புற்றுநோய் அறிவியல் & சிகிச்சை

Bone Markers in the Treatment of Cancer Related Bone Disease in Patients with Metastatic Breast Cancer

Abstract

Brancíková D, Mechl Z, Adam Z, Protivánková M, Ostrížková L, Bednarík O and Mayer J

Bone metastases and treatment-induced osteoporosis are frequently the maincauses of morbidity in patients with malignancies. Monitoring the level of bone markers (markers of bone metabolism) has been fairly well mapped in osteoporosis, where medical procedures can be modified according to the kinetics of marker levels before an answer can be evaluated by densitometry and before the onset of fractures. In bone metastases the role of these levels is not clear. The metabolic markers of bone resorption under review in this set were ß-Cross Laps (CTX) - a peptide that is a part of C - telopeptide, and N-terminal propeptide of collagen type 1 (P1NP).

Material and methods: We monitored a group of 52 female patients with metastatic breastcancer. The patients received appropriate systemic treatment based on the immunohistochemistry of the tumor; the treatment consisted of hormone therapy or chemotherapy, and included parenteral bisphosphonates (ibandronate and zoledronic acid alternately). Routine biochemical tests and blood count done prior to the initiation of therapy also included taking laboratory markers of bone metabolism CTX and P1NP and measuring bone mineral density (according to T-score). These bone markers were then checked in three, six, nine and twelve months, and matched with the progress of the disease. Total monitoring time was fifteen months.

Results: The patients in this set whose CTX value in the first sampling was less than 0.425 ran 8.5 times higher risk of death; the patients whose P1NP value reached more than 74 in the first collection ran 8.7 times higher risk of death. According to Cox proportional-hazards regression analysis for CTX, the significance level of p-value was 0.0452 and HR was 8.516 (95% CI 1.047 to 69.262), a difference which is not statistically significant. Regarding P1NP in Cox regression analysis, the significance level of p-value is 0.0433 and HR 8.673 (95% CI 1.067 to 70.520). Even this difference is therefore not statistically significant. When comparing the kinetics of marker levels, the difference is below statistical significance: p-value 0.6131 for P1NP and p-value 0.6357 for CTX.

Conclusion: The results of this study confirm a correlation between the starting levels of CTX and P1NP with the overall survival rate, which corresponds to the other results presented in literature.