Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Int J Epidemiol. 2014 Dec;43(6):1855-64. doi: 10.1093/ije/dyu202. Epub 2014 Oct 16.
Incidence of contralateral breast cancer (CBC) is much less studied than primary breast cancer. We aimed to assess incidence rates of CBC in relation to age, calendar period and time since first breast cancer.
Using the nationwide Danish Cancer Registry, we identified 85 863 women with a first primary invasive breast cancer without distant metastases in Denmark during 1978-2009. Among these, 3120 women developed metachronous CBC. Crude incidence rates for CBC were calculated by age and calendar period at first breast cancer as well as time since first breast cancer. Mutual adjustments were made by use of Poisson regression models.
The incidence of CBC decreased with increasing age at first breast cancer. Before 1998, incidence rates of CBC showed little variation. The rates decreased by period of first primary from 546 per 10(5) person-years in 1993-97 to 328 per 10(5) person-years in 2003-09. After adjustment for age and calendar period, no clear trend was observed in the overall incidence according to time since first breast cancer.
Occurrence of cancer in the contralateral breast seems to be rather independent of time passed since the first primary. The finding of a decreasing incidence of CBC after 1997 is likely to be due to more women receiving systemic adjuvant therapy such as tamoxifen and longer duration of this treatment as well as the introduction of aromatase inhibitors.
与原发性乳腺癌相比，对侧乳腺癌（CBC）的发病率研究得较少。我们旨在评估与年龄、日历时间和首次乳腺癌后时间相关的 CBC 发病率。
使用全国性的丹麦癌症登记处，我们确定了 1978-2009 年期间在丹麦首次患有原发性浸润性乳腺癌且无远处转移的 85863 名女性。其中，3120 名女性发生了异时性 CBC。通过首次乳腺癌的年龄和日历时间以及首次乳腺癌后的时间计算 CBC 的粗发病率。使用泊松回归模型进行相互调整。
CBC 的发病率随首次乳腺癌年龄的增加而降低。1998 年前，CBC 的发病率变化不大。首次原发性的发病时间从 1993-97 年的每 105 人年 546 例降至 2003-09 年的每 105 人年 328 例。在调整年龄和日历时间后，根据首次乳腺癌后的时间，总体发病率没有明显趋势。
对侧乳房发生癌症的情况似乎与首次原发性肿瘤后经过的时间相当独立。1997 年后 CBC 发病率下降的发现可能是由于更多的女性接受了他莫昔芬等全身性辅助治疗，且这种治疗的持续时间更长，以及芳香化酶抑制剂的引入。
