Skin cancer is the most common form overall, but lung cancer causes the most deaths
Skin cancer is diagnosed more often than any other cancer in the United States. Melanoma and non-melanoma skin cancers (basal cell and squamous cell) together account for roughly one in three cancer diagnoses. However, when doctors talk about the "most serious" common cancers, they usually mean lung cancer, which kills more people than any other cancer type, followed by colorectal and breast cancers.
The reason skin cancer is so common is straightforward: skin cells are exposed to the sun constantly, and ultraviolet (UV) radiation damages DNA in those cells over time. Most skin cancers are highly treatable when caught early, which is why survival rates are much higher than for cancers caught at later stages. Lung cancer, by contrast, is often found after it has spread, making it harder to treat despite advances in therapy.
Key Takeaways
- Non-melanoma skin cancers (basal cell and squamous cell) are the most frequently diagnosed cancers, but most are curable when treated early.
- Lung cancer is the leading cause of cancer death in both men and women, even though it is diagnosed less often than skin or breast cancer.
- Colorectal and breast cancers are the third and fourth most common cancers in the United States, with well-established screening methods that can detect them before symptoms appear.
- The most common cancers share risk factors including age, smoking, sun exposure, and family history, though each has its own primary causes.
Why skin cancer is diagnosed so frequently
Skin cancer develops when UV radiation from the sun or tanning beds damages the DNA in skin cells, causing them to grow abnormally. Because skin is constantly exposed and the damage accumulates over decades, skin cancer risk rises with age. Fair skin, a history of sunburns, and time spent outdoors all increase risk.
Non-melanoma skin cancers—basal cell carcinoma and squamous cell carcinoma—account for the vast majority of skin cancer diagnoses. These cancers grow slowly and rarely spread to other parts of the body, which is why five-year survival rates exceed 95 percent when treated. Melanoma, the more dangerous form, is less common but more likely to spread if not caught early.
The high frequency of skin cancer diagnoses also reflects increased awareness and screening. Dermatologists now examine skin more routinely, and people are more likely to report suspicious spots, so more cancers are caught and counted.
Lung cancer: the deadliest despite being less common
Lung cancer is diagnosed less often than skin, breast, or colorectal cancer, but it causes more deaths than all three combined. Smoking is the primary risk factor—about 80 percent of lung cancer deaths occur in current or former smokers—but non-smokers can develop lung cancer too, particularly from secondhand smoke, radon exposure, or family history.
Lung cancer is often found at an advanced stage because early tumors rarely cause symptoms. By the time a person notices coughing, chest pain, or shortness of breath, the cancer may have already spread to the lymph nodes or other organs. This is why five-year survival rates for lung cancer are much lower than for skin or breast cancer, even though treatment options have improved significantly in recent years.
Low-dose CT screening can detect lung cancer earlier in high-risk individuals—people aged 50 to 80 with a 20-pack-year smoking history (20 cigarettes per day for 20 years, or equivalent). This screening is recommended by major medical organizations but is not yet as widespread as mammography or colonoscopy.
Breast and colorectal cancers: common and increasingly preventable
Breast cancer is the most common cancer in women and the second most common overall. Colorectal cancer ranks third or fourth depending on the year and population. Both have established screening methods—mammography for breast cancer and colonoscopy or other tests for colorectal cancer—that can detect cancer before symptoms appear, when treatment is most effective.
Breast cancer risk increases with age, family history, certain genetic mutations (like BRCA1 and BRCA2), obesity, and hormone use. Colorectal cancer risk rises with age, inflammatory bowel disease, family history, and lifestyle factors including smoking, heavy alcohol use, and diets high in red meat.
Screening guidelines recommend mammography starting at age 40 to 50 for women at average risk, and colonoscopy starting at age 45 to 50 for both men and women. These recommendations vary by organization and individual risk, so a person's doctor can advise on the right timing and frequency.
Other common cancers and their risk factors
Prostate cancer is the most common cancer in men and the second leading cause of cancer death in men after lung cancer. It grows slowly in most cases and may never cause symptoms or death, which is why screening decisions are more complex than for other cancers. Prostate-specific antigen (PSA) testing can detect early cancer but may also find slow-growing cancers that would never harm the person, leading to unnecessary treatment.
Endometrial cancer (cancer of the uterine lining) has become more common in recent decades, largely due to rising obesity rates. Abnormal vaginal bleeding is often an early warning sign, which is why it is often caught at an earlier stage than many other cancers.
Pancreatic cancer, ovarian cancer, and leukemia are less common but tend to be diagnosed at later stages and have lower survival rates. Age is a risk factor for most cancers—the median age at diagnosis for all cancers combined is in the mid-60s—but cancer can occur at any age.
How cancer incidence differs from cancer mortality
The number of people diagnosed with a cancer (incidence) is different from the number who die from it (mortality). Skin cancer has the highest incidence but one of the lowest mortality rates because most skin cancers are caught and treated early. Pancreatic cancer has a much lower incidence but a much higher mortality rate because it is usually found late and responds poorly to current treatments.
This distinction matters because it shapes how much research funding, screening effort, and public attention each cancer receives. A cancer that is common but highly treatable may receive less urgent attention than a rarer cancer with a poor prognosis, even though the common cancer affects more people overall.
Frequently Asked Questions
Is melanoma more common than other skin cancers?
No. Non-melanoma skin cancers (basal cell and squamous cell carcinomas) are about 20 times more common than melanoma. However, melanoma is more dangerous because it is more likely to spread. Most skin cancer diagnoses are non-melanoma, which have very high cure rates.
Can you get lung cancer if you have never smoked?
Yes. About 10 to 15 percent of lung cancer cases occur in people who have never smoked. Risk factors include secondhand smoke exposure, radon gas in the home, occupational exposures, air pollution, and family history. Radon is the second leading cause of lung cancer after smoking.
Why is colorectal cancer less common now than it used to be?
Colorectal cancer rates have declined in recent decades, partly because colonoscopy screening can detect and remove precancerous polyps before they become cancer. Improved awareness of risk factors and lifestyle changes have also contributed. However, rates in younger adults have been rising in recent years.
Does having a family history of cancer mean I will definitely get cancer?
No. Family history increases risk but does not may provide cancer will develop. Most people with a family history of cancer never develop the disease. A doctor can assess your individual risk based on which relatives had cancer, at what age, and what type, and recommend screening or other steps if needed.
Are cancer rates increasing or decreasing overall?
Overall cancer rates have been relatively stable or declining slightly in recent years in the United States, though this varies by cancer type and age group. Lung cancer rates have declined due to fewer smokers. Melanoma rates have increased. Colorectal cancer rates have declined in older adults but risen in younger ones.