into the light joseph g. morelli, m.d

INTO THE LIGHTINTO THE LIGHT

Joseph G. Morelli, M.D.Joseph G. Morelli, M.D.Professor of Dermatology and Pediatrics, Professor of Dermatology and Pediatrics,

UCDUCDSection Head, Pediatric Dermatology, TCHSection Head, Pediatric Dermatology, TCH

INTO THE LIGHTINTO THE LIGHT

• The effects of the sun on the skin and the need for sun protection

DISCLOSURE INFORMATIONDISCLOSURE INFORMATION

• I have no relevant financial relationships with the manufacturers of any commercial products and/or provider of commercial services discussed in this CME activity.

THE PROBLEMTHE PROBLEM

TYPES OF SKIN CANCERTYPES OF SKIN CANCER

• Melanoma

• Non melanoma (basal cell and squamous cell carcinoma)

Types of Skin Cancer:Types of Skin Cancer:Basal Cell CarcinomaBasal Cell Carcinoma

Types of Skin Cancer:Types of Skin Cancer:Squamous Cell CarcinomaSquamous Cell Carcinoma

Skin Cancer Age of Onset (all Skin Cancer Age of Onset (all types)types)

• May be seen as early as late teens

• Incidence rises rapidly after age 40

• Continues to increase with age

Skin Cancer DeathsSkin Cancer Deaths• 10,071 skin cancer deaths in the US (2006)

• Over 3X the number of motorcycle deaths

• Over 3X the number of drowning

• 10X the number of people killed on a bicycle

MELANOMAMELANOMA

• Because most of the deaths due to skin cancer are from melanoma, I will concentrate on it for the rest of the talk, although the sun protection advice which will be given later is applicable to minimizing all types of skin cancer

Years of Potential life lost due to cancerYears of Potential life lost due to cancer

• Melanoma is the most common cancer for women 25-29

• 2nd to breast cancer for women 30-34• Melanoma deaths represent an average of

17.1 years of potential life lost (YPLL)• Ranks second in YPLL only to adult leukemia• Outranks breast cancer (12.2 YPLL) and

colon cancer (9.5 YPLL)

Skin Cancer in ColoradoSkin Cancer in Colorado• Colorado’s high altitude and sunny climate

increase risk• UV intensity increases approx. 4% with every

1000 feet of altitude• From 1993-2003 the melanoma incidence rate

for non-Hispanic whites rose 12% for men, and 30% for women

10

12

14

16

18

20

22

24

Year

Inc

ide

nc

e

COUS

Melanoma in Colorado

•Consistently outpaces US Incidence

•Incidence increasing over time

MELANOMAMELANOMA

• Cause of melanoma is a combination of genes and sun exposure

MELANOMA AND GENES IMELANOMA AND GENES I

• There is a single gene which if mutated causes melanoma

• There are families in which this mutated gene is inherited

• In these families, almost everyone will get melanoma

• Fortunately, this is very rare

MELANOMA AND GENES IIMELANOMA AND GENES II

• In other melanoma susceptible individuals, there are varied genetic abnormalities, that are not completely understood

MELANOMA AND SUN MELANOMA AND SUN EXPOSUREEXPOSURE

• In those people susceptible to melanoma, sun exposure increases their risk for the development of that problem

SUN EXPOSURESUN EXPOSURE

• Ultraviolet radiation is the portion of the spectrum of light involved in skin cancer development

ULTRAVIOLET RADIATIONULTRAVIOLET RADIATION

• UVC <290 nm (blocked by ozone)

• UVB 290-320 nm (sunburn, DNA damage)

• UVA 320-400 nm (photo aging)

MelanomaMelanoma

• If melanoma is rare in childhood, why is a Pediatrician talking to you?

