Carcinoma of Rectum

Dr M Adnan Haider

Post Graduate Resident General Surgery

Surgical Unit 1

Sheikh Zayed Hospital

Rahim Yar Khan

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History

• Patient M Ashiq S/O M Pehlawan Resident of Sadiqabad presented to OPD with complaints of
• Per Rectal Bleed for 3 years
• Diarrhea for 1 year
• Weight loss of more than 50 kilos over the period of 3 years

History of Presenting Illness

• My patient was in usual state of health 4 years back when he experienced
• Per rectal bleed that was
• Sudden in onset
• Continuous
• Fresh
• Copious at times and in small amount at other times

HOPI

• It was not associated with any significant anal or rectal pain (procatlgia)
• There was history of repeated episodes of loose motions, more in the early morning, with loss of control over feces, worsening over last few years
• Loose motion were mixed with blood at times and blood less at others
• There was history of mucus mixed with the stools
• There was history of significant weight loss over last four years up to 50 kilos
• There was history of fever not associated with rigors or chills. It was low grade, on and off

HOPI

• There was history of tenesmus associated with diarrhea

Past history

• Took treatment for Hepatitis C 2 years back when it was diagnosed
• History of multiple hospitalizations in the last 1 year
• History of biopsy taken per rectum

Associated Illness

• DM +ve (4 years)
• HTN -ve
• IHD -ve
• Bleeding tendency -ve
• Tb -ve
• Chronic bronchitis / COPD +ve
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Family History

• Married
• 9 offsprings
• No history of colorectal cancer in the first or second degree relatives

Personal history

• Alcoholic (Abstained in 2010)
• Smoker 2 packs per day for last 40 years
• Uneducated
• Truck driver

Examination: General

• A person of average built and height looking weak and cachexic
• Well oriented in time place and person
• No significant pallor or jaundice
• Moderately dehydrated
• Non engorged neck veins
• No clubbing, koilonychia
• No edema
• GCS 15/15
• No palpable lymph nodes

Examination: Vital Signs

• Bp 110/70 Pulse 80 bpm Temperature Afebrile Respiratory Rate 16 per minute

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Examination: CVS

• JVP not raised
• No prominent veins
• Apex beat in 5th lics
• Heart sounds s1 and s2
• No murmur palpated or heard

Examination: Respiratory System

• Chest movement equal and normal
• Expansion is reduced
• No obvious deformity
• Trachea central
• Percussion note resonant
• Vesicular breath sounds
• With added rhonchi
• Decreased air entry at the bases

Examination: Abdomen

• Inspection: No bruise, stretch marks, striae or scar marks. Umbilicus inverted
• Palpation: Soft and non tender
• Percussion: Normal
• Auscultation: Bowel Sounds were audible and 3-5 contractions per minute

Examination: Digital Rectal

• No skin tag, fissure, sinus or hemorrhoids
• Decreased anal tone
• Fungating mass 2 cm from the anal verge more circumferentially involving rectum more on the right side
• Prostate enlarged

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Examination: Lymph nodes

• Inguinal lymph nodes were not enlarged

Differential Diagnoses

• Rectal Carcinoma
• Rectal polyp
• Hemorrhoids
• Amoebic granuloma

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Provisional Diagnosis

• Rectal Carcinoma

Investigations: Biopsy

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Investigations: CT CAP

• Malignant neoplastic lesion in the mid and lower rectum with multiple small perilesional lymph nodes
• Enhancing circumferential wall thickening causing moderate luminal narrowing approx 7 cm from anal verge. Craniocaudal extent measures up to 6 cm. Maximum unilateral wall thickness measures 2.1 cm at 9’O clock. Multiple subcentimetric lymph nodes in the mesorectal fat.
• No evidence of hepatic, adrenal, pleuro-pulmonary or skeletal metastasis
• Cholelithiasis
• Prostatomegaly

Investigations: CEA levels

MRI Pelvis

Treatments already Received

• 28 sessions of radiotherapy over 3 month period
• 6 sessions of chemotherapy over 6 month period

Treatment given at Surgical Unit 1

• Preoperative preparation was done
• Midline laparotomy was made
• APR done
• End Colostomy made
• Drains placed
• Patient is now in ward being carefully monitored

Anatomy of Rectum

• Follows the curve of the sacrum and ends at anorectal junction.
• Anorectal angle is about 120 degree, encircled by puborectalis muscle
• Three lateral curvatures, upper and lower are convex to the right, middle is convex to the left
• Rectum is 12-18 cms in length
• Divided into 3 equal parts
• Upper third covered by peritoneum anteriorly and laterally
• Middle third covered by peritoneum only anteriorly and lower third is below the peritoneal reflection

Anatomy of Rectum

• 2 important fascias are there anteriorly and posteriorly at the level of lower third of rectum
• Denonvillier’s fascia (Separates it from prostate/vagina)
• Waldeyer’s fascia (Separates it from lower 2 sacral vertebrae and coccyx
• These fascial layers act as barriers to malignant invasion
• A fat filled envelope of connective tissue surrounds the rectum posteriorly and laterally containing vessels and their associated lymphatics. It is called “mesorectum”.

