Colon Cancer

Colon cancer is a malignant tumour involving the large intestines. It is one of the more common cancers in our society. The commonest type of colon cancer are adenocarcinomas (95%) with the remaining 5% comprising of mesenchymal tumours (GIST), neuroendocrine tumours, lymphomas and sarcomas.

Surgical specimen of colon cancer with polyps

The risk factors include:
- older age
- diet high in fat and low in fibre
- hereditary (20% of cases including Familial Adenomatous Polyposis & Hereditary Non-Polyposis Colon Cancer)
- male sex
- patients with inflammatory bowel disease (especially ulcerative colitis)
- colonic polyps
- obesity
- cigarette smoking
- acromegaly
- patients with an uretero-sigmoidostomy

Patients usually present with:
- altered bowel habits: constipation alternating with bouts of foul smelling watery stools
- bloody stools
- mucous in the stools
- loss of weight and loss of appetite
- incidental finding on screening colonoscopy
- symptoms of metastasis (malignant spread) eg difficulty breathing, liver swelling, abdominal distension, bone pain, confusion, weakness

Patients can also present as an emergency case with:
- intestinal obstruction with or without abdominal distension
- perforation of the large intestines
- symptoms of anaemia due to profuse bleeding from the tumour

Investigations include:
- colonoscopy which can visualise and biopsy the tumour
- CT-scan to look for spread (metastasis) of the tumour to the lungs, liver or lymph nodes
- serum CEA levels (tumour marker for colon cancer): raised CEA reinforces the diagnosis and can be used for surveillance to detect recurrence
- genetic testing for hereditary colon cancers eg APC, hMLH1, hMSH2, hPMS1 genes

Colonoscopy image of colon cancer

Management of patients with colon cancer will depend on the stage and extent of the disease. The mainstay of treatment for colon cancer is surgery. The type of surgery will depend on the site of the cancer. A right hemicolectomy is done for cancers at the right side of the colon. Left hemicolectomy for cancers of the left colon, anterior resection for cancers of the sigmoid and rectum.

Patients with advanced stage 2 and stage 3 colon cancers will require chemotherapy after surgery. Common chemotherapy regimes used include 5-FluoroUracil, Oxaliplatin and Irinotecan. Radiotherapy is indicated when surgical margins are involved. Newer treatment options include the use of molecular targeted therapy such as bevacizumab and cetuximab.   
Patients who present with metastatic disease (stage 4) will usually be treated with palliative and supportive care. However, recent advances have shown that resection of metastatic liver and lung lesions improves patient survival.

Acute Appendicitis

The appendix is a tubular, blind-ended, vestigial structure which is attached to the caecum. Anatomically the location of the appendix corresponds to the right iliac fossa which is at the lower right quadrant of our abdomen. The human appendix is hypothesised to have lost its original function through evolution.

 Some of the functions of the appendix are:

-immunological functions - it contains lymphoid follicles which secrete immunoglobulins

-it contains serotonins which are neuroendocrine hormones

-it has a bacteriological function where it helps to control the normal gut bacterias

-Surgical functions - where the appendix is used as an 'urinary conduit' in bladder reconstruction in bladder surgery & it can also be used as an 'appendicostomy' which can be used for antegrade colonic enema (wash-out of faeces) in patients with constipation.

The appendix lies in close proximity to the caecum (the beginning of our large intestines). Approximately 75% of the appendix lies behind the caecum (retrocaecal), 20% in the pelvis and the remaining 5% either pre- or post-ileal (infront or behind the small bowel).

Appendix attached to the caecum

Acute appendicitis is the inflammation of the appendix. It is the commonest acute surgical condition in the abdomen. It typically presents with an initial pain around the umbilical region which later migrates and localises in the right iliac fossa. Usually the patient will have a low grade fever, loss of appetite and nausea. There will be tenderness of the abdomen localised at the right iliac fossa which is typically described as at McBurney's point (2/3 along the line drawn between the umbilicus and the anterior superior iliac spine).
Severe cases of appenditis can present with severe abdominal pain, high spiking temperature & dehydration. This usually happens when there is a delay in diagnosis and the appendix perforates leading to purulent or faeculent peritonitis (contamination of the abdominal cavity with pus or faeces).

