Beral V, Banks E, Reeves G, Appleby P
Imperial Cancer Research Fund Cancer Epidemiology Unit, Oxford, UK.
J Epidemiol Biostat. 1999;4(3):191-210; discussion 210-5.
At least 20 million women in developed countries are estimated to be currently using hormone replacement therapy (HRT). Almost 100 epidemiological studies have reported on the relationship between the use of HRT and the risk of cancer of female reproductive organs, namely the breast, uterus or ovary. Cancer at these sites is common and there are a priori reasons why the use of hormonal therapy to 'replace' the endogenous production of ovarian hormones after the menopause might increase the risk of these cancers. The available evidence indicates that the risk of breast cancer or endometrial cancer is increased while women are using HRT, the risk increasing with increasing duration of use. Most of the evidence about these cancers relates to use of HRT preparations containing oestrogens alone. The limited evidence about combination therapy, with oestrogens and progestogens, suggests that, compared to oestrogens alone, the effect on the breast is similar, but the effect on the endometrium is diminished, the diminution in risk being greater the more days each month that progestogens are used. The effect of HRT on breast cancer wears off after use ceases and has disappeared largely, if not wholly, within 5 years, whereas the effects on endometrial cancer take longer to wear off, if at all. The breast and endometrial cancers that are diagnosed in HRT users are less aggressive clinically than cancers in never-users but, as yet, there is little reliable information about the relationship between use of HRT and mortality from these cancers. For other cancer sites, the existing data about the effects of HRT are inconclusive. The longer the period of use of HRT, the greater the excess incidence of cancer of the breast and endometrium is likely to be. Use of HRT for short periods of time should have little effect on the incidence of these cancers. The cumulative excess incidence in 1000 women who used HRT for 10 years, beginning at age 50, is estimated to be six for breast cancer, 42 for endometrial cancer in women with an intact uterus using oestrogen therapy alone and about 20 for endometrial cancer in women with an intact uterus using oestrogen-progestogen combinations. The estimate for combined therapy is based on small numbers and may well vary with the type of preparation used. The overall balance between the excess incidence of these cancers and other effects of HRT needs to be evaluated carefully and will require more reliable data than exist at present.
据估计，发达国家目前至少有2000万女性正在使用激素替代疗法（HRT）。近100项流行病学研究报告了HRT的使用与女性生殖器官癌症风险之间的关系，这些生殖器官即乳房、子宫或卵巢。这些部位的癌症很常见，而且绝经后使用激素疗法“替代”卵巢激素的内源性分泌可能会增加这些癌症的风险，这是有先验原因的。现有证据表明，女性使用HRT时乳腺癌或子宫内膜癌的风险会增加，风险随着使用时间的延长而增加。关于这些癌症的大多数证据都与单独使用含雌激素的HRT制剂有关。关于雌激素和孕激素联合疗法的有限证据表明，与单独使用雌激素相比，对乳房的影响相似，但对子宫内膜的影响减弱，使用孕激素的天数越多，风险降低得就越大。HRT对乳腺癌的影响在停药后会逐渐消失，并且在5年内基本（即使不是完全）消失，而对子宫内膜癌的影响则需要更长时间才会消失（如果会消失的话）。在使用HRT的女性中诊断出的乳腺癌和子宫内膜癌在临床上比从未使用过HRT的女性所患癌症的侵袭性要小，但目前关于HRT的使用与这些癌症死亡率之间的关系几乎没有可靠信息。对于其他癌症部位，关于HRT影响的现有数据尚无定论。HRT使用时间越长，乳腺癌和子宫内膜癌的额外发病率可能就越高。短期使用HRT对这些癌症的发病率应该影响不大。从50岁开始使用HRT 10年的1000名女性中，乳腺癌的累积额外发病率估计为6例，单独使用雌激素疗法的有完整子宫的女性子宫内膜癌为42例，使用雌激素 - 孕激素联合疗法的有完整子宫的女性子宫内膜癌约为20例。联合疗法的估计基于少量数据，并且很可能因所用制剂类型而异。这些癌症的额外发病率与HRT的其他影响之间的总体平衡需要仔细评估，并且需要比目前更可靠的数据。
