Evaluating the effectiveness and safety of mFOLFOXIRI chemotherapy with or without radiotherapy before surgery in patients with locally advanced rectal cancer

This study evaluated the effectiveness and safery of administering modified (m) FOLFOXIRI (folinic acid, fluorouracil, irinotecan, oxaliplatin) chemotherapy with or without radiotherapy before surgery in patients with locally advanced rectal cancer (LARC). The results showed that this treatment was safe and improved survival without disease in these patients.

Rectal cancer (RC) is one of the most common types of cancer worldwide. RC involves the final part of the large intestine or rectum. The first choice for treatment of RC is usually surgery. Often, patients are given chemotherapy after surgery to make sure any remaining cancer cells are killed. However, in more advanced stages like LARC, chemotherapy with radiation is given before surgery (standard neoadjuvant chemoradiotherapy; CRT) to shrink the cancer so that it can be completely removed by surgery. LARC means the cancer has spread from the rectum to the nearby organs.

Radiotherapy can have long-term side effects such as chronic diarrhea, urCT ine leakage or other bladder problems. It is important to evaluate whether administering chemotherapy with mFOLFOXIRI with radiation only in selected cases before surgery in patients with LARC is safe and effective.

The study included 106 patients with stage II and III LARC. All patients received mFOLFOXIRI CT. Before surgery, an MRI (Magnetic resonance imaging) was performed to evaluate the response to CT. Patients with more extended tumors also received CT. All patients further received surgery to remove the tumor. The average follow-up period was 43.3 months.

After 3 years, 78.9% of patients were alive without disease. 7.8% of patients had a local recurrence. 

23.3% of patients in the CT only group had no tumor signs after surgery compared to 13.7% in the CRT group. This difference was not considered statistically significant. After 3 years, 87.6% in the CT only group were alive without signs of disease compared to 75.8% in the CRT group. Patients in the CT only group were 54% more likely to be disese-free after surgery compared to the CRT group.

5.5% of patients in the CT only group had a local recurrence compared to 4.1% in the CRT group. This difference was not considered statistically significant. Fewer patients in the CT only group (5.5%) had an abnormal connection at the surgically joined parts of the intestine (anastomotic fistula) as compared to 17.8% in the CRT group.

This study concluded that CT with mFOLFOXIRI with RT given only to selected cases before surgery is safe and effective in patients with LARC.

This study had a small number of participants. Larger studies are needed.