2016 GI Symposium: New Regimen for Locally Advanced Rectal Cancer as Effective as, but Less Toxic Than, Chemoradiation
Findings from a Polish phase III study point to an additional treatment option for patients with advanced rectal cancer. Patients who received short-course (5-day) radiation followed by consolidation chemotherapy before surgery achieved outcomes similar to those of patients treated with 5-week chemoradiation. The study was presented by Bujko et al at the 2016 Gastrointestinal Cancers Symposium in San Francisco (Abstract 489).
“There is a great need for improvement of preoperative strategies for patients with locally advanced rectal cancer,” said Lucjan Wyrwicz, MD, PhD, Head of the Medical Oncology Unit in Department of Gastrointestinal Cancer at the Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology in Warsaw, Poland. “The new regimen has similar efficacy but causes fewer side effects and is more convenient for patients. It is also less costly compared to standard chemoradiation, so it may be especially valuable in limited-resource settings.”
Study Background
Chemoradiation therapy is often used in rectal cancer before surgery to reduce tumor size and lower the chance that the cancer will recur. Chemoradiation is the standard of care in the United States and some European countries. The radiation treatment lasts more than 5 weeks, with concurrent use of chemotherapy in the 1st and 5th week. The experimental regimen explored in this study consists of 5 days of radiation therapy and 6 days (three 2-day cycles) of chemotherapy delivered over a period of 7 weeks.
The study enrolled 515 patients with locally advanced rectal cancer (stage cT3 or cT4). The patients were assigned to chemoradiation or the experimental (short-course radiation) regimen. Patients in the chemoradiation group received fluourouracil (5-FU), leucovorin, and oxaliplatin chemotherapy with the radiation, whereas those in the experimental group received the same agents in the so-called FOLFOX4 regimen after the short-course radiation. It should be noted that the addition of oxaliplatin to 5-FU and radiation is not considered standard therapy and is known to be more toxic than 5-FU with radiation. Both groups of patients underwent surgery about 12 weeks after starting radiation therapy.
Key Findings
A similar proportion of patients in either group were able to undergo radical surgery after radiation therapy.
The rates of acute toxicity were lower in the experimental group compared to the chemoradiation group (74% vs 83%). The major toxicities associated with radiotherapy include inflammation of the rectum, diarrhea, inflammation of the bladder, and local skin radiation response.
At 3 years, disease-free survival rates were not statistically different between the two groups (53% in the experimental group vs 52% in the chemoradiation care group). The initial report indicates improvement in the rates of overall survival (73% in the experimental group vs 63.5% in the chemoradiation group).
“If this survival benefit is confirmed with longer follow-up, it might ultimately result in change to the clinical practice in patients with locally advanced rectal cancer similarly to the studied group of patients,” added Dr. Wyrwicz.
According to the authors, short-course radiotherapy may be a particularly helpful option for patients with advanced rectal cancer with metastases in the liver or lungs who are potential candidates to have all sites of disease resected. A shorter duration of radiotherapy allows such patients to start chemotherapy to control metastases much earlier.
“This method is implemented in the treatment strategy of our patients in the Maria Sklodowska-Curie Memorial Cancer Center, and seems to be feasible and effective also in this rare subgroup of patients,” stated Dr. Wyrwicz.
This study was conducted by the Polish Colorectal Study Group led by Prof. Krzysztof Bujko and received funding from Polish Ministry of Science and Higher Education.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
