Eye cancer: More common than thought

In adults, eye cancer can appear on the eyelid, surface of the eye, inside the eyeball or on the back of the eye, causing the eye to bulge forward from its socket. Eyelid cancers are common in sun-exposed individuals

People are not aware that cancers, or tumours, can appear in the eye as well. However, I came across around 200 patients with eye cancer in just one year at Tilganga itself. This data excludes the benign tumours of the eye. So is eye cancer quite common?

The impact of eye cancer on a patient is three-fold: there are chances of going blind and losing life to cancer. The third is childhood cancer, called retinoblastoma, occurs in babies at birth and up to five years of age, which is shocking to the new parents. Last year, 40 new cases of retinoblastoma were presented to us from Bhojpur in the east to Kailali in the west. Many were from the Terai belt and from the neighbouring states of India. The smallest one was a 28-day-old baby and the oldest one four-and-a-half years old. The younger the age, the more likely of the patient to get a tumour in both the eyes.

The earliest sign of retinoblastoma is the white papillary reflex (instead of black in normal light). Some parents notice this early and visit the hospital out of curiosity. While some old people assure them that it is a good luck sign and wait, until it grows out of the eye, putting both the vision and life at risk. Other signs of retinoblastoma are squinting, abnormal persistent red eye without infection or one eye appearing larger than the other. If the patients are not treated on time, the tumour grows outside the eye on the face. The treatment options are surgery, chemotherapy, laser therapy, radiation and cryotherapy (use of extreme cold), depending on the tumour type.

Retinoblastoma is caused by genetic mutation before birth; it is not attributed to food habits or any other medical condition of the mother during pregnancy. The other malignant tumours of the eye in children are rhabdomyosarcoma, medulloepithelioma, leukaemia and metastasis.

In adults, eye cancer can appear on the eyelid, the surface of the eye, inside the eyeball or on the back of the eye, causing the eye to bulge forward from its socket. Eyelid cancers are common in sun-exposed individuals, and they are basal cell carcinoma, sebaceous cell carcinoma and squamous cell carcinoma. Here, too, if they present early, the tumour can be excised completely, and the patient can be free of disease easily.

However, late presentation means that the tumour has grown big, thus requiring larger resection, or the tumour has spread in the eyeball or behind it in the orbit where a simple surgery, like an excision biopsy, is not enough. So we may need to remove the eyeball or the whole of the orbital content, called exenteration, and give radiation as well. Therefore, any growth of mass or appearance of painless ulcers in the eyelids or sudden enlargement of the nevus could be eyelid carcinoma. Unlike the other cancers of the body, eyelid tumours should present themselves early because any growth is easily visible.

Ocular surface squamous neoplasia (OSSN) is a tumour of the outer part of the eyeball that is the conjunctiva (the white part of eye) and cornea (the black part of eye).  The pre-cancerous lesion, called CIN, and its cancerous part called invasive squamous cell carcinoma are difficult to differentiate in the early stages. However, it is advisable to seek advice whenever there is some growth of mass, a persistent painless red eye or white lesions on the cornea. Smoking, sun exposure and immune-compromised stage are the risk factors.

The treatment of choice is complete excision biopsy with base and margin cryotherapy whenever possible in small lesions. Topical chemotherapy and immunotherapy drugs are also available for use in selected cases. However, again, if the patients present themselves late, then destructive surgery is again required as for eyelid tumours.

Apart from retinoblastoma, there are other intraocular cancers seen in adults. The common ones are melanoma and adenocarcinoma. We frequently encounter metastasis of the breast, lung and bones. These cancers cause a decrease in the vision, and sometimes go unnoticed if the vision in the other eye is good. Treatment options are plaque brachytherapy (radiation therapy) in the early stage and enucleation (eye removal surgery) in the late stages. Therefore, metastasis of the eye should be suspected in patients with breast and lung cancers when they complain of a decrease in vision.

Cancer can arise in any part of the eye and orbit. Tumours from orbital contents (the structures around the eyeball like lacrimal gland, muscles, nerves and bones) generally produce proptosis, that is, outward bulging of the eyeball. Though proptosis is commonly caused by thyroid-related disease or by inflammation, we send it for a CT scan or MRI scan to rule out tumours of the orbit. Common cancers of the orbit are lacrimal gland adenocarcinoma, lymphoma, multiple myeloma, local invasion from paranasal sinus cancers, rhabdomyosarcoma and neuroblastoma in children and metastasis of the breast, lung, prostrate and kidney cancers to name a few.

Apart from the above malignant lesions of the eye, there are many more benign tumours. So although the eye appears to be a small organ, cancer of the eye can be of varied types, which could be sight threatening to life threatening. As with other cancers of the body, early diagnosis and treatment are always recommended.

Dr Sthapit is an ocular oncologist at Tilganga Institute of Ophthalmology