Blood Supply of Rectum

• Superior, middle and inferior rectal arteries
• Superior rectal artery is the main supply and it is the direct continuation of inferior mesenteric artery. It lies posteriorly in mesorectum
• Middle rectal artery arises on each side from internal iliac artery. Lies in lateral ligaments
• Inferior rectal artery is the branch of internal pudendal artery

Venous drainage of Rectum

• Superior hemorrhoidal veins unite to form rectal veins and then superior rectal vein
• Which becomes inferior mesenteric vein
• Drains into splenic vein
• Part of the portal venous system

Lymphatic Drainage of Rectum

• Usual drainage flow is upwards
• Lymphatics follow the rectal vessels
• In carcinoma of the rectum, surgical clearance concentrates on proximal lymph nodes
• If the proximal pathway is blocked, involved lymph nodes can be found on the side walls of pelvis or even in the inguinal region

COLORECTAL CANCER

• Colon and rectal cancers are often grouped together under one umbrella term
• World Health Organization (WHO) and American Cancer Society use "colorectal cancer" (CRC) for surveillance, prevention, and treatment guidelines
• The reason for umbrella term being their similar anatomy, embryology and histology, risk factors of the disease process, pathogenesis, screening protocols and treatment strategies.

Distribution of colorectal cancer by site

Incidence of Colorectal Cancer (CRC)

• Second most common malignancy worldwide
• Fourth most common cause of cancer related death after lung, gastric and liver cancer
• Greater in men than women (56 % versus 44 %)
• 14% rise in incidence since 1970s, more so in men (20%)
• Most colorectal cancers are due to old age, with around 60% of cases affecting patients 70 years or older

Risk Factors

NON-MODIFIABLE:

• Age
• Family history (Those with a family history in two or more first-degree relatives have two to three fold greater risk of disease and this group accounts for 20% of cases)
• Genetic syndromes like Lynch Syndrome (Hereditary Non Polyposis Colorectal Cancer HNPCC) ~ 3% of cases
• Gardner syndrome and FAP

Risk Factors

MODIFIABLE:

• Up to 80% of CRCs occur in people with little or no genetic risk.
• Their risk factors may include:
• Diet (Low-fiber, high-fat diet especially processed red meat)
• Obesity
• Smoking
• Lack of physical exercise
• Alcohol consumption

Pathogenesis

HEREDITARY:

• Originates from premalignant precancerous lesions in the epithelial lining of the colon or rectum
• In a stepwise progression
• Results in increasing dysplasia due to accumulation of genetic abnormalities

Pathogenesis

SPONTANEOUS:

• Adenoma-carcinoma sequence.

Pathogenesis

GENETIC ABNORMALITIES:

• Mutation in Wnt signalling pathway, increases cell signalling activity
• It can be inherited or acquired
• APC gene is the most commonly mutated gene
• Leads to accumulation of Beta-catenin protein
• Beta-catenin protein activates the transcription of various proto-oncogenes that are responsible for normal cell division but when overexpressed can cause cancer
• Other gene mutations include tp53, KRAS, PTEN

Pathogenesis

EPIGENETIC ABNORMALITIES:

• Genes on and off switching due to external or environmental factors
• Can affect hundreds of genes and their expressions

Clinical Features

• Diagnosis is often delayed because symptoms are attributed to benign causes
• Bleeding per recum
• Tenesmus
• Alteration of bowel habit/Early morning diarrhea
• Pain
• Weight loss

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Clinical Features: Bleeding

• Earliest and most common symptom
• Bright red and painless
• Can be indistinguishable from hemorrhoidal bleeding particularly in younger patients

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Clinical Features: Tenesmus

• Needing to evacuate the rectum but unable to pass the motion
• Most common in patients with tumours of the lower half

Clinical features: Alteration of bowel habits

• Spurious diarrhea: Patient may attempt to empty rectum several times a day
• Passage of flatus, looser stool and a little blood-stained mucus (bloody slime)
• Early morning bloody diarrhea with passage of blood and mucus is a typical symptom of rectal carcinoma
• Increasing constipation can also be a sign of rectal carcinoma

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Clinical features: Pain

• Pain is a late symptom
• Colicky pain may occur in advanced tumors of the rectosigmoid
• Intractable pain may also occur in advanced cancers invading outside the mesorectum invading bladder/prostate anteriorly or sacral plexus posteriorly

Clinical Features: Abdominal Examination

• Normal in early cases
• What can be other features?

