Cancer is a large group of diseases that can start in almost any organ or tissue of the body when abnormal cells grow uncontrollably, and go beyond their usual boundaries to invade adjoining parts of the body. According to the World Health Organization (WHO), it is the second most common cause of death globally, accounting for millions of deaths every year. Lung, prostate, colorectal, stomach and liver cancer are the most common types of cancer in men, while breast, colorectal, lung, cervical and thyroid cancer are the most common among women. However, these are not necessarily the deadliest forms of cancer.

What makes cancer the deadliest depends upon how many people have it and what percentage of those people actually survive. Cancer researchers determine this on the basis of five-year relative survival. This is the percentage of people who are expected to survive the effects of a given cancer, excluding their risk of other possible causes of death, for five years past a diagnosis. It is also important to note that what makes cancer really deadly is that practically no cure for it. A cure for cancer would imply that there are no cancerous cells remaining in the body.

Here are the 5 deadliest cancers in the U.S., according to SEER five-year relative survival data for cases diagnosed between 2014 and 2020.

1. Pancreatic cancer occurs when cells in your pancreas, a gland in your abdomen that aids digestion, mutate and multiply out of control, forming a tumour. Major risk factors include smoking, obesity, diabetes, chronic pancreatitis, certain genetic mutations and environmental chemical exposure.

2. Esophageal cancer develops in the oesophagus, which is the tube that connects your throat to your stomach.

3. Liver cancer and intrahepatic bile duct cancer originate in the liver or bile ducts, often linked to hepatitis infections, heavy alcohol use, obesity, and aflatoxin exposure.

4. Lung and bronchus cancer primarily caused by smoking, secondhand smoke, and environmental pollutants, affects the lungs and airways, making it the leading cause of cancer death in the US.

5. Acute myeloid leukaemia (AML) is an aggressive blood and bone marrow cancer that progresses rapidly, often linked to genetic mutations, radiation exposure, and certain chemicals.

ALSO READ: Why Are Lifestyle Factors Making Millennials Vulnerable To Cancer?

Irish middle-distance runner and two-time Olympian Ciara Mageean has died at the age of 34 after battling stage 4 bowel cancer. Her death, announced by her family on November 1, comes 16 months after she publicly revealed her diagnosis.

Mageean represented Ireland at the 2016 Rio and 2020 Tokyo Olympic Games. She won the women's 1,500m gold at the 2024 European Athletics Championships in Rome, becoming only the second Irish athlete to win an individual European title.

Her family announced her death in a statement on social media, saying, "At 6:30am this morning, Ciara lost her battle with cancer surrounded by her loved ones."

The athlete had revealed her cancer diagnosis in July 2025. In a subsequent interview with Irish broadcaster RTÉ, she spoke about the symptoms she initially noticed but how she attributed them to digestive problems.

"I would get up in the morning and I would need the toilet four times. I thought, 'That's not normal,'" she said.

She also described experiencing abdominal cramps and initially wondered whether something she had eaten had upset her stomach.

"I kept finding logical reasons for it, which many people would. I thought, 'Oh great, on top of everything else, I have an irritable bowel.'"

Mageean said her partner, Thomas Moran, encouraged her to seek medical advice. Further investigations revealed that she had stage 4 bowel cancer, which had spread to her liver and lungs.

Also read: India Cancer Drug Price Cuts: New Analysis Reveals 159 Out Of 643 Brands See No Reduction

Bowel Cancer Symptoms In Young Adults

Bowel cancer, also called colorectal cancer, develops in the colon or rectum. Although the risk increases with age, younger adults can also develop the disease. According to the NHS, symptoms can include:

• Changes in bowel habits: Chronic diarrhoea, constipation, softer stools or needing to use the toilet more frequently than usual.
• Blood in stools: Blood may appear bright red or make stools look dark or black.
• Abdominal pain: Persistent stomach cramps, discomfort or bloating.
• Feeling that the bowel has not emptied completely: A continuing urge to pass stools even after using the toilet.
• Unexplained weight loss: Losing weight without changes in diet or physical activity.
• Constant fatigue: Feeling unusually tired or breathless, sometimes due to anaemia caused by blood loss.

