Cancer is not just one disease. It starts with uncontrolled growth and division of normal cells which makes it hard for the body to control. Most cancers take the form of a lump, these lumps are referred to as tumors. These tumors can be benign or malignant. Cancer cells do not have a defined and controlled growth pattern. They can either remain localized to a specific area or spread to other areas which are called metastasis. It means that cancer has spread to a different area of the body from where it initially started. This metastatic cancer is often termed as ‘advanced cancer’ of ‘stage 4 cancer’.
To explain the process of metastasis in easier words, when cancer/tumor cells break off from the main tumor and enter the circulatory system of the body like bloodstream or lymphatic system which run through all the areas of the body, that cancer/tumor cell can settle anywhere in the body and continue to grow in an uncontrolled fashion. This way it can take over any area of the body.
Lung cancer is one of the most common and serious types of cancer. In the UK, almost 47,000 cases of lung cancer are reported every year. The initial symptoms of lung cancer could be persistent cough or blood in sputum or cough. These symptoms do not present right away, these can also present in later stages of the disease. Lung cancer can affect other parts of the body as well. One of these is the eyes.
As explained by the American Cancer Society,
“Cancers of the upper part of the lungs are sometimes called Pancoast tumors. These tumors are more likely to be non-small cell lung cancer than small cell lung cancer. Pancoast tumors can affect certain nerves to the eyes and part of the face, causing a group of symptoms called Horner syndrome.”
Signs and symptoms of Horner syndrome include drooping or weakness of one upper eyelid, persistently small pupil size such that a notable difference is appreciated between the pupil size of both eyes, delayed dilation of the affected pupil in dim light, the sunken appearance of the eye, little or no sweating on either side of the face, slight elevation of the lower eyelid, etc. In children under 1 year of age, lighter iris color is noted in the affected eye. All these signs could be an indicator of underlying cancer particularly lung cancer.
It was considered a rare occurrence for lung cancer or tumor to metastasize to the eyes and the first-ever case was reported in 1872. But, now eyes and symptoms related to eyes are evaluated thoroughly to rule out any underlying cancer. The majority of metastatic cancers involve the choroid part of the eye but, lesions involving the retina, optic nerve, and iris are also reported.
Around 8% of patients suffering from lung cancer present with eye symptoms involving only one eye and about 20% of lung cancer patients present with symptoms of metastatic tumors that involve both eyes. Most of the patients reported are men in this case.