GI Upper
Adjuvant pancreas RT stays unsettled: the trial is negative overall, and the node-negative signal needs prospective confirmation on a modern systemic backbone.
RTOG 0848 NCT01013649
ForResected pancreatic head adenocarcinoma, post 6 cycles adjuvant gemcitabine-based chemo
HR 0.96
90% CI 0.79-1.18, 1-sided P=.38; did not meet OS
TL;DRAdjuvant CXRT after 6 cycles gemcitabine-based chemo missed OS (HR 0.96), but node-negative pts gained: 5yr OS 48.1% vs 28.6%.
The whole RT read sits in 91 node-negative pts: 5yr OS 48.1% vs 28.6%, median OS 3.9 vs 3.0 yr, with interaction P=.022. Delivery was standard and QA'd (50.4 Gy/28 fx, tumor bed plus pancreatojejunostomy plus regional nodes, 81% IMRT), so the technique transfers directly. G4-5 toxicity was unchanged (6% v 5%).
In a resected pancreatic head adenocarcinoma pt who is node-negative and progression-free after adjuvant chemotherapy, this supports discussing CXRT; it does not extend to node-positive disease, where no treatment effect was seen, or to margin-positive pts (only 10 node-negative/margin-positive across both arms).
The RT signal is confined to 91 node-negative pts: 5yr OS 48.1% vs 28.6%, median OS 3.9 vs 3.0 yr, interaction P=.022. Technique transfers unchanged (50.4 Gy/28 fx, tumor bed plus pancreatojejunostomy plus regional nodes, 81% IMRT, real-time central review), and G4-5 toxicity was flat at 6% v 5%.
The systemic backbone dates the result: 67% got single-agent gemcitabine, 28% gemcitabine plus erlotinib, and no pt received FOLFIRINOX. Unselected CXRT after six cycles adds nothing (OS HR 0.96), so referral for adjuvant RT stays off the default path, though the grade 3 excess (38% v 19%) is GI and lymphopenic, not prohibitive.
10 details 2 trials watching
Prospective randomized phase IIR/III, two-step, multicenter (RTOG then NRG). Step 2 opened November 2009, closed October 2018, analyzed December 2023. Randomization 1:1, unmasked, stratified by nodal status, CA19-9, margins and adjuvant systemic treatment.
Curative-intent gross total resection of pancreatic head adenocarcinoma with documented microscopic margin status; body/tail excluded. Only pts without recurrence after five cycles of chemotherapy entered step 2: 546 entered step 1, 354 randomized (174 chemo, 180 chemo+CXRT). 74% node-positive, 17% margin-positive, 81% T3.
Step 1 was gemcitabine (67%), gemcitabine plus erlotinib (28%) or non-oxaliplatin gemcitabine combinations (5%); no pt received FOLFIRINOX. Both arms then took a sixth cycle; the experimental arm followed with CXRT within 21 days, sensitized by capecitabine (83%) or infusional 5-FU (15%).
50.4 Gy in 28 fractions to the postoperative tumor bed, pancreatojejunostomy and regional nodes; median delivered dose 50.4 Gy over 28 fractions and 38 days. 81% IMRT, 19% 3D conformal, 79% with no interruptions, 88% received ≥50 Gy. Centers were IROC-credentialed and every plan underwent real-time central review before start.
Primary: overall survival from second-step randomization. Secondary: DFS and adverse events (CTCAE v4.0). Final analysis triggered at the earlier of 316 OS events or 5 years of potential follow-up for all pts; it fired on the latter with 270 events, cutting power to 72%.
Grade 4 or 5 AEs were not increased (6% v 5%, P=.68), with one grade 5 in each arm (hepatic failure, sepsis). Grade 3 rose to 38% v 19% (P<.001), driven by GI events and decreased lymphocyte count; grade 3 nonhematologic 22% v 11% (P=.004).
ESPAC-1 reported adjuvant CXRT as detrimental, but accrued 1994-2000 with split-course lower-dose 2D planning, no postoperative imaging to exclude incomplete resection or early metastases, and no QA. RTOG 9704's post hoc analysis linked RT protocol deviations to worse survival, the specific failure mode 0848 designed its real-time review to prevent.
Accrual took almost 9 years and the OS event rate ran below projection, so the trial read out on a follow-up trigger at 270 of 316 planned events (power 72% for the hypothesized HR 0.76). The node-negative arms hold 42 and 49 pts, and the subgroup rests on an interaction P=.022 across nine tested subgroups.
The negative primary settles that unselected adjuvant CXRT adds nothing after gemcitabine-based chemotherapy, while the safety profile removes the ESPAC-1-era objection that RT here is harmful. What stays open is whether the node-negative signal reflects a real locoregional benefit in pts with lower competing distant risk, and whether it survives a modern FOLFIRINOX backbone.
| Endpoint | Chemo (n=42) | Chemo+CXRT (n=49) |
|---|---|---|
| 5yr OS (95% CI) | 28.6 (14.9-42.2) | 48.1 (33.3-62.9) |
| Median OS, yr (95% CI) | 3.0 (2.2-4.0) | 3.9 (2.5-NR) |
| Median DFS, yr (95% CI) | 1.5 (0.8-2.7) | 2.3 (1.4-NR) |
CONSORT flow
Prespecified stratified phase III, primary OS endpoint negative overall. Node-negative benefit rests on a subgroup interaction (P=.022) in 91 pts, hypothesis-generating not definitive.
- Does the node-negative CXRT benefit hold on a FOLFIRINOX backbone?
- Can SBRT substitute for conventional CXRT in this setting? active mFOLFIRINOX With or Without Stereotactic Body Radiotherapy in Locally Advanced Pancreatic Adenocarcinoma Phase 2n=92 · primary completion 2025-01 · candidate match
- How to select for RT benefit when nodal status follows neoadjuvant therapy? active Carboplatin, Nab-Paclitaxel, Durvalumab Before Surgery and Adjuvant Therapy in Head and Neck Squamous Cell Carcinoma Phase 2n=39 · primary completion 2022-02 · candidate match