Anal Cancer FRCR CO2A Flashcards
Anal Canal Anatomy
3 to 4 cm long
anal verge is the lower end of anal canal
Types of Anal Cancer
- Anal margin Tumors: small and well diff and common in men
- Anal Canal Tumors: women > men, mod to poorly diff, worse prognosis
- Dual Components (both above)
Peak incidence of anal cancer
60 to 65 yrs
Bimodal younger 35 to 40 yrs
RFs for anal cancer
HPV 16 and 18, sexually transmitted
more in homosexuals, multiple sexual partners, HIV/AIDS
MC pathology of Anal Cancer?
Squamous Cell Carcinomas (90%)
What is AIN?
graded from I to III (as in CIN)
precancerous
usually flat or raised, ulceration suggest invasion
Spread of Anal Cancer
- Direct from primary
- Lymphatic
- Distant
direct from primary spread anal cancer
upward : submucosally to the rectum and bladder
Laterally : ischio rectal fossa and sphincter muscle
women: vagina/urethra
men: prostate
Downward: perianal skin
Lymphatic spread of Anal Cancer
low anal tumors, anal verge and anal margin tumors : perirectal node f/b inguinal nodes and then to Ext Iliac and common iliac/para aortic
mid and upper : int iliac including the hypogastric and obturator nodes and not infrequently to PA/RPLNs
Distant spread
Liver
less frequently to the lungs and bones and rarely to the brain
S/S of anal cancer?
lump/mass either found by pt on wiping or causing pt the discomfort
Bleeding
discharge and anal discomfort
rarely inguinal LNs
Investigations for anal cancer
Biopsy of the primary
is inguinal LNs removed in anal cancer ?
usually no, increased risk of lymphedema and wound infection with subsequent delay or complication in delivery of RT
Ix for anal cancer
- FBC
- Biochemical panel
- HIV test
- MRI pelvis
- CT Thorax and Abdomen
when is Sx done in anal cancer pt?
Well differentiated margin tumors < 2 cm in diameter if clear surgical margins are possible
post op RT in anal cancer
+ margin
Dose: at least 30 Gy
Nigro et al Rx of anal cancer
30 Gy/ 15 # with 2 cycles of ChT (5 FU and mitomycin 2 cycles, 4 weeks apart)
current RT Dose for anal cancer
T1-2N0: 50.4 Gy/ 28 #, Nodal Volume : 42 Gy/ 28#
T3-4N0: 54 Gy/ 30 #, Nodal Volume: 45 Gy/ 30 #
Any T, N+ : 54 Gy/ 30 #,
Involved Node: 50.4 Gy/ 30#
Nodal Volume: 45 Gy/ 30 #
UK practice of Concurrent ChT in anal cancer
5 FU 1 gm/m2 D1 to D4 and mitomycin C 12 mg/m2 on D1,
2nd Cycle during last week of RT consisting of 5 FU alone
when is bolus added
all anal margin tumors and anal canal tumors that reach a superficial level (< 2 cm)w
where is bolus kept for Anal Cancer RT?
applied to the natal cleft
Elective Nodal Regions in Anal Canal Cancer Rx
B/L inguinal
Femoral
Ext Iliac
Int Iliac
Obturators
lower 5 cm of mesorectum and
Presacral LNs
What’s Rx of locally recurrent anal cancer
APR or exenteration
if Sx not possible and RT given 2 yrs back, RE RT can be considered
what if isolated Inguinal LN recurrence
LN Dissection
Fungating mass RT Dose
30 Gy/ 10#
or frail pts, 6 Gy / # weekly for 5 to 6 weeks
Palliative ChT for anal canal cancer
Cisplatin and 5 FU
MMC with 5 FU
Rx of Adenocarcinoma of Anal canal
should be Rx as low rectal adenocarcinoma with APR
prognostic factor for anal cancer
TNM staging
Female better than male
