Fact.

Following ASCO 2023, The New York Times wrote a story about the PROSPECT clinical trial that could lead many to believe radiation may no longer be a needed or effective therapy for some patients with rectal cancer. Here’s what you need to know.  

About the PROSPECT study 

The PROSPECT study was a clinical trial run by national clinical trial cooperative groups (networks or organizations composed of medical researchers, healthcare institutions, and other stakeholders working together to conduct large-scale clinical trials).  

The main goal of these groups is to find out if new approaches for treatment work better and can help more people than the current ones (standard of care). They compare new treatments with the ones we use now to see which is more effective. By doing this, they can figure out if it's worth using the new therapies instead of the ones we already have.  

Who participated in it 

Participants in the PROSPECT study were a subset of adults with stage II or stage III rectal cancer, whose cancer may have spread to lymph nodes. (Stage II or stage III patients who may need a colostomy or whose tumors were located too close to the anus were not included in this study.) 

Physicians and patients from the United States, Canada, and Switzerland participated in the PROSPECT study.

What it studied 

The standard of care for stage II and stage III rectal cancer is chemotherapy and radiation therapy (also called chemoradiation), and surgery. However, advancements in chemotherapy have led researchers to investigate whether a specific group of patients with stage II or stage III rectal cancer could be treated with FOLFOX (5-FU, leucovorin, and oxaliplatin) alone – without the need for radiation therapy – before having surgery. 

Important context

The PROSPECT study was a special type of clinical trial called a "de-escalation study," where a standard of care treatment is taken away to see if it's actually needed. So, while radiation is currently a standard of care for the subset of participants with stage II or stage III rectal cancer, the goal of the PROSPECT study was to find out if radiation actually needs to remain one. 

What it found

The PROSPECT clinical trial found that radiation did not make a difference in overall survival for participants. This doesn’t mean that all patients with stage II or stage III rectal cancer should forgo radiation therapy. But the study suggests that depending on tumor location, some patients with stage II or stage III rectal cancer may not benefit from radiation. For these patients, FOLFOX alone before surgery may be sufficient. 

PROSPECT study highlights 

The PROSPECT study found:  

• After five years, there was no significant difference between the two treatment arms in any of the endpoints studied. This means radiation therapy can be safely omitted before surgery if the tumor responds to treatment with FOLFOX (5-FU, Leucovorin, and Oxaliplatin).  
• Disease-free survival at five years was comparable with 78.6% for patients in the study who did not receive the new treatment option vs. 80.8% for patients who did. 
• Out of all the patients assigned to the group that received the new treatment, FOLFOX was effective enough that 91% of patients didn’t need radiation before surgery. 
• When tumors respond to six cycles FOLFOX (before surgery), radiation can be safely omitted.

Ask the expert: Was The New York Times article misleading to patients? 

Joel Tepper, MD; Professor, Dept. of Radiation Oncology, UNC School of Medicine 

Overall, there was a minimization of the side effects of chemotherapy, but those are real and can be substantial. For some patients, chemotherapy-induced neuropathy may be a much more significant side effect than the radiation-induced issues.” 

Implications for patients: Fact or crap – Some patients with rectal cancer don’t need radiation?

Fact.

Patients with stage I rectal cancer don’t typically need chemotherapy or radiation and often do well with surgery alone. Patients with stage IV rectal cancer need to continue aggressive treatment with the current standard of care. 
 

If you’ve been diagnosed with stage II or stage III rectal cancer, you may or may not need radiation. Be sure to talk to your treatment team. Don’t just assume that it’s OK to skip radiation. 

Are you a patient currently receiving radiation? 

Don’t panic! Radiation is still the standard of care.  

If you’re a patient currently receiving radiation, keep going. Radiologists are not trained in how to manage patients who have received some radiation therapy. It’s not safe for you to stop. 

Also, it’s crucial to remember that not everyone with stage II or stage III rectal cancer can forgo radiation. If you’re currently receiving radiation therapy, you may not fit into the PROSPECT study group.

Newly diagnosed rectal cancer patients: 5 questions to ask your doctor 

If you’re a newly diagnosed colorectal cancer patient, some questions to ask your doctor include: 

1. In light of the PROSPECT study, would it be appropriate for my treatment not to include radiation? 

2. How do I know if I’m qualified for this approach? 

3. Are there reasons I should have radiation?  

4. Can I be treated with chemotherapy only – not radiation and surgery?  

5. What do you think the best course of treatment for my rectal cancer is? Why? 

Patient Pro Tip 

“The thing that I really liked about this PROSPECT study is that treatment de-escalation strategies were being studied. The trial showed that de-escalation of treatment dosing and methodology used in standard of care for the past 20 years was non-inferior, producing similar outcomes while sparring toxicities and side effects.”  –Julie Krause, stage IV survivor, and research advocate 

Your Guide in the Fight 

We are fighting alongside you from your day of diagnosis and beyond. You can find additional resources in our Resource Library, or here are a few quick links to help you apply this information:

• Surgery brochure 
• Clinical Trial finder
• Radiation
• Skin rash 
• Side effect management 

To talk with someone about this information and/or ask questions, join us at our next Resource Meetup or find out how to Get Support now.

Medical Input and Review 

Joel Tepper, MD, Professor, Dept. of Radiation Oncology, UNC School of Medicine

Disclaimer 

The information and services provided by Fight Colorectal Cancer are for general information purposes only. The information and services are not intended to be substitutes for professional medical advice, diagnoses, or treatment. If you are ill, or suspect that you are ill, see a doctor immediately. In the event of an emergency, call 911 or go to the nearest emergency room. Fight Colorectal Cancer never recommends or endorses any specific physicians, products, or treatments for any condition.