The addition of hypofractionated ablative radiation therapy (A-RT) after multiagent chemotherapy resulted in durable locoregional tumor control in patients with locally advanced pancreatic cancer (LAPC), according to the results of a study published in JAMA Oncology.
Preliminary evidence has suggested that RT dose escalation to an ablative threshold may improve tumor control and prolong survival in patients with LAPC. The aim of this study was to evaluate the outcomes of an LAPC cohort who underwent A-RT.
The single-center study evaluated 119 consecutive patients with LAPC who underwent A-RT from 2016 to 2019. Patients had tumors that were inoperable, with a less than 5 cm luminal abutment. A-RT was delivered at a 98 Gy biologically effective dose. The primary endpoint was overall survival (OS) and secondary outcomes included progression of disease and progression-free survival (PFS).
During a median follow-up of 18.4 months after A-RT, the median OS was 18.2 months with a median of 26.8 months from diagnosis. This translated to a 12- and 24-month OS rate of 74% and 38%, respectively, from the time of A-RT.
The median PFS was 6.3 months from A-RT and 13.2 months from diagnosis. The cumulative locoregional progression was 17.6% at 12 months and 32.8% at 24 months.
There was no radiographic evidence of disease in 25 patients at the time the report was written.
Improved PFS was associated with a postinduction decrease in CA19-9 (hazard ratio [HR], 1.33; 95% CI, 1.03-1.70; P =.03) and presence of central tumor high dose (HR, 2.20; 95% CI, 1.12-4.30; P =.02) in a multivariate analysis.
Grade 3 and 4 adverse events due to A-RT developed in 16 patients. There were no grade 5 events.
The authors concluded that “…A-RT following multiagent induction therapy for LAPC was associated with durable locoregional control and favorable survival.” They added that these results suggest that a randomized trial is warranted.
Reyngold M, O’Reilly EM, Varghese AM, et al. Association of ablative radiation therapy with survival among patients with inoperable pancreatic cancer. JAMA Oncol. Published online March 11, 2021. doi:10.1001/jamaoncol.2021.0057