Takeaway
- High serum N-terminal propeptide of type-1 collagen (P1NP), C-telopeptide of type-1 collagen (CTX), and pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen (1-CTP) shortly after diagnosis of early breast cancer (BCa) were associated with higher risk of developing bone metastasis during the disease course.
- P1NP was the most sensitive marker but did not predict benefit from zoledronate.
Why this matters
- The evidence showing adjuvant bisphosphonates can reduce development of bone metastases and death from BCa, but benefits are confined to postmenopausal patients at the time of bisphosphonate initiation.
- There remains a need for a simple blood-based test in early breast cancer that can identify patients at high risk for bone metastasis.
- The findings presented here show P1NP, CTX, or 1-CTP are clinically useful, easily measured markers with good prognostic ability for bone-specific BCa recurrence.
Key results
- In adjusted continuous log-transformed analyses, increases in P1NP, CTX, or 1-CTP were strongly associated with statistically significantly increased risk of developing bone metastasis (P=.006, P=.009 and P=.008, repectively).
- In categorical analyses, P1NP >70ng/mL (P=.03) and CTX >0.299ng/mL (P=.03) but not CTX >0.566ng/mL (P = .12) were prognostic for recurrence in bone at any time.
- 1-CTP >4.2ng/mL was not (P=.10).
- No associations between baseline P1NP, CTX, or 1-CTP and development of distant recurrence at any site, demonstrating that the markers are prognostic of recurrence specifically in bone, but not distant metastasis as a whole.
- Optimal cut-off point for P1NP was ~64nmol/mL.
- Harrell’s c-index values for each biomarker (approximately 0.57) suggested low-to-moderate discrimination.
Study design
- Secondary analysis of data from the UK AZURE trial.
- Funding: Cancer Research UK, Novartis Pharmaceuticals.
Limitations
- Only baseline biomarker measurements were available.
- Biomarker population comprised approximately 25% of total AZURE population.
References
References