TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Biology > Oesophageal Cancer
- Oesophageal cancer is one of the least studied and deadliest cancers worldwide.
- It is the 6th leading cause of death from cancer worldwide, despite being relatively uncommon with around 14,000 new cases and 13,000 deaths in the USA in 2003.
- More than 90% of tumours are either squamous cell carcinomas (SSCa) or adenocarcinomas.
- Adenocarcinomas are most commonly found in the distal oesophagus, close to the gastro-oesophageal junction
- SSCa’s are more evenly distributed throughout the middle and lower oesophagus
- The upper (cervical) oesophagus is an uncommon site of neoplastic disease.
- The pathogenesis of oesophageal cancer is thought to be due to oxidative damage from factors such as tobacco smoke and acid reflux
- This causes inflammation, oesophagitis and increased cell turnover which is thought to initiate the carcinogenic process
Epidemiology
Squamous Cell Carcinoma
- Environmental:
- Alcohol use
- Cigarette smoking
- Betel nut chewing (common in India and parts of Asia)
- Caustic ingestion
- Oesophageal radiation exposure
- Diet high in saturated fats
- Diet low in vitamin C, folate, ß-carotene or vitamin E
- Demographic
- Residing in endemic region
- Male gender
- African-American race
- Low socio-economic status
- Associated Medical Conditions
- Head/Neck SSCa
- Plummer-Vinson syndrome
- Alchalasia
- Tylosis
- Celiac disease
- Human papilloma virus infection
Adenocarcinoma
- Environmental
- Cigarette smoking
- High fat diet
- Diet low in vitamin C, folate, ß-carotene or vitamin E
- Demographic
- High socio-economic status
- Caucasian race
- Male gender
- Associated Medical Conditions
- Barrett’s metaplasia
- Zollinger-Ellison syndrome
- Scleroderma
- Prior oesophageal dilations
Smoking cessation and moderation of alcohol intake are important steps in reducing the risk of SSCa of the oesophagus – the risk of developing cancer is substantially decreased within a decade of smoking cessation.
Adenocarcinoma risk on the other hand, is not significantly affected by cessation, even 30 years after quitting.
Substituting fresh fruit and vegetables for poorly preserved, high-salt foods may reduce the risk of all oesophageal cancers by as much as 50%.
Clinical Presentation
- A careful history and physical examination are required to determine the appropriate diagnostic test.
- A typical presentation will include: Dysphagia (74%), Odynophagia (pain on swallowing – 17%), Chest pain, Anorexia, Weight loss (57% - an independent indicator of poor prognosis if there is a loss of >10% of body mass), Aspiration pneumonia, Anaemia, and/or Haematemesis.
- The first step in diagnosis is the identification of an oesophageal lesion.
- Endoscopy is the favoured method of definitive diagnosis as it allows for direct visualisation of the lesion, evaluation of its extent and ability for biopsy.
- A CT scan of the chest, abdomen and pelvis should be obtained to detect any possible metastases
- Transoesophageal Ultrasound is currently the most accurate method of evaluating the extent of tissue invasion and identifying superficial lesions without the need for biopsy.
- It also allows the evaluation of regional lymphadenopathy.
Staging
Tis=carcinoma in situ; T1=tumour invades lamina propria or submucosa; T2=tumour invades muscularis propria; T3=tumour invades adventitia; T4=tumour invades adjacent structures.
N0=No regional lymph node metastases; N1=regional lymph node metastases.
M0=no distant metastases; M1a=distant metastases in celiac lymph nodes or cervical nodes; M1b=other distant metastases.
Management
The management of end-stage, advanced disease is via chemotherapy, to which 15-30% of patients respond, with tumour shrinkage of up to 50% when treated with flourouracil, and a taxane or irinotecan. This response can extend to over 50% of patients if cisplatin is added to the combination therapy. Irrespective of responsiveness to treatment, the effects rarely last beyond a couple of additional months, with survival beyond 1yr unlikely.
The management of more localised tumours is considerably more successful and can take a number of forms.
Surgery
- Most commonly achieved with use of either a right transthoracic or transhiatal approach
- Right transthoracic approach combines a laparotomy and right-sided thoracotomy
- Results in an oesophago-gastric anastomosis in either the chest or neck.
- The transhiatal approach uses a laparotomy with blunt dissection of the thoracic oesophagus
- The oesophago-gastric anastomosis is placed in the neck.
- Whilst the former technique allows for a better field view, the thoracotomy increases the risk of cardiopulmonary complications
- Patients undergoing surgery as the sole method of treatment had a median survival rate of between 13 and 19 months.
- 5yr survival is between 15% and 24%
Radiotherapy
- The primary advantage of radiotherapy is the avoidance of perioperative morbidity and mortality
- As a result it is a good alternative for patients for whom surgery is not a viable option.
- Not as effective a palliative method as surgery in providing reliable and prolonged relief of dysphagia and odynophagia.
- Associated with a higher probability of catastrophic local and regional complications (e.g. oesophageal fistulas)
Pre-operative Radio-/Chemo-therapies
- These are of little benefit over no preoperative therapy, with studies disagreeing over the effectiveness of chemotherapy.
- Radiotherapy alone offers no preoperative benefit.
Post-operative Treatment
- Postoperative chemotherapy/radiotherapy combination treatments are often offered to patients whose tumour cells extend into the surgical margin
- This has proven to be of some benefit
- This is of little benefit to patients who have no evidence of residual disease.
Non-surgical Combination Chemotherapy/Radiotherapy
- Combines radiotherapy with cisplatin and fluorouracil regimens
- Has led to long-term survival in approximately 25% of patients
- This outcome is comparable to that of surgical management
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