Anal canal cancer treatment with chemotherapy combined with intensity-modulate radiation therapy (IMRT) had same effectiveness with chemotherapy combined conventional radiation, but with less adverse events
Currently, anal cancer treatment of chemotherapy with combined conventional radiation of 5-fluorouracil (5FU), and mitomycin-C (MMC) for non-metastatic squamous cell cancer of the anal canal remain effective strategy, however, it also associated with significant acute morbidity.
Due to this, the researchers investigated whether dose-painted (DP) intesity-modulated radiation therapy (IMRT) plus chemotherapy had an effective strategi compared with current chemotherapy for anal cancer patients plus conventional radiation therapy.
They found that after short-term follow-up, IMRT had same effectiveness with current chemotherapy combined conventional radiation therapy, but with less adverse events from IMRT use.
This suggestion based on new data from the Radiation Therapy Oncology Group (RTOG) 0529 trial and presented at the 2011 Gastrointestinal Cancers Symposium (GICS) on January 22, 2011, in San Francisco, California, organized by the American Society of Clinical Oncology.
According to the findings, at a median follow-up of 26.7 months, 2-year disease-free survival was 77% for patients treated with IMRT and 75% in conventional radiation therapy, and less difference on 2-year overall survival (86% with IMRT and 91% with conventional radiation).
The lead author of the study, Lisa Kachnic, MD, chair of radiation oncology at Boston University, Massachusetts, noted that although the primary endpoint was not met in the study, because combined grade 2 or higher gastrointestinal (GI) and genitourinary (GU) toxicity was similar between the group received IMRT and conventional radiation therapy, however, when looking at grade 3 or higher toxicity, there was a significant sparing of GI/GU toxicity with IMRT ( = .0052).
She added, on futher analysis, it emerged that it was primarily the GI component tha was spared, not the GU component.
Also, she pointed out that there was a dramatic improvement in dermatologic toxicities with IMRT, with grade 3 or higher toxicities being cut by more than half, and some significant grade 2 or higher hematologic sparing.
Overall, Dr. Kachnic conclude, “DP-IMRT with real-time quality assurance will be our platform in future RTOG anal canal trials incorporating novel agents, and may allow for further radiation dose escalation in advanced-stage disease.”
