Hopeful Cancer Cure: Small Study Clears 14 People Of Rectal Cancer

Cancer affects millions around the globe. It’s a leading cause of death and one of the most extensively researched diseases.

According to the National Cancer Institute, an estimated 18.1M new cancer cases and 9.5M cancer-related deaths occur each year.¹

The International Agency for Research on Cancer estimates that by 2040, there will be 20.5M new cancer cases and 16.4M cancer-related deaths annually.¹

Yet, as scientists continually search for new treatments and cures, exciting advancements are happening.

For example, a promising new study² by a team at the Memorial Sloan Kettering Cancer Center has helped 14 people become free of rectal cancer, and so far, they have stayed in remission for two years.²

This phase II clinical trial is the first to study dostarlimab therapy for individuals with rectal cancer (colorectal tumors). Complete remission is seemingly possible, giving much-needed hope to those diagnosed with what can be a life-threatening disease.

Until recently, the typical treatment for rectal cancer has included a mix of chemotherapy, radiation treatment, and surgery — all with varying success outcomes and often accompanied by life-altering side effects.

About 5% of people get rectal cancer

In 2020, there were an estimated 1.8 million new cases of cancer and 600,000 deaths in the US.² Rectal cancer is among the most commonly diagnosed cancers in the US population, along with breast, lung, and prostate cancer.

Rectal cancer affects both males and females, though research indicates that males are at a slightly higher risk.³

An estimated 5% of people will develop rectal cancer at some point in their lifetime, and generally, the risk increases with age.¹

According to the American Cancer Society, the average age of rectal cancer diagnosis is 63 years old.⁴

There is also a notable rise in colon and rectal cancer cases among young people.⁵ Concerningly, the causes for early onset are not yet well understood. Any groundbreaking research that could transform the standard of care is more timely than ever.

Standard therapy for rectal cancer

As of right now, treatment for rectal cancer usually involves:

  • Chemotherapy

  • Radiation treatment

  • Surgery

These established treatments often come with significant emotional, physical, and reproductive side effects, and success rates vary considerably.⁴ ⁶

Moreover, the spread of rectal cancer to other parts of the body can significantly reduce survival rates.⁷

An experimental study eradicates rectal cancer in all 14 patients

As mentioned, a small immunotherapy study² for rectal cancer treatment by Memorial Sloan Cancer Center shows astounding results.⁸

Starting in December 2019, patients diagnosed with rectal tumors were given the drug dostarlimab (Jemperli). Dostarlimab is an immunotherapy agent known as a checkpoint inhibitor every three weeks for six months.⁹

After six months, all 14 participants were physically examined and received diagnostic testing including endoscopy, PET, and MRI scans. Remarkably, no cancer was detectable among any of the patients in the study — also known as a 100% complete response rate.¹⁰

Furthermore, all 14 patients were expected to undergo chemoradiotherapy or surgery following receiving dostarlimab, but it was unnecessary. 

Dr. Andrea Cercek, a medical oncologist at the Memorial Sloan Kettering Cancer Center (MSK), told ABC News, “The most exciting part of this is that every single one of our patients has only needed immunotherapy. We haven’t radiated anybody, and we haven’t put anybody through surgery.”¹⁰

"I believe this is the first time this has happened in the history of cancer," said Dr. Luis Alberto Diaz, Jr., a member of the MSK research team.¹¹

Without immunotherapy, cancer cells would usually shut down immune cells — allowing tumors to grow without being attacked. Dostarlimab’s role is to reverse that block on immune cells, allowing the immune system to recognize and attack cancer cells. 

This pioneering treatment has been named immunoablative therapy. Dr. Hannah K. Sanoff is the quality and innovation officer of the North Carolina Cancer Hospital and a professor at the UNC School of Medicine Division of Oncology. In a recent New England Journal of Medicine article by Dr. Sanoff, she describes the dostarlimab study as “small but compelling.” Still, she adds that “very little is known about the duration of time needed to find out whether a clinically complete response to dostarlimab equates to cure.”¹²

While the early results are exciting, assessing whether the treatment can be helpful in a broader context will require larger studies and replication of the findings.

Dostarlimab’s potential to treat other types of cancer

The participants in the rectal cancer study all had a type of cancer called mismatch repair-deficient (MMRd) rectal cancer.  

Hopefully, other forms of rectal cancer can benefit from immunoablative therapy, but it will need to be studied. Doctors conducting the clinical trial expect that the treatment will be helpful for other cancers as well. For example, trial enrollment is open for dostarlimab therapy for patients with pancreatic, stomach, and prostate cancer.¹³

What causes rectal cancer?

Rectal cancer occurs in a chamber of the colon between the end of the large intestine and the anus. Rectal cancer and colon cancer are similar and sometimes referred to as colorectal cancer.¹⁴

People develop rectal cancer when healthy cells in the rectum continue growing past their typical lifespan. These atypical cells can build up, bind and form growths known as polyps. These polyps can progress and become cancerous.¹⁵

If the polyps become cancerous, there is a risk of the cancerous cells traveling to other areas of the body, a process known as metastasis.¹⁶

Rectal cancer warning signs: what to look out for

Early rectal cancer can be symptomless. However, it’s essential to speak with your doctor if you experience possible warning signs and symptoms, such as:

  • Rectal bleeding 

  • Blood in the stool 

  • Constipation 

  • Sudden changes in bowel habits 

  • Diarrhea 

  • Tiredness

  • Weakness

  • Unexplained weight loss

Risk factors for rectal cancer

The exact cause of cellular mutations that cause rectal cancer is currently unknown. Fortunately, many of the risk factors are preventable by addressing lifestyle, and daily habits, including

