | Finland | PC | Women with stage I-IV BC | 31,236 | 58.6 | Any statin use before, at, or after the diagnosis of BC | 3.3 | BC-mortality (3,619) | Medical record | Age, tumor stage, morphology and treatment selection |
| Cardwell et al. (21) | UK | RC | Women with stage I-IV BC 1 year after diagnosis | 17,880 | NR | Any statin use within 1 year before or during follow-up after the diagnosis of BC | 5.7 | BC-mortality (2,222) | Medical record | Age, cancer treatment, hormonal therapy, comorbidities, and concurrent medications |
| Sakellakis et al. (23) | Greece | RC | Women with stage I-III BC after treatment | 610 | 56.8 | Any statin use at the diagnosis of BC | 3.4 | Recurrence (133) | Medical record | Age, tumor stage, and HR status |
| Mc Menamin et al. (22) | Scotland | RC | Women with stage I-IV BC after treatment | 15,140 | NR | Statin use within 1 year before or during follow-up after diagnosis of BC | 4. | BC-mortality (1,190) | Medical record | Age, cancer stage and grade, cancer treatments, comorbidities, socioeconomic status and use of aspirin |
| Smith et al. (25) | Ireland | PC | Women with stage I-III BC after treatment | 6,314 | 68.1 | Any statin use before or after the diagnosis of BC | 4.9 | BC-mortality (773) | Medical record | Age, smoking status, comorbidity score, tumor stage and grade, HR status, cancer treatments, hormonal therapy, and concurrent medications |
| Shaitelman et al. (24) | the US | RC | Women with stage I-III TNBC after treatments | 869 | 51.0 | Any statin use after the diagnosis of BC | 6.3 | Recurrence (151) | Medical record | Age, BMI, tumor stage and grade, and cancer treatments |
| Tryggvadottir et al. (26) | Sweden | PC | Women with stage I-III BC | 985 | 61.0 | Any statin use after the diagnosis of BC | 7 | Recurrence (150) | Medical record | Ag, BMI, tumor stage and histological grade, ER status, alcoholism, and treatments |
| Li et al. (27) | the US | RC | Women with stage I-III BC | 1,523 | 64.9 | Any statin use after the diagnosis of BC | 6.9 | Recurrence (219) | Medical record | Ag, BMI, tumor stage, HR status, and CCI |
| Borgquist et al. (17) | Sweden | PC | Women > 40 years with BC | 20,559 | 69.0 | Any statin use before or during follow-up after the diagnosis of BC | 5.1 | BC-mortality (2,669) | Medical record | Age, tumor stage, DM, and treatments |
| Bjarnadottir et al. (28) | Sweden | PC | Women with stage I-III BC | 910 | 65.5 | Any statin use before or during follow-up after the diagnosis of BC | 5.4 | BC-mortality (37) | Medical record | Age, tumor stage and histological grade, ER status, and cancer treatments |
BC, breast cancer; NOS, the Newcastle-Ottawa Scale; US, United States; UK, United Kingdom; TNBC, triple-negative breast cancer; IBC, inflammatory breast cancer; NR, not reported; PC, prospective cohort; RC, retrospective cohort; cDDD, cumulative defined daily dose; BMI, body mass index; DM, diabetes mellitus; HER-2, human epidermal growth factor receptor-2; HR, hormone receptor; ER, estrogen receptor; PR, progesterone receptor; TMX, tamoxifen; CCI, Charlson comorbidity index.