Also read: Colorectal Cancer Rates Rising in US Across Nearly All Age Groups After 20 Years of Decline

Why Bowel Cancer Can Be Overlooked In Younger People

One challenge in diagnosing bowel cancer in younger adults is that its symptoms can overlap with common digestive conditions like irritable bowel syndrome (IBS), haemorrhoids and inflammatory bowel disease.

Changes in bowel habits, abdominal cramps and bloating may therefore be attributed to dietary changes, stress or gastrointestinal infections.

However, unexplained symptoms should be assessed clinically. Rectal bleeding, ongoing changes in bowel habits, unexplained weight loss and fatigue should not automatically be attributed to benign digestive problems.

A family history of colorectal cancer, particularly in a close relative diagnosed at a young age, can also increase a person's risk.

Doctors may recommend blood tests to check for anaemia, stool tests such as the faecal immunochemical test (FIT), or further investigations including a colonoscopy, depending on the symptoms and clinical assessment.

An experimental pancreatic cancer vaccine triggered an immune response against genetic mutations related to cancer in nearly 99% of patients according to a Phase 2 clinical trial. This has offered a new treatment strategy in tackling one of the deadliest cancers.

The vaccine, called camupepimut, is designed to train the immune system to attack cancer cells carrying mutations in the KRAS gene. The findings, published in Nature Medicine, come from a randomised trial led by researchers at Mayo Clinic.

KRAS mutations are found in approximately 90% of pancreatic ductal adenocarcinomas, the most common type of pancreatic cancer. These mutations help cancer cells grow and survive, making the gene an important target for researchers developing new treatments.

The trial included 144 patients with KRAS-mutated pancreatic cancer who had undergone surgery and chemotherapy. None had visible signs of cancer on imaging when they entered the study. Researchers randomly assigned 96 patients to receive the vaccine, while 48 were placed in an observation group.

Of the 90 vaccinated patients whose immune responses could be evaluated, 89, or 98.9%, developed increased T-cell responses against mutated KRAS. In more than 80% of these patients, the immune response was over nine times stronger than before vaccination.

How Does The Pancreatic Cancer Vaccine Work?

Also read: Top Neurologist Says Stroke Could Be First Sign of Undiagnosed Cancer: Red Flags to Know | Interview

Camupepimut is an investigational therapeutic cancer vaccine designed to target seven common mutations in the KRAS gene.

Unlike preventive vaccines that protect people against infections that can cause cancer, therapeutic cancer vaccines aim to help the immune system recognise and attack cancer cells.

The vaccine is designed to direct an immune response towards the body's lymph nodes, where immune cells are activated. It stimulates T cells, a type of white blood cell that can identify and destroy abnormal cells carrying specific mutations.

The researchers found that the vaccine activated both CD4 and CD8 T cells. These immune cells play different roles in recognising abnormal cells and coordinating attacks against them. Also, among patients who could be evaluated at least 46 weeks after starting vaccination, 95.5% continued to show a detectable KRAS-specific T-cell response.

"Historically, pancreatic cancer has been very difficult to treat with immunotherapy," said Ben George, a Mayo Clinic medical oncologist and lead author of the study.

"What is encouraging is that we were able to generate a strong immune response against KRAS mutations in nearly every patient we evaluated. In an exploratory analysis, patients with greater immune responses to the vaccine appeared protected with longer disease-free survival times."

Did The Vaccine Prevent Pancreatic Cancer From Returning?

Despite the strong immune response, the trial did not establish that camupepimut prevents pancreatic cancer recurrence.

There was no significant difference in survival without disease between the vaccinated and observation groups, which was the trial's primary outcome.

Median disease-free survival was 23.8 months among patients who received the vaccine, compared to 21.2 months in the observation group.

Researchers did, however, find a link between stronger immune responses induced by vaccines and longer periods without disease recurrence.