Other causes of a right iliac fossa pain are:
-urinary tract infection
-kidney stones (renal colic)
-Meckel's diverticulitis
-mesenteric adenitis (usually associated with flu)
-colonis diverticulitis (usually in elderly people)
-torsion of ovary
-ectopic pregnancy
-pelvic inflammatory disease
-intestinal obstruction

The treatment for acute appendicitis is appendicectomy (surgical excision of the appendix). This procedure was traditionally done as an open surgery but most surgeons are doing laparoscopic (minimally invasive) appendicectomies now. The complications of appendicetomy includes:
-wound infection (<5% risk)
-intra-abdominal abscess
-faecal fistula (leakage of faeces from the resected appendix stump)

The sequelae of acute appendicitis includes:
- Perforated appendix: - as a result of inflammation and ischaemia (reduced blood supply) to the appendix, the wall weakens and perforates. This will lead to localised or generalised, purulent or feaculent peritonitis. The patient will be more ill.
- Appendicular mass: - a swelling noted at the right iliac fossa which is a mass of omentum covering the inflammed appendix. This typically happens a few days after the initial episode of right iliac fossa pain when our body tries to wall of the inflammed appendix.
- Chronic appendicitis: - this usually occurs in patients who were treated with antibiotics or anti-inflammatories for a bout of lower abdominal pain. They develop a chronic grumbling right iliac fossa pain which is very vague. It is usully a diagnosis of exclusion.

Abdominal Hernias

Hernias are abnormal protrusion of organs from the wall which contains it. Abdominal hernias are usually inguinal hernias, femoral hernias, paraumbilical hernias or incisional hernias.
Inguinal & femoral hernias occur in the inguinal (groin) region and may occur on one side (unilateral) or both sides (bilateral).

A huge Right sided indirect inguinal hernia which has entered the scrotum

Inguinal hernias are the commonest type of abdominal hernias. The main causes are: chronic cough, straining due to constipation or urine obstruction, weakness of the abdominal muscles or congenital defects (patent processus vaginalis). Inguinal hernias can be further divided into direct or indirect inguinal hernias but the management for both is the same. Direct inguinal hernia occurs thru the weakness in the transversalis muscle of the abdominal wall while indirect inguinal hernia occurs thru a defect in the deep inguinal ring. 
Both present with a swelling in the groin which expands on standing or upon straining. Most of the time the swelling is reducible. Sometimes the hernia may be stuck (incarcerated) or obstructed or strangulated (blood supply compromised). The swelling in an indirect inguinal hernia may enter into the scrotum in men. 
The management for inguinal hernia include treatment of the causes of the hernia and the mainstay of treatment is surgery.
Surgery can be either open surgery or laparoscopic surgery. Open surgery is a simple procedure which can be done under local anaesthesia as a day case in uncomplicated hernias. The hernia is reduced, the hernial sac excised and a polypropylene mesh inserted above the muscles to strenghten it. This is known as the Lichtenstein repair. Complicated cases (incarcerated or obstructed or strangulated) would need general anaesthesia and hospital stay. At the moment laparoscopic is indicated for recurrent hernias or bilateral inguinal hernias. The scars are smaller, it is less painful and patients are discharged earlier. 

Femoral hernias occur thru the femoral canal in the groin. The presentation is the same as inguinal hernias with a groin swelling. However, it has a much higher risk of strangulation due to the narrow opening of the femoral canal. Femoral hernias are more common in women. Treatment is with surgical repair which can be done under local anaesthesia for uncomplicated cases. Some surgeons approximate the femoral canal with sutures and reinforce with a pectineal fascia flap while some use a polypropylene mesh plug repair. Laparoscpoic repair can also be done. 

