What Are the Deadliest Cancers?

Learn which cancers are the most and least aggressive

Determining which cancer is the most aggressive depends on a number of factors. These include the type you have, the stage of cancer when you're diagnosed, and the treatment you receive.

The American Cancer Society estimated 1.9 million new cases of cancer and 608,570 cancer deaths occurred among Americans in 2021.

This article takes a closer look at the five deadliest cancers, the ones that are fastest killing, and the least aggressive cancers.

5 of the Deadliest Cancers

After heart disease, cancer is the second most common cause of death in the US. These cancers are listed as the deadliest cancers because they have the most deaths per year.

Lung Cancer

Estimated cases of lung and bronchus cancer in 2021: 235,760

Estimated deaths caused by lung and bronchus cancer in 2021: 131,880

Many people with lung cancer are diagnosed when the disease is already at an advanced stage. That means it's more likely they will eventually die of the disease. Smoking is the most common cause of lung cancer.

The disease is divided into two types—small cell lung cancer and non-small cell lung cancer. Depending on the type and stage, treatment can include surgery, chemotherapy, and/or radiation therapy.

Colorectal Cancer

Estimated cases of colorectal cancer in 2021: 149,500

Estimated deaths caused by colon cancer in 2021: 52,980

At first, colorectal cancer causes few or no symptoms. If caught early, it's treatable and has good five-year survival rates. Five-year survival rates measure how many people with the condition are still living five years after they were diagnosed.

The survival rate for people with early-stage colorectal cancer is around 90%. Five-year survival rates for advanced colorectal cancer are much lower.

A colonoscopy can detect and treat colon cancer in its early stages. A colonoscopy uses a tiny camera on a thin, flexible tube to check for signs of cancer in your colon.

Small, early-stage cancers may be removed during a colonoscopy. Larger tumors usually call for surgery. Sometimes it is combined with chemotherapy, radiation, targeted therapy, and/or immunotherapy. These treatments shrink tumors and limit their spread.

Breast Cancer

Estimated cases of female breast cancer in 2021: 281,550

Estimated deaths caused by female breast cancer in 2021: 43,600

Estimated cases of male breast cancer in 2021: 2,650

Estimated deaths caused by male breast cancer in 2021: 530

Breast cancer is caused by cancer cells in the lining of the lobules or ducts of the breast. About 1% of all breast cancers affect men. Typically, it takes time for cells to become fully malignant and invade other body tissues.

Breast cancer treatments vary. Surgery can be extensive (mastectomy) or breast-conserving (lumpectomy).

In addition to breast surgery, the disease can be treated with:

  • Radiation therapy, which uses protons or x-rays to kill cancer cells
  • Chemotherapy, which uses medications to treat cancer
  • Hormone therapy, which slows or stops the growth of tumors that respond to specific hormones like estrogen
  • Biological therapies, which use your own immune system to treat cancer
  • Targeted therapies, which kill specific cancer cells or stop them from growing

Pancreatic Cancer

Estimated cases of pancreatic cancer in 2021: 60,430

Estimated deaths caused by pancreatic cancer in 2021: 48,220

Pancreatic cancer is aggressive. It often kills quickly and causes painful symptoms like:

  • Stomach pain
  • Blocked bile ducts, which are the tubes that carry digestive fluids out of the liver
  • Bleeding
  • Ascites, which is fluid buildup in your abdomen

There aren't any reliable screening options for pancreatic cancer yet. People with higher risk should have regular ultrasound and MRI/CT imaging tests.

People with this type of cancer often need surgery and chemotherapy. Radiation can be used to shrink tumors when they can't be removed, but not all doctors agree with this approach. Surgery to cure pancreatic cancer is only possible in 10% to 20% of cases.

Blue ribbon symbolic of prostate cancer

Chinnapong / Getty Images

Estimated cases of prostate cancer in 2021: 248,530

Estimated deaths caused by prostate cancer in 2021: 34,130

The prostate is a gland found in the middle of the lower pelvis between the rectum and bladder. The prostate makes the fluid that nourishes sperm.

