CLINICO-PATHOLOGICAL FEATURES OF PROSTATE CANCER AT THE UNIVERSITY HOSPITAL YALGADO OUEDRAOGO, OUAGADOUGOU, BURKINA FASO

Abstract

Background

Prostate cancer is not uncommon in Burkina Faso and presents late, often advanced at presentation as is the case in most countries of West Africa.

Aim

To describe the clinical and histopathological characteristics of prostate cancer at the University Hospital Yalgado Ouedraogo, Burkina Faso.

Patients & Methods:

We conducted a cross-sectional descriptive study of patients treated at the Urology Department of the University Hospital Yalgado Ouedraogo, Burkina Faso for prostate cancer from March 2012 to May 2013. The parameters studied were patients’ demographics, clinical features, PSA, histological diagnosis, tumour grading, management and outcome.

Results

In this study, 82 patients satisfied the inclusion criteria within the 15 months period of the study. The mean age was 68.9 years (standard deviation: 9.52) with a range of 49-95 years. They presented with symptoms of lower urinary tract obstruction in 57 (69.5%) patients, and irritative symptoms in 59 (72%) patients. At diagnosis 33 (40.2%) of patients had metastases and the most common metastatic sites were the spine in 18(21. 95%), the ribs in 6 (7.31%) and the pelvis in 5 (6.09%) patients. The mean PSA level was 746 ng/ml with a range of 13 - 9224ng /ml. Advanced T3 and T4 tumors accounted for 25.4% and 73.2% respectively. Adenocarcinoma was the only histological form. Gleason score was less than 7 in 41(49.4 %) cases.

Androgen deprivation therapy (ADT) was the treatment for 79 (96.34%) patients. In all, 51 (62.19%) patients received medical ADT while 20 (24.39%) patients underwent bilateral orchiectomy. One patient underwent radical prostatectomy.

Conclusion

In this environment, prostate cancer is diagnosed at an advanced stage with distant metastasis. It is therefore useful to develop effective screening policy for early detection and better outcome of management.

Introduction

In sub-Saharan African countries, prostate cancer is a real public health problem. It represents 16% of all new cancers. It is the commonest cancer in males1. Prostate cancer is the sixth commonest cause of death from cancer worldwide. The mortality rate from prostate cancer in sub-Saharan Africa is among the highest2. However, the incidence and the mortality of the prostate cancer are extremely variable worldwide. The lowest incidence is seen in Asia where it is between 3.8 and 4.6 per 100,000 populations,3 while the highest incidence is seen in USA where it is between 161.4 and 255.5 per 100,000 of the population3. The clinical, natural history and pathological behaviour of prostate cancer is also variable4.

The purpose of this study was to describe the clinical and histopathological characteristics of prostate cancer in a tertiary hospital in Burkina Faso.

Patients & Methods

It is a transverse descriptive study carried out at the Department of Urology-Andrology of the University Hospital YALGADO OUEDRAOGO, from March 2012 to May 2013. The study included all patients managed for prostate cancer in the department. The diagnosis was based on digital rectal examination (DRE), PSA level and histopathological examination.

Histopathological features were obtained from pre-operative prostate biopsies and post-operative prostatic tissue specimens.

All the patients had transabdominal pelvic ultrasonography while CT scan was used for staging. The parameters studied were frequency, age of the patients at the time of the diagnosis, clinical features, PSA level, tumor stage according to 2009 TNM staging system, histopathological features of the prostate cancer, management offered and outcome. These data as well as the demographics of the patients were analysed for mean and standard deviations using SPSS.

Results

During the study 620 urology patients were hospitalized in this tertiary hospital.

A total of 82 patients had prostate cancer within the study period out of which, 58 (70.73%) patients were managed as inpatients while 24 (29.26%) were treated as outpatients. Prostate cancer accounted for 9.35 % of all hospital admissions during the period of the study. The main clinical characteristics and histopathological features of the patients were are as shown in Table 1. The patients were ill looking in 39(47.56%) of cases while weakness, weight loss, and anemia were recorded in 31(37.80%), 27(32.92%) and 25(30.48%) of cases respectively.

