carcinoma rectum
TRANSCRIPT
INCIDENCE
• Currently third leading cause of death in US in both gender
• 41000 new cases diagnosed in US each year and 10000 deaths attributed to rectal carcinoma
• Incidence rate in India is quite low about 2 to 8per 100,000
• Median age- 7th decade but can occur any time in adulthood
Etiology and risk factors
• The lifetime risk of colorectal carcinoma is 6% in western population
1. Family history in first degree relative
i) FAP
ii) HNPCC
2. Inflammatory bowel disease
i) ulcerative colitis: 25% risk in 25 years
ii) crohn’s disease
Etiology and risk factors
3. Dietary fats –
• red meat fats
• 20% of diet as fat
4.Synergistic effect of alcohol and smoking with increased risk
Adenoma to carcinoma sequence
• First described by DUKES in 1926
• The time course is 5-10 years
• Non inherited cases has ras, p53 mutations
• Malignant potential –
villous adenoma
Diameter >2cm
Diagnosis
• HISTORY
Symptoms : bleeding p/r , change in bowel habit (fixed mass), pain in defecation (sphincter)
Constitutional symptoms
Family history
Relevant medical conditions
Diagnosis
PHYSICAL EXAMINATION
• DRE : size, mobility, fixation, location, distance from anal verge, relationship with anal sphincter
• RIGID PROCTOSCOPY : distance from anal verge, circumferential involvement , orientation, relationship with surrounding structures
Diagnosis
PHYSICAL EXAMINATION
• COMPLETE COLONOSCOPY : synchronous growth in 2-8%
• Pelvic examination in females and prostate examination in males
Preoperative staging
• Abdominal and pelvic CT scan:
sensitivity
• for distant metastasis (75-87%)
• for perirectal nodal involvement (45%)
specifity considered close to 100%
• depth of transmural invasion (70%)
iv contrast for assessment of liver mets and ureteral involvement
Preoperative staging
• Endoluminal ultrasound :
Accuracy of 80-95% for T staging
Instrumental in assessing T1 & T2 lesions
Con: intra-observer difference, understage the tumor
Preoperative staging
uT1 Invasion confined to mucosa and submucosa
uT2 Penetration of muscularis propria but not through to the mesorectal fat
uT3 Invasion into the perirectal fat
uT4 Invasion into the adjacent organ
uN0 No enlargement of lymph nodes
uN1 Perirectal lymph node enlarged
ENDOSCOPIC ULTRASOUND STAGING OF RECTAL TUMORS
Preoperative staging
• ENDORECTAL COIL MRI :
Larger field of view
less operator dependent
Assessment of stenotic tumor
Identification of perirectal nodes (accuracy of 95%)
Identification of sphincter involvement (100%)
Preoperative staging
• PET
For assessing the pathological response of primary tumor to pre-op chemoradiation
Metastasis in brain and bones
Preoperative staging
• CEA (carcinoembryonic antigen )
Baseline CEA preoperatively for
staging,
assessment of prognosis (>5ng/ml worse prognosis)
Presence of persistence disease after resection
GOAL OF SURGERY
• PRIMARY GOAL IS ERADICATION OF PRIMARY TUMOR ALONG WITH ADJACENT MESORECTAL TISSUE AND SUPERIOR HEMORRHOIDAL ARTERY PEDICLE
RESECTION MARGIN
• Traditional margin of 5cm
• NSABP demonstrated no difference in survival or local recurrence in distal margin of 2, 2-2.9, >3cm
• Therefore, 2cm distal margin Is now acceptable considering the limitation of distal intramural spread of 2cm below the peritoneal reflection
RESECTION MARGIN
• Circumferential radial margin is more crucial
• Length of mesorectum removed beyond the primary tumor is between 3 to 5 cm as tumor implants have not been shown further than 4cm
LOCAL EXCISION
• Provide adequate oncological control with significantly less morbidity than APR in a subset of patients.
LOCAL EXCISION
Tumors amenable to local excision
• T1N0 or T2N0 lesion
• <4cm in diameter
• <40% in circumference of lumen
• <10 cm from dentate line
• Well to moderately differentiated histology
• No evidence of lymphatic or vascular invasion
• Local control for advanced disease
LOCAL EXCISION
TECHNIQUES:
Transsphincteric excision
Transanal excision
Transcoccygeal excision
Transanal endoscopic microsurgery
LOCAL EXCISION
TRANSANAL EXCISION
• Tumors 6-8 cm from anal verge
• 1 cm circumferential margin
• Full thickness excision
LOCAL EXCISION
TRANSCOCCYGEAL EXCISION
• Popularized by KRASKE
• Useful for more proximally placed, posterior lesions
• 1 cm circumferential margin
• Complication: fecal fistula ( 5 to 20%)
LOCAL EXCISION
• TRANSANAL ENOSCOPIC MICROSURGERY
• the procedure of choice for early mid to upper rectal lesion
• Offers better visualization, complete intact excision
LOW ANTERIOR RESECTION WITH TME
• local failures are most often due to inadequate surgicalclearance of radial margins.
• conventional resection violates the mesorectalcircumference during blunt dissection, leaving residualmesorectum.
• TME involves precise dissection and removal of the entirerectal mesentery as an intact unit.
