Squamous Cell Skin Cancer (Cutaneous SCC), from the CureRays guide library.

Cutaneous squamous cell carcinoma is the second most common skin cancer — usually very curable, but with a small chance of spreading, which is why high-risk cases get extra attention, and radiation offers a precise, non-surgical cure for delicate areas.

What it is.

Cutaneous squamous cell carcinoma (SCC) is a cancer that begins in the squamous cells, the flat cells that make up the surface of the skin. After basal cell carcinoma, it is the second most common skin cancer, and like basal cell cancer it is driven mostly by years of ultraviolet (UV) light from the sun or tanning beds. It tends to appear on sun-exposed areas — the face, ears, scalp, lips, neck, the backs of the hands, and the forearms — often as a firm red bump, a rough or scaly patch, a wart-like growth, or a sore that won't heal and may bleed or crust. Many SCCs start from precancerous rough spots called actinic keratoses. The large majority of squamous cell skin cancers are caught early and cured easily. The important difference from basal cell carcinoma is that SCC has a real, though small, ability to spread — first to nearby lymph nodes and, rarely, beyond — particularly when a tumor is large, deep, on the lip or ear, growing along nerves, or arising in someone whose immune system is suppressed (for example, organ transplant recipients, who develop these cancers far more often and more aggressively). For that reason, doctors pay close attention to a tumor's risk features. Treatment is usually highly effective and may involve surgery, radiation, or a combination, with radiation playing a key role both as a stand-alone cure for cancers in hard-to-operate locations and as an add-on after surgery for high-risk tumors.

How radiation treats it.

Radiation therapy treats squamous cell skin cancer by aiming focused beams of energy at the tumor to damage the DNA inside the cancer cells, so they lose the ability to grow and divide and gradually die, while the healthy skin around them recovers. Because skin cancers sit at or just below the surface, the radiation can be precisely matched to that depth: superficial X-rays and electron beams concentrate the dose on the tumor and spare the tissue underneath — cartilage, bone, the eye, or the brain. This makes radiation an excellent cure for squamous cell cancers on the lip, ear, nose, and eyelid, where surgery can be difficult or alter appearance, and for older patients or anyone who cannot have an operation. Treatment is painless and usually given as a series of short sessions over several weeks, which lets healthy skin heal between visits and gives a good cosmetic result. Radiation has a second important role in squamous cell carcinoma that sets it apart from basal cell cancer: because SCC can be more aggressive and can travel along nerves or to lymph nodes, radiation is frequently used after surgery for high-risk tumors — for example, when the cancer grows along nerves, when the edges could not be fully cleared, or when it has reached the lymph nodes — to sharply reduce the chance it comes back. In those situations the radiation can be directed not only at the original site but also at the nerve pathways or node regions at risk. Modern planning, including high-frequency ultrasound to map a tumor's depth and intensity-modulated techniques for larger or deeper areas, lets the dose be shaped tightly around the target while protecting nearby healthy tissue. For appropriately selected cancers, cure rates with radiation are very high, and the surrounding structures and appearance are preserved.

The ways we can treat it.

Superficial radiation therapy (SRT). Low-energy X-rays treat the tumor at the skin surface and just below, sparing deeper tissue — a non-surgical cure for cancers on delicate facial areas, often guided by high-frequency ultrasound for accuracy.

Electron-beam radiation. Electrons deliver their dose to a controlled shallow depth and then stop, matching the depth of most skin cancers and protecting underlying structures like cartilage, bone, and the eye.

Postoperative (adjuvant) radiation. Radiation to the surgical area after removal of a high-risk tumor — especially one growing along nerves or with incomplete margins — lowers the chance the cancer returns.

Radiation to lymph node areas. When cancer has reached or threatens nearby lymph nodes, targeted radiation to those regions, sometimes after node surgery, helps control regional spread.

Questions we hear often.

How is squamous cell skin cancer different from basal cell carcinoma? Both are common sun-related skin cancers and both are usually very curable. The key difference is that squamous cell carcinoma has a small but real ability to spread to lymph nodes and, rarely, beyond — especially when it is large, deep, on the lip or ear, growing along nerves, or in someone with a weakened immune system. That is why high-risk squamous cell cancers get extra attention.

When is radiation used for this cancer? Radiation can be the main treatment — curing cancers on the lip, ear, nose, or eyelid without surgery, and helping older patients or those who prefer to avoid an operation. It is also used after surgery for high-risk tumors, such as those growing along nerves or with edges that couldn't be fully cleared, and to treat lymph node areas, to lower the chance the cancer returns.

I had an organ transplant — why am I getting these so often? Medicines that suppress the immune system to protect a transplanted organ also make squamous cell skin cancers far more common and sometimes more aggressive. If this is your situation, close skin surveillance, diligent sun protection, and prompt treatment of new spots are especially important, and your team may adjust how aggressively each tumor is treated.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.