WHY IS A PEDIATRICIAN WHY IS A PEDIATRICIAN TALKING TO YOUTALKING TO YOU

• Risk factors for developing melanoma can be identified in childhood

• These are the children who must be extra vigilant about sun protection

Risk FactorsRisk Factors

• Freckling• Sunburns• Multiple nevi (moles)• Abnormal nevi (moles)• Susceptible phenotype• Chronic sun exposure• Presence of multiple factors can lead to a

200 fold increase in risk

MOLES IN CHILDHOODMOLES IN CHILDHOOD

• An increase number of moles in childhood is a major sign of risk for developing melanoma later in life

MOLES IN CHILDHOODMOLES IN CHILDHOOD

• I am part of a group at the University of Colorado who have been studying mole development in childhood

MEDIAN TOTAL NEVI BY MEDIAN TOTAL NEVI BY RACE/ETHNICITY AGE 3-8 RACE/ETHNICITY AGE 3-8

YEARSYEARS

0

5

10

15

20

25

30

35

3 4 5 6 7 8Age in years

Med

ian

no

. of

nev

i

White, Non-Hispanic

White, Hispanic

Black

Asian/Pacific Islander

SUMMARYSUMMARY

• Non Hispanic white children in Colorado develop 4-6 new nevi per year from age 3 to 8 years

• >90% remain < 2mm in size

GENDER DIFFERENCESGENDER DIFFERENCES

a. All nevi, whole body

0

5

10

15

20

25

30

35

3 4 5 6 7 8

Age in years

SUMMARYSUMMARY

• Accumulation of nevi in intermittently exposed areas is the same in males and females

• Accumulation of nevi in chronically exposed areas is greater in males than females starting at age 6

DEVELOPMENT OF NEVIDEVELOPMENT OF NEVI

• Genetic predisposition (including skin color)

• Sun exposure


• Environment (geography and climate)

• Behavior


• Estimated that 80% of lifetime UV sunlight exposure occurs in childhood

BEHAVIORBEHAVIOR

• As boys get older parents may be less vigilant with sun protection

• Boys may just be outside more

RED HEADSRED HEADS

• Children with red hair increase risk for the development of melanoma

• Children with red hair have increased freckling

• But, children with red hair have less nevi

RED HEADSRED HEADS

• Children with light brown and hair and increased freckling have more nevi

RED HEADSRED HEADS

• Red hair is determined by polymorphisms of the melanocortin 1 receptor

• Homozygotes or compound heterozygotes at certain alleles have red hair

• 4 highly penentrant alleles (R alleles)

• V92M, R151C, R160W,D294H

RED HEADSRED HEADS

• Red heads have increased risk of melanoma, but have less nevi

• Is the mechanism for melanoma development different in red heads?

NEVUS DENSITYNEVUS DENSITY

• Effect of sunburn

• Sunburn history at age 5 and 6 years

• Nevus counts age 7 years

SUNBURNSUNBURN

• More than 2/3 reported at least one sunburn

• Face and shoulders most commonly burned

• Followed by back and arms

EFFECT OF SUNBURNSEFFECT OF SUNBURNS

• Higher prevalence of nevi over the total body was associated with the total number of sunburns

• This may be the effect of circulating inflammatory mediators or just a sign that increased sunburns mean less overall protection

EFFECT OF SUNBURNSEFFECT OF SUNBURNS

• Three or more sunburns on the back were associated with higher nevus number on the back

• No number of sunburns on the face, arms or legs was not associated with any increase in nevi

EFFECT OF SUNBURNS EFFECT OF SUNBURNS SUMMARYSUMMARY

• Any history of sunburn leads to greater overall nevus number

• Sunburns on the back an area of intermittent exposure lead to greater nevus density on the back

• Sunburns on chronically exposed areas do not increase local nevus density

THE WHITEST OF THE WHITETHE WHITEST OF THE WHITE

• Well established that lighter skinned children have more nevi than darker skinned children

• What about the whitest of the white?

• Does tanning effect nevus development in very light skinned children?


