Squamous cell carcinoma skin

scc skin

1. Cancer of the Skin Squamous cell carcinoma (SCC ) Dr Nabeel Yahiya Kottayam Medical college

2. Epidemiology skin cancer is the most common of all cancers 97% of these are nonmelanoma skin cancer (NMSC). Basal cell carcinoma (BCC) comprises about 80% S quamous cell carcinoma (SCC) 20% of NMSC

3. Etiology Exposure to ultraviolet solar radiation, especially ultraviolet B Painful sunburn before age 20 is related to later development of premalignant lesions as well as NMSC and melanoma Cumulative lifetime sun exposure is related to increased risk of SCC and BCC.

4. Host risk factors blonde or red hair, fair complexion, blue eyes, and tendency to burn rather than tan

5. Genetic predisposition xeroderma pigmentosum basal cell nevus ( Gorlin's ) syndrome epidermodysplasia verruciformis Muir-Torre syndrome Porokeratosis Bazex syndrome Rombo syndrome Albinism phenylketonuria .

6. Infections- An association exists between cutaneous SCC and human papillomavirus Immunosuppression - Transplant recipients on immunosuppressive therapy AIDS , multiple myeloma, leukemia , and lymphoma also are at increased risk

7. more frequent and aggressive in areas of chronic skin damage ulcers, osteomyelitis , sinus tracts and burn ( Marjolin's ulcer), or vaccination scars. Areas of chronic skin inflammation discoid lupus erythematosus , lichen sclerosus , lichen planus , dystrophic epidermolysis bullosa , and lupus vulgaris

8. IONIZING RADIATION Exposure to ionizing radiation is a risk factor for both BCC and SCC especially in those people with sun-sensitive phenotype and younger age at exposure risk is directly related to cumulative radiation dose Increased incidence of NMSC also occurs with chronic radiation dermatitis following therapeutic radiation.

9. Chemical skin cancer carcinogens Arsenic (herbicide, pesticide ), soot, and polycyclic aromatic hydrocarbons from coal tar, cutting oils An association exists between cigarette or pipe smoking and cutaneous SCC

10. Premalignant Skin Lesions Actinic (Solar) Keratoses - Actinic keratoses tend to be multiple. AKs are red, pink, or brown papules with a scaly to hyperkeratotic surface They occur on sun-exposed areas and are especially common on the balding scalp, forehead, face, and dorsal hands

11. Malignant transformation to SCC occurs in about 1% of lesions with cumulative lifetime risk 6% to 10% depending on number and length of time lesions are present

12. Treatment Excision Cryotherapy desiccation and curettage Dermabrasion topical therapy with 5-FU or imiquomod laser resurfacing .

13. Bowen's Disease typically appears as a reddish-brown scaly patch or thin plaque on the sun-exposed head, neck, extremities, or trunk of an older individual On histopathologic evaluation demonstrates full-thickness epidermal atypia , with more pronounced nuclear polymorphism and apoptosis

14. Other features include confluent parakeratosis , and, not infrequently, the adnexal extension of neoplastic cells It may arise from a pre-existing actinic keratosis or de novo. Progression to invasive SCC occurs in 5% to 20% of cases

15. TREATMENT Surgical excision is usually preferred radiation therapy may be considered as an alternative. 45 to 50 Gy at 2.5 to 3.5 Gy per fraction Facial lesions require 56 Gy at 2.0 Gy per fraction for improved cosmesis

16. Keratoacanthoma benign, self-healing lesions presents as a rapidly enlarging papule that becomes a crateriform nodule with a central keratinous plug over a period of weeks to months. have the potential to destroy large volumes of tissue and may be associated with SCC

17. Lesions can be treated with radiation Doses of 35 Gy in 12 to 14 fractions or 45 Gy in 15 to 20 fractions have been used

18. Lentigo Maligna and nevi are precursors of melanoma

19. PATHOLOGY a neoplasm of keratinizing cells that shows malignant characteristics Anaplasia rapid growth local invasion metastatic potential

20. Invasive tumor lobules push downward from the overlying epidermis and detached tumor islands are noted within the dermis Both cytoplasmic and cystic keratinization may be observed. The degree of keratinocyte differentiation within these tumors is variable and an important prognostic factor.

