Did the Polish Rectal Cancer Trial Publish pCR Results?
Yes, the Polish II rectal cancer trial (POLISH II) published pathologic complete response (pCR) results. 1
Study Details
The POLISH II trial was a phase III randomized controlled trial conducted in Poland that compared:
- Standard arm: 5-fluorouracil chemoradiation (5FUCRT) or FOLFOX with chemoradiation → surgery (n=254)
- Total neoadjuvant therapy (TNT) arm: Short-course radiation therapy (SCRT) → FOLFOX4 (3 cycles) → surgery (n=261)
The trial enrolled patients with primary or locally recurrent cT4 or palpable fixed cT3 rectal cancer, with 56% having tumors ≤5 cm from the anal verge. 1
pCR Findings in Context
The POLISH II trial was included in a meta-analysis of four major TNT trials that demonstrated significantly improved pCR rates with TNT compared to standard chemoradiation (OR 1.74,95% CI 1.45-2.10). 1 This meta-analysis encompassed RAPIDO, POLISH II, PRODIGE-23, and STELLAR trials.
Important Caveats About pCR as an Endpoint
While the POLISH II trial reported pCR data, recent evidence questions the reliability of pCR as a surrogate for survival outcomes:
- A 2025 meta-analysis of 25 RCTs (11,882 patients) found no trial-level correlation between pCR and overall survival (β=0.37, P=0.57) or disease-free survival (β=-0.84, P=0.32) 2
- The route to achieving pCR matters—patients achieving pCR after TNT had worse overall survival than those achieving pCR after chemoradiation alone, suggesting pCR does not uniformly predict favorable prognosis 3
This disconnect between improved pCR rates and survival outcomes represents a critical limitation in using pCR as a primary endpoint for rectal cancer trials.