Does Aspirin Have a Protective Role Against Chemotherapeutically Induced Ototoxicity?

Cisplatin has the highest ototoxic potential of all platinum containing compounds. It is used in the treatment of squamous cell carcinoma of the head and neck, germ cell tumours of the testis and bladder carcinoma.

42% of 400 patients receiving high-dose cisplatin (70-85 mg/m2, median cumulative dose 420mg) experienced common toxicity criteria (CTC: appendix 1) grade 3 or 4 symptoms (De Jongh 2003). Ototoxicity is dose related: 75-100% of patients receiving a very high dose and 20-40% with a low dose regime will develop significant ototoxic symptoms. In one study, 50% of head and neck cancer patients treated with cisplatin develop ototoxicity (Blakley 1994).

Cisplatin ototoxicity can present as a variable collection of symptoms and signs. These include bilateral and symmetrical hearing loss that is permanent and irreversible. High frequency sensorineural hearing loss with progression towards lower frequencies. Tinnitus, that is also permanent and irreversible.

There are a number of known factors that can predispose to cisplatin ototoxicity. They include: Dose, duration and mode of administration, age extremes, previous or concurrent cranial irradiation, previous history of hearing loss, renal disease, concomitant use of other ototoxic drugs, noise exposure with concomitant cisplatin administration, decreased serum albumin level, low hemoglobin level, low red blood cell count and a low haematocrit. Interestingly, cisplatin ototoxicity is considered to be exclusively confined to the cochlear, the vestibular system is unaffected (Myers 1993).

Ototoxicity from chemotherapeutic agents is due, in part, to reactive oxygen species. Reactive oxygen species can be attenuated by antioxidants. Salicylates are antioxidants that can be administered as aspirin.