Cancer is typically broken down into four stages influenced by tumor size, the presence of cancerous cells in the lymph nodes, and the extent to which the malignancy has spread to other organs in the body.

Cancer is a group of diseases characterized by the uncontrolled growth of abnormal, mutated cells that can spread throughout the body.

How does cancer spread through the body?

Cancer usually begins with one tumor, but it can spread to other organs if not removed. This video breaks down how cancer moves to these new areas and why some organs are more likely to get infected than others.

Metastasis: When cancer cells begin to travel through the body

Metastatic cancer starts in one part of the body and moves to another over time. This is known as metastasis. Such cancers are much more harmful since they attack multiple parts of the body, adapting new metabolic changes to suit the various environments found throughout a body.

There are hundreds of subtypes of cancer, making a universal cure nearly impossible.

Timeline of cancer research milestones

While cancer remains incurable, there's been so much progress in its treatment over the last two decades. Nature provides an abridged history of milestones and major triumphs in cancer research and treatment. Start in the year 2000, and see how much has changed in the first quarter of the new millennium

The term 'cancer' is roughly 3,000 years old and derives from the Greek word for 'crab,' which may refer to how a malignant tumor can feel like a hard shell.

How does cancer actually kill someone?

While the emotional and physical tolls of cancer are often clear, the innerworkings of how cancer kills can be confusing — and terrifying to discuss. Here, oncologists explain how cancer can progress.

Explore more statistics about cancer

The American Cancer Society's Cancer Statistics Center estimates there will be more than 2 million new cancer cases and almost 620,000 cancer deaths in the US during the course of 2025. Breast, prostate, and lung cancers remain the most prevalent. This interactive tool provides detailed statistics on cancer incidence, mortality, and survival rates, allowing users to explore data by state, cancer type, demographics, and risk factors.

Patients are a part of the progress

Navigating a cancer diagnosis can be terrifying and overwhelming. There is a robust community of patient advocates dedicated to prevention and diagnosis, research and clinical trials, legislation, needs of individual cancer types, among others. See how patient advocacy improves cancer research leading to improved treatment options and patient care.

Large animals like giraffes and elephants have evolved unique cancer defenses.

Lung cancer advances are making a big difference

Lung cancer deaths are declining faster than new cases due to advances in treatment. The progress illustrates what is possible, even for a cancer that has long had a poor prognosis.

Breast, prostate, and lung cancer are the most common forms of cancer.

Explore the National Cancer Institute's archive on cancer treatments, including complementary and alternative medicine.

The immune system is in a constant fight to detect and eliminate cellular mutations.

Chemotherapy is a cocktail of powerful drugs that slows cancer by interfering with cell division.

What is cancer bioengineering?

While new treatments for cancer are under continuous development, researchers are increasingly using engineering principles to find wholly new strategies to combat the disease. Directions include nanoparticle drug delivery, advanced imaging tools, developing new materials to interact with cells, tissue engineering, robotic surgeries, and more. Such interdisciplinary efforts are expected to unlock new tools and therapies beyond traditional drug formulation.

About 40% of cancer cases are linked to preventable risk factors

Maintaining a healthy weight, engaging in regular physical activity, and consuming a balanced diet can lower cancer risk. Research indicates that about 40% of US cancer cases are linked to preventable factors, including poor diet and inactivity. Understanding these mechanisms empowers individuals to adopt healthier lifestyles for cancer prevention.

Immunotherapy focuses on boosting the immune system to fight cancer

The immune system detects and destroys abnormal cells, curbing the growth of many cancers. Immunotherapy works to boost the body’s immune system to target and kill cancer cells. There are many ways to accomplish this, including adaptive cell therapy, checkpoint inhibitors, vaccines, and monoclonal antibodies.

Tumor genetic profiling can lead to targeted treatments

Genetic profiling of tumors—based on a sample from the tumor, a patient's blood, or both—can help clinicians determine if targeted therapies known to block the growth of certain types of tumors would be appropriate for specific patients.

Many cancers arise from genetic mutations inherited from your parents

These mutations may happen in response to environmental or lifestyle factors, or may be passed down through family members. Genetic testing can be important in catching certain family cancers early and ensuring patients receive the right treatment for their disease.

