The biggest study of its kind in North America finds a watch-and-wait strategy can have excellent long-term results for some people with rectal cancer.
Cancers of the colon and rectum are often grouped together as colorectal cancer because both are part of the large intestine, the digestive organ that is nearly six feet long. Rectal cancer can be particularly challenging to treat because the rectum — the last six inches of the organ — sits close to other organs and is encased by the bones of the pelvis.
Since 2006, Memorial Sloan Kettering has helped pioneer a method of treating rectal cancer called watch and wait, or nonoperative management. The aim is to spare people unnecessary surgery to remove the tumor, which can compromise quality of life by disrupting bowel, bladder, and sexual function.
Instead of surgery, doctors treat the person with intensive radiation and chemotherapy to shrink or eliminate the tumor. Then, they closely monitor their patient for five years, watching for any sign that the cancer has grown back. If it does, they’re able to intervene quickly.
Recent research shows the clear benefits of watch and wait. The results, published on January 10 in JAMA Oncology, show the approach is associated with excellent long-term outcomes for many people. Ninety percent of the 113 MSK patients studied who were treated with watch and wait over ten years were disease free and 80% preserved their rectum.
However, foregoing surgery inevitably involves some risk. The research also underscores that selecting the right patients for this option is crucial.
To learn more about this approach to care, we spoke with the senior author for the study, Philip Paty. Dr. Paty is an MSK surgeon who specializes in colon and rectal cancers.
What is a typical course of treatment with the watch-and-wait approach for rectal cancer?
There are three components. The first is radiation combined with chemotherapy, which lasts about six weeks, then eight cycles of chemotherapy over four months. This treatment is called total neoadjuvant therapy. Neoadjuvant means before surgery. We then pause for a few months, which is the second component, to give the treatments time to shrink or destroy the tumor. If the tumor disappears completely, we go on to the final component, which is closely monitoring the person with multiple exams per year for five years.
In our study, for people whose tumor disappeared from total neoadjuvant therapy, more than 80% remained disease-free long term and did not need surgery. For those who required surgery because the tumors grew back, the cancer was removed safely. And for people who required surgery because their tumors got smaller but did not disappear completely, many still benefited. The surgery was both easier to accomplish and more likely to have removed all the tumor cells. Also, people generally tolerate chemotherapy and radiation better before surgery than after it.Back to top
Which people with rectal cancer are appropriate candidates for the watch-and-wait option?
First, it’s people with a tumor in the lower half of the rectum. That’s the area where it’s most difficult to perform surgery while preserving normal function. When we began this approach 12 years ago, we mostly focused on older people and those with advanced cancers. However, over time we found this approach is effective for younger people and people with early-stage cancer, who typically would go straight to surgery.
We are convinced watch and wait is an excellent way to treat rectal cancer for many people when their tumor completely disappears after neoadjuvant treatment. To improve the approach, we are looking at the genetic profiles of tumors to see why some people respond better than others. And we are refining our MRI imaging techniques so we can make sure that no cancer remains. Around 40% of our rectal cancer patients are now treated using the watch-and-wait approach.Back to top
What are the benefits of the option for people with rectal cancer?
Preserving normal rectal function is enormously important to quality of life. Knowing you can eat, travel, work, and be outdoors with confidence in your bowel function really improves a person’s life. One of the first questions nearly every person asks is, “Will I have to use a colostomy bag?” When successful, this approach eliminates that anxiety. We also feel that preserving sexual function is important for people of any age and degree of sexual activity.Back to top
What drawbacks should people with rectal cancer be aware of with watch and wait?
The commitment to treatment is intensive — a minimum of six months initial treatment plus five years of active surveillance. And about 5 to 10% of people’s tumors don’t shrink despite the treatment, so they may not benefit from the neoadjuvant therapy.
For people in our study who entered the surveillance phase of watch and wait, the rectal tumor grew back 20% of the time. In every case, our surveillance caught the regrowth when it was still treatable by surgery. But these people may be at higher risk for the cancer to metastasize, or spread, to other tissues or organs.Back to top
Does watch and wait pose more risk for people than surgery?
In our research, any increase in risk appeared to be small. It’s important to understand that regrowth and metastasis can happen after surgery, just as it can after watch and wait. In those people who died in the follow-up period, most deaths were from a noncancer cause, which may have been because our study often involved older, more frail patients who had other health issues as well.
That underscores another big conclusion from our research. It’s vital that patients be selected carefully and given a full understanding of the risks and benefits. People who were treated with watch and wait had a 90% likelihood of being cured of cancer and an 80% chance of preserving their rectum, which is excellent. So we feel watch and wait is a good approach for many people with rectal cancer who have a complete elimination of their tumor after neoadjuvant therapy.Back to top