Introductory paragraph
The lungs’ primary function is for breathing and is part of the respiratory system. The respiratory system comprises the lungs, the nose, the mouth, the trachea (windpipe), and the airways (tubes) to each lung. The body also has large airways known as bronchi, and small airways called bronchioles.[1] These are the airways that are most irritated when exposed to cigarette smoking. As a result, cigarette smoking is the number one risk factor for lung cancer. In the U.S., cigarette smoking is linked to about 80% to 90% of lung cancer deaths.[2]

Lung cancer develops when abnormal cells grow and multiply in an uncontrolled way in one or both lungs. There are two types of lung cancer; in general, cancer that starts in the lungs is known as primary lung cancer.[3] If the cancer spreads (metastasis) to other parts of the body, it can affect the lymph nodes, the brain, the adrenal glands, the liver, and the bones. If cancer starts to develop in another part of the body and spreads to the lungs, it is called secondary or metastatic cancer in the lung.[4]
Types of Lung Cancer
There are two main types of primary lung cancer. These are classified according to the type of cells affected.

I. Non-small cell lung cancer (NSCLC)[5]
NSCLC makes up about 85% of lung cancers. Therefore, it may be classified as 1) adenocarcinoma, 2) squamous cell carcinoma starts in thin, flat cells, usually found in larger airways, and 3) large cell undifferentiated carcinoma.
Other types of cancer can also affect the lung area but are not considered lung cancer. These include tumors that start in the space between the lungs (mediastinum) or in the chest wall.
II.Small cell lung cancer (SCLC)[6]
SCLC makes up about 15% of lung cancers. It starts in the middle of the lungs and usually spreads more quickly than NSCLC.
People with lung cancer must make important cancer treatment decisions. For example, to treat NSCLC, the most common treatments are surgery, radiation therapy, chemotherapy, and in some cases, targeted therapy and immunotherapy.[7] The most common remedies to treat SCLC are chemotherapy and radiation therapy. Surgery is not used.
What are the side effects expected from lung cancer treatments?
Some common side effects can include[8]:

- Breathing issues
- Tiredness, lack of energy
- Infections,
- Bleeding
- Anemia (chemotherapy can lower blood counts)
- Nausea, vomiting, diarrhea, or constipation
- Hair loss
- Pain and discomfort
Some of the most serious side effects of chemotherapy include low white blood cell counts, which increase the risk of infection, and problems with heart function.
Therefore it is crucial to do the very best to make the side effects as manageable as possible. People with lung cancer have the option to select alternative and natural remedies to reduce the side effects caused by this condition, and to improve their Quality of Life.
What is Fucoidan?
In some cases, the cancer patient may decide to opt for surgery, radiation, chemotherapy, or other treatments and at the same time, a natural alternative to enhance their immunity. For these patients, it is essential to understand the health benefits offered by these ingredients, which at times may be obtained naturally in food or in dietary supplements. One ingredient that has been shown to effectively support lung cancer patients by reducing the side effects caused by certain cancer treatments is known as Fucoidan.

Fucoidan is a brown seaweed extract obtained from brown seaweeds, particularly from Mozuku, Mekabu and Fucus. Fucoidan has also been shown to prevent a metastasis (spread of cancer cells), which is important to avoid the cancer cells to affect other organs and tissues within the body. It has also shown to reduce the size of the tumors by apoptosis (controlled cell death). In addition, Fucoidan has been used to enhance the immune system, to reduce inflammation, to promote healthy energy, and it is a great antioxidant.
The Effectiveness of Fucoidan Against Lung Cancer
A study demonstrated that Fucoidan inhibited lung metastasis in mice with transplanted Lewis lung cancer cells.[9] The results showed that continous administration of Fucoidan showed only an antimetastatic effect, and not an antitumor effect when combined with the immunosuppressive drug known as cyclophosphamide.[10]

In another study, it was found that when A549 human lung cancer cells were treated with Fucoidan, there was a significant inhibition in tumor cell proliferation with low cytotoxicity against normal tissue.[11] In particular, Fucoidan from Undaria pinnatifida has been used for treating A549 cells because it has shown to offer an antiproliferative effect, and regulates MAPK p38.[12]
Research has also shown that when Fucoidan is given along with anticancer drugs, there seems to be a more beneficial effect in terms of cancer prevention. Additionally, another study investigated the effects of Fucoidan and gefitinib in lung cancer cell lines and it was was found to have a positive effect. The combination of gefitinib and Fucoidan significantly inhibited lung cancer cells by inducing an apoptotis.[13]