The seven viruses that cause human cancers

Certain viruses have been linked to the development of human cancers. These viruses account for up to 20% of cancers worldwide, causing cancer by interacting with host proteins, proliferating within weak immune systems, and commandeering susceptible human cells. Unlike other viruses, human tumor viruses don't kill host cells, allowing them to establish persistent infections. The seven viruses include the Epstein-Barr Virus, the Human Papillomaviruses, and more.

Prostate cancer is both manageable and the second-deadliest cancer for men

One in 44 men in the US will die from prostate cancer, while one in eight will be diagnosed with it. Commonly viewed as the safest cancer to have, screenings can save lives—but they can also cause complications for otherwise benign cases of the disease.

Cells become cancerous if checkpoints in the cell cycle are damaged

Before cells divide, a protein called p53 can halt the cell cycle if damaged DNA is identified, preventing the fault from propagating to daughter cells. If p53 and other tumor-suppressing molecules cannot function due to mutations or other instabilities, damage can accumulate over successive generations until nothing stops cells from dividing uncontrollably, creating tumors.

Explore the differences between healthy and cancerous cells using a DNA microarray

In this simulation, you will learn how scientists use microarrays to experiment on thousands of genes at the same time. By determining which genes are on or off, users can identify those that contribute to cancer formation.

Low cell division rates in heart cells make heart cancer particularly rare

The heart's location in the chest also offers protection from external cancer-causing factors. The disease affects about 3 in every 10,000 people, though most cases arise from metastasis from other body parts.

Roughly 1 in 5 cancers are caused by viruses

About 20% of cancers are caused by viruses, with seven specific oncoviruses causing between 10% and 15% of cancers worldwide. These include human papillomavirus and hepatitis B and C viruses, which can lead to diseases such as cervical and liver cancer. Understanding the mechanisms of these viruses is crucial for prevention and treatment strategies.

A snapshot of progress in cancer treatments

The American Association for Cancer Research's "Snapshot of a Year of Progress" offers an overview of significant advancements in cancer research and treatment over the past year. Take a quick look at the rapid pace of scientific discovery and the translation of research findings into clinical practice. In 2024 alone, health regulators approved 15 new anticancer therapies alone.

The earliest evidence of cancer was found in a 1.7-million-year-old fossil—discovered in the toe of an ancestor of modern-day humans.

The difference between standard cancer treatments and emerging immunotherapies

If you've ever wondered what the difference was between immunotherapy and chemotherapy, this short video takes you through the steps. Briefly, chemotherapy attacks cancer in tumor cells directly, while immunotherapy encourages your immune system to fight it. There's more to it than that, but this delightful two-and-a-half-minute video provides a good primer.

How race science influences breast cancer research

Despite researchers' and physicians' pushback, race is still used in studies and clinics to categorize human differences in health conditions and treatment responses. This article explores how race has influenced breast cancer research. Considering race as a factor in cancer research, diagnosis, and treatment can lead to racial inequalities. Sociocultural factors, including food access and air pollution, greatly influence health outcomes.

Explore global maps of cancer prevalence, with incidences that reflect various risk factors, including smoking rates, HPV infections, sunscreen use, and alcohol consumption.

US cancer mortality rates have been falling for 25 years

The American Cancer Society's "Cancer Facts & Figures 2025" report provides comprehensive statistics on cancer incidence, mortality, and survival rates in the United States. Cancer rates in the US continued a long-running downward trend, driven primarily by a steep drop in lung cancers (mostly from a decrease in habitual smoking) and better preventative monitoring. This site leads to incredibly in-depth reports and slides on the current state of the fight against cancer.

What is immunotherapy and how does it work?

Immunotherapy is a type of treatment that harnesses the body's immune system to combat cancer. This video explainer from the American Cancer Society discusses various types of immunotherapies and their roles in targeting cancer cells. Still a new and quickly evoliving field, immunotherapy represents a significant advancement in cancer treatment and offers new options for patients.