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Clinical Features: Rectal Examination and Vaginal Examination

• Can vary depending upon the location of the tumour
• For example, if it is situated 7-8 cm from the anal verge
• Elevated, irregular, hard endoluminal mass can be felt
• Central ulceration will be felt as shallow depression and raised everted edges
• Mobility and tethering need to be assessed
• Per vaginal examination may show findings in cases where posterior vaginal wall involvement is suspected
• Anal sphincter complex needs to be evaluated for reconstruction or anastomosis plan

Investigations

• Proctoscopy
• Carcinoembryonic antigen (CEA) levels in blood
• Rigid sigmoidoscopy
• Colonoscopy
• CT Colonography
• Barium Enema
• Biopsy and histological analysis
• CT SCAN
• MRI Pelvis
• PET Scan

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Investigations: Rigid or Flexible Sigmoidoscopy

• Can be done in outpatient setting
• Needs prior bowel preparation
• Biopsy can be taken

Investigations: Colonoscopy

• Required in most cases to exclude a synchronous tumor be it an adenoma or carcinoma
• Proximal adenoma can be removed
• Dye-Spray techniques have been evolved for better differentiation (For example, mucosal pit patterns in malignant lesions versus none in adenomas after a special stain)

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Investigations: CT Colonography

• Less invasive
• Extremely sensitive (Can pick up polyps even up to 6mm)
• Has replaced barium enemas

Differential Diagnosis

• Rectal polyps
• Endometriomas
• Carcinoid tumours
• Solitary rectal ulcers
• Inflammatory stricture
• Amoebic granuloma

Types of Carcinoma Spread

• Local Spread
• Lymphatic Spread
• Venous Spread
• Peritoneal dissemination

Carcinoma Spread: Local

• Circumferentially than longitudinally
• After penetration of muscular coat, mesorectum is involved but limited by mesorectal fascia
• Anteriorly, prostate, seminal vesicles or bladder in males and vagina or the uterus in females can be invaded
• Posteriorly, sacrum and sacral plexus may be involved
• Laterally, a ureter may get involved

Carcinoma Spread: Lymphatic Spread

• Depends upon the location of the tumor
• If the tumor is in part of the rectum covered by peritoneal reflections, spread is upwards
• If the tumor is below peritoneal reflections in the rectum, lateral spread occurs in 20 % of such cases
• Downward spread is exceptional
• Late disease and more undifferentiated carcinomas have atypical and widespread metastases.
• Cephalad spread follows superior rectal vessels up to para-aortic nodes

Carcinoma Spread: Venous Spread

• Liver 34 %
• Lungs 22 %
• Adrenals 11 %
• Remaining 33 % are in the routine metastatic deposit sites including brain

Carcinoma Spread: Peritoneal dissemination

• Following penetration of peritoneal coat by a high-lying rectal carcinoma

Stages of Progression

• Duke’s Staging
• TNM Staging
• Astler-Coller Staging
• Radiological Staging
• Histological Grading

Stages of Progression: Duke’s Staging

• A: The growth is limited to the rectal wall (15 %)
• B: Growth extends to the extrarectral tissues but without metastasis to the lymph nodes (35%)
• C: There are secondary deposits in the regional lymph nodes
• C1: Local pararectal lymph nodes are involved
• C2: Nodes accompanying the supplying blood vessels to their origin from aorta are involved
• D: (Not described by Dukes himself) The presence of widespread metastasis

Stages of Progression: TNM Staging

• Tumor-node-metastasis classification
• Now recognised internationally as the optimum staging classification

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Stages of Progression: Radiological Staging

• CT Chest, Abdomen and Pelvis (CT-CAP) must be done in all patients with Rectal carcinoma to stage both local and metastatic disease
• MRI Pelvis is THE BEST modality:
• Assessment of soft tissue extent of tumor
• Degree of infiltration of the mesorectum
• Mesorectal LN involvement
• Mesorectal fascia involvement

Solitary 2.5 cm metastasis in segment 6 of the liver in a patient with rectal cancer

