MedWire News: Patients with locally advanced pancreatic cancer (LAPC) have a more favorable prognosis after palliative chemoradiotherapy (CRT) if they have previously been treated with a gemcitabine-based therapy, say Danish researchers.
Conversely, a large tumor volume is associated with shorter survival, they add.
"Patients with LAPC can safely be treated with CRT," say Jon Bjerregaard (Odense University Hospital) and colleagues.
"The survival of patients is still low, but our analysis provides evidence that subpopulations who are treated with gemcitabine before undergoing CRT and have a low tumor burden are likely to have more benefit."
The team assessed data from a cohort of 176 LAPC patients who received 50 Gy CRT in 27 fractions over 5.5 weeks combined with tegafur-uracil/folinic acid. After a follow-up time of 67.0 months, the median overall survival was 11.5 months with a 1- and 2-year posttreatment survival of 47% and 17%.
The overall resection rate in the group was 13%, and overall survival among resected and nonresected patients was 44 and 10 months, respectively. Thirty-seven patients (21%) had received gemcitabine-based therapy before entering the study.
Multivariate analysis revealed that pretreatment with gemcitabine (yes vs no) and patients' resection status (yes vs no) were both significantly associated with longer survival, with respective hazard ratios (HRs) of 0.57 and 0.12.
By contrast, increasing gross tumor volume was significantly associated with shorter survival, with a HR of 1.14 per 25 cm3 increase.
Bjerregaard et al suggest that their data suggest that in an unselected group of patients with initially nonresectable disease, "there should be two treatment goals, secondary resection and optimal palliation."
The team also reports patients' toxicity experiences after CRT. A total of 12 did not complete the course for reasons including concerns about kidney damage (n=1), rapid tumor progression and deteriorating performance status (n=6), gastric perforation (n=1), and acute small bowel obstruction (n=1).
Overall, 36% of study participants experienced a grade 3 (on the Common Terminology Criteria for Adverse Events v2.0) adverse event, some of which - including vomiting and diarrhea - were CRT-related, but many - including pain and infection - were likely disease-related.
"We suggest that future studies with survival as a primary endpoint should focus on the sequence of therapies," conclude Bjerregaard and co-investigators in the International Journal of Radiation Oncology Biology Physics.
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