20 Prostate Cancer

Prostate Cancer

5

THE GEC ESTRO HANDBOOK OF BRACHYTHERAPY | Part II: Clinical Practice Version 1 - 01/12/2014

Table 21.1: T STAGE according to the TNM staging system

Table 21.2: Indications for LDR brachytherapy (ESTRO/EAU/EORTC recommenda- tions 2000 [9])

T STAGE ACCORDING TO THE TNM STAGING SYSTEM

RECOM- MENDED DOWELL

INVESTIGA- TIONAL DO POORLY

OPTIONAL FAIR

4. PATHOLOGY The vast majority of adult prostate malignancies are adenocar- cinomas; other types including transitional cell cancer, duct- al acinar tumour, lymphoma and sarcoma are not suitable for treatment with brachytherapy. Adenocarcinomas are described by their differentiation, using the Gleason grading system. Grade 1 is the most well differentiated and Grade 5 the most poorly differentiated. Tumours are often heterogeneous and it is usual to give a combined score for the two most common appearanc- es, which varies from 2 (1+1) to 10(5+5) In practice today few cancers are graded Gleason 1 or 2 and the lowest grade prostate cancer Is given a score of 3+3=6.. The scoring has a good corre- lation with outcome; low grade tumours with a Gleason score of 6 have excellent cancer specific survival with low probability of metastases whereas Gleason scores of 8 to 10 have a higher prob- ability of developing metastases within a few years of diagnosis. There is also a premalignant entity recognised in the prostate gland which is termed Prostatic Intraepithelial Neoplasia (PIN). This is characterised by malignant cytology but lack of invasion. Unlike other sites such as the bladder and cervix the natural his- tory of PIN is not as well defined; it is thought likely that many cases do eventually progress to invasive prostatic cancer but management is usually by continued surveillance and repeat bi- opsies rather than radical ablative techniques in the absence of invasive components. It is important to realise biopsies are generally performed in a random systematic way, currently 12 core biopsies are consid- ered appropriate [4]. Further, biopsy Gleason score seems to T1: Tumour impalpable detected incidentally. • T1a: Cancer is found incidentally during a TURP in no more than 5% of the tissue removed. • T1b: Cancer is found during a TURP but is in more than 5% of the tissue removed. • T1c: Cancer is found by needle biopsy that was done because of an increased PSA. T2: Palpable on digital rectal exam (DRE) confined to the prostate gland. • T2a: The cancer is in one half or less of only one side of the prostate. • T2b: The cancer is in more than half of only one side of the prostate. • T2c: The cancer is in both sides of the prostate. T3: The cancer is outside the prostate • T3a: The cancer extends through the prostate capsule but not to the seminal vesicles. • T3b: The cancer has spread to the seminal vesicles. T4: The cancer has grown into adjacent tissue such as the urethral sphincter the rectum, the bladder, and/or the pelvic sidewall.

PSA (ng/ml) Gleason score

<10 5-6

10-20

>20 8-10

7

Stage IPSS

T1c-T2a

T2b-T2c

T3

0-8

9-19

>20

Prostate volume (ml)

<40

40-60

>60

Q

(ml.s- 1 )

>15

10-15

<10

max

Residual volume (ml)

>200

TURP

±

±

+

have a poor agreement with prostatectomy Gleason scores, where Gleason 5-6 undergrading occurs in 35%, Gleason 8-10 overgrading in 35% (n=1670) [5]. MRI is another option to eval- uate the GTV location particularly in the anterior gland which might not be detected by biopsies although still it is insufficient to detect all cancers, especially lower grade Gleason 6 tumours. It cannot be used without pathology [6].

5. WORK UP

Prostate cancer is a disease of ageing men and is rarely seen un- der the age of 45 years. Clinical presentation of localised disease may arise in one of two ways: 1) Asymptomatic men who have a PSA blood test either as part of a general health check or at their request as a screening measure, particularly where there is a close family history. 2) Symptoms of prostatic dysfunction. This will most common- ly be due to prostatic enlargement causing urinary outflow symptoms of frequency, urgency and nocturia. Other events may include haematuria, haematospermia and erectile dys- function. Outside the scope of this chapter, other less fortunate patients will present with symptoms of metastatic disease, typically bone metastases. Clinical evaluation should include: 1) A full medical history including comorbidities and evaluation of fitness for brachytherapy. 2) Objective measure of urinary function; the International Prostate Symptom Score (IPSS) is the most common scale used. 3) Objective measure of erectile function; the International Erectile Function Score (IEFS) is one example. 4) Digital Rectal Examination (DRE) to define clinical T stage. Blood tests should include serum PSA alongside a more general evaluation of the patient. There is controversy around the role