Paraumbilical hernias occur commonly is people with ascites (excess fluid collection in the abdominal cavity), those who are obese and those who have abdominal wall weakness. The swelling is usually noted just around the umbilicus. This should not be confused with umbilical hernias which occur in babies due to congenital defects. Paraumbilical hernias are repaired surgically. The surgery entails reduction of the hernial contents, excision of the hernia sac and application of a big piece of polypropylene mesh to cover the defect. 

Incisiona hernias occur as a late complication of abdominal surgery. A history of infection of the abdominal wound, malnutrition, complicated bowel surgery and obesity are predisposing causes. The swelling occur just under the incision scar of the abdominal wound. Surgery includes revision of the previous scar, reduction of the hernial contents and excision of the hernial sac. A big polypropylene mesh is used to cover the defect. Laparoscopic repair is also feasible for both paraumbilical and incisional hernias.

The complications of hernial repair are: bruising, bleeding, infection of the wound, infection of the mesh, seroma collection and recurrence. 
Complications specific to inguinal hernia repair include: ischeamic orchitis, testicular atrophy, scrotal oedema, hydrocoele, chronic pain due to neuroma or osteitis and numbness around the groin area.      

Breast Cancer

Breast cancer is the commonest cancer in women all over the world. The incidence is highest in women around the age of 40 - 60 years but it may also occur at any age. The lifetime risk of developing a breast cancer in a woman is 11%.

Patients with breast cancer commonly present with:
- breast lump
- retracted nipple
- lymph node swelling in the axilla (armpits)
- ulcerated swelling on the breast
- redness & inflammation of the breast
- nipple discharge which can be blood or mucous
- incidental finding on screening by mammogram

95% of breast cancer occur sporadically while only 5% are due to genetic factors. The genes which are implicated in breast cancer are BRCA-1 and BRCA-2. Patients with BRCA genes have a 50% lifetime risk of breast cancer and a 30% risk of getting a breast cancer on the opposite breast. Women with BRCA-1 also have a 30% risk of getting ovarian cancer.

Other genetic syndromes associated with breast cancer are:
- Li Fraumeni syndrome which includes brain tumours, sarcomas and leukaemias
- Cowden syndrome which includes thyroid tumours and skin lesions
- Peutz-Jaghers syndrome which includes gastro-intestinal tract polyps, pigmentation of the lips and increased risk of gastro-intestinal cancers.

To confirm the diagnosis of breast cancer, 'Triple Assesment' is recommended. This includes:
- breast examination by the doctor
- tissue biopsy with Fine Needle Aspiration Cytology (FNAC) or Core Biopsy
- radiological investigations with a Mammogram or Ultrasound or MRI

Mammogram

Patients with strong family history of breast cancer should undergo genetic testing for BRCA-1 and BRCA-2 genes.

Once the diagnosis of breast cancer is confirmed, a patient is counselled on her diagnosis and the plan of management. The management will depend on the stage of the cancer, type of cancer (DCIS vs Invasive Ductal/Lobular Cancer) and patient's Estrogen/Progestrone Receptor (ER/PR) status.

For patients with non-metastatic (have not spread beyond the breast) cancer, the initial treatment is mastectomy (breast removing surgery) with removal of lymph nodes. The indications for mastectomy are:
- Invasive breast cancer more than 3cm
- multifocal DCIS
- patients with recurrent cancer after breast conserving surgery
- young patients who have a high risk of cancer recurrence (BRCA carriers)
- old patients who do not want to undergo further surgery
- male patients with breast cancer

Patients with DCIS (ductal carcinoma in situ) or Invasive breast cancer less than 3cm can undergo Breast Conserving Surgery (BCS) with post-operative radiotherapy. However, there is a 10% chance that further surgery might be required with BCS.