CT and PET-CT showing 1.5 cm solid lesion in the right lung of a patient with rectal carcinoma

Stages of Progression: Histological Grading

• Adenocarcinomas and Mucoid/Signet-ring carcinomas
• Majority are adenocarcinomas
• The more the cells are well differentiated, the better the prognosis
• Vascular and perineural invasion, infiltrating margins and tumor budding are poor prognostic factors
• Mucoid carcinomas grow rapidly, metastasize early and have a poor prognosis

Treatment

• Multidisciplinary team (MDT) discussions
• Surgical Excision of the tumor and/or rectum
• Local Excision; Organ Preserving Techniques: Transanal Endoscopic Micro Surgery (TEMS)
• Radical Excision; Sphincter preserving: Anterior Resection (High or Low) Low is called Total Mesorectal Excision (TME)
• Radical Excision; Sphincter preserving: Transanal Total Mesorectal Excision (TaTME)
• Radical Excision; Sphincter removing: Abdominoperineal resection (APR)
• Pelvic Exenteration
• Liver resection
• Neoadjuvant Chemoradiotherapy
• Neoadjuvant Radiotherapy
• Adjuvant Radiotherapy
• Adjuvant Chemotherapy
• Brachytherapy
• Contact Radiotherapy
• Palliative Procedures
• Palliative radiotherapy
• Endoluminal Stenting
• Palliative Colostomy

Treatment: MDT

• Surgeons
• Radiologists
• Oncologists
• Pathologists
• Specialty Nurses
• Patient himself and/or his relatives/attendants

Treatment: Surgical Excision of the tumor and/or Rectum: Principles of surgical treatment

• Radical excision of the rectum together with mesorectum should be the aim in most cases
• The use of neo-adjuvant chemoradiotherapy should be considered if the tumor is locally advanced (invading a neighbouring structure or threatening to breach circumferential resection margin)

Preoperative Preparation

● Counselling and siting of stomas

● Correction of anaemia and electrolyte disturbance

● Type and screen for blood transfusion

● Bowel preparation

● Deep vein thrombosis prophylaxis

● Prophylactic antibiotics (IV antibiotics at the time of induction plus course of oral antibiotics beforehand

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Local Excision

• In early T1 and even T 2 cancers
• ‘Organ-preserving’ techniques with good prognostic features
• TEMS: Transanal Endoscopic Microsurgery
• Histological analysis of the specimen is then used to assess the adequacy of excision with respect to the probability of positive lymph nodes left
• Defect may be closed or left open
• Higher lesions may be difficult to resect

Radical Excision: Anterior Resection

• Restoration of gastrointestinal continuity and continence is possible by this method
• Sphincter saving procedure
• Lower margin of the tumor should be greater than or equal to 2 cm above the anorectal junction
• Two types
• High Anterior Resection
• Low Anterior Resection

High Anterior Resection

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• For tumors in the upper third of rectum
• Rectum and mesorectum are taken to a margin of at least 3 cm distal to the tumor
• Colorectal anastomosis is performed
• Better postoperative function i.e. less risk of anterior resection syndrome, a condition characterized by defecatory urgency, incomplete evacuation and incontinence secondary to removal of normal reservoir

Low Anterior Resection

• For tumors in the middle and lower thirds of rectum
• Complete removal of the rectum and mesorectum is required i.e TME (Total Mesorectal Excision)

Anterior Resection: Technique

• Open
• Minimal Access

Anterior Resection: Open Technique

• Midline laparotomy done
• Sigmoid and descending colon freed by dividing the peritoneal reflection on left side and mobilising on their mesentery
• Splenic flexure is mobilized to gain sufficient colonic length for anastomosis
• Rectal dissection is performed in the embryological planes with preservation of autonomic nerves (Supply of pelvic floor and urogenital organs)
• Once the rectal dissection has reached anorectal junction (low AR) or 3 cm below the tumor (High AR), rectum is divided using a stapling device

Plane of dissection for Total Mesorectal Excision

Anterior Resection: Open Technique

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• Trunk of the inferior mesenteric artery is ligated and divided at its origin from aorta
• Resection is then done at proximal site
• Colorectal anastomosis can then be done in 3 ways:
• Double stapling
• Single stapling
• Hand-sewn anastomosis

Anastomosis in Anterior Resection

• Double stapling: A circular device inserted transanally and both ends are stapled
• Single stapling: A circular device is inserted transanally and purse strings sutures are already applied to the proximal colon and single firing secures the staples
• Hand-sewn anastomois

