ON14 Skin Cancer

The skin is the body’s largest organ.

Skin cancer is the most [blank_start]common[blank_end] cancer in New Zealand. New skin cancers total about 82,000 per year, compared to a total of 16,000 for all other types of cancer. Our skin cancer rates are the [blank_start]highest[blank_end] in the world.

Risk factors for skin cancer: • [blank_start]Light[blank_end] skin color, hair color, eye color, freckles • Genetics • Certain types of [blank_start]moles[blank_end] • Long-term [blank_start]sun[blank_end] exposure • History of childhood [blank_start]sunburns[blank_end]

Skin Cancer Basics = an abnormal change in the skin resulting from uncontrolled cellular growth. • Pre-Cancerous skin cancer » [blank_start]Actinic keratosis[blank_end] • There are three main types of skin cancer: » [blank_start]Basal[blank_end] Cell Carcinoma (BCC) » [blank_start]Squamous[blank_end] Cell Carcinoma (SCC) » [blank_start]Melanoma[blank_end]

Causes of Skin Cancer? • [blank_start]Ultraviolet[blank_end] (UV) radiation is the main cause. NZ UV radiation is 40% [blank_start]higher[blank_end] during summer compared to northern hemisphere. The [blank_start]low[blank_end] ozone levels here – the ozone layer absorbs a good deal of UVB ultraviolet light from the Sun. • Artificially-produced UV radiation • Chemicals (rare)

Actinic (solar) Keratosis: •A [blank_start]pre[blank_end]-cancerous condition of thick, scaly [blank_start]patches[blank_end] of sun-damaged skin. • Benign but can progress to invasive malignant disease if left [blank_start]untreated[blank_end] • Cryosurgery or topical treatment (more soon)

Basal Cell Carcinoma (BCC): - Basal Cells form the [blank_start]deepest[blank_end] layer (basal layer) of the epidermis, and function as the precursors of all the skin cells above them. - BBC is the [blank_start]least[blank_end] dangerous of the skin cancers, grows [blank_start]slowly[blank_end], and rarely [blank_start]spreads[blank_end] beyond original location. • Easily [blank_start]detected[blank_end] and treated • Seldom life-threatening - Appearance: • Open [blank_start]sores[blank_end], reddish patches, [blank_start]shiny[blank_end] bump, pink growth, [blank_start]scar[blank_end] like area, lump that bleeds and crusts

Two in every three NZers will develop a non-melanoma skin cancer.

Squamous Cell Carcinoma (SCC) - Squamous Cells arethe most [blank_start]abundant[blank_end] cells in the skin, located primarily in the [blank_start]epidermis[blank_end] - About SCC: Can spread to other areas (metastasize) and cause death, but this is [blank_start]rare[blank_end]. Most cases are not dangerous if detected and treated early. Considered “more aggressive” than basal cell carcinoma, although they are both highly [blank_start]treatable[blank_end]. [blank_start]20[blank_end]% of skin cancers are SCC. - Appearance: • [blank_start]Wart[blank_end]-like growth, • [blank_start]scaly[blank_end] red patch(es), • open sore(s) that persist • Often appear as [blank_start]elevated[blank_end] growths with a central depression

BCC and SCC can usually be removed by: • [blank_start]Surgical[blank_end] excision • [blank_start]Freezing[blank_end] tumor (cryosurgery) • Topical treatments ([blank_start]fluorouracil + imiquimod[blank_end]) • Radiation is used in [blank_start]some[blank_end] cases

Topical Tx: 1. Fluorouracil 5% cream (20g subsidised tube.) MoA: incorporates into [blank_start]RNA[blank_end] inhibiting [blank_start]DNA[blank_end] replication. Application likely to cause [blank_start]redness, tenderness, ulceration[blank_end], etc, which repairs afterwards. 2. Imiquimod cream 5% (sold as 12 satchets). MoA: Immune response modification, [blank_start]local cytokine inductor[blank_end]. Can cause [blank_start]itching, flaking,[blank_end] and painful erosions on mucus [blank_start]membranes[blank_end].

Melanoma (MM): A skin cancer that arises in a [blank_start]pigment[blank_end] producing cell. - 80-96% is caused by [blank_start]UV[blank_end] exposure - One of the most common types of cancer for [blank_start]25–44[blank_end] year olds - [blank_start]Deadliest[blank_end] form of skin cancer – Can be found [blank_start]anywhere[blank_end] on the body – Melanoma was the [blank_start]6th[blank_end] most common cancer that people died from in New Zealand

(Appearance) Melanoma can: • appear as a [blank_start]new[blank_end] spot • be an existing spot, freckle or mole that [blank_start]changes[blank_end] colour, size or shape • sometimes be [blank_start]itchy[blank_end] or bleed • look different to other spots • appear [blank_start]anywhere[blank_end] on the body (even on parts that aren’t usually exposed to the sun, such as the soles of your feet or under your toenails) • be [blank_start]raised[blank_end] ('sticky out') and look [blank_start]shiny[blank_end] in appearance • appear quickly

Detection: • [blank_start]Self[blank_end]-examination • Apps • Mole [blank_start]maps[blank_end] • Healthcare visits • [blank_start]Early[blank_end] detection is KEY ABCDEs of Melanoma Screening: - [blank_start]AYSMMERTRY[blank_end] (bad) - [blank_start]BORDERS[blank_end] (round = healthy) - [blank_start]COLOURS[blank_end] (uniform colour = healthy) - [blank_start]DIAMETER[blank_end] (>[blank_start]6mm[blank_end] = bad) - [blank_start]ELEVATION[blank_end] (raised/flat combined = bad)

Prognostic features - melanoma: based on "Breslow" depth. 1. Good prognosis – Breslow [blank_start]< 1mm[blank_end]. 2. Intermediate prognosis – Breslow [blank_start]1-4mm[blank_end]. (10 year survival rate 100% - [blank_start]59[blank_end]%.) 3. Bad prognosis – Breslow [blank_start]>4mm[blank_end]. (10 year survival rate [blank_start]36[blank_end]%.)

Sentinel lymph node biopsy for MM: Recommended for MM with Breslow [blank_start]1-4[blank_end]mm. – Lymphadenectomy for [blank_start]positive[blank_end] nodes • Powerful [blank_start]prognostic[blank_end] feature for disseminated disease... (bad sign...) • It does not affect [blank_start]survival[blank_end] of patients

Treatment of Melanoma: - Surgical excision (Mohs*) • In situ = [blank_start]5 mm[blank_end] margin • Invasive= [blank_start]1-3[blank_end] cm depending on [blank_start]Breslow’s[blank_end] depth - Immunotherapy e.g. [blank_start]Keytruda[blank_end] (Pembrolizumab) - Radiotherapy Can specifically [blank_start]target[blank_end] areas Mohs surgery (a certain method invented by a mr mohs) yields higher [blank_start]clearance[blank_end] rates than standard excision, and smaller wounds - therefore better [blank_start]cosmetic[blank_end] results. Widely accepted as treatment of first choice for [blank_start]neck and face[blank_end] melanoma and [blank_start]high risk[blank_end] basal cell carcinoma and squamous cell carcinoma.

Prevention • Avoid Artificial Sun – [blank_start]Tanning[blank_end]/sun lamps - Limit Sun Exposure: • Avoid [blank_start]midday[blank_end] sun • Apply [blank_start]sunscreens[blank_end] often (at least [blank_start]30[blank_end] SPF) • Use UVA/UVB blocking [blank_start]SUNGLASSES[blank_end]

Sand, water, snow, and ice magnify UV exposure.

Clouds reduce UV exposure.