Fucoidan (brown seaweed extract) can reduce the spread of cancer cells by inhibiting normal mitosis and cell cycle regulation.[14] When Fucoidan was injected into C57 mice with transplanted Lewis lung adenocarcinoma cells, it was observed that the number of tumors and lung metastasis was significantly lesser than that in cyclophosphamide treated mice, indicating that metastasis and tumor cell growth is effectively inhibited by Fucoidan.[15]
The great health benefits of Fucoidan (brown seaweed extract) vary from providing an immune-enhancing effect, antioxidant benefits, anticancer effects, inhibition tumor growth, and preventing the spread of cancer cells to other organs and itssues. Additionally, as the studies have shown, when Fucoidan is combined with common cancer treatments like chemotherapy and radiotherapy, if acts as an immune modulator and reduces the side effects of these treatments, which is a good sign that Fucoidan has great potential in cancer treatment.
References
[1] American Lung Association. How lungs work.
[2] Centers for Disease Control and Prevention. Lung Cancer.
[3] Araujo, L.H., Horn, L., Merritt, R.E., Shilo, K., Xu-Welliver, M., Carbone, D.P. (2020). Ch. 69 – Cancer of the Lung: Non-small cell lung cancer and small cell lung cancer. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier.
[4] Perisano, C., Spinelli, M.S., Graci, C., Scaramuzzo, L., Marzetti, E., Barone, C., Fabbriciani, C., & Maccauro, G. (2012). Soft tissue metastases in lung cancer: a review of the literature. Eur Rev Med Pharmacol Sci 2012;16:1908-1914.
[5] Thomas, P., Rubinstein, L. (1990). Cancer recurrence after resection: T1 N0 non-small cell lung cancer. Lung Cancer Study Group. Ann Thorac Surg 49 (2): 242-6; discussion 246-7.
[6] National Cancer Institute. Small Cell Lung Cnacer Treatment.
[7] Wirsdörfer, F., de Leve, S., Jendrossek, V. (2018). Combining Radiotherapy and Immunotherapy in Lung Cancer: Can We Expect Limitations Due to Altered Normal Tissue Toxicity?. Int J Mol Sci. 20(1):24.
[8] American Thoracic Society. Treatment of Lung Cancer.
[9] Huang, T.H., et al. (2015). Prophylactic administration of fucoidan represses cancer metastasis by inhibiting vascular endothelial growth factor (vegf) and matrix metalloproteinases (mmps) in lewis tumor-bearing mice. Mar. Drugs, 13, 1882–1900.
[10] Vo, T.S., and Kim, S.K. (2013). Fucoidans as a natural bioactive ingredient for functional foods. J. Funct. Foods, 5, 16–27.
[11] Mak, W., et al. (2019). Anti-proliferation potential and content of fucoidan extracted from sporophyll of new zealand undaria pinnatifida. Front. Nutr. 1, 9. Link:
[12] Boo, H.J., et al. (2011). Fucoidan from undaria pinnatifida induces apoptosis in a549 human lung carcinoma cells. Phytother. Res. 25, 1082–1086.
[13] Qiu, W.L., et al. (2020). Fucoidan increased the sensitivity to gefitinib in lung cancer cells correlates with reduction of tgfβ-mediated slug expression. Int. J. Biol. Macromol. 153, 796–805.
[14] Wu, S.Y., et al. (2020). Low molecular weight fucoidan inhibits hepatocarcinogenesis and nonalcoholic fatty liver disease in zebrafish via asgr/stat3/hnf4a signaling. Clin. Transl. Med. 10, e252. Link: https://pubmed.ncbi.nlm.nih.gov/32169452/
[15] Alekseyenko, T., et al. (2007). Antitumor and antimetastatic activity of fucoidan, a sulfated polysaccharide isolated from the okhotsk sea Fucus evanescens brown alga. Bull. Exp. Biol. Med. 143, 730–732.