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Anatomy of anus. . Pathology. Anal Canal Malignant epithelial tumours Squamous cell -keratinising Squamous cell -non keratinising(basaloid/cloacogenic) Adenocarcinoma -rectal type or anal gland Small cell UndifferentiatedAnal Margin Squamous cell/basal cell /Bowens /Pagets.
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1. The Management of Anal CancerDr C. M. McLeanEdinburgh Cancer Centre 2010
3. Pathology Anal Canal
Malignant epithelial tumours
Squamous cell -keratinising
Squamous cell -non keratinising(basaloid/cloacogenic)
Adenocarcinoma -rectal type or anal gland
Small cell
Undifferentiated
Anal Margin
Squamous cell/basal cell /Bowens /Pagets
4. TNM staging Tis Ca insitu
T1 <2cm
T2 2-5cm
T3 >5cm
T4 involving adjacent organs
M0 no mets
M1 distant mets Canal
N0 no regional LN
N1 perirectal LN
N2 unilateral internal iliac or inguinal LN
N3 bilateral internal iliac
or inguinal nodes
Margin
N0 no regional nodes
N1 regional nodes
5. Lymphatic and metastatic spread Based on surgical series 26% of patients have involved nodes, but 50% of palpable nodes are reactive hyperplasia
Lymph node involvement is directly related to the degree of involvement of the sphincter muscles
Extrapelvic metastases at presentation is rare - 8%
Locoregional recurrence 30%
6. Anal cancer Uncommon in western countries- but rising
Median age 60-65yrs
approx 300 cases per annum in the U.K
demography changing- occurring in the younger age group and immunocompromised
link between sexual behaviour
many parallels between anal cancer and cervical cancer
7. Anal Intraepithelial Neoplasia Like cervical cancer, anal cancer has an in situ change- intraepithelial neoplasia (AIN)
occurs most commonly in the transitional zone.
AIN1 nuclear abnormalities in lower third of epithelium
AIN2 effect lower two thirds
AIN3 full thickness and microvascular invasion of the basement membrane
Atypical squamous cells,condylomata and AIN are all manifestations of HPV infection
8. Anal Intraepithelial Neoplasia and HIV Prevalence of anal cytological abnormalities
in Edinburgh
30% in HIV+ve homosexuals
4.7% in HIV –ve homosexuals
0% in heterosexual males
Increase risk if CD4 count <500 x 106/l
9. Management of AIN In immuno-competent patients AIN does not usually progress to invasive cancer.
- AIN1 and 2 can be managed by anoscopy at 6 monthly intervals and if 3 consecutive examinations show no cytological progression then discharge
- AIN3 requires excision and ongoing anoscopy. Small lesions can be treated with trichloroacetic acid
Immunocompromised patients carry significant risk of progression to invasion
- monitor CD 4 counts and 6 monthly anoscopy
10. Anal Cancer and HIV increase in incidence of anal cancer in homosexual men with AIDS
in other AIDS cohorts eg drug abusers/ haemophiliacs anal cancer is rarely seen
immunocompetence leads to progression of AIN
toxicity of treatment is greater
pretreatment CD4 levels < 200 is associated with increased toxicity
11. Evolving management of anal cancer APR was treatment of choice until 1980’s
Radiotherapy alone was in vogue in 1930’s but was associated with unacceptable morbidity
Nigro et al 1974 - used combined chemoradiation for preoperative downstaging - 30Gy in 15# with mitomycin-C and 5FU
- first 3 patients had had a pathological CR at
surgery
studies began to demonstrate local control rates of 61-87% without surgery
12. Chemoradiation vs RT alone EORTC 1987-1994
110 pts randomised RT vs chemoRT
45Gy/25#
mitomycin C 15 mg/m2 d 1 5FU 750 mg/m2 d 1-5
UKCCCR 1987-1991
577 patients randomised
45Gy/20-25# gap 6/52 boost 15Gy in 6# or 25Gy in 2-3 days by implant
mitomycin C 12 mg/m2 d 1 5FU 1000 mg/m2 d 1-4 and #21-25
13. Chemoradiation studies cont
14. UKCCCR TRIAL (ACT I) At 5 years 50% were dead
Of disease failures only 58% were suitable for salvage surgery
