Top Line: After the Dutch TME trial showed a significant reduction in local recurrence with short course RT, as many as 80% of resectable rectal cancer patients in the Netherlands received neoadjuvant radiation.
The Study: But as MRI became increasingly utilized and surgery quality improved, the question arose whether some patients with lower risk, resectable rectal cancer were being overtreated. In 2014, guidelines in the Netherlands were revised to recommend more selective use of neoadjuvant RT for MRI-defined low risk disease. This included cT1-3N0-1 tumors with 5mm or less extramural invasion and >1mm distance between tumor and the mesorectal fascia. This cross-sectional, population-based study compared outcomes between patients with MRI-defined low risk disease treated in 2011 and 2016 in the Netherlands. The majority of patients in 2011 received neoadjuvant therapy (87%) compared to a third of patients (37%) by 2016. Very few patients received any form of neoadjuvant systemic therapy (20% in 2011 v 7% in 2016). Despite the decrease in RT utilization, there was no difference in the rate of local recurrence at 4 years (5.8% v 5.5%). Furthermore, OS was actually significantly higher in the 2016 cohort (86.4% v 79.6%). It’s important to note, here, that neoadjuvant RT wasn’t eliminated nor was systemic therapy increasingly utilized. Rather, MRI was utilized to better select patients who are or are not likely to benefit from neoadjuvant therapy.
TBL: Between 2011 and 2016 in the Netherlands, better MRI-based risk stratification led to reduced (but more rational) utilization of neoadjuvant RT without compromising treatment outcomes. | Hazen, JAMA Oncol 2023
The Study: But as MRI became increasingly utilized and surgery quality improved, the question arose whether some patients with lower risk, resectable rectal cancer were being overtreated. In 2014, guidelines in the Netherlands were revised to recommend more selective use of neoadjuvant RT for MRI-defined low risk disease. This included cT1-3N0-1 tumors with 5mm or less extramural invasion and >1mm distance between tumor and the mesorectal fascia. This cross-sectional, population-based study compared outcomes between patients with MRI-defined low risk disease treated in 2011 and 2016 in the Netherlands. The majority of patients in 2011 received neoadjuvant therapy (87%) compared to a third of patients (37%) by 2016. Very few patients received any form of neoadjuvant systemic therapy (20% in 2011 v 7% in 2016). Despite the decrease in RT utilization, there was no difference in the rate of local recurrence at 4 years (5.8% v 5.5%). Furthermore, OS was actually significantly higher in the 2016 cohort (86.4% v 79.6%). It’s important to note, here, that neoadjuvant RT wasn’t eliminated nor was systemic therapy increasingly utilized. Rather, MRI was utilized to better select patients who are or are not likely to benefit from neoadjuvant therapy.
TBL: Between 2011 and 2016 in the Netherlands, better MRI-based risk stratification led to reduced (but more rational) utilization of neoadjuvant RT without compromising treatment outcomes. | Hazen, JAMA Oncol 2023