Radiation combined with chemotherapy, also known as chemoradiotherapy, is routinely given to people with rectal cancer whose tumours can be removed with surgery. Worldwide, approximately 800,000 individuals are expected to receive a rectal cancer diagnosis in 2023, with nearly half having locally advanced tumours.

Over the past 30 years, the approach of giving chemotherapy and radiation before surgery, known as neoadjuvant chemoradiotherapy, has been the usual treatment for individuals dealing with locally advanced rectal cancer. When this treatment is combined with modern surgical techniques, it proves to be highly effective. However, pelvic radiation brings along various short- and long-term side effects, including issues with bladder, bowel, and sexual functions, pelvic fractures, and the potential for secondary cancers.

The results of a recent clinical trial on chemoradiotherapy in rectal cancer can be practice-changing. It has been demonstrated that radiation may not be needed before surgery for all people with a specific form of rectal cancer, called locally advanced, because it has spread within the rectum but not to other organs. A newer form of combination chemotherapy before surgery appears to be just as effective as chemoradiotherapy at keeping the disease at bay.

The clinical trial, called PROSPECT, enrolled 1,194 people with locally advanced rectal cancer who were randomly assigned to receive either a chemotherapy regimen called FOLFOX or chemoradiotherapy, which uses just one chemotherapy drug, before surgery. After a median follow-up of nearly five years after surgery, 81% of people in the FOLFOX group were still alive with no signs of cancer (known as disease-free survival), compared with 79% of people in the chemoradiotherapy group.

When it comes to side effects, there were some differences between the two groups. During treatment, fewer people in the radiation group had problems like loss of appetite, constipation, tiredness, and nerve issues compared to the FOLFOX group.

Throughout their treatment period, individuals in the chemoradiotherapy group experienced fewer side effects than those in the FOLFOX group. However, as time progressed to one year after the surgery, individuals in the FOLFOX group reported a lower incidence of side effects than those in the chemoradiotherapy group. These noteworthy findings were recently published in the Journal of Clinical Oncology.

The PROSPECT study introduces a valuable alternative. Patients now possess a choice beyond the conventional chemoradiotherapy approach. The implications are particularly pertinent for younger individuals concerned about radiation’s potential impact on their fertility. For this subgroup, FOLFOX might emerge as a preferable option. Conversely, individuals who find it challenging to endure the side effects associated with FOLFOX might see chemoradiotherapy as a more suitable path.

For many individuals grappling with locally advanced rectal cancer, the ability to sidestep the potential repercussions of radiation therapy can be immensely empowering. With PROSPECT, we had confirmation that there is indeed a safe approach to avoiding radiation if that aligns with the patient’s preference. While multiple factors go into such a decision, the key takeaway is that now patients can make that choice.

Preoperative Treatment of Locally Advanced Rectal Cancer – PubMed (nih.gov)

Patient-Reported Outcomes During and After Treatment for Locally Advanced Rectal Cancer in the PROSPECT Trial (Alliance N1048) – PubMed (nih.gov)