Editor—Stallard et al suggest that breast tumours that develop in users of hormone replacement therapy have no favourable prognostic features.1 Their data conflict with those reported by other groups2,3 and with data from our unit.
We performed a cross sectional study of 309 symptomatic postmenopausal women to investigate the effect of hormone replacement therapy on tumour biology (58 users and 251 non-users). The mean duration of hormone replacement therapy was 5.4 years (range 4 months to 23 years). In contrast to non-users, users had smaller tumours (P=0.022), had lower grade tumours (P<0.01), more frequently had an in situ component (P<0.001), and had a lower rate of axillary lymph node disease (table).
What possible reasons could there be for the difference between the findings of the Glasgow group and those of other authors, including us? The paper from Glasgow does not give any data on the duration of use and type of hormone replacement therapy. These factors are known to influence the risk of developing breast cancer.4,5 The duration of use and the dose and type of therapy taken could well differ between the two datasets.
The Glasgow group limited its study to screened patients; our study comprised women in whom cancer was detected on screening (45%) and symptomatic users (55%), but in both screen detected and symptomatic women there were no differences in tumour characteristics between users of hormone replacement therapy and non-users in our study.
Table.
Comparison of tumour characteristics in users and non-users of hormone replacement therapy. Values are numbers (percentages) of patients
| Users (n=58) | Non-users (n=251) | P value | ||
|---|---|---|---|---|
| Tumour size (cm): | ||||
| T1 (<2) | 46 (79) | 140 (56) | 0.022* | |
| T2 (2-5) | 12 (21) | 108 (43) | ||
| T3 (>5) | NA | 3 (1) | ||
| Histology: | ||||
| Ductal | 43 (74) | 192 (76) | >0.10 | |
| Other† | 6 (10) | 12 (5) | ||
| In situ component: | ||||
| Present | 43 (74) | 102 (41) | <0.001 | |
| Absent | 15 (26) | 149 (59) | ||
| Grade: | ||||
| 1 | 18 (31) | 34 (14) | <0.01 | |
| 2 | 23 (40) | 107 (43) | ||
| 3 | 17 (29) | 110 (44) | ||
| Lymph node status: | ||||
| 0 | 40 (69) | 103 (41) | <0.001 | |
| 1-3 | 15 (26) | 70 (28) | ||
| 4-7 | 2 (3) | 49 (20) | ||
| 8-10 | 0 | 13 (5) | ||
| >10 | 1 (2) | 16 (6) | ||
Odds ratio=3.04 (95% confidence interval 1.1 to 3.5).
Mucinous, medullary, tubular.
NA = Not applicable.
References
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