Local control still a challenge in post-SBRT advanced Pancreatic cancer - A single institute series
PO-1282
Abstract
Local control still a challenge in post-SBRT advanced Pancreatic cancer - A single institute series
Authors: Rahul Krishnatry1, AKANSHA ANUP2, Anant Ramaswamy3, VIKRAM Chaudhari4, MANISH Bhandare4, Sujay Srinivas3, Prabhat Bhargava3, VIKAS OTSWAL3, Akshay Baheti5, Shailesh Shrikhande4, REENA Engineer2
1TATA MEMORIAL CENTRE, RADITION ONCOLOGY, Mumbai, India; 2TATA MEMORIAL CENTRE, RADIATION ONCOLOGY, Mumbai, India; 3TATA MEMORIAL CENTRE, MEDICAL ONCOLOGY, Mumbai, India; 4TATA MEMORIAL CENTRE, SURGICAL ONCOLOGY, Mumbai, India; 5TATA MEMORIAL CENTRE, RADIOLOGY, Mumbai, India
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Purpose or Objective
Outcomes for the borderline resectable (BRPC) and
locally advanced pancreatic cancer (LAPC) remain poor despite treatment
advances. We review the factors associated with outcomes in our institutional
cohort of BRPC & LAPC receiving neoadjuvant chemotherapy (NACT) and
stereotactic body radiotherapy (SBRT) followed by surgery when feasible.
Material and Methods
We retrospectively analyzed the medical records
of consecutive BRPC and LAPC patients treated with NACT for a median of 2
months, followed by SBRT (36-46 Gy over 5-6 fractions) from May 2015 to Dec 2020. Factors
associated (p<0.05: significant) with overall survival (OS), disease-free
survival (DFS), progression-free survival (PFS), local failure and distant metastasis-free survival (LFFS or DMFS) were estimated using Kaplan Meier and Log-rank test
for univariate and multivariate analysis.
Results
100 (58 BRPC and 42 LAPC) patients with 64 males and median age (Inter Quantile range) of 57 (51-65) years were identified. 69 patients received FOLFIRINOX, and the remaining others gemcitabine-based NACT, with SBRT to a median dose (Inter Quantile range) of 75 (75) Gy (BED Gy10). Overall 36 patients underwent exploration with 26 (72.2%) proceeding with R0 resection where 10 achieved pathological complete response. At a median follow up of 16 months, the DFS, PFS, LFFS and DMFS were 60.5+5, 36.5+5, 54.1+6.3 and 62.6+5.7% respectively. The ECOG >1 (HR: 0.02[0.006-0.067]; p<0.001) was the only factor associated with OS, whereas, poor DFS was significantly associated with ECOG >1 (HR: 0.39[0.01-0.15]; p=0.001), local (HR: 6.67[3.31-13.43]; p<0.001) and distant failure (HR: 6.08[2.98-12.42];p<0.001). The overall PFS was significantly associated with post-NACT response (HR: 2.2[0.99-4.92]; p=0.05), local (HR: 4.97[2.72-9.05]; p<0.001) and distant failure (HR: 8.39[4.39-16.05]; p<0.001). Among them, the LFFS was only associated with post NACT response (HR: 7.82 [5.62-10.02]; p<0.001); while ECOG >1 (HR: 0.38[0.16-0.91]; p=0.03) and local progression (HR: 0.28[0.1-0.80]; p=0.018) were significantly associated with DMFS.
Conclusion
Local failure remains an important challenge in
advanced pancreatic cancers despite standard chemotherapy, SBRT and surgery as
feasible. Selecting patients with ECOG <1, good response post-chemotherapy and further
dose escalation with SBRT may be helpful in future.