21. HISTOLOGICAL VARIANTS Verrucous carcinoma is an indolent, well-differentiated squamous cell carcinoma grows slowly as an exophytic , cauliflower-like lesion may be associated with human papilloma virus infection

22. This may arise in the anogenital region ( Buschke -Lowenstein tumor) oral cavity (oral florid papillomatosis ) on the plantar surface of the foot ( epithelioma cuniculatum )

23. Spindle cell carcinoma a rare subtype of squamous cell carcinoma usually develops in sun-exposed areas in lightly-pigmented individuals older than 40 years of age. The prognosis primarily depends on the depth of invasion Verrucous and spindle cell carcinomas are managed similar to more conventional squamous cell carcinomas.

24. subtypes associated with clinically aggressive behavior adenoid ( pseudoglandular ) Acantholytic Adenosquamous desmoplastic squamous cell carcinoma.

25. PRESENTATION A careful history should include questions regarding patient risk factors personal and family history of skin cancer UV exposure history, history of ionizing radiation therapy occupational exposures immunosuppression

26. CLINICAL PICTURE Slowly enlarging growth on or just beneath the skin surface History of sore that will not completely heal Bleeding or pain unusual Paresthesia and formication in case of perineural spread (3-14%)

27. Physical examination Site, size, mobility of the primary lesion should be documented Evidence of PNI is assessed Any features of cartilage or bone invasion should be examined Complete skin examination should be done Regional lymph nodes

28. Typical lesions are round-to-irregular, plaquelike nodular, and overlaid with a warty keratotic scale or conical keratinized cutaneous horn. Surrounding erythema may be present, and bleeding results from minimal trauma usually superficial, invasion of the subcutis does occur with muscle invasion and extension along periosteal , perineural , and angiolymphatic channels.

29. INVESTIGATIONS Biopsy should be performed before deciding on treatment Small lesion occurring on free skin areas ( not involving eye lid, ear or periorbital areas ) can undergo biopsy and simultaneous excision Larger lesion or those involving areas where cosmetic or functional deficit will occur with excision Incisional biopsy or punch biopsy

30. Biopsy should include deep reticular dermis This is preferred because infiltrative pathology may be found only in deep tissues Superficial biopsy will frequently miss this

31. Imaging Done in extensive disease such as bone involvement PNI deep soft tissue involvement lymphovascular invasion is suspected

32. In the case of carcinomas involving the medial or lateral canthi of the eyes one should consider obtaining either a (CT) or (MRI) scanto assess the depth of invasion because apparently superficial cancers sometimes extend along the wall of the orbit

33. CT Scan is done to role out bone and cartilage invasion Lymph node status can also be assessed MRI preferred over CT when PNI is suspected

34. Clinically or radiologically if lymph node present Proceed with fnac If negative repeat fnac or excision biopsy of node

35. STAGING OF NMSC

36. MANAGEMENT SURGERY RADIOTHERAPY offer equivalent excellent cure rates of 90% to 95% treatment approach must be individualized based on specific risk factors and patient characteristics for the most acceptable cosmetic and functional outcome.

37. The management of skin cancer is guided by the biologic and histologic nature of the tumor, the anatomic site, the underlying medical status of the patient It is desirable to avoid RT in young patients Late effect of RT progress with time

38. SURGERY Localized scc are most commonly treated with surgery Curettage with electrodesiccation is the alternatively scraping away the tumor tissue with a curette down to a firm layer of normal dermis and denaturing the area with electrodessication It is fast and cost effective Margin cannot be assessed

39. Curettage with electrodesiccation reserved for actinic keratoses (AKs), and SCC in situ without follicular involvement located on the trunk or extremities but are contraindicated in deeply infiltrating lesions Wound contracture may cause tissue distortion and impaired cosmesis Cure rate is about 90-95% for low risk tumors Recurrence rate high about 20-25% for high risk features

40. EXCISION WITH POST OP MARGIN ASSESSMENT (POMA) Standard surgical excision followed by post op pathological evaluation of margins For low risk tumors < 2 cm – 4-6mm margin For high risk tumors higher margins are required

41. Mohs surgery or excision with intra operative frozen section assessment Preferred technique for high risk scc

42. Mohs ' micrographic surgery involves fixation of tumor to enable tumor mapping and surgical excision with multiple frozen sections taken until microscopically clear. Cosmesis , often poor just after the procedure, improves with time.

