Hartman Mikael, Czene Kamila, Reilly Marie, Adolfsson Jan, Bergh Jonas, Adami Hans-Olov, Dickman Paul W, Hall Per
Department of Medical Epidemiology and Biostatistics, Stockholm Söder Hospital and Oncologic Center, Clintec, Stockholm, Sweden.
J Clin Oncol. 2007 Sep 20;25(27):4210-6. doi: 10.1200/JCO.2006.10.5056.
Because the incidence of breast cancer is increasing and prognosis is improving, a growing number of women are at risk of developing bilateral disease. Little is known, however, about incidence trends and prognostic features of bilateral breast cancer.
Among 123,757 women with a primary breast cancer diagnosed in Sweden from 1970 to 2000, a total of 6,550 developed bilateral breast cancer. We separated synchronous (diagnosed within 3 months after a first breast cancer) and metachronous bilateral cancer, and analyzed incidence and mortality rates of breast cancer using Poisson regression models.
The incidence of synchronous breast cancer increased by age and by 40% during the 1970s, whereas the incidence of metachronous cancer decreased by age and by approximately 30% since the early 1980s, most likely due to increasing use of adjuvant therapy. Women who developed bilateral cancer within 5 years and at age younger than 50 years were 3.9 times (95% CI, 3.5 to 4.5) more likely to die as a result of breast cancer than women with unilateral cancer. Women with a bilateral cancer diagnosed more than 10 years after the first cancer had a prognosis similar to that of a unilateral breast cancer. Adjuvant chemotherapy of primary cancer is a predictor of poor survival after diagnosis of early metachronous cancers.
We found profound differences in the incidence trends and prognostic outlook between synchronous and metachronous bilateral breast cancer diagnosed at different ages. Adjuvant chemotherapy therapy has a dual effect on metachronous cancer: it reduces the risk, while at the same time it seems to worsen the prognosis.
由于乳腺癌发病率上升且预后改善，越来越多的女性有患双侧乳腺癌的风险。然而，关于双侧乳腺癌的发病趋势和预后特征却知之甚少。
在1970年至2000年于瑞典确诊原发性乳腺癌的123,757名女性中，共有6550人患双侧乳腺癌。我们区分了同时性（在首次乳腺癌诊断后3个月内确诊）和异时性双侧癌，并使用泊松回归模型分析了乳腺癌的发病率和死亡率。
同时性乳腺癌的发病率随年龄增长，在20世纪70年代上升了40%，而异时性癌的发病率随年龄下降，自20世纪80年代初以来下降了约30%，这很可能是由于辅助治疗的使用增加。在5年内发病且年龄小于50岁的双侧乳腺癌女性因乳腺癌死亡的可能性是单侧乳腺癌女性的3.9倍（95%可信区间，3.5至4.5）。在首次患癌10年以上被诊断为双侧癌的女性预后与单侧乳腺癌相似。原发性癌的辅助化疗是早期异时性癌诊断后生存不良的一个预测因素。
我们发现不同年龄诊断的同时性和异时性双侧乳腺癌在发病趋势和预后前景上存在显著差异。辅助化疗对异时性癌有双重作用：它降低了风险，同时似乎又使预后恶化。