Removal of lymph node is needed for control of loco-regional disease and for more accurate staging of the disease. A few techniques commonly used are lymph node dissection or sampling or Sentinel Lymph Node Biopsy.

Post mastectomy, if the patient has got lymph node involvement or the tumour is bigger than 1.5cm, it is necessary for the patient to undergo chemotherapy which will further destroy the cancer cells in the body. The common regime used is a combination of 5-FluoroUracil, Epirubicin and Cyclophosphamide.

Patients who have ER/PR positive should be started on Tamoxifen tablets (20mg daily) which will reduce the level of estrogen in the body and reduce the risk of recurrence of the cancer. Post menopausal patients can be started on aromatase inhibitors such as anastrozole or letrozole which also reduces estrogen levels.

Patients who are HER-2 (human epidermal growth factor receptor-2) positive can be started on trastuzumab which is shown to improve disease  free survival. However, this drug is contraindicated in women with heart failure.

Patients with locally advanced breast cancer (size more than 5cm or with involvement of chest wall or skin) should undergo pre-operative chemotherapy to reduce the size of the cancer. The regime is the same as the post-operative one or a taxane based (docetaxel) chemotherapy can also be used.

Post-mastectomy, patients who are keen for reconstruction of their breast should be referred to a Plastic Surgeon for reconstructive surgery. The breast can be reconstructed with the patients own muscles and skin (free or pedicled flap reconstruction) or with a prosthetic breast implant.

What is a Cancer?

A Cancer is defined as an abnormal mass of tissue, growth of which is uncoordinated and exceeds that of normal tissue which persists even after cessation of the stimuli which provoked it. The main hallmarks of cancer are that it is purposeless, it preys on its host and it is autonomous.

The biology of Cancer growth are:
- Self sustained growth signals
- Insensitivity to inhibitory growth signals: Normal cells respond tumour suppressor genes.
- Limitless growth potential: It does not stop growing unlike normal cells.
- Evasion of apoptosis (programmed cell death): Normal cells have a fixed life-span.
- Ability to metastasise and invade
- Ability to produce own blood supply (angiogenesis)

The common causes of cancer can be divided into:
- Radiation eg UV light, ionising radiation, nuclear radiation exposure
- Infection eg H.Pylori (stomach cancer), schistosomiasis (bladder cancer), Hepatitis B & C (liver cancer)
- Genetic abnormalites eg Familial Adenomatous Polyposis, Li Fraumeni Syndrome
- Chemicals eg aniline dye (bladder cancer), cigarette smoking
- Others eg diet, chronic irritation (Marjolin's ulcer)

Treatment options for Cancers include:
- Radiotherapy
- Chemotherapy
- Surgery
- Hormonal Therapy
- Molecular Targeted Therapy

Deep Venous Thrombosis

Deep Venous Thrombosis (DVT) is a commonly discussed medical condition. It is a condition where a blood clot forms in the deep venous system of the lower legs. DVT is the third commonest cardiovascular disease. Around 20% of DVTs occur post surgery. 25% of DVTs are associated with cancers and 50% happen due to unknown reasons.

Anatomy of Deep Venous System

The aetiology of DVT is summarised by Virchow's triad of:
-Hypercoagulability (increased tendency to form blood clots)
-Venous Flow Stasis
-Vessel wall damage


Patients who have DVT usually complain of:
-calf pain
-calf swelling
-redness around the lower leg
-unilateral pitting oedema
-low grade fever


Sometimes the lower leg can be bluish (cyanotic), severely painful and swollen in a condition described as Phlegmasia Caerulia Dolens. Phlegmasia Alba Dolens describes a pale, painful, swollen limb.


