Chpt 9 Skin Cancer W & L 40

1. Basal cell carcinoma (BCC) is a slow-growing form of skin cancer that does not tend to metastasize.

ANS: T BCC, a slow-growing form of skin cancer that does not tend to metastasize, arises from the stem cells of the stratum basale.

7. The risk of metastatic involvement increases as the depth of a squamous cell carcinoma (SCC) increases.

ANS: T Size and invasion—tumors greater than 1 cm in size and more than 4 mm deep have a higher propensity for metastasis, even in sun-exposed areas.

5. The skin is the largest organ of the human body.

ANS: T The skin is the largest organ of the body, covering about 17 to 20 sq ft on the average person.

What is CEA?

Carcinoembryonic Antigen

What is the staging system for melanomas?

Clark and Breslow

What is Mohs surgery?

During Mohs surgery, thin layers of cancer-containing skin are progressively removed and examined until only cancer-free tissue remains. Mohs surgery is also known as Mohs micrographic surgery.

nonmelanomas have higher mortality rates than melanomas

False

in late stage disease, melanomas tends to ulcerate and have a rolled border on exam?

False (nonmelanomas)

What is the etiology of skin cancer

UV radiation exposure genetic disorders such as albunism ionizing radiation exposure of skin to chemicals like arsenic chronic irritation and inflammation

What are the RT fields for nonmelanomas?

focused with 1 to 2 cm margin around lesion

What is the dose for melanomas?

lower since radiation is adjuvant to chemotherapy and depends on patients life expectancy; 30 Gy in 10 fractions, 36 Gy in 6 fractions or 50 Gy in 25 fractions for solitary metastatic lesions

What kind of chemotherapy can be used for nonmelanomas?

topical

Skin cancers make up ___ of all cancer incidence in men and women in the US

1/3

When does dry desquamation occur?

30 Gy

When does wet desquamation occur?

40 Gy

What is the total dose for nonmelanomas?

45 to 70 Gy depending on location. daily fractionation of 2 Gy

The treatment of choice for most melanoma skin cancer is a. surgery b. isolated limb perfusion c. chemotherapy d. RT

a surgery

Control rates for stage I basal cell carcinoma are about a. 90% b. 70% c. 50% d. 205

a. 90%

The main triggering mechanism for skin cancer is a. exposure to UV light b. therapeutic radiation exposure c. chronic heat exposure d. traumatic exposure

a. UV light

Melanocytes are found in the ___ layer of the skin a. basal b. subcutaneous c. corneum d. sebaceous

a. basal

Melanocytes are found in the ___ layer of the skin stratum a. basale b. granulosum c. spinosum d. corneum

a. basale

The layer of the epidermis that contains cells that is most sensitive to radiation is the a. stratum basale b. stratum granulosum c. stratum lucidum d. stratum corneum

a. stratum basale

cells most sensitive to radiation are located in which layer of the epidermis a. stratum basale b. stratum granulosum c. stratum lucidum d. stratum corneum

a. stratum basale

What happens if larger areas need treatment?

adjacent, matched electron fields (overdose areas should be identified using computerized dosimetric treatment planning and skin gaps may be necessary)

What are the fields for RT of melanomas?

adjuvant RT will have margins of 3 to 4 cm and may include regional lymphatics; deeply invasive, large nonmelanomas may need regional node dose

The technique in which the tumor is removed and examined one layer at a time is a. currettage and electrodesiccation b. Moh's surgery c. cryosurgery d. laser surgery

b. Moh's surgery

Clark method for classifying melanoma is based on a. width of growth b. depth of invasion c. maximum thickness in millimeters d. nodal mets

b. depth of invasion

How is incisional biopsy used?

if lesion is large, expected benign or in a cosmetically compromising location

When does RT play a definitive role?

in nonmelanomas, especially if partial excision and/or to preserve cosmesis

What are the blood markers?

keratin, CEA, S-100 protein

What are the histologies of melanomas?

lentigo maligna superficial spreading nodular palmar/plantar acral lentiginous

What are the late signs of melanoma?

lesions may be tan or black, itching and/or bleeding lentigo maligna: flat pigmented grow radially, penetrates vertically Superficial spreading: disorderly appearance, extends horizontally and vertically Nodular: grow vertical, uniform, blue-black color, sharp delineation

What is cryotherapy?

liquid nitrogen for injury to vasculature for nonmelanomas

What are late signs of basal cell and squamous cell?

loss of skin markings, change in pigment, hyperkeratosis, ulcerating lesions show very late as lesions grow it ulcerates and bleeds and may have a rolled border and look crusty

What are the two main types of primary skin cancers?

melanoma and nonmelanomas

What is immunotherapy used for?

melanomas

What role does immunotherapy play in the management of melanoma?

melanomas have been known to regress. regression is thought to be the body's immune response to disease. immunotherapy attempts to take advantage of this response and gives the immune system a boost to help fight disease

how to melanomas spread?

penetrate deep into dermal layers and will met via the blood route easily since blood vessels are in the dermal layers of the skin area lymph nodes are considered when managing melanomas

how should the patient surface be?