Searching for the history of cancer in ancient human bones

Nestled under archaeology lies bioarchaeology, which involves the study of bones, human or animal. This subfield recently birthed another field of study: paleo-oncology. Paleo-oncology looks for cancer and related biomarkers in bioarchaeological remains. This TED article explains how this nascent multidisciplinary field challenges the idea that cancer is modern.

Physician teaches course on being a cancer patient

Stanford physician and professor Bryant Lin was diagnosed with stage four lung cancer, a terminal diagnosis. Despite its difficult implications for his life, Lin embraced the chance to teach his students from the unique perspective of a lung cancer patient. The course explored the journey from diagnosis to treatment; how to respect a patient's physical, emotional, and spiritual dimensions; and more.

The additive effects of smoking, diabetes, and poor diet are the biggest risk factors for developing pancreatic cancer.

Scientists now know that Henrietta Lacks, a Black woman whose 'immortal' cancer cells were nonconsensually sampled and used for research, had been infected with human papillomavirus, a group of pathogens responsible for most cervical cancers.

Specific gut microbiome 'fingerprints' are associated with cancer recurrence, with up to 94% accuracy.

Cancer rates are on the rise among GenXers and Millennials

Cancer rates are rising among Gen X and Millennials, with more cancer diagnoses being made in their 30s and 40s than previous generations. Factors such as prenatal exposures, environmental toxins, and lifestyle choices may contribute to this trend. Memorial Sloan Kettering Cancer Center's experts discuss these issues, exploring how these insights could reshape cancer risk understanding.

mRNA vaccines alter immune response, not DNA, to combat diseases like cancer.

A 40-something science journalist was getting more winded during workouts, and experiencing night sweats, forgetfulness and tiredness—she thought it was perimenopause, but these common symptoms turned out to be signs of her blood cancer.

Teaching immune cells to fight cancer

CAR T-cell therapy is a type of immunotherapy, which involves strengthening the immune system to attack cancer cells. Patient T cells, which manage immune responses and are responsible for killing pathogen-infected cells, are collected and re-engineered to produce surface-level proteins called chimeric antigen receptors. These CARs, now able to bind to specific proteins on cancer cell surfaces, are multiplied into the millions and infused back into the patient.

Using deep learning to analyze tumors

The explosive growth of life sciences data is driving artificial intelligence methods to gain traction in biology and medicine — including cancer research.

The HPV vaccine reduces cervical cancer rates by about 90%.

Chronic inflammation can cause cellular damage and could lead to cancer

Over time, this cellular defense system can inadvertently damage cells and tissues when it's in this heightened alarm mode over a prolonged period. This occurs because, when immune cells are sent somewhere without a true target, they may attack healthy cells and tissues.

Frequently asked questions on immunotherapy

The Cancer Research Institute takes a close look at immunotherapy and its potential for treating cancer. Immunotherapy teaches the patient's own immune system to recognize and fight cancer cells. It's especially promising as an alternative for cancers that resist chemotherapy and radiation treatment. Have all your questions about the process and its promise here.

Combining two cancer drugs increased the life space of mice by 30%

A study shows trametinib and rapamycin, two drugs used for cancer treatment in humans, increased mouse lifespan when used together. The medications delayed the onset of cancer and reduced chronic inflammation, results that will be explored in future research.

How is immunotherapy used to fight cancer?

The Dana-Farber Cancer Institute provides a delightful Science Illustrated animation explaining PD-1/PD-L1 immunotherapy and how it fights cancer. Briefly, the treatment helps T-cells recognize cancerous cells that would ordinarily be "disguised" by proteins and attack. The fight is made more fair and effective by immunotherapy and similar cancer treatments.

At a 2026 cancer conference, news that a novel pancreatic cancer drug doubled survival times in clinical trials led to a standing ovation.

How medical robots could cure cancer

Medical robots are on the verge of being able to be injected into the body, where they will be responsible for semi-autonomous behavior, such as detecting cancer cells and distributing medication. This six-minute video dives into the science of these nanorobots, which are smaller than blood cells. Applications of these nanobots could range from disease discovery and condition monitoring to tissue repair and artificial blood delivery.