Jaime Lewis (Host): Summer is upon us, and if you're like many other Americans, you'll gravitate to spend more time in the sun. But, did you know that skin cancer is the most common cancer in the United States? To give us insight on how to stay safe in the sun and prevent skin cancer this summer, we're talking with Dr. Srilakshmi Madhusudhan. She is a Board Certified Family Medicine Physician with Dignity Health Medical Group in Bakersfield. This is Hello Healthy, a Dignity Health Podcast. I'm your host, Jaime Lewis. Dr. Madhusudhan, thank you so much for joining me.

Srilakshmi Madhusudhan, MD: Thanks for having me.

Host: Let's start with some definitions. So what is skin cancer and how is it caused?

Srilakshmi Madhusudhan, MD: So skin cancer is an abnormal growth of skin cells and most common reason is sun exposure and hence UV radiation that causes damage to the skin cell DNA, which in return causes abnormal growth of these cells. And depending on what type of cells are involved, for example, like a top layer, squamous cells or little deeper cells, basal cells or the pigment producing cells called melanocytes, you could have different types of skin cancers.

Host: So what are some of the risk factors then of skin cancer?

Srilakshmi Madhusudhan, MD: The most important risk factor is sun exposure. We get UV radiation through sun exposure. That's one of the most common and preventable reason for skin cancers. The other factors that are not in our hands, not preventable, are genetic factors like certain condition called xeroderma pigmentosa. That's an inherited disorder that can cause increased risk for squamous cell cancers or melanomas.

 Also certain mutations like BRACA genes and if you have a family history of breast cancers or ovarian cancers or family history of melanomas or pancreatic cancers, would have an increased risk also for skin cancers and also, if somebody has a personal history of skin cancer, that puts them under more risk for future skin cancers and also certain phenotypes, meaning your skin color like fair skinned people, and your hair color could be red, blonde or light brown.

Or for people who have a more freckles. And also if somebody has light colored eyes like blue, gray or green, those are also at increased risk for getting skin cancers. And I would also say that your occupation could put you under a more risk. Like if somebody is working outside most of the time, they could have increased risk for skin cancers and also if you're taking certain medications that would increase your sensitivity to sunlight. Even some of the acne medications we prescribe, like doxycycline can increase your sensitivity to sunlight, could put you under more risk. And also for you have some of the medical conditions that would lower your immunity. You might have an increased risk for developing skin cancers. Also, males more than 50 years of age tend to develop more skin cancers.

And although the risk for dark skinned people seems to be less, but the mortality risk is very high; means dying from skin cancers is much higher in that group because either they're diagnosed late, that could be one of the reasons why. So it's very, very important if you are dark skinned, you might be more cautious in checking in non sun exposed areas, like your palms and soles or your mucosal membranes to check for those cancers too. Also, if somebody is doing a lot of recreational activities like in high attitudes, or somebody is doing more of swimming or close to snow, those reflective areas would also increase your risk for skin cancers.

Host: All right. Well, let's talk about what to look for then. What are the signs, what are the common symptoms of skin cancer?

Srilakshmi Madhusudhan, MD: Depending on the type of skin cancer, again, we are talking about non-melanoma skin cancers and melanomas. Non-melanoma skin cancers are either basal cell cancers or squamous cell cancers and melanomas are that are developed from your moles. So you basal cell carcinoma can be looked like a fleshy bump or nodule on mostly sun exposed areas, which is like head, neck areas and ears and scalp, which are growing and not healing. And any squamous cell carcinomas could look as just scaly patches, and red or they could be bumps. And again, if they are not healing for a few weeks, or if they are bleeding or itching, you definitely need to be checked for a skin cancer. And your moles, even if they are new moles developing or the existing moles, which are changing in their characteristics.

Like I would say, normally we follow this formula as A B C D E F. A is for asymetry, which means when you fold the mole if it's not equal on both sides, that's called asymmetrical mole and your borders; if they are irregular or growing more on one side. And color, if your mole has more than one or two colors and diameter, which is the length of the mole is more than your pencil eraser size and evolution means how it's progressing. And, F I would say for funny looking or ugly duckling, we say if one mole is looking very different than your other moles, that would be of a concern for a developing melanoma. And mind you, melanomas are the most serious type of skin cancers, even though we have basal cell and squamous cells, which are more treatable. And they are the most common skin cancer. Melanoma, the percentage wise, they're less, but they are the more deadly ones.

Host: Well, we always hear about UV rays. Can you give a simple breakdown maybe on UV rays and what they mean to skin cancer?

Srilakshmi Madhusudhan, MD: Definitely. So our UV radiation exposure mostly comes from sunlight, and sunlight has UV A, B, and C. Those are the types of rays and the ones that reach the earth are the A and B, and C are usually they are filtered by the ozone layer, so we don't get the C rays. Out of the A and B rays, the A, which have a longer wavelength, they reach the deeper part of the skin and cause more skin damage.

And the B is mild percentage of the UV radiation, which only cause damage to the top layer of the skin, which mostly cause the sunburns.

Host: So along those lines, we also hear about sunscreen and the protection that wearing SPF provides. Is there a certain SPF we should all be wearing? And what are some of the best practices for wearing sunscreen?

Srilakshmi Madhusudhan, MD: Definitely, most of the dermatologists recommend the SPF or sun protective factor 30 and above. Minimum of 30, and that's still recommended. And the way you want to do your sunscreen or sunblock is highly recommended. You would put your sunblock, 365 days of the year, whether it's sunny or even on the cloudy days. Just because it's cloudy doesn't mean you're not getting the UV radiation exposure. But the risk is more during summer months and when you are outside.

So those times you want to put your sunblock at least 15 to 30 minutes before you go out in the sun and you want to keep applying every couple of hours. And the way you would apply is more generously and more frequently. That is the recommended application for your sunblock.

Host: Great. That's very helpful coming into summer. What general practices should people follow to reduce their risk of skin cancer?

Srilakshmi Madhusudhan, MD: So protection, protection from sun, applying sunblock and wearing long sleeve shirts or trousers to cover most of your skin from sunlight, and also avoiding going outside when there's more risk for UV radiation, which is between normally 10:00 AM and 4:00 PM that's recommended.

Also, you want to seek shade whenever it's hot to avoid direct sun exposure and also wearing large, or wide brim hats. That's highly, highly recommended because your baseball caps are not going to protect you from sunlight and wearing glasses with UV protection. That's another good practice.

And also you can always check your UV index, you could go on the EPA or, environmental Protection Agency website and download a link to see how is your UV index in your area on that particular day, and then at that particular time, which normally ranges from zero to 11.

Zero means like less risk of radiation and the higher number, is more risk. You could get the information from the site epa. As a general rule, it's called a shadow rule. If your shadow is longer than you, probably have less exposure to UV radiation. And as your shadow gets shorter, if it's less than a length of your body, then you definitely have more risk. So it's a good idea to stay inside.

Host: That's such a great practical rule of thumb for determining if it's a good time to be outside and, how careful to be with your skincare. Well, thank you Dr. Madhusudhan. We really appreciate all of your expertise and for spending time telling us all about preventative measures for skin cancer. Thank you so much.

Srilakshmi Madhusudhan, MD: Thank you so much for having me.

Host: To learn more about how Dignity Health Bakersfield can help you have your best summer yet, visit Dignityhealth.org/bakersfield. Thanks for joining me. This is Jaime Lewis.