[Clinicopathological features of second primary lung cancer and pulmonary metastasisin patients with breast cancer].

Objective: To compare the clinicopathological characteristics of second primary lung cancer following breast cancer and lung metastases from breast cancer, and then to analyze the risk factors in breast cancer patients with second primary lung tumor. Methods: Clinical data of 55 breast cancer patients with second primary lung tumor and 205 breast cancer patients with solitary pulmonary metastasis in Shandong Cancer Hospital from January 2006 to January 2017 were retrospectively analyzed. The risk factors of primary lung cancer following breast cancer were analyzed using logistic regression model. Results: Second primary lung cancer in patients with first breast cancer accounted for approximately 21.2%(55/260) of pulmonary malignant solitary nodules, and 0.84%(55/6 580) of all breast cancer patients. The median intervals between the diagnosis of second primary lung cancer or lung metastasis and first breast cancer were 52 months and 42 months, respectively. These two groups showed significant difference between age, time interval between diagnoses, breast tumor size, axillary lymph node metastasis, estrogen receptor, molecular subtype (luminal B and triple-negative) and history of radiotherapy (P<0.05 for all). A multivariate logistic regression model confirmed that age (OR=1.088, P<0.001), breast tumor size(OR=0.480, P<0.001), and radiotherapy history (OR=3.460, P=0.004) were all independent factors for second primary lung cancer. Conclusions: For isolated pulmonary nodules in patients with breast cancer, especially for those with elder age, larger tumor size and radiotherapy history, we should distinguish the second primary lung cancer from pulmonary metastasis. The treatment regimen for lung metastasis and primary lung cancer in patients with breast cancer are entirely distinct. The timely histopathology examinations for pulmonary nodes in patients with breast cancer are recommended.目的： 探讨乳腺癌合并原发性肺癌以及乳腺癌肺转移患者的临床病理特征，并分析乳腺癌合并原发性肺癌的疾病相关因素。 方法： 回顾性分析2006年1月至2017年1月经山东省肿瘤医院病理证实的55例原发性乳腺癌合并原发性孤立性肺癌患者的临床病理资料，与同期收治的205例乳腺癌孤立性肺转移患者进行比较，并对乳腺癌合并原发性肺癌的相关因素进行logistic回归分析。 结果： 乳腺癌合并原发性肺癌占乳腺癌肺部恶性孤立性结节的21.2%(55/260)，占同期乳腺癌的0.84%(55/6 580)。乳腺癌手术至确诊原发性肺癌和乳腺癌孤立性肺转移的中位间隔时间分别为52个月和42个月。乳腺癌合并原发性肺癌组患者的发病年龄、间隔时间、乳腺肿瘤大小、腋窝淋巴结转移数目、雌激素受体状态、分子分型(Luminal B型和三阴性型)和放疗史与乳腺肺转移癌组比较，差异有统计学意义(均P<0.05)。多因素回归分析结果显示，乳腺癌患者的发病年龄(P<0.001)、乳腺肿瘤大小(P<0.001)和放疗史(P＝0.004)与乳腺癌合并原发性肺癌有关。 结论： 对于乳腺癌患者合并的肺部孤立性结节，不能只考虑乳腺癌肺转移，要考虑到乳腺癌合并原发性肺癌的可能，尤其是高龄、乳腺肿瘤较大和有放疗史者。乳腺癌合并原发性肺癌与乳腺癌肺转移的处理原则不同，必要时应对乳腺癌合并的肺部占位及时进行组织病理学检查。.