Esophageal cancer
| Esophageal cancer | |
|---|---|
| Specialty | Oncology, general surgery, gastroenterology  |
Esophageal cancer is malignancy of the esophagus. There are various subtypes. Esophageal tumors usually lead to dysphagia (difficulty swallowing), pain and other symptoms, and are diagnosed with biopsy. Small and localized tumors are treated with surgery, and advanced tumors are treated with chemotherapy, radiotherapy or combinations. Prognosis depends on the extent of the disease and other medical problems, but is fairly poor.[1]
Signs and symptoms
Dysphagia (difficulty swallowing) is the first symptom in most patients. Odynophagia (painful swallowing) may be present. Fluids and soft foods are usually tolerated, while hard or bulky substances (such as bread or meat) cause much more difficulty. Substantial weight loss is characteristic as a result of poor nutrition and the active cancer. Pain, often of a burning nature, may be severe and worsened by swallowing, and can be spasmodic in character.
The presence of the tumor may disrupt normal peristalsis (the organised swallowing reflex), leading to nausea and vomiting, regurgitation of food, coughing and an increased risk of aspiration pneumonia. The tumor surface may be fragile and bleed, causing hematemesis (vomiting up blood). Compression of local structures occurs in advanced disease, leading to such problems as superior vena cava syndrome. Fistulas may develop between the esophagus and the trachea, increasing the pneumonia risk; this symptom is usually heralded by cough, fever or aspiration.[1]
If the disease has spread to elsewhere, this may lead to symptoms related to this: liver metastasis could cause jaundice and ascites, lung metastasis could cause shortness of breath, pleural effusions, etc.
Cause and risk factors
Increased risk
There are a number of risk factors for esophageal cancer.[1] Some subtypes of cancer are linked to particular risk factors:
- Age. Most patients are over 60, and the median in US patients is 67.[1]
- Sex. It is more common in men.
- Tobacco smoking and heavy alcohol use increase the risk, and together appear to increase the risk more than these two individually.
- Swallowing lye or other caustic substances.
- Particular dietary substances, such as nitrosamine.
- A medical history of other head and neck cancers increases the chance of developing a second cancer in the head and neck area, including esophageal cancer.
- Plummer-Vinson syndrome (anemia and esophageal webbing)
- Tylosis and Howel-Evans syndrome (hereditary thickening of the skin of the palms and soles).
- Radiation therapy for other conditions in the mediastinum.[1]
- Celiac disease and primary biliary cirrhosis predispose toward squamous cell carcinomas
- Gastroesophageal reflux disease (GERD) and its resultant Barrett's esophagus increase esophageal cancer risk due to the chronic irritation of the mucosal lining (adenocarcinoma is more common in this condition, while all other risk factors predispose more for squamous cell carcinoma).[1]
Decreased risk
- Risk appears to be less in patients using aspirin or related drugs (NSAIDs).[2]
- Statistically, it appears that Helicobacter pylori, known for increasing risk for gastric cancer, actually decreases the risk of esophageal cancer; the exact mechanism for this phenomenon is unclear.[3]
- "Based on fair evidence, diets high in cruciferous (cabbage, broccoli, cauliflower) and green and yellow vegetables and fruits are associated with a decreased risk of esophageal cancer."[4]
- Drinking tea daily (Camellia sinensis, generally green or white tea) also seems to decrease the risk of developing esophageal cancer.[5]
- According to one Italian study, eating pizza more than once a week appears to halve incidence of esophageal cancer in population studies. While "The secret could be lycopene, an antioxidant chemical in tomatoes, which is thought to offer some protection against cancer, and which gives the fruit its traditional red colour," a BBC News report cautions: "Before people start dialling the pizza takeaway, they should consider that pizza can be high in saturated fat, salt and calories" and that "some experts cast doubt on the idea that pizza consumption was the explanation for why some people did not develop cancer. They said other foods or dietary habits could play a part.".[6]
Diagnosis
Although an occlusive tumor may be suspected on a barium swallow or barium meal, the diagnosis is best made with esophagogastroduodenoscopy (EGD, endoscopy); this involves the passing of a flexible tube down the esophagus and visualising the wall. Biopsies taken of suspicious lesions are then examined histologically for signs of malignancy.
Additional testing is usually performed to estimate the tumor stage. Computed tomography (CT) of the chest, abdomen and pelvis, can evaluate whether the cancer has spread to adjacent tissues or distant organs (especially liver and lymph nodes). The sensitivity of CT scan is limited by its ability to detect masses (e.g. enlarged lymph nodes or involved organs) generally larger than 1cm. FDG-PET (positron emission tomography) scan is also being used to estimate whether enlarged masses are metabolically active, indicating faster-growing cells that might be expected in cancer. Esophageal endoscopic ultrasound (EUS) can provide staging information regarding the level of tumor invasion, and possible spread to regional lymph nodes.
Most tumors of the esophagus are malignant. A very small proportion (under 10%) is leiomyoma (smooth muscle tumor) or gastrointestinal stromal tumor (GIST). Malignant tumors are generally adenocarcinomas, squamous cell carcinomas, and occasionally small-cell carcinomas. The latter share many properties with small-cell lung cancer, and are relatively sensitive to chemotherapy compared to the other types.