TABLE 1. Demographic and pathological features of the patients.

characteristics at the time of diagnosis	Population (N=82)
Age (years)	n
< 50	2
[50-60[	12
[60-70[	19
[70-80[	40
≥ 80	9
Average age: 68.9 years
range: 49 to 95 years
PSA	ng/ml
Average PSA	746
Range	13 - 9224
Tumoral stage (T)	N (%)
T2	1 (1,2)
T3	21 (25,6)
T4	60 (73,2)
Metastasis	n (%)
Present	33 (40.3)
Missing	20 (24.4)
Undetermined	19 (23.1)
Gleason score	n (%)
< 7	43 (59,72)
3+4	14 (19,44)
4+3	7 (9,72)
> 7	8 (11,11)

The average age of the patients was 68.9 years (Standard deviation: 9.52) with a range of 49 - 95 years. The patients were more than 70 years old in 49 (59.75%) of the cases. At the time of diagnosis, only one patient presented with clinically localized tumor stage (T2) while 60 (73.17%) patients presented with clinically advanced tumours in stage (T4). The main presenting complains are summarized in Table 2. Most patients had lower urinary tract symptoms (LUTS) which were seen in 92.7% of cases. Neurological deficit was seen in 8(9.75%) cases; 3(3.65%) patients had paraparesis while 5(6.09%) had paraplegia. Digital rectal examination revealed the characteristic features suggestive of prostate cancer in 80(97.56%) cases. CT scan was performed in 34 (41.5%) patients. Chest X-ray was done in 22 (27%) patients who had chest symptoms while nuclear scintigraphy was done in 3 (3.6%) patients. Abdominal and pelvic ultrasonography revealed invasion of the base of bladder in 13(15.85%) cases and hydronephrosis in 31(37.80%) patients.

TABLE 2. The features of the patients at presentation.

	The features of the patients	Frequency(n)	Percent(%)
Lower urinary tract symptoms	Dysuria/acute urinaryretention	57	69.5
	pollakiuria	59	72
	haematuria	09	11
	lumbar pain	13	15.8
Non-urinary symptoms	dorsal vertebrae pain	10	12.2
	Paraplegia/paraparesis	08	9.7
	constipation	06	7.3
	Perineal pain	05	6.1
	Pelvic pain	04	4.8
	High PSA level	02	2.4

Prostate cancer was diagnosed in two symptomless patients during routine medical check-up. However, 33(40.2%) patients had metastases at presentation. The various metastatic sites were as indicated in Table 3. Staging could not be performed in 19(23.2%) of patients. The histological diagnosis was obtained in 72(87.8%) of the cases. Adenocarcinoma was found in all the cases. Aggressive forms with a score of Gleason 7 and above were recorded in 8(9.75%) cases.

TABLE 3. Distribution of metastatic sites.

metastatic sites	Frequency(n)
Vertebrae	18
ribs	6
Pelvic bone	5
Femur	4
lungs	2
liver	2
*Brain, *manibrium,*humerus	1
* one case of each

Androgen deprivation therapy (ADT) was the treatment in 79(96.34%) patients. In all, 59 (71.95%) patients received medical ADT that consisted of anti-androgen (ciprosterone acetate 300mg daily) in 54 (65.85%) patients and luteinizing hormone-releazing hormone (LHRH) analogue (triptoreline 3.75mg per month) in 5(6.09%) patients. However, 20(24.39%) patients underwent bilateral orchiectomy. Orchiectomy was done as monotherapy in 11(13.41%) cases while it was augmented with ciproterone acetate in 9(10.87%) cases.

One patient underwent radical prostatectomy while 2 (2.43%) patients refused the treatment. We recorded 9 (10.97%) deaths while 10(12.19%) patients were lost to follow-up.

Discussion

The main finding in this study is the late presentation of a common cancer in this environment. There were 82 patients with prostate cancer managed in the 15 months period of this study. Similar high hospital based prevalence of prostate cancer had been reported by Ouattara et al5 in Benin where prostate cancer represented 12% of all hospital admissions and 69% of all urologic cancers. The incidence of prostate cancer in Africa is variable6 . The paucity of routine screening of middle aged and elderly men in most countries in sub-Saharan Africa makes it difficult to determine the real prevalence.

