Yingxian Dong

Ph.D.

West China hospital of Sichuan University

Dr.

PLCO (Learn more about this study)

PLCO-1549

Apr 29, 2024

Risk and Influencing Factors for Subsequent Primary Lung Cancer After Treatment of Breast Cancer

Among patients with pulmonary nodules and a history of breast cancer, the proportion of primary lung cancer exceeds the proportion of breast cancer metastases. Unfortunately, because of our insufficient knowledge and understanding of the occurrence of primary lung cancer in patients with breast cancer, the primary pulmonary malignant lesions of some patients have not been pathologically confirmed.To date, some relevant studies have explored the risk factors for developing primary lung cancer after treatment for breast cancer, and most of these studies have focused on treatments for breast cancer, such as chemotherapy and radiotherapy. Radiotherapy is an important means of comprehensive treatment after surgery and can inhibit the recurrence of breast cancer. However, there is a corresponding increase in the risk for subsequent lung cancer in the radiation exposure area. In addition, some scholars deem that medium and small doses of radiation are far more carcinogenic than large doses of radiation. Approximately 70% of patients with breast cancer receive postoperative adjuvant chemotherapy or neoadjuvant chemotherapy, and a great number of studies have revealed that most chemotherapeutics are carcinogenic, such as alkylating agents cyclophosphamide) and doxorubicin. These chemotherapy drugs can not only directly damage DNA and RNA but can also reduce the immune function of patients with cancer, leading to the subsequent occurrence of other malignant tumors. In addition, some other treatment measures, such as surgery, radiotherapy and targeted therapy, may also inhibit the cellular immune function of patients with cancer, representing a decrease in CD3þ, CD4þ and CD4þ-toCD8þ ratios and an increase in CD8þ cells. There are also some studies showing that the expression of some oncogenes and loss of tumor suppressor genes is closely related to the occurrence of primary lung cancer in patients with breast cancer, such as RhoA (one oncogene of the Rho family) and RhoE (one tumor suppressor gene of the Rho family). Meanwhile, some other parameters may also have an influence on the risk of developing primary lung cancer in patients with breast cancer, such as family history of malignancy and alcohol consumption. However, no studies have summarized these influencing factors or provided high-quality evidence of their influence to date. Therefore, the aim of this study was to compare the risk of developing lung cancer between patients with breast cancer and the general population and to explore the risk factors for subsequent primary lung cancer after treatment for breast cancer.