The location of the tumor is generally measured by the distance from the teeth. The esophagus (25 cm or 10 inches long) is commonly divided into three parts for purposes of determining the location. Adenocarcinomas tend to occur distally and squamous cell carcinomas proximally, but the converse may also be the case.
Treatment
General approaches
The treatment is determined by the cellular type of cancer (adenocarcinoma or squamous cell carcinoma vs other types), the stage of the disease, the general condition of the patient and other diseases present. On the whole, adequate nutrition needs to be assured, and adequate dental care is vital.
If the patient cannot swallow at all, a stent may be inserted to keep the esophagus patent; stents may also assist in occluding fistulas. A nasogastric tube may be necessary to continue feeding while treatment for the tumor is given, and some patients require a gastrostomy (feeding hole in the skin that gives direct access to the stomach). The latter two are especially important if the patient tends to aspirate food or saliva into the airways, predisposing for aspiration pneumonia.
Tumor treatments
Surgery is possible if the disease is localised, which is the case in 20-30% of all patients. If the tumor is larger but localised, chemotherapy and/or radiotherapy may occasionally shrink the tumor to the extent that it becomes "operable"; however, this combination of treatments (referred to as neoadjuvant chemoradiation) is still somewhat controversial in most medical circles. Esophagectomy is the removal of a segment of the esophagus; as this shortens the distance between the throat and the stomach, some other segment of the digestive tract (typically the stomach or part of the colon) is placed in the chest cavity and interposed. If the tumor is metastatic, surgical resection is not considered worthwile, but palliative surgery may offer some benefit.
Laser therapy is the use of high-intensity light to destroy tumor cells; it affects only the treated area. This is typically done if the cancer cannot be removed by surgery. The relief of a blockage can help to reduce dysphagia and pain. Photodynamic therapy (PDT), a type of laser therapy, involves the use of drugs that are absorbed by cancer cells; when exposed to a special light, the drugs become active and destroy the cancer cells.
Chemotherapy depends on the tumor type, but tends to be cisplatin-based (or carboplatin or oxaliplatin) every three weeks with fluorouracil (5-FU) either continuously or every three weeks. In more recent studies, addition of epirubicin (ECF) was better than other comparable regimens in advanced nonresectable cancer.[7] Chemotherapy may be given after surgery (adjuvant, i.e. to reduce risk of recurrence), before surgery (neoadjuvant) or if surgery is not possible; in this case, cisplatin and 5-FU are used. Ongoing trials compare various combinations of chemotherapy; the phase II/III REAL-2 trial - for example - compares four regimens containing epirubicin and either cisplatin or oxaliplatin and either continuously infused fluorouracil or capecitabine.
Radiotherapy is given before, during or after chemotherapy or surgery, and sometimes on its own to control symptoms. In patients with localised disease but contraindications to surgery, "radical radiotherapy" may be used with curative intent.
Follow-up and prognosis
Patients are followed up frequently after a treatment regimen has been completed. Frequently, other treatments are necessary to improve symptoms and maximize nutrition.
Prognosis of esophageal cancer is fairly poor. Even in patients who undergo surgery with curative intent, the five year survival rate is only 25%, and prognosis is poorer in those who are not fit for surgery. Early emphasis on symptom control and palliative care may improve the quality of life.
Epidemiology
Esophageal cancer is a relatively rare form of cancer, but some world areas have a markedly higher incidence than others: China, India and Japan, as well as the United Kingdom, appear to have a higher incidence, as well as the region around the Caspian Sea.[8]
Annual incidence is between 3-11 per 100,000 for males and 0.6-6 per 100,000 for females.[8]
References
- ^ a b c d e f Enzinger PC, Mayer RJ. Esophageal cancer. N Engl J Med 2003;349:2241-52. PMID 14657432.
- ^ NCI Prevention.
- ^ O'Connor HJ. Helicobacter pylori and gastro-oesophageal reflux disease-clinical implications and management. Aliment Pharmacol Ther 1999;13:117-27. PMID 10102940.
- ^ NCI Prevention: Dietary Factors.
- ^ Tea and Cancer NCI Press Release.
- ^ Gallus S, Bosetti C, Negri E, Talamini R, Montella M, Conti E, Franceschi S, La Vecchia C. Does pizza protect against cancer? Int J Cancer 2003;107:283-4. PMID 12949808. Cf. "Eating Pizza 'Cuts (Oesophageal) Cancer Risk'" (BBC News).
- ^ Ross P, Nicolson M, Cunningham D, Valle J, Seymour M, Harper P, Price T, Anderson H, Iveson T, Hickish T, Lofts F, Norman A. Prospective randomized trial comparing mitomycin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) with epirubicin, cisplatin, and PVI 5-FU in advanced esophagogastric cancer. J Clin Oncol 2002;20:1996-2004. PMID 11956258.
- ^ a b Stewart BW, Kleihues P (editors). World cancer report. Lyon: IARC, 2003. ISBN 9283204115.