Colorectal + Prostate Flashcards
Prostate Gland function
Secretes proteolytic enzymes into the semen, which act to break down clotting factors in the ejaculate
Three zones of the prostate
Central-Surround ejaculatory ducts. 25% of normal prostate volume
Transitional-surround urethra 10-15% normal prostate volume. Most prone to BPH
Peripheral-makes up main body of prostate (65%). Commonly felt on DRE. High association with prostate carcinoma
Blood supply: prostate
Prostate artery (internal iliac arteries)
Prostate carcinoma signs and symptoms
Nocturia
Urinary frequency All in late stages or in BPH
Dysuria
Abnormal DRE- Asymmetrical nodular prostate
Risk factors for prostate cancer
Age>50 Black North american/northwest european Fhx High fatty intake
Management of prostate cancer
Low risk: Expectant management
Brachytherapy
Med risk: External beam radiography
Antiandrogen (Bicalutamide, flutamide)
AND LHRH agonist (leuprorelin, goserelin)
High risk: Radical prostatectomy and pelvic lymph node dissection
Complication of radical prostatectomy
Peripheral zone is next to neurovascular bundles hence in surgery inevitably one of the bundles gets damaged resulting in erectile dysfunction.
Management of BPH
Alpha blocker (Terazosin, Doxazosin, Tamsulosin, Silodosin) PDE-5 (Sildenafil, Tadalafil, vardenafil)
Four parts of the colon, intra or retro, artery supply and mid/hindgut
Ascending colon (retro)-ileocolic + R.colic (SMA)-midgut Transverse colon (Intra)- R.,M.Colic (SMA), L.Colic (IMA)-mid/hind gut (2/3 mid) Descending colon (retro)- L.Colic (IMA)-hindgut Sigmoid colon- sigmoid art. (IMA)-hindguut
Colorectal cancer presentation
Rectal bleeding
change in bowel habit (more common in left sided colon
Rectal mass
Risk factors for colorectal cancer
Increasing age (common incidence 40-60) Adenomatous polyposis coli (APC) gene mutation Lynch syndrome IBD Obesity
Common ways patients present to hospital
Outpatients with suspicious symptoms and signs
Asymptomatic individuals discovered by routine screening of average and high-risk subjects
Emergency admission with intestinal obstruction, peritonitis or, rarely, bleeding.
Key diagnostic investigations
Endoscopy:
flexible sigmoidoscopy in low risk patients
Colonoscopy indicated in all patients except of obstruction contraindicated bowel preperation
Biopsy of lesions
When does it become rectal cancer
any cancer whose distal margin is seen at 15 cm or less from the anal verge using a rigid sigmoidoscope
Management for rectal cancer stage 1 (T1 + T2, NO)
Low risk is local excision done via:
Transanal resection of tumour (TART)
Transanal endoscopic microsurgery (TEM)
High risk
anterior resection with sphincter preservation and colorectal anastomosis
for tumours in the distal 2/3 of the rectum excision is by low anterior resection (LAR) and colo-anal anastomosis
Low risk stage 1 rectal cancer
<3 cm diameter
Involves <30% of the circumference of the bowel
Moderately or well-differentiated histology
Localised (T1, N0, M0).
High risk stage 1 rectal cancer
contraindicated for local excision
> 3 cm diameter
Poor differentiation
Lymphovascular or perineural invasion
Invasion of the anal sphincter complex.
Management of rectal cancers II and III
Pre-op radiotherapy with concomitant fluoropyrimidine-based chemo-radiotherapy
LAR and sphincter preservation or APR depending on site
Post op Chemotherapy
Cancer staging
Primary tumour (T) Regional lymph nodes (N) Distant metastasis (M)
Cancer staging Primary tumour (T)
Tx: Primary tumour cannot be assessed
T0: No evidence of primary tumour
Tis: Tumour involves only the mucosa. Also known as intramucosal carcinoma (carcinoma in situ)
T1: Tumour extends through the mucosa and into submucosa
T2: Tumour extends through the submucosa and into muscularis propria
T3: Tumour extends through the muscularis propria and into the subserosa but not to any neighbouring organs or tissues
T4a: Tumour extends through to the surface of the visceral peritoneum
T4b: Tumour directly invades other organs or tissues.
Cancer staging: Regional lymph nodes (N)
NX: Regional lymph nodes not assessed
N0: No lymph node involvement is found
N1: Metastasis in 1 to 3 regional lymph nodes
N1a: Metastasis in 1 regional lymph node
N1b: Metastasis in 2 to 3 regional lymph nodes
N1c: Tumour deposits in subserosa, mesentery, or non-peritonealised pericolic or perirectal tissues, without regional lymph node metastasis
N2: Metastasis in 4 or more regional lymph nodes
N2a: Metastasis in 4 to 6 regional lymph nodes
N2b: Metastasis in 7 or more regional lymph node
Cancer staging: Distant metastasis (M)
MX: Distant metastasis cannot be assessed (not evaluated by any modality)
M0: No distant metastasis
M1: Distant metastasis
M1a: Metastasis in 1 organ or site
M1b: Metastasis in more than 1 organ or site, or the peritoneum.
Cancer staging: Group staging
Stage 0 : Tis, N0, M0
Stage I: T1-T2, N0, M0
Stage II-III: T2-T4, N0, M0 to any T, N1-N2, M0
Stage IV: Any T, any N, M1
Stage IIA: T3, N0, M0
Stage IIB: T4a, N0, M0
Stage IIC: T4b, N0, M0
Stage IIIA: T1-T2, N1/N1c, M0; T1, N2a, M0
Stage IIIB: T3-T4a, N1/N1c, M0; T2-T3, N2a, M0; T1-T2, N2b, M0
Stage IIIC: T4a, N2a, M0; T3-T4a, N2b, M0; T4b, N1-N2, M0
Stage IVA: Any T, any N, M1a
Stage IVB: Any T, any N, M1b
Management for rectal cancer stage IV
Systemic combination chemotherapy
Chemoradiotherapy targerted at primary tumour and met lesions followed by resection
OR
Mets resected, followed by chemoradiotherapy for primary tumour and then resection of the primary tumour
Management for rectal and colon cancers where surgery not suitable
Chemotherapy Monoclonal antibodies (bevacizumab, cetuximab) Stenting (for those with obstructive tumours)
Management of colon cancer stage 1-3
Colectomy with en bloc removal of regional lymph nodes and immediate anastomosis
Post op chemo
extent of the colectomy depends on resection of the portion of the colon and arterial arcade that contains the regional lymph nodes
Minimum of 12 nodes is needed for accurate staging
Management of colon cancer stage IV
Preoperative Chemo
Synchronous or segmental resection (colectomy)
