Department of Radiology, University of Ottawa, Ottawa, ON, Canada.
Centre for Population Health Data at Statistics Canada, Ottawa, ON, Canada.
Can Assoc Radiol J. 2024 Nov;75(4):847-854. doi: 10.1177/08465371241246422. Epub 2024 Apr 25.
Breast cancer (BC) incidence is increasing globally. Age-specific BC incidence trend analyses are lacking for women under age 50 in Canada. In this study, we evaluate the incidence trends in breast cancer in women under age 50 in Canada and compare them with corresponding trends among women 50 to 54. BC case counts were obtained from the National Cancer Incidence Reporting System (1984-1991) and the Canadian Cancer Registry (1992-2019) both housed at Statistics Canada. Population data were also obtained from Statistics Canada. Annual female BC age-specific incidence rates from 1984 to 2019 were derived for the following age groups: 20 to 29, 30 to 39, 40 to 49, 40 to 44, 45 to 49, and 50 to 54. Changes in trends in age-specific BC incidence rates, if any, and annual percent changes (APCs) for each identified trend, were determined using JoinPoint. Statistically significant increasing trends in BC incidence rates were noted for almost all age groups: since 2001 for 20 to 29 (APC = 3.06%, < .001); since 2009 for 30 to 39 (APC = 1.25%, = .007); since 1984 for both 40 to 49 (APC = 0.26%, < .001) and 40 to 44 (APC = 0.19%, = .011), increased since 2015 for 40 to 49 (APC = 0.77%, = .047); and since 2005 for 50 to 54 (APC = 0.38%, = .022). Among women 45 to 49 there was a non-significant increase since 2005 (APC = 0.24, = .058). Statistically significant average annualized increases in BC incidence rates were observed for each age group studied. Examining age-specific incidence rates formed a more complete picture of BC time trends with significant increasing trends in the incidence of BC among women in their 20s, 30s, 40s, and early 50s. A greater awareness regarding the increasing number of cases of BC in women younger than 50 is critical to allow for earlier diagnosis with its resultant reduced mortality and morbidity.
乳腺癌（BC）的发病率在全球范围内呈上升趋势。加拿大缺乏针对 50 岁以下女性的特定年龄乳腺癌发病率趋势分析。本研究评估了加拿大 50 岁以下女性乳腺癌的发病率趋势，并将其与 50-54 岁女性的相应趋势进行了比较。BC 病例数来自国家癌症发病率报告系统（1984-1991 年）和加拿大癌症登记处（1992-2019 年），这两个数据库均由加拿大统计局管理。人口数据也来自加拿大统计局。从 1984 年到 2019 年，获得了以下年龄段女性特定年龄乳腺癌的年度发病率：20-29 岁、30-39 岁、40-49 岁、40-44 岁、45-49 岁和 50-54 岁。使用 JoinPoint 确定了特定年龄乳腺癌发病率趋势的任何变化以及每个确定趋势的年度百分比变化（APC）。几乎所有年龄段的乳腺癌发病率都呈上升趋势：自 2001 年以来，20-29 岁（APC = 3.06%， <.001）；自 2009 年以来，30-39 岁（APC = 1.25%， =.007）；自 1984 年以来，40-49 岁（APC = 0.26%， <.001）和 40-44 岁（APC = 0.19%， =.011），自 2015 年以来，40-49 岁（APC = 0.77%， =.047）有所增加；自 2005 年以来，50-54 岁（APC = 0.38%， =.022）有所增加。在 45-49 岁的女性中，自 2005 年以来呈非显著上升趋势（APC = 0.24， =.058）。在所研究的每个年龄组中，均观察到乳腺癌发病率的平均年化增长率呈显著上升趋势。通过对特定年龄的发病率进行检查，形成了一个更完整的乳腺癌时间趋势图，显示了 20 多岁、30 多岁、40 多岁和 50 岁出头的女性乳腺癌发病率呈显著上升趋势。对于 50 岁以下的女性，对越来越多的乳腺癌病例的认识至关重要，这有助于实现早期诊断，从而降低死亡率和发病率。
