Benefits of Pre-Surgery Chemoradiation for Rectal Cancer

Pre-surgical treatment reduces local but not distant recurrence

Colorectal cancer affects the large intestine and/or the rectum, the last part of the digestive tract before the anus. It is the third leading cause of cancer deaths worldwide, with rectal cancer accounting for about 30% of these cancers.

Roughly half of all rectal cancers in the United States are found when they are at stages 2 or 3. This means cancer has not metastasized, or spread, to distant parts of the body like the brain, but it has advanced at the original site or grown into nearby lymph nodes.

This article discusses how radiation therapy, chemotherapy, and surgery together are used to treat rectal cancer at these stages. It also explains why this approach may lead to better outcomes.

Man receiving chemotherapy
Martin Barraud / OJO+ / Getty Images

Landmark 2004 Study

At one time, the typical practice was to remove stage 2 and stage 3 rectal cancer surgically and follow up with radiation and chemotherapy treatment. But research published in 2004 suggested that reversing this order and having the surgery after the other treatments (or not at all, in some cases) would lower the chances of the cancer's return.

In fact, among the more than 800 patients followed during that study, just 6% of the group that did this had a local recurrence of their cancer within four years after receiving treatment. That compared with 13% of the group who had their surgery first and then chemoradiation.

The chemoradiation-first group also saw fewer side effects, with no indication that delaying the surgery to complete this treatment led to worse outcomes.

Since that time, researchers and healthcare providers have continued to refine this approach with the addition of new drugs and techniques. They're meant to improve rectal cancer survival rates, even as overall colorectal cancer rates continue to rise, particularly among younger people.

Colorectal Cancer Screening

People over 50 are generally at higher risk of colorectal cancers (CRC), but the number of cases in people younger than 50 is notably on the rise. For this reason, the American College of Gastroenterology revised its screening guidelines in 2021. It's now recommended that screening begin at age 45 for people of average risk for CRC.

Adjuvant and Neoadjuvant Therapy

Generally, a treatment approach to cancer that involves surgery followed by other therapies is called adjuvant therapy. The types of treatments that may be used alongside surgery to complete this comprehensive approach include:

When these options are instead used before surgery, they are called neoadjuvant therapy. That's the case when surgery for people diagnosed with rectal cancer is delayed, in order to get the maximum benefit from the radiation and chemotherapy drugs first.

The treatments are meant to work together. Radiation, for example, may shrink a rectal tumor so that surgery is more likely to be successful. That may be because the tumor size is smaller and easier to remove, or because the size change makes it easier to reach in a previously hard-to-access spot.

Revisiting the Research

With chemotherapy, there may be a survival benefit when drugs such as oxaliplatin are used to kill cancer cells that would not be removed during surgery. That was the result when members of the 2004 research team, conducted another study and added the drug to their previous regimen.

Total Neoadjuvant Therapy

The shift toward neoadjuvant drugs used in stage 2 and stage 3 rectal cancer has led to even more comprehensive treatment options known as total neoadjuvant therapy (TNT).

TNT relies on the same concept, but involves giving both chemotherapy and neoadjuvant chemoradiation therapy before surgery.

A 2020 review of research studies included 2,400 people with rectal cancer in these stages, half of them treated using a TNT approach. The authors caution that more research is needed, but the review results show clear benefits to treating rectal cancer with TNT.

In fact, surgery may not even be needed in all cases because the neoadjuvant treatments appear to be working so well on their own.

Positive total neoadjuvant therapy results have led to a wait-and-see approach for some people when rectal cancer fully responds to chemoradiation therapies. That said, about 30% of people will see their cancers return at or near the original site while following a wait-and-see strategy after TNT.


Rectal cancer once was treated with surgery followed by chemotherapy and radiation. For nearly 20 years, though, there's been an evolution in how rectal cancer is treated. The use of chemotherapy and radiation first, before surgery, led to today's neoadjuvant treatment strategies.

It's now the treatment standard and research continues to build on the possibilities. In some cases, the success of chemoradiation has even made the surgery unnecessary. Future directions may offer even more promise, with total neoadjuvant therapy making it possible to "wait and see" if the cancer returns before doing surgery.

A Word From Verywell

If you're concerned about rectal cancer, be sure to keep up with your colorectal cancer screenings and discuss any symptoms with your healthcare provider. Newer treatment options are improving survival and quality of life for people living with the disease.

7 Sources
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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  5. Rödel C, Graeven U, Fietkau R, et al. Oxaliplatin added to fluorouracil-based preoperative chemoradiotherapy and postoperative chemotherapy of locally advanced rectal cancer (the German CAO/ARO/AIO-04 study): final results of the multicentre, open-label, randomised, phase 3 trial. Lancet Oncol. 2015 Aug;16(8):979-89. doi: 10.1016/S1470-2045(15)00159-X

  6. Kasi A, Abbasi S, Handa S, Al-Rajabi R, Saeed A, Baranda J, et al. Total neoadjuvant therapy vs standard therapy in locally advanced rectal cancer: a systematic review and meta-analysisJAMA Netw Open. 2020;3(12):e2030097. doi:10.1001/jamanetworkopen.2020.30097

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