Table 4.
Median (IQR) of total aluminum concentrations [nmol/g dry weight] in breast tissue samples of cases and controls stratified by underarm cosmetic product (UCP) use. Subgroup analyses for cases with tumors in the upper outer quadrant (a) and for cases with tumors in other quadrants (b).
| Cases | n | Controls | n |
p-value sampling location |
p-value UCP use |
p-value cases vs controls |
|
|---|---|---|---|---|---|---|---|
| a) Tumor located in the upper outer quadrant | |||||||
| Median (IQR) of Al3 + concentrationa | 7·00 (3·10–16·15) | 55 | 3·77 (2·47–5·78) | 52 | 0·0003 | ||
| UCP use in women when they were under the age of 30b | |||||||
| Never | 3·43 (1·55–9·69) | 14 | 2·74 (1·90–4·21) | 11 | 0·757 | 0·0116 | 0·0028 |
| Several times per week | 7·71 (4·74–7·77) | 5 | 3·07 (2·75–4·52) | 4 | |||
| Daily | 8·35 (3·19–24·87) | 31 | 4·34 (2·67–6·42) | 34 | |||
| Several times per day | 12·25 (8·56–14·68) | 4 | 2·51 (1·86–4·86) | 3 | |||
| UCP use during last 5 years before BC diagnosis in cases/during last 5 years before interview in controlsb | |||||||
| Never | 3·09 (1·55–5·34) | 10 | 3·32 (1·90–4·21) | 10 | 0·916 | 0·0079 | 0·0054 |
| Several times per week | 7·71 (3·27–7·77) | 5 | 3·07 (2·55–5·86) | 6 | |||
| Daily | 7·69 (3·59–18·41) | 32 | 3·96 (2·54–5·99) | 31 | |||
| Several times per day | 12·90 (3·83–16·15) | 7 | 4·86 (2·51–10·23) | 5 | |||
| b) Tumor located in other quadrants | |||||||
| Median (IQR) of Al3 + concentrationa | 3·94 (1·90–10·92) | 45 | 3·77 (2·47–5·78) | 52 | 0·2642 | ||
| UCP use in women when they were under the age of 30b | |||||||
| Never | 4·63 (1·90–8·82) | 14 | 2·74 (1·90–4·21) | 11 | 0·017 | 0·3457 | 0·3558 |
| Several times per week | 11·16 (7·08–16·18) | 4 | 3·07 (2·75–4·52) | 4 | |||
| Daily | 3·48 (1·24–8·99) | 22 | 4·34 (2·67–6·42) | 34 | |||
| Several times per day | 3·62 (3·39–12·91) | 5 | 2·51 (1·86–4·86) | 3 | |||
| UCP use during last 5 years before BC diagnosis in cases/during last 5 years before interview in controlsb | |||||||
| Never | 4·63 (1·90–7·91) | 10 | 3·32 (1·90–4·21) | 10 | 0·015 | 0·1316 | 0·3731 |
| Several times per week | 10·92 (3·23–11·40) | 5 | 3·07 (2·55–5·86) | 6 | |||
| Daily | 3·94 (1·51–9·76) | 25 | 3·96 (2·54–5·99) | 31 | |||
| Several times per day | 3·62 (3·39–12·91) | 5 | 4·86 (2·51–10·23) | 5 | |||
a
Independent samples t-test with log10(x + 1) transformed data.
b
Three-way analysis of variance with log10(x + 1) transformed data. Repeated aluminum measurements at three different sampling locations (upper outer, mammilla and lower inner breast quadrant) were considered as within-subject factor in the ANOVA. P-values < 0.0125 (Bonferroni correction for multiple comparisons) indicate statistical significance.