43. A key defining feature of MMS is that the surgeon excises, maps, and reviews the specimen personally, minimizing the chance of error in tissue interpretation and orientation This technique is employed for BCC and SCC in embryonic fusion zones recurrent or deeply invasive lesions tumors with potential for diffuse lateral spread or perineural invasion

44. RADIATION THERAPY Although surgery is main treatment for nmsc Patient preference and other factor may lead to choice of RT early skin cancer of eyelid, external ear ,or nose may result in significant cosmetic deformity and necessitates complex reconstructions

45. Elderly patients who are not fit for surgery Patients with PNI with gross tumor extending to the sites which makes lesion unresectable Such lesions are treated with RT alone

46. POST OP RT positive surgical margins perineural invasion invasion of bone, cartilage, and skeletal muscle

47. Superficial therapy Cure rates lower Reserved where surgery or radiotherapy is contraindicated or impractical Cryotherapy , topical 5 FU, imiquimod , Photo dynamic therapy

48. Imiquimod immune-response modifier that promotes a cell-mediated immune response through induction of cytokine production, particularly interferon @ and b and interleukin-12. treatment of Aks , scc insitu and superficial BCCs on the trunk, neck, or extremities

49. PDT involves application of photo sensitizing agent on skin followed by irradiation with light source Used for premalignant or low risk superficial on face and scalp

50. Cryotherapy exposes skin cancers to destructive subzero temperatures. Heat transfer occurs from the skin, which acts as a heat sink. Tissue damage is caused by direct effects initially subsequently by vascular stasis, ice crystal formation, cell membrane disruption, pH changes, hypertonic damage, and thermal shock

51. inability to evaluate thoroughness of tumor eradication. The absence of margin control development of dense scar, which might obscure recurrence

52. Regional lymph node Involvement increase the chance of recurrence and mortality Associated with PNI, LVI, poor differentiation

53. Management of lymph node Lymph node dissection followed by adjuvant RT Cervical node Neck dissection alone if only one involved If 2 or more or ECE neck dissection followed by RT

54. Metastatic to parotid node is common if cervical lymph nodes are involved (60-80%) Superficial or total parotidectomy followed by RT If inoperable parotid node – high dose preop RT 60-70 Gy followed by parotidectomy 20 % decrease in local recurrence with addition of RT 5 YR survival also increased by 15-20%

55. RT TECHNIQUES EBRT Ortho voltage x rays Electron beam High energy x rays OR INTERSTITIAL IMPLANT

56. ORTHOVOLTAGE RT 100- 250 Kvp Most early skin cancer can be treated Advantages Maximum dose at skin surface, no bolus required Less beam constriction both at surface and at deapth so smaller field can be used Shielding of eye is easier

57. DISADVANTAGES Higher dose to deeper tissues and to underlying bone and cartilage It is unavailable in most RT Dept.

58. Electron beam therapy It is usually used for treatment of scalp lesion inorder to reduce dose to brain If tumor is located near eye – gold plated lead eye shield is directly placed over anaesthetised cornea

59. HIGH ENERGY PHOTONS Advanced skin cancer that are deeply invasive are often treated with higher energy To adequately cover the deeper tissue Bolus is kept to ensure the adequate surface dose Field arrangement may vary depending on sites

60. Wedge pair technique – external ear 3 field technique- lesion extending along 5 th nerve Even IMRT can be used when we have to treat till base of skull in case of PN

61. Proper immobilization to ensure consistent delivery of treatment is essential primary skin collimation with custom lead cutouts can also be used to define the field in case of electrons To minimize normal-tissue toxicity, underlying structures such as the lens, cornea, nasal septum, and teeth should be protected by placing a lead shield under the eyelids over or in the nasal cavity or under the lips

62. The margin of normal-feeling tissue included in the target volume is usually 0.5 to 1.0 cm for skin cancers of 2.0 cm 1.5 to 2.0 cm for larger cancers. At least a 0.5-cm margin on the suspected depth of invasion should be included in the target volume Wider margin while using electrons

63. RT DOSE

64. Sequelae of Radiation Therapy Moist desquamation The skin in the radiation field may gradually become telangiectatic , atrophic, and hypopigmented over a period of years and is more sensitive to trauma. healing may be delayed after surgery on an irradiated region. Hair loss and a loss of sweat gland function are usually permanent

65. Ectropion and epiphora may develop after the treatment of eyelid carcinomas (particularly ones involving the lower eyelid) The incidence of soft tissue necrosis is typically less than 3%. Osteoradionecrosis occurs in approximately 1% of patients radiochondritis is rare

66. Metastatic scc 3-4 % of scc can have distant metastases Systemic chemotherapy Platinum based chemotherapy Interferon @ or cis - retinoic acid Cetuximab and gefitinib is also tried

67. NCCN GUIDELINES