Hitting a Nerve

The Parkinson’s disease and melanoma dilemma


 

One of the biggest challenges I (and I suspect many) neurologists face is treating Parkinson’s disease in patients with a history of melanoma.

This is always tricky. Every medicine used for the condition has warnings about it, but on the other hand, we also want to help these people.

This is confounded by the fact that there clearly is an increased risk of melanoma with Parkinson’s disease alone. But you can’t tell patients with a history of melanoma not to get Parkinson’s disease and vice versa.

Our only real control here is what medications we prescribe. Data now suggest that medications have nothing to do with the risk of melanoma, but how well would that stand up in court? The labeling for most Parkinson’s medications clearly lists melanoma as a contraindication, and I don’t see anyone willing to sink the money needed to get that taken off anytime soon.

A tenet of medicine is "do no harm." We all try to live by that. But which is more harmful? Putting a patient at risk of a (relatively) incurable cancer? Or letting them suffer, day by day, of a degenerative illness when effective treatments are just a prescription pad away?

I don’t know what the right answer is. I try to explain all the angles to patients as best I can, and let them make an informed decision. But at the end of the day I still worry. I worry about them. I worry about their families. I worry about lawsuits.

The situation gets worse if they DO develop a melanoma. The knee-jerk response is to stop their Parkinson’s medications, with immediate (sometimes disabling) worsening of their tremor, balance, and other symptoms. But is that the right thing to do?

The relationship between Parkinson’s disease, its treatment, and melanoma remains murky even today. But the association is there, and no one wants to guess wrong. We’re all trying to do our best for the patient, but the definition of what’s best varies from person to person.

The lack of a crystal ball in medicine is a real problem. The most we can do some days is educate the patient, work with them as best we can, and hope things work out in their favor.

Dr. Block has a solo neurology practice in Scottsdale, Ariz.

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