Introduction:
Bladder cancer (BC) is the 11th most common cancer in the general population of Europe, with the worldwide age-standardized mortality rate (per 100.000 persons/year) is estimated at 3.2 for men and 0.9 for women, respectively. Over the years, a distant effort by researchers has been made to provide new prognostic biomarkers in the assessment of accurate response to treatment and prompt detection of recurrences. Among several markers, the carbohydrate-rich glycoprotein, Carbohydrate Antigen (CA) 19-9 has showed some usefulness as it is linked with the tumour aggressiveness and the prognosis of the disease.
Material and methods:
We searched the pub med database for a systemic review of evaluation of carbohydrate antigen 19-9 use in the management of bladder cancer. A total of 36 useful and valued studies were found on the database. These studies evaluated relation of Carbohydrate Antigen 19-9 to various different aspects of bladder cancer. These aspects include use of Carbohydrate antigen 19-9 as a tool for detection of bladder cancer, its role in the assessment of the prognosis at diagnosis and also looked at the significance of the CA 19-9 in the response to treatment of bladder cancer.
Results:
CA 19-9 urinary levels were high in patients with urothelial cancer and levels were higher in high-grade tumours as compared to low-grade tumours. In general, the marker offered adequate sensitivity and specificity of 71.6% and 91.6%, respectively. CA 19-9 with tissue polypeptide antigen (TPA) demonstrated a sensitivity of 74% and 83% in Ta and T1 tumours, respectively, and 62% in well-differentiated tumours. Also urinary levels of the biomarker achieved a similar detection rate comparing to urinary cytology regarding high-grade tumours and better for lower grade tumours. Urinary levels of CA 19-9 > 300 u/ml in patients with infiltrating disease were also strongly associated with poor prognosis. Also, in another prospective study, the role of CA 19-9 as an independent prognostic factor of mortality in patients with bladder cancer was highlighted by the authors; patients with known bladder cancer and increased serum levels (> 29 U/ml) experienced significantly shorter survival time and carried a 2.54 higher risk of death. The normalization of serum levels of the biomarker is associated with success of treatment, whereas the fluctuation of serum levels of CA 19-9 indicates recurrence. In a notable, recent study it was reported that patient who had the biomarker normalized after neoadjuvant chemotherapy had longer time to recurrence or progression and overall longer survival, whereas at the same time the pathological stage did not differ between responders and non-responders.
Conclusion
To sum up, results from studies are encouraging, but due to the limited evidence, there can be no strong recommendation for the usage of the biomarker CA 19-9 as a tool in the diagnosis and follow-up of non-muscle invasive bladder cancer. On the other hand, it seems that in cases of invasive disease and advanced or metastatic urothelial carcinoma, this biomarker could be a useful part in the assessment of the possible progression, future recurrence and overall survival of patients with this condition. Further cohorts are necessary in order that the exact role, if any, of this biomarker to be clarified.