Excessive red meat and processed meats

Aim to limit or eliminate your consumption of red meat and processed meat. Many studies¹⁷ link red meat and processed meat consumption to colorectal cancer.¹⁸

Lack of physical activity

A lack of exercise causes an estimated 12-14% of colon cancers.¹⁹ So, increasing your activity level can significantly reduce your risk of developing rectal cancer. Evidence points to exercise’s ability to promote digestion, immune system function, healthy insulin levels, and body weight.¹⁹


Excess body weight, particularly around the waist, is associated with an increased risk of

experiencing rectal cancer. For example, a study²⁰ ​​of 85, 256 women found that those with obesity — defined as a body mass index ≥30 — were at almost twice the risk of experiencing early-onset colorectal cancer.²⁰


Studies²¹ have found that as smoking increases, so does the risk of rectal cancer.²¹

Consuming Alcohol

Alcohol consumption, particularly in higher amounts, is linked to various cancers, including cancers of the rectum and colon.²²

Genetic factors

Many genetic factors can contribute to developing rectal cancer. A family history of Lynch Syndrome or Familial Adenomatous Polyposis, a history of cancer, and a history of inflammatory bowel disease can all put you at a higher risk.²³ ²⁴

Tips for preventing rectal cancer

Since rectal cancer is often associated with lifestyle factors, experiencing the disease can be preventable in many cases. To reduce your risk of developing rectal cancer, start by:

Get screened — it could be lifesaving

If you have a history of rectal cancer in your family or have other risk factors mentioned, it’s essential to have rectal cancer screenings to spot cancer early. If you are over 45 or think you could be at risk of developing rectal cancer, speak to your doctor about screening.²⁵

Maintain a healthy weight

Individuals with obesity are at a significantly higher risk of developing rectal cancer.²⁰ To maintain a healthy weight, eat a well-balanced diet. Eat an abundance of fruits, vegetables, and whole grains, while avoiding red meats and processed food as much as possible. Regular exercise is another way to maintain a healthy weight and reduce the risk of developing rectal cancer.

Avoid alcohol

Consuming alcohol is associated with an increased risk of developing rectal cancer. The CDC recommends that men limit alcohol consumption to two drinks (or less) a day, and women are advised not to exceed one drink daily.²⁶ If you have concerns about alcohol dependency or safely reducing alcohol consumption, speak to your doctor. 

Quit smoking

Smoking elevates the risk of many diseases and health issues, including the risk of developing rectal cancer. Of course, quitting can be challenging, so consider speaking to your doctor to help build a quit plan. 

The lowdown

Rectal cancer can be a life-threatening disease, with current treatment options usually involving significant side effects. However, a promising small-scale study is offering hope. 

One limitation of the dostarlimab trial is that patients were all treating a type of rectal cancer known as mismatch repair–deficient (MRD), locally advanced rectal cancer.

So, while it’s still unknown whether other types of rectal cancer will benefit from this type of immunotherapy, there is reason to be optimistic.

Oncologists and doctors are excited about what this may mean for other cancer patients. Even though this ongoing study is small, it opens the door for further research advancements.

If you have concerns or are experiencing bowel-related symptoms or changes, speak to your doctor. If you’re 45 or older or have a family history of rectal cancer, ask about rectal cancer screening.

The information provided is designed to support, not replace, the relationship between a patient/site visitor and their existing health care professional(s).

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  1. Cancer statistics | NIH: National Cancer Institute

  2. ASCO 2022: 100% Complete response rate in MMRd locally advanced rectal cancer seen in pivotal ‘immunoablative’ neoadjuvant immunotherapy clinical trial | Memorial Sloan Kettering Cancer Center

  3. Cancer statistics (2021)

  4. Colorectal cancer: Facts & figures 2017-2019 | American Cancer Society

  5. Age at initiation of lower gastrointestinal endoscopy and colorectal cancer risk among US women (2022)

  6. Improving quality of care and clinical outcomes for rectal cancer through clinical audits in a multicentre cancer care organisation (2020)

  7. Colorectal cancer: Statistics | Cancer.Net

  8. PD-1 Blockade in mismatch repair–deficient, locally advanced rectal cancer (2022)

  9. Study of induction PD-1 blockade in subjects with locally advanced mismatch repair deficient solid tumors | ClinicalTrials.gov

  10. Study by memorial Sloan Kettering on immunotherapy eradicated rectal cancer for all patients | Eye Witness News

  11. This small cancer trial led to remission in every single person: 'There were a lot of happy tears' | Upworthy

  12. Improving treatment approaches for rectal cancer (2022)

  13. Rectal cancer disappears after experimental use of immunotherapy | Memorial Sloan Kettering Cancer Center

  14. What is colorectal cancer? | American Cancer Society

  15. Colon and rectal polyps | University of Michigan Health

  16. What is metastasis? | Cancer.Net

  17. Discovery and features of an alkylating signature in colorectal cancer (2021)

  18. Pattern of DNA damage links colorectal cancer and diet high in red meat | NIH: National Cancer Institute

  19. Physical activity and colorectal cancer (2004)

  20. Association of obesity with risk of early-onset colorectal cancer among women (2018)

  21. Cigarette smoking and colorectal cancer risk by molecularly defined subtypes (2010)

  22. Alcohol use and cancer | American Cancer Society

  23. Lynch syndrome | Centers for Disease Control and Prevention (CDC)

  24. Familial adenomatous polyposis | NORD

  25. Colorectal cancer screening tests | Centers for Disease Control and Prevention (CDC)

  26. Dietary guidelines for alcohol | Centers for Disease Control and Prevention (CDC)

Chloe Garnham is a writer exploring a broad range of topics, including healthcare, education, and technology.

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