Nonmelanoma Skin Cancer: A Primer for Primary Care

February 6, 2017

Primary care physicians will see many patients with early signs of nonmelanoma skin cancers. Test your visual diagnostic skills in this series.

[[{"type":"media","view_mode":"media_crop","fid":"56227","attributes":{"alt":"","class":"media-image media-image-right","id":"media_crop_6254127549476","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"7062","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 392px; width: 300px; float: right;","title":" ","typeof":"foaf:Image"}}]]Skin cancer is the most common form of cancer in humans. The incidence of skin cancer has been increasing over recent decades, at least in part related to increased sun and tanning booth exposure. Skin cancers are most often categorized as melanoma, the most aggressive type, or non-melanoma skin cancer (NMSC), with the latter being the most common. Prognosis for melanoma and management guidelines differ significantly from those for NMSC.

More than 5.4 million cases of NMSC occur in the United States annually, affecting more than 3.3 million Americans, with many individuals having more than one type. The most common of these cancers is the basal cell carcinoma (BCC [image, top]), accounting for about 80% of NMSC. Squamous cell carcinoma (SCC [image, bottom]) accounts for 20% of the NMSC. While estimates are difficult to make since NMSC are not typically followed by registries, about 2000 people in the US die annually from NMSC. NMSC more commonly causes local tissue destruction and disfigurement. Even more common than BCCs are actinic keratosis (AKs), which are considered pre-cancers of the SCC type.

Melanoma is generally a more dangerous skin cancer that develops from the pigment cells of the skin. More than 76,000 cases of invasive melanoma are diagnosed in the US annually and the cancer is responsible for more than 10,000 deaths every year-a mortality rate 5 times higher than for NMSC. Melanoma and NMSC present in clinically distinct manners which we will describe in the segments of the Special Report to follow.

Prevention of skin cancer is of primary importance and primary care physicians have a critical role to play in educating patients on how to minimize exposure. Ultraviolet energy has been identified as the major risk factor in skin cancer development. Sun avoidance and protection can prevent the DNA damage that results in cancer development, sometimes not until decades after exposure. “Sun avoidance” does not mean staying indoors. Outdoor activities can be safely performed and enjoyed with use of effective protection to avoid tan and burn of the skin. Good skin protection can be achieved with sun-protective clothing made with UPF (UV protection factor) 50+ rated fabrics or by wearing dark-colored fabrics that do not allow light to penetrate. Wearing a hat for head and neck protection, glasses for eye protection is also recommended and finally use of a good sunscreen is advisable. Suncreens can be organic/chemical or physical blockers. In general higher SFP (sun protection factor) sunscreens block out more light. Also, physical sunblocks containing micronized zinc or titanium are more stable, inert, and less irritating to the skin than organic/chemical blockers. They will not disintegrate in heat as chemical blockers do.

Early diagnosis of skin cancer is key in preventing complications from cancer growth or spread. The diagnosis of skin cancer can be challenging to clinicians faced with time constraints in examining and treating patients. This Special Report focuses on clinical diagnosis and basic management of common NMSC types that may be encountered in the primary care setting. Installments to follow will cover:

 â–º Basal cell carcinoma

 â–º Pigmented basal cell carcinoma

 â–º Squamous cell carcinoma, actinic keratosis

 â–º Keratoacanthoma

 

First up: a multiple-choice pretest on dermatologic neoplasms aimed at primary care physicians. The questions will be answered in upcoming segments of this Special Report and you will see them again, as a post-test, at the conclusion of the series.

 
Continue to Nonmelanoma Skin Cancer for PCPs Special Report Pretest

 

Question 1:

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Answer and Question #2 on Next Page »

 

The correct answer is C. Basal cell carcinoma

 

Question 2.

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The patient reports this lesion on left lateral canthus eyelid has come and gone over the last 3 years, but most recently has been present. It is not itchy or painful, but it feels like sandpaper and will not become smooth despite moisturizer use.

Answer and Question #3 on Next Page »

 

The correct answer is B. Actinic keratosis (AK)

 

Question 3.

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A patient who has undergone renal transplant is seen for evaluation of numerous skin lesions like the one identified in the image above.

Answer and Question #4 on Next Page »

 

The correct answer is D. The majority of these lesions will be basal cell carcinomas (BCCs) is a false statement.

 

Question 4.

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A 60-year-old female patient is seen 6 months after a total skin checkup and you notice this spot on the back of her thigh. The patient has had numerous non-melanoma skin cancers over the years.

Answer and Question #5 on Next Page »

 

The correct answer is A. True

D. This is a melanoma and is likely still in the horizontal growth phase is true.

 

Question 5.

Answer and Question #6 on Next Page »

 

The correct answer is A. Moh’s micrographic surgery

 

Question 6.

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Answer and Question #7 on Next Page »

 

The correct answer is A. Chronic sun exposure resulting in pre-cancerous lesions

 

Question 7.

Answer and Question #8 on Next Page »

 

The correct answer is A. True

 

Question 8.

Answer and Question #9 on Next Page »

 

The correct answer is B. False (Horizontal growth phase has a good prognosis)

 

Question 9.

Answer and Question #10 on Next Page »

 

The correct answer is H. All of the above

 

Question 10.

Answer on Next Page »

 

The correct answer is A. 65%

 

Click on links below for other sections of this Special Report, Non-melanoma Skin Cancer: A Primer for Primary Care
Go Back to Part 1: Introduction and Pre-test
Part 2: A Pearly-pink Lesion on a 68-year-old Woman's Face
Part 3: Three Suspicious Lesions on an Elderly Woman's Face