Evaluation of prostate specific antigen level in different age group of Patients in Eastern part of Nepal *

Background A study was conducted to evaluate Prostate specific antigen (PSA) level in different age group of patients in Nobel Medical College Teaching Hospital (NMCTH), Biratnagar, Eastern Nepal. Material and Methods A total of 1870 male patients (age 51-88), attending OPD in different departments of NMCTH, were sent to Clinical Laboratory Services for estimation of Prostate specific antigen from 1 January 2013 to 30June 2014 and recruited for this study after Institutional ethical approval. Blood serum of these patients was tested for Prostate specific antigen level by Chemiluminescence Immunoassay (CLIA). Mean value and standard deviation were calculated using Student’s two–tailed t–test. Analysis of data was performed using one– way ANOVA. Results are considered statistically significant if p ≤0.05. Results Out of 1870 patients, 178 patients showed significantly higher level of PSA in their serum when compared to normal individuals. Out of this 178, 37 were from age group of 51-60, 51 were from age group of 61-70, 42 were from age group of 71-80 and 48 were from age group of 81-88. The remaining 1692 patients were having PSA within normal limit. PSA was found to be elevated up to a maximum of 34.5 ng/ml in patient. PSA level of <4 ng/ml was considered normal for this study. Conclusion This study, thus determines the diagnostic level of PSA, in different age group of patients comparing with normal individuals in eastern Part of Nepal that can help in diagnosis, prognosis and management of prostate cancer.


Introduction
The prostate specific Antigen (PSA) has been widely used to screen men for prostate cancer and it is the most common cancers afflicting men today.PSA level has got prognostic value too in diagnosed patients.PSA is accurate and precise noninvasive biomarker and its diagnostic significance is well documented.One of the most common causes of death in men is Prostate cancer and it is the second most common cancer worldwide in males.Several factors like older age, ethnicity, family history and genetic and environmental factors are the causes of the disease [1,2].A serine protease enzyme, i. e. PSA having the mol.weight 33 kDa, is a set marker for screening, diagnosis and management of prostate cancer [3,4].In Asian countries, the incidence of Prostate cancer (PCa) has been increasing in recent years, but until date it is still much lower than in Western countries.PSA testing has been widely used for more than two decades to detect early PCa.However, its specificity is low, especially in the PSA "grayzone" (PSA 2.5-10.0ng/ml) [5], while the mortality of PCa has greatly declined in many developed countries, it is increasing in less developed regions worldwide during the recent decade [6].Genetic susceptibility has been indicated as a vital risk factor for PCa.51 patients of 61-70 year age group were having very high level of PSA, the highest and lowest PSA level of this group were 28.7ng/ml and 11.1ng/ml respectively.42 patients of the age group of 71-80 years were also having very high level of PSA, the highest and lowest PSA level of this group were 31.2ng/ml and 16.4 ng/ml respectively.Similarly, 48 patients had elevated level of PSA in the age group of 81-88 years, in which the highest and lowest PSA level of this group were 34.5 ng/ml and 15.2ng/ml respectively as shown in Fig. 2. The elevated mean value of PSA level of the patients in the age group of 51-60 years showed15.4±5.3 ng/ml, whereas the elevated mean PSA level of the patients in the 61-70 year age group showed 18.5±6.8ng/ml.The age group of 71-80 & 81-88 years had 21.8±5.0ng/ml and 24.7±7.2ng/ml as the elevated mean PSA level respectively.The age group of 81-88 had more elevated mean PSA than the other age group as shown in Fig. 1.The mean PSA of the total patients of all age group, who were having normal PSA level, was 2.6±2.05ng/ml as shown in Fig. 1.The elevated PSA value (the data of 20 samples for each group) in patients of all age group is shown in scatter diagram in Fig. 3.

Discussion
PSA is considered as the most valuable serum tumor marker for the successful diagnosis and post-surgical management of Pca.The improved rate of detection of prostate cancers has become largely possible because of routine use of PSA immunoassays.These days, PSA is measured in its various molecular forms and been employed in clinical practice [7,8].
Epithelial cells of all types of prostatic tissue, benign and malignant produce PSA.
The peri urethral glands produce extra prostatic PSA, which is measurable in urine but cannot be detected in serum in women and in men.The liquification of the ejaculate, done by PSA, increases the motility of sperms [9].

Figure 3 .
Figure 3.The elevated PSA value in different age group of patients The blood samples of patients of the respective age groups were assayed for PSA level.The elevated PSA value in the different patients of all age group.(The data of 20 samples of each group is shown).

Figure 4 .
Figure 4. Normal level of PSA in patients of different age group PSA level was estimated by the blood samples of patients of all age group.Normal level of PSA in the different patients of all respective age group.(The data of 20 samples of each group is shown).

. The elevated mean PSA level in different age group of patients PSA
Techniques like transrectal ultrasound, biopsies, serum PSA and digital rectal examination are the tools used for early detection.The most reliable techinuqe is PSA.In other conditions such as benign prostate hyperplasia and prostatitis, PSA can also be elevated.Statistical Analysis The data on PSA levels were analyzed using nonparametric kruskal-walli's oneway analysis of variance by ranks.Mean value and standard deviation were calculated using Student's two-tailed t-test.Analysis of data was performed using a student T-test or one-way ANOVA.Figure 1was estimated in the blood samples of patients of different age group by CLIA.Each bar represents Mean±SD of the elevated PSA level of different patients in respective age groups.Statistical significance was compared with Normal limit by student t test.****p =0.001; ***p = 0.005, **p =0.02, *p =0.01.[The data of 37 patients in (51-60), 51 patients in (61-70), 42 patients in (71-80) and 48 patients in (81-88) age group is shown as Mean±SD].

Figure 2. The highest and lowest PSA level in different group of patients
Blood samples of patients of different age group were tested for PSA level.The highest and lowest PSA level in all age group of patients, who showed elevated level of PSA.
value of other age group as shown in Fig.4.So the present study reveals that there is association between PSA level in serum and age of the patients.ConclusionPSA is used as a tool in the diagnosis and management of prostate cancer.However, the number of deaths related to prostate cancer diagnosed by PSA screening has appreciably decreased, it is dubious to say that this is only due to PSA.The distinction between the patients with prostate cancer from those without can't be done exactly by the level of PSA. with not much of clinical benefit.So in this study, we have shown the elevated and normal range of PSA, in different age group of patients in eastern part of Nepal, which has got the significant value in the differential diagnosis of prostate.
The escape of high concentrations of PSA are generally restricted to general circulation by