Breast cancer and Lung cancer in women are the most common cancer with high morbidity and mortality rate. During the last few decades advances in early detection and treatment have significantly resulted in increased survival rates among breast cancer patients. Women with early breast cancer basically received post-surgical adjuvant treatments for breast cancer as radiation therapy, chemotherapy or hormonal therapy or as a combination of any of these modalities.
In many early breast cancers the lifelong expectancy exposes the patients to the possibility of developing second primary cancer. Many studies have reported that by 10 yrs. of early breast cancer diagnosis, about 10% of survivors have a high risk of developing a subsequent malignancy, of which lung cancer has accounted for the largest number*.
Lung cancer is the most common cause of cancer death. Thus, knowing the cause and the risk factors of breast cancer patients developing the second primary lung cancer becomes very important. Women diagnosed before the age of 50 yrs. Breast cancer is considered to have an increased risk of having lung cancer at a later stage of life. Also, post-surgery radiotherapy side effects are considered to increase the risk of developing second primary lung cancer. And even the quality of life of an individual considering smoking, exposure to carcinogenic agents significantly elevates the risk of having second primary lung cancer or metastatic lung cancer.
But ever wonder why this breast cancer affects other organs, known to be metastatic breast cancer. The mechanism through which breast cancer spreads to the lungs is considered to be the direct extension and true metastatic spread through the bloodstream, airway or lymphatic system. Although metastatic is an extraordinarily complex process and a non-random process is known as “metastatic organotropism”, which is administrated by multiple factors such as cancer subtype, molecular features of cancer cells, host immune micro-environment (region of primary cancer), and cross-talk and interactions with local cells. The cancer cells and host organs cross-talk initiates the construction of the pre-metastatic slot and is increased by factors released from cancer cells. Moreover, host micro-environment and specific organ structure influence metastatic slot construction and interactions between cancer cells and local resident cells, modulating the survival of cancer cells and leads to the construction of metastatic lesions. Understanding the molecular mechanisms of organotropic metastasis is essential for biomarker-based prediction and prognosis, expansion of innovative therapeutic strategy, and eventual improvement of patient outcomes.
Despite the remarkable progression over the past decade with clinical trial data and experimental models, our knowledge of metastasis remains limited. Genetic changes, stem-ness, and signaling pathways have a great impact on metastatic progression. Some of these factors are considered to affect the tumor cells’ capacity for circulation and colonization.
Although a genetic test is available to find the risk of recurrence and a breast cancer treatment plan analyzer, EndoPredict. It is a multi-gene test for breast cancer patients provided by Myriad Genetics USA. in contrast to older multi-gene tests, EndoPredict provides more prognostic information for late-metastasis (i.e., metastasis formation after more than five years) and can also guide treatment decisions for chemotherapy as well as extended anti-hormonal therapy (i.e. endocrine therapy), which is considered as targeted therapy. The EndoPredict, analysis method is based on tumor genes in combination with the classical prognostic factors of nodal status and tumor size.
- Burness ML, Grushko TA, Olopade OI. Epidermal growth factor receptor in triple-negative and basal-like breast cancer: promising clinical target or only a marker?Cancer J.(2010) 16:23–32. DOI: 10.1097/PPO.0b013e3181d24fc1
- Chen, W., Hoffmann, A. D., Liu, H., & Liu, X. (2018). Organotropism: new insights into molecular mechanisms of breast cancer metastasis. NPJ precision oncology, 2(1), 1-12.
- Hunter, K. W., Crawford, N. P., & Alsarraj, J. (2008). Mechanisms of metastasis. Breast Cancer Research, 10(1), S2.