• local recurrence with conventional surgery averagesapprox. 25-30% vs. TME 4-7% by several groups (althoughseveral series have higher recurrence)
LOW ANTERIOR RESECTION WITH TME
PROCEDURE :
A. MOBILIZATION OF COLON
B. TRANSECTION
C. RECONSTRUCTION
Double stapling technique
• Diverting loop ileostomy
• Colonic pouch/ transverse coloplasty
LOW ANTERIOR RESECTION WITH TME
Specific complications
• Impotence (10-28%)
• Retrograde ejaculations
• Urinary incontinence
LOW ANTERIOR RESECTION WITH TME
TME ALONE (%) TME+RT (%) TME +LND (%)
LOCAL RECURRENCE
12.1 5.8 6.9
LATERAL PELVIC RECURRENCE
2.7 0.8 2.2
PRESACRAL RECURRENCE
3.2 3.7 0.6
ABDOMINOPERINEAL DISSECTION
Suitable for
• Cancers involving the sphincter apparatus
• Incontinent to feces
Very High morbidity (61%)
Mortality 0 to (6.3%)
ABDOMINOPERINEAL DISSECTION
Complications:
• Perineal wound complications (25%)
• Urinary incontinence (as high as 50%)
• Sexual dysfunction (as high as 67%)
• Stoma complications
(ischemia, retraction, hernia, stenosis , prolapse)
ABDOMINOPERINEAL DISSECTION
En block excision :
• Posterior vaginectomy ( 1cm margin)
• prostatectomy
• Pelvic exenteration
( high morbidity and mortality )
Consider prophylactic bilateral oopherectomy
CHEMORADIATION
ADVANTAGES OF NEOADJUVANT CHEMOTHERAPY
• Downstage the tumor (60-80%)
• Achieve complete pathological response (15-30%)
• To allow sphincter preserving procedures
• No radiation to anastomosis, small bowel in pelvis
CHEMORADIATION
• 1990 NIH consensus concluded the efficacy in local control in stage II & III
• To lower local failure rates and improve survival in resectable cancers
• to allow surgery in primarily inoperable cancers
• to facilitate a sphincter-preserving procedure
• to cure patients without surgery: very small cancer or very high surgical risk
5Fu
Leucovorin
Oxaliplatin
Irinotecan
Bevacizumab
cetuximab
Combinations FOLFOX
FOLFIRI
Leucovorin/5FU
Capecitabine
Bevacizumab in combination with the above regimens.
Chemotherapy agents
CHEMORADIATION
Pre-op RT vs. surgery alone
Swedish Rectal Cancer Trial (NEJM 1997;336:980 ): 1168 patients
randomised to 25 Gy (5x5) PRT or no RT.
Surgery alone Preop. RT
Rate of local recurrence 27% 11% p<0.001
5-year overall survival 48% 58% p=0.004
Dutch Colorectal Cancer Group (Kapiteijn E. NEJM
2001;345:638): 1861 patients randomised TME vs PRT+TME
TME PRT+TME
Recurrence rate 8.2% 2.4%
OS ns ns
Pre-op vs. post-op Chemo RT
Randomized trial of the German Rectal Cancer study
Group (Sauer R et al. N Engl J Med 2004;351:1731-40):
Preop CRT Postop CRT
Patients N=415 N=384
5 y. OS 76% 74% p=0.8
5 y. local relapse 6% 13% p=0.006
G3,4 toxic effects 27% 40% p=0.001
• Increase in sphincter-preserving surgery with preop Th.
• No difference in overall survival or disease free survival at 4 years
Polish Trial
• Polish Study (Br J Surg. 2006): 316 patients with resectable T3-4 rectal cancer, no sphincter involvement, tumor palpable on DRE (1999-2002).
Preop short Preop
course RT conventional
RT
5 y. OS 67.2% 66.2%
5 y. local relapse 9.0% 14.2%
DFS 58.4% 55.6%
NO difference in anorectal or sexual dysfunction
CURRENT RECOMMENDATION
• Neoadjuvant Chemoradiation ( 5-FU based chemotherapy with radiotherapy )
• Rest for 4-8 weeks
• Total mesocolic excision
• Rest for 4 weeks
• Chemotherapy in appropriate patients for 4-6 months
STAGE II or III
low/
midlesion
CURRENT RECOMMENDATION
• Palliative surgery
• Adjuvant chemotherapy
• 5-FU + leucovorin +/- irinotecan or oxaliplatin
STAGE IV
SURVEILLANCE
• Screening for rectal recurrence and metachronous colorectal neoplasm
• 60- 80% recurrence in 24 months, 90% in 48 months
• Each visit DRE+ sigmoidoscopy + CEA
• CT scan : 1 year postresection and then annually till 3 years
SURVEILLANCE
• Postoperative at 2 weeks and then every 3 months for 2 years
• After 2 years every 6 months for 5 years
• If no recurrence, then colonoscopy every 3-5 years
• Close observation for high risk patients
REFERENCES
1. Maingots’s abdominal operations 12th ed
2. ACS surgery7 , 2014 ed
3. Sabiston’s textbook of surgery, 18th ed
4. NCCN practical guidelines in oncology v.2.2009
5. Practice Parameters for the Management of RectalCancer (Revised)
J. R. T. Monson, M.D. • M. R. Weiser, M.D. • W. D. Buie, M.D. • G. J. Chang, M.D.
J. F. Rafferty, M.D.; Prepared by the Standards Practice Task Force of the American Society of Colon and Rectal Surgeons