perpendicular to the horizontal axis of the electron beam

What is the physical exam workup for skin cancers?

physical exam: look for asymmetry, borders, color and diameter

photodynaic therapy is?

porphyrin administered to patient then exposure to intense light for nonmelanomas

Are melanomas radiosensitive or resistant?

resistant

Are nonmelanomas radiosensitive or resistant?

sensitive

What are positioning aids?

simple, pillows, sponges, tape

How can hypofractionation be done

single dose of 20 Gy to 32 Gy in four fractions

What are the early signs of basal cell and squamous cell?

small papule with telangiesctasia, firm induration of skin, patches of keratosis and scaling

What kind of chemotherapy can be used for melanomas?

systemic chemotherapy

What is the lymph drainage for nonmelanomas?

tend to remain in the dermal layers of the skin

RT can also be adjuvant for nonmelanomas

true

The most common cancer type overall in the US is nonmelanoma skin cancer?

true

The use of kilovoltage x-rays allows the target volume to be covered with a smaller field size compared with a field that would produce similar effects near the skin through the use of electrons True False

true

melaomas are usually tan or black in color

true

What side effect can be expected with high doses and especially with bolus?

wet desquamation

What margins needed for merkel cell?

wider margins 4 to 5 cm

Can both electron and kilovoltage be used to treat nonmealnomas?

yes

When does skin erythema occur?

20 Gy

Melanomas are not usually treated with RT because they are radioresistant

True

What is laser therapy?

carbon dioxide laser excises with minimal bleeding in nonmelanomas

2. What is the most common form of skin cancer? a. basal cell carcinoma b. squamous cell carcinoma c. melanoma d. Kaposi sarcoma

ANS: A In 2007, the incidence of basal cell and squamous cell skin cancer was estimated to be more than 1 million new cases (basal cell cancers outnumber squamous cell cancers of the skin approximately 5 to 1), whereas malignant melanoma of the skin was expected to account for 59,940 new cases, an increase seen over the last few years.

4. What is the most widely used staging system for melanoma? a. TNM b. Breslow c. Clarke d. ATCG

ANS: B Because the Breslow system has more to do with tumor bulk than penetration, the current thought is that this system is more reproducible and correlates more accurately with the risk of metastatic disease and prognosis than the Clark system.

1. What is the most significant cause of skin cancer? a. radiation exposure b. sun exposure c. arsenic exposure d. human papillomavirus

ANS: B Many factors are directly and indirectly responsible for the development of the various forms of skin cancer, but the major cause is exposure to UV light. REF: Chapter 40, Skin Cancers and Melanoma, p. 915

5. What is the technique in which the tumor is removed and examined one layer at a time? a. curettage and electrodesiccation b. Mohs surgery c. cryosurgery d. laser surgery

ANS: B Mohs, or microscopic, surgery is different from conventional surgery in that the tumor is completely mapped out through the examination of each piece of removed tissue to determine the presence and extent of any tumor. The tumor is removed one layer at a time and examined under a microscope.

11. Which of the following diseases is occasionally treated by total skin electron irradiation? a. Kaposi sarcoma b. melanoma c. mycosis fungoides d. multiple myeloma

ANS: C Cutaneous T-cell lymphoma, including mycosis fungoides—this is a disease of the T lymphocytes. It resembles eczema or other inflammatory conditions and tends to remain localized to the skin for long periods. Total body irradiation with electrons and topical nitrogen mustard has been used to control early stages of the disease. REF: Chapter 40, Skin Cancers and Melanoma, p. 919

3. What form of skin cancer has the highest mortality rate? a. basal cell carcinoma b. squamous cell carcinoma c. melanoma d. Kaposi sarcoma

ANS: C Melanomas are much more lethal than their nonmelanoma counterparts. About 8110 people (5220 males and 2890 females) will die from melanoma in 2007. Although nonmelanomas outnumber melanomas approximately 30:1, more people die each year from melanoma than from nonmelanoma skin cancers.

7. What do the ABCDs of melanoma represent? a. adenocarcinoma, basal cell carcinoma, carcinoma in situ, dermatoma b. abrasion, bruise, cut, dimpling c. asymmetry, border, color, diameter d. appearance, blackness, contour, depth

ANS: C The American Cancer Society released the ABCD rules for early detection of melanoma: asymmetry, border, color, and diameter.

10. Which of the following factors contributes to the incidence of skin cancer? I. geographic location II. skin type III. previous skin cancers IV. gender a. I and II b. II and III c. I, II, and III d. I, II, III, and IV

ANS: D All of the above contribute to the incidence of skin cancer.

9. Which cancer is commonly associated with HIV? a. rhabdomyosarcoma b. mycosis fungoides c. melanoma d. Kaposi sarcoma

ANS: D Kaposi sarcoma is a slow-growing, temperate tumor thought to arise from vascular tissue. The associated nodular purple lesions are often multifocal and common in individuals affected with acquired immunodeficiency syndrome (AIDS) and those living in the Mediterranean region.

12. What is the medical term for a mole? a. actinic keratoses b. nevus c. telangiectases d. xeroderma pigmentosum

ANS: D Melanomas tend to develop from melanocytes (the skin cells that produce melanin), which grow in clusters to form a mole, or nevus.