• We evaluated the effect of tanning on the lightest skinned subjects in our cohort by chromameter readings

• Red heads were excluded

• Tan level determined by chromameter


• Tan level determined by late summer differences between chromameter readings taken from the inner upper arm and outer lower arm


• Year Tan level N Nevi P value

• 2004 <5 20 18.4 0.049

• >5 111 25.2

• 2005 <5 20 23.3 0.020

• >5 111 33.2

• 2006 <5 20 25.9 0.016

• >5 111 38.6


• Similar analysis in darker skinned subjects showed no effect of tanning on nevus development


• In very light skin children tanning leads to an increase in nevus number

• We do not know if the untanned group did not tan because of the inability to tan or because of better sun protection

SUMMARYSUMMARY

• Light skinned children have more nevi than dark skinned children

• Boys have more nevi in chronically exposed areas than girls

• Red heads have less than nevi other children with other hair color

• Sunburns increase the number of moles

SUN PROTECTIONSUN PROTECTION

• Sunscreen does not equal sun protection


• Avoidance is the best protection• 10:00 am to 4:00 pm are peak hours

UVB and Temperature UVB and Temperature Data for JulyData for July A Sunny Day A Sunny Day

0.00

20.00

40.00

60.00

80.00

100.00

120.00

0:00

:00

0:45

:00

1:30

:00

2:15

:00

3:00

:00

3:45

:00

4:30

:00

5:15

:00

6:00

:00

6:45

:00

7:30

:00

8:15

:00

9:00

:00

9:45

:00

10:3

0:00

11:1

5:00

12:0

0:00

12:4

5:00

13:3

0:00

14:1

5:00

15:0

0:00

15:4

5:00

16:3

0:00

17:1

5:00

18:0

0:00

18:4

5:00

19:3

0:00

20:1

5:00

21:0

0:00

21:4

5:00

22:3

0:00

23:1

5:00

Time of Day

Temperature 0F

UVB 25(watts/m2)


• If one must be outside during the peak UV hours of the day, it is best to stay in the shade as much as possible


• Tightly woven cotton long sleeve shirts and pants are excellent sun protection

• Swim shirts worn at the pool are excellent sun protection

• Broad rimmed hair should also be worn


• Cover all exposed skin with sunscreen• Apply ½ hour before going out and again when

you arrive at you destination• Think of it as needing 2 coats of paint to cover a

wall

WHAT SUNCREEN SHOULD I WHAT SUNCREEN SHOULD I USE?USE?

• The higher the SPF the better

• Sunburn is a gross indicator of sun damage

• Even if sunburn is prevented by SPF 15 sunscreen, there is evidence of microscopic sun damage

• Sunscreen should also have UVA protection

NAMES TO LOOK FORNAMES TO LOOK FOR

• Octylcrylene

• Avobenzone

SUMMARY ISUMMARY I

• Skin cancer is the number one cancer in the United States

• Melanoma is a deadly form of skin cancer

• Children with risk factors for the development of melanoma can be identified at an early age

SUMMARY IISUMMARY II

• Sun protection includes avoiding the mid day sun, staying in the shade, clothing and hats, and sunscreen

REFERENCESREFERENCES

• Elwood JM, Jopson J. Melanomaand sun exposure: an overview of published studies. Int J Cancer 1997;73:198-203

• Gallagher RP et al. Suntan, sunburn, and pigmentation factors and the frequency of acquired melanocytic nevi in children. Arch Dermatol 1990;126:770-6

REFERENCESREFERENCES

• Gallagher RP, et al. anatomic distribution of acquired melanocytic nevi in white children. A comparison with melanoma: The Vancouver Mole Study. Arch Dermatol 1990;126:466-71

• Dodd AT, et al. Melanocytic nevi and sun exposure in a cohort of Colorado children: anatomic distribution and site-specific sunburn. Cancer Epidemiol Biomarkers Prev 2007;16:1-8

into the light joseph g. morelli, m.d

Health & Medicine

melanoma cause of melanoma

types of skin cancer

melanoma deaths

risk of melanoma

skin cancer development

skin cancer deaths

red heads red heads

red heads red hair