Division of Surgical Oncology, Department of Surgery, University of Texas Health Science Center, San Antonio, TX, USA.
Future Oncol. 2010 Nov;6(11):1781-8. doi: 10.2217/fon.10.139.
A qualitative age interaction is defined as the reversal of relative risks or rates according to age at onset, and is often evident in studies that examine the etiology, prognosis and treatment of breast cancer. For example, incidence rates (or risks) are higher for aggressive when compared with indolent breast cancers prior to age 40-50 years, after which rates are higher for indolent tumors. Nulliparity and obesity decrease breast cancer risk in younger women, but increase risk in older women. Curves depicting the annual hazard of breast cancer death are shaped differently for the early- and late-onset tumors. Clinical trials for mammography screening, fenretinide chemoprevention and neo-adjuvant chemotherapy show opposite effects in younger and older women. Finally, high-risk/early onset breast cancers are more common among African-American women than Caucasian women, and this may partly account for the racial survival disparities. Taken together, these examples imply that aging may modify breast cancer risk, prognosis and treatment. These qualitative age interactions (or effect modifications) are important because they suggest that high-risk/early-onset and low-risk/late-onset breast cancers are different diseases, derived from different carcinogenic pathways. When age interactions are suspected, breast cancer studies should be stratified by early versus late age of onset or analyzed age specifically.
定性年龄交互作用定义为根据发病年龄逆转相对风险或比率，这在研究乳腺癌的病因、预后和治疗时经常出现。例如，与发病年龄在 40-50 岁之前的惰性乳腺癌相比，侵袭性乳腺癌的发病率（或风险）在这之前更高，而在这之后发病率更高的则是惰性肿瘤。未婚和肥胖会降低年轻女性的乳腺癌风险，但会增加老年女性的风险。描述乳腺癌死亡年风险曲线的形状因早发性和晚发性肿瘤而不同。乳腺 X 线筛查、fenretinide 化学预防和新辅助化疗的临床试验显示，年轻和老年女性的效果相反。最后，非洲裔美国女性比白种女性更容易患高危/早发性乳腺癌，这可能部分解释了种族间生存差异的原因。综上所述，这些例子表明衰老可能会改变乳腺癌的风险、预后和治疗。这些定性年龄交互作用（或效应修饰）很重要，因为它们表明高危/早发性和低危/晚发性乳腺癌是不同的疾病，源自不同的致癌途径。当怀疑存在年龄交互作用时，乳腺癌研究应按发病年龄早或晚分层，或专门按年龄进行分析。