Prostate cancer is a disease of old men in Burkina Faso. The average age of the patients in this study was 68.9 years in concordance with the findings of Amegbor et al7 in Togo and Gueye et al8 in Senegal who found average age of 70 years and 69 years respectively. Prostate cancer is uncommon before 50 years of age. Its incidence increases gradually with age and more than 75% of the new cases are diagnosed in men above 65 years old9. An autopsy study showed that the prevalence of prostate cancers was about 30% at the age of 30 years9. These cases are histological findings without clinical signs. This mean that many people with prostate cancer may die of other causes without manifesting the features of prostate cancer. This highlights the need for early detection and prompt effective treatment protocol. Hence, even if there is no clinical manifestation of the disease, certain individual at risk should benefit from a well structure objective supervision including middle-aged and elderly men with family history of prostatic cancer.

The average PSA level in this study was 746 ng/ml with a range of 13ng/ml and 9224 ng/ml. The average level of PSA in African studies remain very high as shown by Amegbor et al7 and Diallo et al10 who reported an average value of PSA of 88.5ng/ml and 120.8 ng/ml respectively at the time of the diagnosis. The normal value in these centres was less than or equal to 4 ng/ml. These high levels of PSA mean that the prostate cancer is diagnosed at an advanced stage in African environment. The natural history of prostate cancer is often preceded by symptoms before complications arise. Lack of screening policy for detection of prostate cancer, low level of awareness about prostate cancer and the difficulty of accessing specialized healthcare add to the reasons for delayed diagnosis. It is also observed that PSA level correlated well with the stage of the tumour. There is however no PSA threshold value to exclude the presence prostate cancer. In the series reported by Diallo et al10 prostate cancer was discovered in a patient with PSA value as low as 0.1ng/ml. There is also correlation between PSA level and digital rectal examination findings in a patient with prostate cancer.

With the exception of one case, the diagnoses of prostate cancer were made at a late stage (T3 and T4). This is a common trend in developing countries unlike data from developed countries. Cosar et al in Spain11 and Brureau et al in Guadéloupe4 reported 89.8 % and 79.9 % of localized prostate cancer respectively at the time of diagnosis. These early stages provide the possibility for curative treatment unlike the advanced stages as seen in this study which allowed for only palliative treatment with the attendant poor prognosis. The clinical stage of the tumour at the time of diagnosis may be related to accessibility of specialized care12.

The commonest presenting complaint in our study was lower urinary tract symptoms which though not specific to cancer, may point to prostatic disease. In all, 2.4% of the cases were diagnosed during routine medical check-up. In the work of Diallo et al10, the diagnosis of prostate cancer during routine medical check-up was seen in 1% of the cases. The other clinical features seen in our study include low back pain, erectile dysfunction and lower limb weakness - consistent with features of late stage disease. Metastasis was seen in 40.2 % of the cases. Bone scintigraphy performed in search for metastasis13 was done in three cases. Symptoms associated with distant metastasis could mislead the diagnosis. In this study, some patients presented to the department of neurosurgery with metastasis to vertebra with neurological deficit before further evaluation correctly detected prostate cancer as the primary cause.

Adenocarcinoma was the only histological type found in all the cases in this study. It is the most frequent type representing about 97.5 % as reported by Amégbor et al7 and 99% in the work of Ugare et al14. Uncommon histological forms were reported in some African series as four squamous cell carcinomas and a sarcoma were reported by Amégbor et al7. A case of rhabdomyosarcoma was reported by Ugare et al14. Adenocarcinoma was the only histological type found in all the cases in this study. It is the most frequent type representing about 97.5 % as reported by Amégbor et al7 and 99% in the work of Ugare et al14. Uncommon histological forms were reported in some African series as four squamous cell carcinomas and a sarcoma were reported by Amégbor et al7. A case of rhabdomyosarcoma was reported by Ugare et al14. Gleason score is a useful instrument to determine the aggressiveness of the tumour. In this study, about two-thirds of the tumors were moderately differentiated but the work of Diallo et al10 showed that well differentiated adenocarcinoma was the most frequent type. There is inconsistency with regards to the average Gleason scores found in various African series. This may be due to the wide variation in assigning Gleason score between pathologists. These variations between observers depend on the specialization and experience of the pathologists as well as the differentiation of the tumor15. In a study by Brureau et al4 they suggested that harmonization of Gleason score could be achieved if a single pathologist reviewed the films.

Conclusions

In this environment, prostate cancer is diagnosed at an advanced stage with distant metastasis. It is therefore useful to develop effective screening policy for early detection and better outcome of management.