FIGURE 1.
Questionnaire content used for Slovenian International Breast Cancer Intervention Study (S-IBIS) evaluation tool score calculation
| Factors affecting levels of endogenous hormones (menarche, menopause, first birth age). |
| Exogenous hormone intake (menopause hormone replacement therapy). |
| Anthropometric characteristics (height, weight). |
| Breast biopsy (done, not done, presence of atypia, atypical hyperplasia). |
| Family history of breast and ovarium cancer (mother, sisters, half-sisters, daughters, grandmothers, aunts, male relatives). |
| Ovarian cancer of the participants. |
Number of screening mammographies among 3,491 women through their whole screening period (aged 50–69 years) in case of different screening scenarios
| Risk category | Lifetime breast cancer risk | 10-year breast cancer risk | ||
|---|---|---|---|---|
| Age-based screening (current screening)17 | Slovenian risk-based screening18 | Age-based screening (current screening)17 | PROCAS risk-based screening27 | |
| Low risk | – | – | 11,860 | 4,744 |
| Population risk | 34,130 | 34,130 | 21,720 | 15,204 |
| Moderately increased risk | 770 | 1,540 | 1,190 | 1,190 |
| High risk | 10 | 20 | 140 | 280 |
| Total | 34,910 | 35,690 | 34,910 | 21,418 |
10-year and lifetime breast cancer risk frequencies in the study group (risk calculated with the Slovenian International Breast Cancer Intervention Study (S-IBIS) evaluation tool, breast density information included) (N = 3,491)
| Risk category | Frequency (N) | Per cent (%) |
|---|---|---|
| 10-year breast cancer risk | ||
| low | 1,186 | 34.0 |
| population | 2,172 | 62.2 |
| moderately increased | 119 | 3.4 |
| high | 14 | 0.4 |
| Lifetime breast cancer risk | ||
| population | 3,413 | 97.8 |
| moderately increased | 77 | 2.2 |
| high | 1 | 0.03 |
Characteristics of study participants (n = 3,491)
| Frequency (N) | Per cent (%) | |
|---|---|---|
| Family history: first-degree relatives with breast/ovarian cancer (mother, father, sisters, daughters) | ||
| positive (1 relative) | 326 | 9.3 |
| positive (2 or more relatives) | 28 | 0.8 |
| negative | 2,854 | 81.8 |
| unknown | 283 | 8.1 |
| Family history: second-degree relatives with breast/ovarian cancer (aunts, uncles, grandmothers, half-sisters) | ||
| positive (1 relative) | 437 | 12.5 |
| positive (2 or more relatives) | 148 | 4.2 |
| negative | 2,552 | 73.1 |
| unknown | 354 | 10.1 |
| Age (years) at menarche | ||
| < 13 | 1,138 | 32.6 |
| 13 | 940 | 26.9 |
| > 13 | 1,339 | 38.4 |
| unknown | 74 | 2.1 |
| Age (years) at first birth | ||
| < 25 | 1,570 | 45.0 |
| 25–28 | 736 | 21.1 |
| 29–34 | 659 | 18.9 |
| 35 | 191 | 5.5 |
| nulliparous | 335 | 9.6 |
| unknown | 0 | 0.0 |
| Menopausal status | ||
| premenopausal | 1,392 | 39.9 |
| perimenopausal | 632 | 18.1 |
| postmenopausal | 631 | 18.1 |
| unknown | 836 | 23.9 |
| HRT usage | ||
| yes | 286 | 8.2 |
| no | 3,123 | 89.5 |
| unknown | 82 | 2.3 |
| Breast biopsy | ||
| no biopsy | 3,123 | 89.5 |
| biopsy (hyperplasia, atypical hyperplasia, LCIS) | 21 | 0.6 |
| biopsy (else) | 44 | 1.3 |
| biopsy (unknown result) | 256 | 7.3 |
| unknown if biopsy done | 47 | 1.3 |
| Breast density | ||
| BI-RADS a | 215 | 6.2 |
| BI-RADS b | 1,802 | 51.6 |
| BI-RADS c | 1,410 | 40.4 |
| BI-RADS d | 34 | 1.0 |
| unknown (no screening mammography) | 30 | 0.9 |
| BMI | ||
| < 19 | 48 | 1.4 |
| 19–25 | 1,165 | 33.4 |
| > 25 | 1,336 | 38.3 |
| unknown | 942 | 27.0 |
Breast cancer risk categories for Slovenian women at the age of 50 and risk-based screening scenarios according to different protocols18,24,26
| Breast cancer risk category | Lifetime risk | 10-year risk | Slovenian risk-based screening guidelines18,25 | PROCAS study protocol27 |
|---|---|---|---|---|
| Low risk (%) | ** | < 1.3 | ** | 5-year mammography screening interval |
| Population risk (%) | < 16 | 1.3–3.9 | 2-year mammography screening interval | 3-year mammography screening interval |
| Moderately increased risk (%) | 16–30 | 4.0–6.5 | 1-year mammography screening interval | 2-year mammography screening interval |
| High risk (%) | > 30 | > 6.5 | 1-year mammography screening interval | 1-year mammography screening interval |