8. What primary skin cancer (other than malignant melanoma) is aggressive and has a tendency to spread through the lymphatics and blood stream? a. adenocarcinoma b. basal cell c. squamous cell d. Merkel cell

ANS: D Merkel cell carcinoma—this is a rare tumor thought to arise from Merkel (tactile) cells. It is known for high rates of recurrence after surgical excision, frequent involvement of regional lymph nodes, and distant metastatic failure.

6. What is the most superficial layer of the skin? a. hypodermis b. dermis c. subdermis d. epidermis

ANS: D The epidermis, dermis, and hypodermis are the layers of tissue associated with the skin. The epidermis is the most superficial layer.

13. Which of the following is the correct order to the layers of the skin from deep to superficial? a. stratum granulosum, stratum spinosum, stratum lucidum, stratum basale, stratum corneum b. stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale c. stratum basale, stratum granulosum, stratum spinosum, stratum corneum, stratum lucidum d. stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

ANS: D The layers of the skin from deepest to most superficial are stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.

2. Most skin cancers are treated with parallel-opposed photon beams.

ANS: F Because most skin lesions tend to be superficially located, electrons and kilovoltage x-rays are often used in their treatment

8. Traditional fraction doses of 180 to 200 cGy should be used when treating malignant melanoma with radiation.

ANS: F Because of the initial shoulder of the cell survival curve of melanoma cells exposed to radiation, standard fraction sizes of 180 to 200 cGy are not effective. Larger doses per fraction are needed to overcome the apparent repair processes that melanoma cells seem to possess.

4. Smoking is the leading cause of skin cancer.

ANS: F Many factors are directly and indirectly responsible for the development of the various forms of skin cancer, but the major cause is exposure to UV light.

3. Malignant melanomas are extremely radiosensitive.

ANS: F Traditionally, malignant melanoma has been considered a radioresistant tumor when treated with conventional dose fraction sizes; radiation therapy was reserved mainly for the treatment of metastases. Recently, however, the role of radiation therapy has expanded to that of an adjuvant and, in some instances, the primary treatment modality.

6. The incidence of skin cancer has declined over the past two decades.

ANS: F Unfortunately, the incidence of skin cancers and melanomas is rising and continues to grow throughout the world.

What is the staging system for nonmelanomas?

TNM

What are the histologies of nonmelanomas?

basal cell squamous cell keratochanthoma - resembles SCC Bowen disease - single plaque with red scaly border paget disease-single plaque in nipple, genital areas merkel tumor - asymptomatic tumor verrucous carcinoma - wartlike, fungating marjolin ulcer - SCC like with slow growth kaposi sarcoma - AIDS related Adnexal (sebaceous gland) eccrine (sweat gland)

What can be used along with electrons to increase surface dose?

bolus

How is an excisional biopsy used?

both diagnostic and therapeutic in some cases

the following are etiologic factors for skin cancers except a. UV radiation exposure b. chemical carcinogens c. epstein-barr virus d. genetic albinism

c. epstein barr virus

lentigo maligna is a histologic type of melanoma characterized by a. growth in a radial pattern with notches and reddish color b. tan or brown flat stainlike patterns on the palms or soles c. growth in a radial pattern with tan or black color d. raised pattern with black, blue-black color

c. growth in a radial pattern with tan or black color

The disease that is occasionally treated by total skin irradiation with electron is a. kaposis sarcoma b. malignant melanoma c. mycosis fungoides d. glandular adenocarcinoma

c. mycosis fungoides

Tanning of the skin in the treated area after a course of RT is caused by a. damage to the basal layer b. increased vascularity of the epidermis c. stimulation of melanocytes d. inflamamtion of the dermis

c. stimulation of melanocytes

What is the Clark staging system?

categorizes lesion according to invasion through the levels of the epidermis and dermis

What is the Breslow staging system?

categorizes lesion according to vertical thickness between the granular layer of the epidermis and the deepest part of invasion

How is beam shaping done?

cerrobend cutouts or thin-lead cutouts placed on patient's skin surface (use wax or equivalent to absorb scatter radiation on the underside of lead cutout)

What are the early signs of melanoma?

change in size, thickness or contour of existing mole

What are setups for melanomas?

clinical setups

With the use of shielding to protect the eye during irradiation, backscatter can be minimized by a. using a shield composed of cerrobend b. using a shield at least 1.7 mm in thickness c. using a larger diameter shield d. coating the outer surface of the shield with a low atomic number material such as wax

d

nonmelanoma type skin cancers are not usually seen in children. one possible reason is a. children have a strong resistance to damaging uv rays b. screening for skin cancer is only recommended for adults c. adult skin cells are more mature and are resilient against injury d. nonmelanomas are a result of long-term exposure to UV rays

d

What is surgery used for?

diagnosis and treatment; Mohs technique for recurrent basal cell and squamous cell, questionable borders, or suspicious for melanoma

The layers of the skin, starting with the most superficial to the deepest are a. subcutaneous layer b. epidermis c. dermis d. basement layer

epidermis-basement layer-dermis-subcutaneous layer