Prostate cancer starts in a gland, so it is considered an adenocarcinoma. It usually affects older men and is more common among Black men and those with a family history of the disease.

Most prostate cancers grow slowly. People with this type of cancer may not have symptoms right away. For this reason, doctors may take a wait-and-watch approach to treatment. In fact, many people with prostate cancer die of unrelated causes, like a heart attack or stroke.

Older men were once routinely screened for prostate cancer using digital rectal exam and prostate-specific antigen (PSA) testing, even if they had no symptoms. Today, many experts question the value of prostate screening.

Treatment of prostate cancer includes:

  • Prostatectomy, which involves surgical removal of part or all of the gland
  • External beam radiation therapy
  • Brachytherapy

In brachytherapy, radioactive iodine is implanted into the prostate to treat cancer.

The Fastest Killing Cancer

If defining "fastest-killing" cancer is based on which cancer has the worst 5-year relative survival rate, then it would be a tie between pancreatic cancer and malignant mesothelioma (a relatively rare cancer in the U.S. with about 3,000 cases a year). However, there are some differences in survival rates for these two cancers, depending on the stage of cancer when it's diagnosed.

For example, the 5-year relative survival rate for localized pancreatic cancer is 44%, whereas localized malignant mesothelioma is 22%. But when statistics for all three stages are combined (localized, regional, and distant) then both cancers have a 5-year relative survival rate of 12%.

Keep in mind that:

  • These survival rates don't apply later on (after diagnosis) if the cancer grows, spreads, or comes back after treatment.
  • Treatments improve over time, and these numbers are based on people who were diagnosed and treated at least five years earlier.

5 Least Aggressive Cancers

Some of the cancers that are the deadliest can also be least aggressive depending on when they're diagnosed, meaning the stage of cancer at diagnosis, as well as other factors. This list of least aggressive cancers is defined by 5-year relative survival rates

Breast Cancer

The 5-year relative survival rate for localized breast cancer is 99%. Localized means there's no sign that cancer has spread outside of the breast. Relative survival rates compare people with a specific disease to those in the general population without the disease, so in this case people with localized breast cancer are almost as likely to survive for at least 5 years as people without the condition.

Doctors can isolate and treat these types of breast cancer before they develop into more severe forms of cancer.

Prostate Cancer

Just like breast cancer, prostate cancer can be one of the deadliest cancers, but oftentimes prostate cancers grow very slowly or don't grow at all, and they're very treatable. The 5-year relative survival rate of localized prostate cancer is greater than 99%.

Prostate cancers are diagnosed by biopsy and then given a score from two to 10, which indicates how likely it is to spread. Treatment may include watchful waiting, active monitoring with blood tests and biopsies, surgery, or radiation therapy.

Hodgkin Lymphoma

Hodgkin lymphoma, also called Hodgkin disease, is a type of cancer that starts in the lymph system, which is part of your immune system. This type of lymphoma has a 5-year relative survival rate of 89%.

Although it can spread relatively quickly, it's also one of the most easily treated types of cancer. The main treatments are chemotherapy alone or chemotherapy followed by radiation therapy.

Testicular Cancer

For localized tumors in the testicles, the 5-year relative survival rate is 99%. For regional tumors, where cancer has spread to tissues or lymph nodes near the testicles, the 5-year relative survival rate is 96%.

Treatment will depend on the type and stage of cancer and may include surgery to remove one or both testicles, radiation therapy, and chemotherapy.

Thyroid Cancer

The thyroid is a gland in the neck that makes hormones to support many bodily functions. The 5-year relative survival rate is 98%.

Treatment for thyroid cancer may include:

  • Watchful waiting
  • Surgery to remove part or all of the thyroid gland and lymph nodes
  • Radiation therapy
  • Chemotherapy
  • Hormone therapy to stop cancer cells from growing
  • Targeted therapy to attack specific cancer cells
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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Naveed Saleh, MD, MS
Naveed Saleh, MD, MS, is a medical writer and editor covering new treatments and trending health news.