Skin Cancer

Question 1

(Canadian #s) skin cancer accounts for about ____ of cancer diagnosis

Answer 1

1/3

Question 2

what are the 3 common types of skin cancer

Answer 2

• Basal cell carcinoma (highest prevalence)
• squamous cell carcinoma
• malignant melanoma (lowest prevalence and the worst)

Question 3

skin cancer can be _______ & starts with ______ lesion

Answer 3

skin cancer can be avoided & starts with precancerous lesion

Question 4

what is the precancerous lesion called?

Answer 4

actinic keratosis

Question 5

what is the etiology of skin cancer

Answer 5

• excessive exposure to sun (UV ligh -UVA & UVB)
  - cumulative skin exposure
• proportional directly to age (the older you get the more likely you are to get skin cancer)
• inversely proportional (as one goes up one goes down): melanin (protective factor) decreases risk (more melanin less likely to get skin cancer)

Question 6

skin cancer has a ____% cure rate if detected and treated early

Answer 6

95

Question 7

Basal cell carcinoma

Answer 7

• most common
• begins in basal layer
• common type in light skin
• basal cell origin
• slow progression
• local invasion if left untreated, but rarely metastasizes
• on exposed areas to sun: mostly head & neck
• begins as nodular lesion
• biopsy for Diagnosis

Question 8

Malignant melanoma

Answer 8

• arise in melanocytes (melanocytes produce melanin which is pigment)
• increase risk in fair skin (more melanin means less skin cancer risk)
• worst form: -progresses rapidly
  - mets (easily & early)
• mostly exposed but also non exposed surfaces (major lesions changes (mnths)):
  - doubling in size (3-8 mnths)
  - colour
  - irregular border
  - pruritus
  - crusting
  - ulceration
• mets to brian, bone, lung, liver (reason for fatality is because of metastasis) can be fatal, curable if caught early

Question 9

squamous cell carcinoma

Answer 9

• 2nd most common
• origin in keratinocytes
• on exposed areas: nose, forehead, lower lip
• intraepidermal & invasive types
• faster progression
• variable appearance of lesion ex.nodule, papules, ulcerative lesions
• mets: -to local lymph nodes & via blood
• if treated early 95% cure rate, if left than metastasizes 75% mortality rate

Question 10

basal cell carcinoma & squamous cell carcinoma collectively combined account for ____% of skin cancer

Answer 10

90

Question 11

what kind of cells does basal cell carcinoma originate in?

Answer 11

-basal cell origin

Question 12

what kind of cells does squamous cell carcinoma originate in?

Answer 12

-origin in keratinocytes

Question 13

what kind of cells does malignant melanoma originate in?

Answer 13

-origin in melanocytes

Question 14

what is the general rule for detecting skin cancer

Answer 14

any suspicious change to a lesion should be investigated, better to be told it is not a malignancy then it is a malignancy & dont know

Question 15

treatment of skin

Answer 15

• early detection
• Sx excision (in all cases)
• AND chemo if systemic (spread to secondary site)

Question 16

ABCDE changes may indicate skin cancer

Answer 16

A- asymmetry (lesion no longer symmetrical)
B- border (border becomes irregular)
C- colour (changes in colour)
D- diameter (size, generally doubling in size in short time)
E- elevation (raised borders)