What is skin cancer, really?

At its core, skin cancer is the uncontrolled growth of abnormal cells that develop in the outermost layer of your skin. It most often develops in areas exposed to the sun, but it can appear anywhere on your body. Don't worry, we'll explain it all in simple terms so you can grasp the fundamentals without getting lost in confusing medical jargon.

Image Source: "Skin Cancer Ribbon" by Zun_Graphic via Creative Fabrica. Used under the Creative Fabrica License.Click here to add text.

Decoding the derm jargon

Let's demystify some of the most common terms you might hear. Understanding these words is the first step to feeling more comfortable and knowledgeable about SC (skin cancer):

Cutaneous vs. Subcutaneous

  • Cutaneous SCs
    • This refers to anything related to the skin itself.
  • Subcutaneous SCs
    • This refers to the layer of tissue directly beneath the skin.

Image Credit: “The Three Layers of Skin” by Healthline Media. © 2026. All rights reserved.

Invasive vs. Non-invasive SCs

 

  • Invasive SCs
    •  An SC that has grown beyond the top layer of skin, potentially into deeper (subcutanous) tissues.
    • If left untreated can metastasize (or spread) to other parts of the body and form more tumors.
    • Non-invasive SCs
      • An SC that sometimes called 'in situ' melanoma, is confined to the very top (cutaneous) layer.
      • Typically much easier to treat and considered highly curable. 

Image Credit: “What is Skin Cancer?” Diagrams by Hawaii Skin Cancer Coalition. © All rights reserved.

Invasive vs. Non-invasive Treatments

 

  • Invasive Treatments (IT)
    • Surgical Treatment (IT) 
      • This involves physically removing the cancerous tissue. It's a common and highly effective method for many types of SC.
  • Non-Invasive Treatments (NIT)
    • Topical Treatment (NIT)
      • This means applying medication directly to the skin surface, often used for non-invasive or very superficial cancers.
        • Flourcacil cream
    • Other types include:
      • Immunotherapy (medications)
      • Physical Therapy 
        • Cryotherapy (freezing off a tumor)
      • Currettage (fancy word for cutting it out)
      • Laser removal 
        • This uses a precise beam of light to "vaporize" or burn away cancer cells on the very surface of the skin.
        • Scar minimizing option for early stage spots, but it isn't used for deeper cancers because it doesn't leave a tissue sample behind for doctors to double check that every single cell was caught.
      • Electrocautery (targeted electric currency that generates heat)
        • Basically used to remove/destroy tissue.

Image Credit: “Mohs Surgery for Melanoma” by California Dermatology and Mohs Surgery Specialists.

Image Credit: Non-Surgical Therapeutic Strategies for Non-Melanoma Skin Cancers - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Non-surgical-therapeutic-strategies-for-non-melanoma-skin-cancers-Schematic_fig1_376518808

[accessed 14 Apr 2026]