The researchers also identified possible differences in response based on patients' previous treatment. Those who had received radiation therapy developed weaker immune responses related to KRAS because radiation was associated with lower levels of lymphocytes, which are important immune cells.

These findings may help researchers identify which patients are more likely to benefit from the vaccine, but they are not yet sufficient to guide treatment decisions.

"We've shown that we can teach the immune system to recognize these KRAS mutations," Dr George said. "The next step is finding out whether doing that can change the course of the disease for patients."

Currently, researchers are planning a Phase 3 clinical trial to investigate whether camupepimut can improve outcomes for patients with pancreatic cancer.

India’s latest cancer drug price revision has reduced the maximum retail prices (MRPs) of several anti-cancer medicines. While the average price reduction comes around to be more than 50%, roughly one in four of the listed drugs still remain unchanged.

Also, the overall decline across all products is only 13.8%, according to an analysis by the Working Group on Access to Medicines and Treatments.

The analysis examined 643 anti-cancer drugs that were a part of the revised price list issued by the National Pharmaceutical Pricing Authority (NPPA). 484 products, or 75.27%, recorded a price reduction, while 159 products, accounting for 24.73%, remained unchanged.

Why Is Overall Price Reduction In Cancer Drugs Only 13.8%?

Also read: Top Neurologist Says Stroke Could Be First Sign of Undiagnosed Cancer: Red Flags to Know | Interview

Among products that became cheaper, the average price reduction was 50.78%. But when the combined listed MRPs of all 643 products were compared, the overall reduction was only 13.8%.

The difference between the two figures reflects the fact that many expensive cancer medicines have remained unaffected.

According to the working group’s analysis, the combined listed MRP of all 643 products fell from approximately ₹2.51 crore to ₹2.17 crore, marking a reduction of around ₹34.57 lakh.

However, the 159 products that recorded no price reduction accounted for 86.2% of the combined revised MRP value of the entire list.

“Of course, average can be misleading,” said KM Gopakumar, researcher with the Third World Network and co-convenor of the working group. “This weighted reduction gives us much more a realistic view.”

Expensive Cancer Drugs Remain Unchanged

Also read: Cancer Drug Prices Slashed For 543 Brands From Nov 9, But A Blockbuster Drug That Treats 21 Cancers Remains Untouched

The analysis found that several expensive cancer drug brands, including medicines manufactured by multinational pharmaceutical companies, retained their earlier MRPs. These include:

• Keytruda (pembrolizumab): The listed price remains ₹2,16,500 for a 100 mg injection.
• Tagrisso (osimertinib): The price remains approximately ₹4.16 lakh for a pack of 30 tablets.
• Avastin (bevacizumab): Roche’s 400 mg vial remains priced at ₹1,23,506.
• Alimta (pemetrexed): Eli Lilly’s 500 mg injection remains priced at ₹29,531.25.

The analysis also found that 110 of 122 products examined across 18 selected multinational pharmaceutical companies recorded no price reduction. Their average price reduction across all 122 products was just 1.3%.

On the other hand, several generic medicines recorded substantial cuts. For example, the price of a 400 mg bevacizumab vial sold as Bevacirel by Reliance Life Sciences fell by 83.27%, while Abbott Healthcare’s Bevacizab recorded an 86.26% reduction.

Call For Further Action

The Working Group on Access to Medicines and Treatments has urged the government to consider additional measures to improve access to expensive cancer medicines.

It has called for public health safeguards under Sections 92 and 100 of the Patents Act, which provide for compulsory licensing and government use of patented inventions in particular circumstances.

Such provisions can allow access to patented medicines under defined legal conditions when public health requirements warrant intervention.

The group has also questioned the trade margin framework, arguing that the margins remain high and that the government should disclose the calculations used to ascertain revised MRPs.

The NPPA introduced the latest intervention to address excessive trade margins and reduce the cost of cancer medicines.

Its October 28 list initially covered 543 brands, with subsequent updates expanding the coverage to 643 products.

The price revisions suggest that the overall impact remains limited because pricey drugs have not become cheaper. So patients who need expensive patented treatments, the latest price cuts may therefore offer little direct relief.