33% of patients undergoing salvage surgery developed metastatic disease
distant met rate in RT group 38% vs 26% in CMT group
? Could chemotherapy add a systemic effect as well as a radiosensitising effect
15. What chemotherapy? RTOG (3)- RT+5FU vs RT + Mitomycin C/5FU
5yr colostomy free survival no difference (p=0.17)
5 yr overall survival improved for mitomycin-C
67% vs 50% (p=0.006)
role of cisplatin in combination with RT and adjuvantly
(ACT II)
RTOG 98-11 neoadjuvant chemotherapy with Mitomycin- C or cisplatin
16. Neoadjuvant chemotherapy RTOG 98-11
682 patients randomised between
2 cycles of 5-FU (1000 mg/m2 x4 + mitomycin-C 10 mg/m2 d 1,29, 57, 85 chemoRT starting day 57
OR
2cycles of 5-FU (1000 mg/m2 x4 + cisplatin 75 mg/m2 d1,29,57,85 chemoRT starting day 57
End point of study – DFS and secondary end point OS, colostomy free survival at 2 years and local recurrence
17. Results of neoadjuvant chemo 634 analysable patients
HR for DFS 1.15 (95%CI 0.87-1.5 p=0.33) ie no difference between the 2 groups
O.S no different
Colostomy rate higher in the cisplatin arm suggesting that cisplatin may be inferior to mitomycin -C
18. ACT II (2x2 factorial design) Epidermoid anal cancer
staged by EUA and CT
GFR >50ml/min
RANDOMISATION
RT+5FU+MMC RT+5FU+ MMC RT+5FU+CDDP RT+5FU+CDDP
No maintenance Maintenance No Maintenance Maintenance
therapy therapy therapy therapy
Patients with progressive/persistent disease following initial chemoradiation or maintenance chemotherapy should be considered for salvage surgery
22. ACT11 Results 940 patients recruited
Median age 58 years
T1/T2 50%, T3/T4 43%
Node –ve 62%
Median FU 3years
Complete response rate MMC 94%, Cisp 95% p=0.53
Gd3/4 haematological toxicities MMC 25%, cisp 13% p<0.01 ( but no increase in neutropenic sepsis)
Non haematological toxicities 61%vs 65%
Recurrence free survival 75%
23. EXTRA Phase II trial Phase II multicentre trial
Same RT dose and technique as in ACTII
Mitomycin C 12mg/m2 day 1, capecitabine 825mg/m2 b.d on radiotherapy days (5 days per week)
End points CR at 4 weeks, 6 month local control and toxicity
31 patients, 14 male, 17female
Compliance 60%with chemo, 81%with RT
Acceptable toxicity (no treatment related deaths)
77% CR, 16% PR
Median FU 14/12, 3 locoregional relapses
Capecitabine should be considered in further randomised studies
24. Elderly/frail patients cont. 16 patients (median age 81yrs)
30Gy in 15# (3cm margins on the tumour)
5FU 600mg/m2 days 1-4
1pt grade 3 skin toxicity
Local control rate 73%
13/16 patients alive at 16 months
25. What radiotherapy? Dose - bearing in mind Nigro’s original dose was 30Gy/15# - report of acceptable local control in elderly and poor P.S patients
Gap – at last we have got rid of it!
Involved nodal irradiation? Is it correct to use the same technique for a T1 N0 tumour as a T4 N2 tumour
26. Prophylactic nodal irradiation? Group from Lyon in a retrospective study of 243 cases of node negative anal cancer treated without prophylactic inguinal nodal RT found an incidence of nodal relapse to be 6.4% for T1/T2 tumours
Small retrospective study from Guys and St Thomas’ Hospital - 30 patients with node negative disease (clinical examination and imaging) underwent involved field RT alone, median FU 41 months.4 patients relapsed, 2 locally, 1 in inguinal region, 1 in liver – all were salvaged surgically and remain disease free
Role of PET scanning, sentinel node biopsy??
27. Toxicity Impact on bowel function
Bladder function
Sexual Function – impotence and vaginal stenosis
Chronic skin toxicity
Osteoradionecrosis
28. SUMMARY Chemoradiation is the standard of care for sqamous cell carcinoma of anus.
Results have improved significantly over the last decade (DFS ACT I 52%, ACT II 75%)
Future trial need to examine RT technique, can we reduce the field in earlier tumours.
What chemotherapy?
Role of PET in staging/ response to RT (earlier salvage surgery)