Skin cancer cells are killed through several proven methods, each working by a different biological mechanism. Surgery physically removes them, radiation shatters their DNA, topical chemotherapy starves them of the building blocks they need to replicate, immunotherapy unmasks them so your own immune system can attack, and cryotherapy freezes them until ice crystals tear them apart from the inside. The right approach depends on the type of skin cancer, where it is, and how far it has spread.
Surgery: Physical Removal
The most straightforward way to kill skin cancer cells is to cut them out entirely. For basal cell and squamous cell carcinomas, a specialized technique called Mohs surgery achieves cure rates up to 99%. The surgeon removes thin layers of tissue one at a time, examining each under a microscope before cutting deeper. This means virtually every cancer cell is accounted for while sparing as much healthy skin as possible.
In high-risk areas like the face, Mohs surgery cures about 98% of cases, compared to 93 to 95% with a standard excision. Standard excision still works well for lower-risk tumors on the body, where the surgeon removes the visible cancer plus a margin of surrounding tissue. For melanoma, the most dangerous form of skin cancer, surgery is almost always the first step regardless of what other treatments follow.
Radiation: Breaking DNA Beyond Repair
Radiation therapy kills skin cancer cells by smashing their DNA into pieces. When ionizing radiation hits a cell, it creates breaks in both strands of the DNA double helix. Healthy cells can usually repair minor damage, but cancer cells divide so rapidly that they’re less able to fix themselves before their next division. They attempt to replicate with broken genetic instructions and die in the process.
A newer form of radiation uses carbon ions accelerated to roughly 70% the speed of light. These heavy particles create far more complex DNA damage than traditional radiation, tearing apart the genetic material while also chemically altering the surrounding bases. This type of damage is significantly harder for cancer cells to repair, making it effective against tumors that resist conventional radiation. Radiation therapy is typically used when surgery isn’t practical, such as cancers on the eyelids, ears, or nose, or in patients who can’t tolerate an operation.
Topical Chemotherapy: Blocking Cell Replication
For precancerous growths and superficial skin cancers, a chemotherapy cream applied directly to the skin can kill abnormal cells without surgery. The active ingredient works by disguising itself as one of the building blocks cells need to copy their DNA. Once inside the cell, it blocks the enzyme responsible for producing that building block, creating a shortage that stalls DNA replication. At the same time, the drug’s breakdown products get mistakenly woven into the cell’s DNA and RNA, corrupting both. The combined damage triggers the cell to self-destruct through programmed cell death.
This approach is selective because cancer cells and precancerous cells divide much faster than normal skin cells, so they absorb more of the drug and are hit harder by the replication blockade. Treatment typically involves applying the cream daily for several weeks. The skin in the treated area becomes red, raw, and inflamed as abnormal cells die off, then heals over the following weeks with fresh, healthy tissue.
Cryotherapy: Freezing Cells From the Inside
Liquid nitrogen, which boils at minus 196 degrees Celsius, can destroy skin cancer cells by freezing them. The critical damage actually happens during the thaw, not the freeze. As tissue cools, ice crystals begin forming inside cells at around minus 5 to minus 10 degrees Celsius. The transformation of water into ice concentrates the salts and molecules outside the cell, creating an osmotic imbalance that pulls water across the cell membrane and causes further structural damage. Malignant skin cancers require temperatures of about minus 50 degrees Celsius to ensure complete cell death, while benign lesions need only minus 20 to minus 25 degrees.
Cryotherapy works best for small, well-defined basal cell or squamous cell carcinomas, particularly in areas where cosmetic outcomes are less of a concern. The treated area blisters and scabs before healing, and the process may leave a pale scar.
Photodynamic Therapy: Light-Activated Destruction
Photodynamic therapy uses a two-step process. First, a light-sensitive chemical is applied to the skin and absorbed preferentially by cancer cells. Then, a specific wavelength of light is directed at the area. When photons hit the sensitizing agent inside the cell, they kick it into an excited energy state. From this excited state, the agent reacts with oxygen molecules in the tissue to produce highly reactive oxygen species, essentially unstable molecules that tear through cell membranes, proteins, and DNA. The resulting damage destroys both the cancer cells themselves and the tiny blood vessels feeding them, cutting off their supply lines.
This technique is most effective for superficial skin cancers and precancerous patches, particularly when they cover a large area. It tends to produce better cosmetic results than surgery or cryotherapy because it selectively targets cells that absorbed the sensitizing agent.
Immunotherapy: Reactivating Your Immune System
Melanoma cells survive partly by hiding from the immune system. They produce a protein on their surface that binds to a receptor on T cells called PD-1. When that binding happens, the T cell essentially stands down, treating the cancer cell as if it were normal tissue. Immunotherapy drugs work by blocking PD-1 so that this “off switch” can never be flipped. With the brake released, T cells recognize melanoma cells as threats and attack them.
This approach has dramatically changed outcomes for advanced melanoma. The five-year survival rate for melanoma that hasn’t spread beyond its original site is effectively 100%. But once it reaches distant organs, that number drops to 34%, according to data from the National Cancer Institute’s SEER program covering 2016 through 2022. Immunotherapy has been a major reason that distant-stage survival rates have improved over the past decade, turning some cases of metastatic melanoma into long-term remissions.
Targeted Therapy for Melanoma
About half of all melanomas carry a specific genetic mutation that causes a growth-signaling protein to become permanently stuck in the “on” position. Targeted therapy drugs are designed to block this exact protein, shutting down the signal that tells cancer cells to keep dividing. These drugs are often paired with a second drug that blocks the next step in the same signaling chain, making it harder for cancer cells to find a workaround. Targeted therapy tends to shrink tumors faster than immunotherapy, but resistance can develop over time, which is why the two approaches are sometimes used in sequence.
Why “Natural” Cancer Salves Are Dangerous
Products marketed as black salve or “natural” skin cancer cures are not a safe alternative. These salves typically contain bloodroot extract and zinc chloride, both of which are escharotic, meaning they destroy tissue indiscriminately. They burn through skin without distinguishing cancer cells from healthy ones. Documented adverse effects include severe pain, full-thickness chemical burns requiring surgical debridement, destruction of underlying tissue structure, and disfiguring scars. Worse, the salve may destroy surface tissue while leaving deeper cancer cells alive, allowing metastatic recurrence from malignant cells the salve never reached. Peer-reviewed case reports in the Journal of the American Academy of Dermatology have documented patients who delayed proper treatment in favor of black salve and ended up with far worse outcomes than if they had pursued standard care from the start.