Conditions which increase the risk of DVT are:
-increasing age
-immobility
-pregnancy
-patients who are diagnosed with cancers
-patients who are on oral contraceptive pills (combined progestrone & oestrogen)
-patients who are on hormone replacement therapy
-obesity
-patients with inflammatory bowel disease
-patients who are planned for knee, pelvic & hip surgeries
-patients with heart failure


Investigations for patients with DVT include:
-Duplex ultrasound scans: - 95% sentitive & specific
-Venography: - can be both diagnostic & therapeutic
-Magnetic Resonance Venography
-Impedence Pletysmography
-Spiral CT-scan / CT Pulmonary Angiography: to rule out Pulmonary Embolism

Image at Left: Deep Vein Thrombosis

Image at Right: Embolus propagating

Treatment for DVT aims to stop further clot formation, to break down the existent clot (fibrinolysis) and to prevent pulmonary embolism. Pulmonary embolism is the propagation of a blood clot from the lower leg into the smaller veins of the lungs. This is a potentially deadly complication of DVT where 10% of patients with symptomatic pulmonary embolism die within the first hour. 


Treatment options include:
-intravenous Heparin infusion
-oral Warfarin tablets
-subcutaneous Low Molecular Weight Heparin (eg enoxaparine) injection
-percutaneous mechanical thrombectomy
-catheter directed thrombolysis
-insertion of an Inferior Vena Cava filter: for prevention of pulmonary embolism in high risk patients


The complications of DVT are:
-pulmonary embolism
-propagation of clot
-chronic venous insufficiency
-varicose veins
-venous ulcers

Varicose Veins

Varicose veins are common among the general population. It is defined as tortuous, dilated, abnormal veins of the lower limbs. The other variants of these unsightly veins are reticular veins (superficial, prominent veins) and thread veins (fine, thin cutaneous veins).

Varicose veins are more common in women, caucasians and in those with a family history. The risk factors are:

-obesity

-pregnancy

-prolonged stationary standing

-women taking oral contraceptive pills or hormone replacement therapy

The aetiology of varicose veins can be due to:

-venous valve insufficiency which is either congenital or acquired. Congenital insufficiency occurs in patients who are born with weakness of the venous valves. Acquired insufficiency is secondary to thrombosis (blood clots) occuring around the valves.

-perforator (the connecting veins between the deep venous & superficial venous systems) insufficiency

-disturbance to venous flow such as deep venous thrombosis (DVT), pelvic vein thrombosis and vascular malformations.

Patients who have varicose veins usually present with:

-unsightly dilated veins

-itchiness around the veins

-aching sensation of the lower llimbs

-swelling of the lower limbs

-throbbing pain of the lower limbs

The complications of varicose veins are:

-bleeding (usually due to accidental trauma)

-ulceration of the lower limbs

-thrombophlebitis (obstruction & inflammation of the veins)

-skin changes ie. pigmentation (haemosiderin extravasation), eczema, inverse 'beer bottle deformity' of the lower leg (lipodermatosclerosis)

Investigations for patients with varicose veins include:

-Duplex/Doppler Ultrasound Scans: to assess the site of incompetence and the patency of the deep venous system

-Magnetic Resonance Venography: to assess for pelvic/abdominal vein patency

Patients with varicose veins can be managed medically or surgically.

Medical management for these patients include:

-regular exercise

-elevate lower limbs when resting

-graduated compression stockings

-compression sclerotherapy (injection of sclerosants into the veins under ultrasound guidance)

-pulsed laser therapy (for thread veins only)

Surgical management is indicated for patients with more severe symptoms. These include:

-disconnection of the sapheno-femoral junction or sapheno-popliteal junction

-long saphenous vein stripping

-phlebectomy

Recent advances in surgery include endovascular procedures such as:

-endovascular laser or radiofrequency

-endovascular foam sclerotherapy

All the surgical procedures can be done under local anaesthesia and as day cases. Post surgery, patients will need to be on graduated compression stockings for at least 1 month. Patients are given regular pain-killers, encouraged to walk and advised to elevate their legs when sitting down.