Skin cancer affects the body in ways that range from minor, easily treated skin damage to life-threatening organ involvement, depending on the type and how far it has progressed. The three main types, basal cell carcinoma, squamous cell carcinoma, and melanoma, each carry different risks, but all of them can cause lasting physical, cosmetic, and psychological effects even after successful treatment.
Local Effects on the Skin and Surrounding Tissue
The most immediate effect of any skin cancer is damage to the skin itself. Basal cell carcinoma, the most common type, typically grows slowly but can be surprisingly destructive if ignored. Left untreated, it invades deeper tissues including muscle, bone, and cartilage. The tumor can become painful and ulcerated, causing bleeding and infection. Because basal cell carcinomas frequently appear on the face, nose, and ears, even small tumors can cause noticeable disfigurement.
Squamous cell carcinoma tends to be more aggressive locally. In some cases, tumor cells spread along the space surrounding nearby nerves, a process called perineural invasion. This is often discovered incidentally during surgery, but when it causes symptoms, it can lead to numbness, tingling, pain, or weakness in the affected area. Perineural invasion raises the risk of the cancer coming back and is associated with worse outcomes overall.
How Skin Cancer Spreads to Other Organs
Basal cell carcinoma almost never spreads beyond its original site. Squamous cell carcinoma does so infrequently, but the risk is real, particularly for people with weakened immune systems. In a study of organ transplant recipients (who are immunosuppressed), about 6% developed metastases within two years of their squamous cell carcinoma diagnosis. The most common destination was regional lymph nodes, accounting for roughly 73% of cases that spread. A smaller number developed distant organ metastases.
Melanoma is the type most likely to spread, and when it does, the effects become systemic and serious. Cancer that reaches the lungs can cause a persistent cough, breathlessness, coughing up blood, or fluid buildup between the chest wall and lung. Melanoma that spreads to the liver may cause pain on the right side of the abdomen, nausea, weight loss, a swollen belly from fluid accumulation, jaundice, and itchy skin. Brain metastases can trigger memory problems, personality changes, seizures, confusion, severe headaches, and weakness in an arm or leg.
Survival Rates Vary Dramatically by Stage
For melanoma, catching it early makes an enormous difference. When melanoma is still localized (stages I and II), the five-year relative survival rate is 97.6%. Once it reaches nearby lymph nodes (stage III), that drops to 60.3%. If it has spread to distant organs (stage IV), the five-year survival rate falls to 16.2%. Across all stages combined, the rate is 90.5%, largely because most melanomas are caught before they spread.
Basal and squamous cell carcinomas have much higher overall survival rates. Common treatments for these non-melanoma skin cancers are at least 95% effective, with an overall five-year recurrence rate of about 3.3%. Recurrence rates are similar whether the tumor is removed by standard excision, destruction techniques, or Mohs surgery, a precision method that removes tissue layer by layer.
Effects of Treatment
Treatment itself carries its own set of effects. Surgery is the most common approach for all skin cancers, and any surgery to remove skin cancer leaves a scar. Mohs surgery minimizes scarring by preserving as much healthy tissue as possible, but larger wounds still require a skin flap (rearranging nearby skin) or a graft (borrowing skin from another part of the body). For cancers on the face, the cosmetic impact can be significant even with the most precise techniques.
When lymph nodes need to be checked or removed, there is a small risk of lymphedema, a condition where fluid builds up and causes swelling in the affected limb. A sentinel node biopsy, which removes only a few nodes, carries a low risk. More extensive lymph node removal raises the likelihood.
For advanced or metastatic skin cancer, immunotherapy has become a standard treatment. These drugs work by releasing the brakes on cancer-killing immune cells, but those same activated cells can attack healthy tissues too. Common side effects include itching and painful skin rashes. Some patients develop more serious inflammatory reactions in other organs, including the colon. The side effects stem from the immune system becoming broadly activated rather than targeting cancer cells alone.
Psychological and Emotional Effects
The mental health impact of skin cancer is substantial and often underrecognized. Roughly 30% of studies on melanoma patients find a significant association with mental disorders, most commonly anxiety and depression. Patients frequently experience physical symptoms driven by psychological distress, including sleep problems and intense nervousness. Those with advanced-stage melanoma score significantly higher on measures of anxiety, particularly phobic anxiety, compared to patients diagnosed at earlier stages.
The psychological burden comes from multiple directions at once: fear about prognosis, the visible physical changes caused by the disease and its treatment, and the ongoing uncertainty about recurrence. Melanoma patients commonly report that their quality of life suffers not just from the cancer itself but from the cumulative emotional weight of diagnosis, treatment, and surveillance. Body image concerns are particularly common when surgery leaves visible scarring on the face or other exposed areas, compounding the anxiety that already accompanies a cancer diagnosis.