Tuesday, January 6, 2015

Esophageal Cancer - An Overview

Esophageal cancer is the eighth most frequently diagnosed cancer worldwide, and because of its poor prognosis it is the sixth most common cause of cancer-related death. It caused about 400,000 deaths in 2012, accounting for about 5% of all cancer deaths (about 456,000 new cases were diagnosed, representing about 3% of all cancers). Rates vary widely between countries, with about half of all cases occurring in China. It is around three times more common in men than in women.

In the United States, esophageal cancer is the seventh-leading cause of cancer death among males (making up 4% of the total). The National Cancer Institute estimated there were about 18,000 new cases and more than 15,000 deaths from esophageal cancer in 2013 (the American Cancer Society estimated that during 2014, about 18,170 new esophageal cancer cases will be diagnosed, resulting in 15,450 deaths).

Esophageal cancer (or oesophageal cancer) is cancer arising from the foodpipe known as the esophagus that runs between the throat and the stomach.  Symptoms often include difficulty in swallowing and weight loss.  Other symptoms may include pain when swallowing, a hoarse voice, enlarged lymph nodes (glands) around the collarbone, a dry cough, and possibly coughing up or vomiting blood.

The two main sub-types of the disease are esophageal squamous-cell carcinoma (often abbreviated to ESCC), which is more common in the developing world, and esophageal adenocarcinoma (EAC), which is more common in the developed world.  A number of less common types also occur.  Squamous-cell carcinoma arises from the epithelial cells that line the esophagus.  Adenocarcinoma arises from glandular cells present in the lower third of the esophagus, often where they have already transformed to intestinal cell type.

The most common causes of the squamous-cell type are: tobacco, alcohol, very hot drinks, and a poor diet.  The most common causes of the adenocarcinoma type are smoking tobacco, obesity, and acid reflux.  The two main types (i.e. squamous-cell carcinoma and adenocarcinoma) have distinct sets of risk factors.  Squamous-cell carcinoma is linked to lifestyle factors such as smoking and alcohol.  Adenocarcinoma has been linked to effects of long-term acid reflux.  Tobacco is a risk factor for both types.  Both types are more common in men and in the over-60s.

Prominent symptoms usually do not appear until the cancer has infiltrated over 60% of the circumference of the esophageal tube, by which time the tumor is already in an advanced stage.  Onset of symptoms is usually caused by narrowing of the tube due to the physical presence of the tumor.

The diagnosis is best made with esophagogastroduodenoscopy (endoscopy); this involves the passing of a flexible tube with a light and camera down the esophagus and examining the wall.  Biopsies taken of suspicious lesions are then examined histologically for signs of malignancy.  Additional testing is needed to assess how much the cancer has spread.  The Computed tomography (CT) of the chest, abdomen and pelvis can evaluate whether the cancer has spread to adjacent tissues or distant organs. Esophageal endoscopic ultrasound can provide staging information regarding the level of tumor invasion, and possible spread to regional lymph nodes.  Staging is based on the TNM staging system, which classifies the amount of tumor invasion (T), involvement of lymph nodes (N), and distant metastasis (M).

Prevention includes stopping smoking or chewing tobacco.  According to the US National
Cancer Institute, "diets high in cruciferous (cabbage, broccoli/broccolini, cauliflower, Brussels sprouts) and green and yellow vegetables and fruits are associated with a decreased risk of esophageal cancer." Dietary fiber is thought to be protective, especially against esophageal adenocarcinoma.

Treatment involves a set of options.  Early-stage EAC may be treated by surgical removal of all or part of the esophagus (esophagectomy), although this is a difficult operation with a relatively high risk of mortality or post-operative difficulties. Esophagectomy is the removal of a segment of the esophagus; as this shortens the length of the remaining esophagus, some other segment of the digestive tract is pulled up through the chest cavity and interposed.  This is usually the stomach or part of the large intestine (colon) or jejunum.  Reconnection of the stomach to a shortened esophagus is called an esophagogastric anastomosis.

If the person cannot swallow at all, an esophageal stent may be inserted to keep the esophagus open.  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).

Chemotherapy and radiotherapy are also solutions.  Chemotherapy depends on the tumor type, and may be given after surgery, before surgery or if surgery is not possible.  Radiotherapy is given before, during, or after chemotherapy or surgery, and sometimes on its own to control symptoms.

Laser therapy is the use of high-intensity light to destroy tumor cells while affecting only the treated area. This is typically done if the cancer cannot be removed by surgery.  Photodynamic therapy, 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.

Patients are followed closely after a treatment regimen has been completed.  Frequently, other treatments are used to improve symptoms and maximize nutrition.

In general, the prognosis of esophageal cancer is quite poor, because most patients present with advanced disease.  By the time the first symptoms (such as difficulty swallowing) appear, the cancer has already well progressed. The overall five-year survival rate (5YSR) in the United States is around 15%, with most people dying within the first year of diagnosis.

Nowadays, some desperate patients look for help outside modern medicine.  A dietary supplement sold in Florida is believed to do more than boosting our immune system, although the Food and Drug Administration (FDA) has not formally endorsed it yet.  Back in December 2012, as Aisha was fighting hard, I desperately tried to reach out to Dr. Enersto Crescenti’s team for their solution.

The good news is that listening to stories of cancer survivors (Bart Frazzitta and Jerry Poisson) gives hope that cancer in general, and esophageal cancer in particular, will be defeated. For good! With God’s blessings.


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