Thinking about skin and ET

Ummm. Balmy and sunny (all night) in Reykjavik,
Iceland. ET patients: Don't forget to take your
sun screen!

My summer here at north latitude 45 around the Great Lakes has so far been unseasonably rainy and cold. In fact, right now it's 55 degrees with a cold drizzle. That means the weather is actually better in Reykjavik, Iceland, where it is 59 and partly sunny (and will be for the next 24 hours because of the Midnight Sun). It's also 63 in Fairbanks, Alaska, and a sweltering 67 in Yellow Knife, Northwest Territories of Canada.

Thanks a lot, Gods of Weather. I hate it when it's hot and humid, but no need to be sarcastic.

But never mind my digressions and resentments of people getting better weather far to the north of me. Today's topic is ET and skin cancer. This comes up fairly frequently among people who read the info that comes with their hydroxyurea, which warns that it may cause skin cancer, and become worried about sun exposure. So I did some digging, and I hope this info will encourage you to talk to your doc about this. Here's what I found:

Non-melanoma skin cancers are higher in MPN patients taking HU, according to a 2009 study reported in Blood Journal of 200+ MPN patients. The study showed two important things:

One: Risk of non-melanoma skin cancer was higher among both light- and dark-skinned patients than among the general population. Dark-skinned  MPN patients taking HU had a much lower rate of skin cancer than light-skinned patients.

Two: All the cancers in the study were non-melanomas, that is, cancers that were easily treated.

Does the HU actually CAUSE these cancers? The study didn't say this. But there is a correlation between elevated skin cancer and HU taken at the dosages MPN patients need. (Sickle cell anemia patients take much smaller doses of HU. they were also a small part of this study, and they did not develop any skin cancers.)

How much higher was the rate of cancer in patients taking HU? Sixteen patients in the group of 237 studied had developed skin cancers, or about 7 percent of the study patients. (In the general population, the rate of skin cancer is less than 1 percent among both light- and dark-skinned people.)  Does this relatively small preliminary study reflect the whole picture? Hard to say, it's small and preliminary.

I am a darker skinned caucasian, and I never worried much about sun exposure until middle age. Since taking HU, I started staying in the shade or sun shelter and using sunscreen. (IMPORTANT: Don't forget the tops of your feet if you're wearing sandals and the top of your head if you're bald!) I'm not afraid to walk on the beach for 30 minutes or take a short boat ride. But I am aware of how much sun I'm getting, and I limit exposure much more than I used to.

People of color do not have immunity from skin cancer. Acral lentiginous melanoma (AML), for reasons that are not clear to doctors, seems to affect people with more skin pigmentation. Having ET or taking HU may not increase the risk of this type of cancer, but it does underscore the fact that patients who are also people of color should ask their doctors about their risk factors. A high natural amount of melanin in your skin does give you an edge with most cancers, but it does not equal immunity.

Avoid homemade sunscreens. The fact that people are making their own sunscreens wasn't something I was aware of until I heard this NPR report. Apparently, some homemade sunscreens are completely ineffective. Other homemade preparations may use valid sun screening ingredients, but not in sufficient amounts or sufficiently mixed throughout the sunscreen.

As the report noted, commercial sunscreens have been tested for effectiveness.  I sympathize with consumers concerned that the sunscreen ingredients can be absorbed through your skin and that these products should be tested more.

If you don't want to use commercial sun screens, you're better off wearing a hat and clothing with good coverage than using homemade sunscreen.

Bottom line: Talk to your doctor. When all is said and done, your doctor is the best person to assess your risks of skin cancer generally and to help you determine how to keep yourself safe in the sun. I am looking forward to a few days at the lake, where I will wear my hat and use my sunscreen, but do plan to soak up some vitamin D, the "sunshine vitamin" that helps your body absorb calcium.

Be well!

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