1. Straight low coloanal anastomosis (end to end) b) a colopouch-anal anastomosis (end to side)

Anterior Resection: Minimal Access

• Laparoscopic or robotic
• 4 or five abdominal ports
• Dissection follows medial to lateral approach i.e.
• Dissection and ligation of vascular pedicle
• Then mobilization of colon
• Then resection of the rectum
• Midline laparotomy wound may still be needed to extract specimen unless extracted transanally

Anterior Resection: Defunctioning Stoma

• Temporary stoma is formed in cases of lower anterior resection (Tumors of the middle or lower third)
• Because of high risk of anastomosis leak and subsequent septic complications

Transanal Total Mesorectal Excision (TaTME)

• Airtight anal device provides transanal insufflation for access of laparoscopic instruments
• Purse string suture below the distal level of tumor and ‘bottom-up’ technique followed to accomplish TME
• Synchronous ‘top-down’ laparoscopic resection by an abdominal operator
• Short-term trials have revealed its good prognostic outcomes
• Risk of urethral injuries

Abdominoperineal Resection (APR)

• For the tumors of lower third of rectum
• Traditionally was performed by two surgeons (Lithotomy position)
• More recently, shift towards completing abdominal surgery first then perineal (Lloyd-Davies position)
• Aim is TME plus cylindrical excision of the extralevator component; achieves wide excision of pelvic floor
• Complete resection rates
• Reduced risk of perforation and local recurrence

Abdominoperineal Resection Technique

• Abdominal procedure is same as in anterior resection; carried out by laparotomy or laparoscopy except:
• Dissection stops at the level of pelvic floor (seminal vesicles in male or cervix in females)
• Perineal dissection is achieved through a circumanal incision
• Deepened into ischiorectal fossa towards the attachment of levator muscles to the pelvic side wall

Separation and division of the pubococcygeus and

puborectalis muscles in the course of the perineal phase of an abdominoperineal excision of the rectum

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Abdominoperineal Resection Technique

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• Posteriorly Waldeyer’s fascia is incised
• Coccyx can be removed to enhance access
• Anteriorly a plane is made between rectum and prostate/vagina
• Resection is completed when the perineal dissection reaches the abdominal dissection
• Specimen is retrieved through the perineal wound
• A permanent end colostomy is formed in the left iliac fossa
• Pelvic drains placed

Pelvic Exenteration

• Performed when carcinoma rectum spreads to contiguous organs
• More radical operation
• Complete Exenteration
• Cystectomy
• Prostatectomy
• Hysterectomy
• Partial Exenteration
• Posterior exenteration including posterior vaginal/uterus
• Total pelvic exenteration
• Will require muscular flaps (gluteal/rectus abdominus to fill perineum)

Liver Resection

• Single or multiple liver mets can now be resected provided careful selection has been done
• 40 % survival rate
• Can be performed synchronously at the time of anterior resection or as a delayed procedure

Radiotherapy

• Neoadjuvant: Given preoperatively to downstage the cancer
• Short course over 5 days with immediate surgery 7-10 days later
• Often combined with chemotherapy and given over a period of 6 weeks with 6 weeks of recovery period before surgery to allow tumor regression
• Adjuvant: Can be given after surgery
• Palliative: For non resectable tumors, to decrease pain and relieve obstruction symptoms

Chemotherapy

• Given as neoadjuvant or adjuvant therapy
• 5-FU remains first line therapy
• Oxaliplatin and biological agents like cetuximab are second line agents

Endoluminal Stenting

• For obstructive carcinoma
• Only for rectosigmoid or upper rectal cancers
• Palliation or conversion of emergency to elective procedure

Palliative colostomy

• Obstructive carcinomas
• Non resectable tumors
• Defunctioning colostomy may be needed during downstaging chemoradiotherapy

Prognosis

• Dukes A: > 90 % 5 year survival
• Dukes B: 70% 5 year survival
• Dukes C: 40 % 5 year survival
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Results of Treatment

• 20 % of rectal cancers treated by neoadjuvant chemoradiotherapy show complete response. Only some 30 % of such cases recur on wait and watch policy
• Resectability rates of rectal cancer 95 % with operative mortality of 5 %
• Overall, 5 year survival rate is 50 %
• Node positive patients worse than node negative patients

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Local Recurrence

• Complex problem
• Vary between 2 to 25 %
• More after APR than after sphincter saving procedures
• Can be diagnosed by surveillance using blood cea levels, CT, MRI, PET-CT
• Endoscopy is of limited importance in their diagnosis because most recurrences are extra rectal
• After recurrence, surgical exenteration is the only hope of cure.