Document Type: Research Articles
Section of Medical Oncology, Department of Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
Department of clinical oncology and nuclear medicine, Suez canal university hospital, Ismailia, Egypt.
College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
Department of Clinical Oncology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Research Unit, Department of Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
Background: Recent data have shown that right-sided colon cancer carries poorer prognosis compared to
left-sided tumors. This study was aimed to evaluate the progression-free survival, overall survival of patients with
metastatic colon cancer of right-sided versus left-sided primaries treated with triplet chemotherapy regimen. Methods:
The medical records of patients with metastatic colorectal cancer treated on phase I-II trial of combination Irinotecan,
oxaliplatin, capecitabine, and bevacizumab were reviewed for sidedness of the primary. The analysis was performed
for progression-free survival and overall survival according to the sidedness and other known prognostic factors.
Results: Out of 53 patients treated with triplet therapy, 11 had right sided and 42 had left-sided primaries. The median
age for right-sided primaries was 46 (range 24-55) compared to 53 (range 32-74) in left-sided primaries. Median
progression-free survival was 14 months for right vs 18 months for left sided tumors (Hazard ratio 0.72, 95% confidence
interval 0.27-1.88, p=0.492) and median overall survival was 21 months for right vs 29 months for left sided tumors
(Hazard ratio was 0.86, 95% CI 0.32-2.26, p=0.752). Conclusion: First-line triplet chemotherapy may overcome the
difference in prognosis between right sided and left sided primaries in metastatic colorectal cancer. A larger analysis