The past 25 years have seen the rates of some cancers fall, thanks to better prevention efforts. During the same period, though, the frequency of some esophageal cancers rose dramatically. The cause of this increase remains a mystery, although important risk factors have been identified.
Understanding the causes of esophageal cancer, and changing a few simple habits can reduce your risk for this uncommon but dangerous disease.
Two Faces of Esophageal Cancer
The esophagus is the tube that carries food from the mouth to the stomach. This year, about 14,550 people will be diagnosed with cancer of the esophagus. There are two major kinds of esophageal cancer:
- Squamous cell cancer
Their names refer to different types of cells in the esophagus that turn into cancer. The two kinds of esophageal cancer have different causes, and affect different parts of the esophagus. Once cancer is present, though, the two kinds of esophageal cancer act similarly.
Squamous cell cancer
Middle portion of the esophagus
Where the esophagus meets the stomach (lowest portion)
Most common causes
Barrett's esophagus (caused by acid reflux)
Groups commonly affected
African-American men, Asian-American men
Prognosis and treatment
About the same
Esophageal Cancer: A Mysterious Change
As recently as 1975, 75% of esophageal cancers were squamous cell cancers. Since then, the pattern of esophageal cancer changed in a major way:
- The rate of squamous cell cancers has fallen slightly.
- Adenocarcinoma rates have risen dramatically. Adenocarcinoma struck four people per million in 1975, but that rate rose to 23 people per million in 2001. This makes it the fastest-growing cancer in the U.S., according to the National Cancer Institute.
- As a result, adenocarcinoma cases now outnumber squamous cell cancers. The total rate of esophageal cancer has also risen.
"Clearly something has happened" to create the change, says Manjit Bains, MD, a thoracic surgeon at Memorial Sloan-Kettering Cancer Center in New York. As for why, though, "at this time there is more conjecture than facts."
Improved detection rates aren't the cause, according to researchers. Experts believe some risk factor for adenocarcinoma must also be increasing--but can't say what. A leading suspect: rising rates of obesity -- possibly causing a higher incidence of reflux, which is a risk factor for adenocarcinoma, according to Bains.
Esophageal Cancer Risk Factors
Numerous factors increase the risk for esophageal cancer:
- Age over 60
- Male sex
- Tobacco use
- Alcohol use
- Barrett's esophagus (see below)
- History of head or neck cancer
- Frequent drinking of very hot beverages
Different risk factors are important for each type of esophageal cancer:
- Squamous cell cancers: tobacco or alcohol use increase risk the most. More than half of these cancers are linked to tobacco. Using both tobacco and alcohol together raises the risk far more than using either alone.
- Adenocarcinomas: A condition called Barrett's esophagus contributes to this form of esophageal cancer. Smoking doubles the risk of adenocarcinoma, but alcohol doesn't play a role.
Barrett's Esophagus: More Serious Than Heartburn
Acid regurgitation from the stomach into the esophagus causes heartburn and indigestion. Nearly everyone experiences this uncomfortable sensation at some time in life. Surveys suggest that tens of millions of Americans feel reflux symptoms at least once a week. Doctors call this "gastroesophageal reflux disease," or GERD.
- The cells at the bottom of the esophagus can change form in response to the acid irritation.
- The new abnormal cell pattern is called Barrett's esophagus.
- People with Barrett's esophagus have a 1 in 200 chance of developing adenocarcinoma each year, far higher than the general population.
Is a rising rate of Barrett's esophagus causing the increase in the adenocarcinoma form of esophageal cancer? No one can say, because we can't accurately estimate how many people have Barrett's esophagus.
Barrett's esophagus is both common and elusive:
- Approximately five to eight percent of people with GERD also have Barrett's esophagus.
- However, as many as 95 percent of people with Barrett's esophagus don't know they have it.
- About one-quarter of people with Barrett's have no reflux symptoms.
- Although well-associated with adenocarcinoma, 90 percent of people with Barrett's esophagus will never develop esophageal cancer.
A physician can only diagnose Barrett's esophagus through upper endoscopy. While generally safe, this procedure requires sedation, expense, and some risk.
According to the American College of Gastroenterology, "patients with chronic GERD symptoms are those most likely to have Barrett's esophagus and should undergo upper endoscopy."
Bains agrees: "Clearly a certain group with chronic reflux disease are at higher risk," and should be screened with upper endoscopy.
However, the National Cancer Institute recommends against screening asymptomatic people with endoscopy.
Esophageal Cancer Symptoms
Symptoms of esophageal cancer include:
- Difficulty or pain with swallowing
- Pain behind the breastbone
- Coughing (sometimes blood is seen in sputum produced by cough)
- Weight loss, which can be severe
- Frequent heartburn or indigestion
These symptoms should trigger an immediate call to your doctor, particularly in someone with frequent reflux symptoms
Treatment for Esophageal Cancer
Doctors use a variety of approaches to cure or control esophageal cancer:
- Surgery (esophagectomy, or removal of the esophagus)
- Radiation therapy
- Photodynamic therapy (using a light-activated chemical to attack the cancer)
Most patients will undergo esophagectomy. This major surgery requires opening the chest or abdomen. Further treatment depends on what physicians find during the surgery.
Unfortunately, esophageal cancer usually spreads microscopically (called metastasis) before patients feel any symptoms. Even after successful surgery, these undetectable cancer deposits eventually grow larger and cause more problems.
For this reason, many cancer centers use chemotherapy and radiation therapy as well as surgery. These methods attempt to kill any cancer that has already spread from the esophagus to the rest of the body.
To try to improve cure rates, the National Cancer Institute is recruiting patients for clinical trials in esophageal cancer. You can find details at www.cancer.gov or by calling (800) 4-CANCER.
Prevention of Esophageal Cancer: Changing Habits for Hope
Prevention is the key for any form of cancer. Because esophageal cancer often spreads before it's detected, prevention is even more important.
There are many things you can do to lower your risk for esophageal cancer:
- Quit tobacco! Stopping smoking will lower the risk for many cancers and other diseases, not just esophageal cancer
- Limit alcohol to one to two drinks per day for men, and one drink per day for women
- Eat a diet high in green and yellow vegetables, and a variety of fruits
- Taking aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) for other reasons may reduce the risk for esophageal cancer. Don't start a new medicine without talking to your doctor.
What about treating reflux symptoms? Since reflux and Barrett's esophagus cause esophageal cancer, it seems likely that treating reflux symptoms would prevent esophageal cancer. Surprisingly, there is so far no proof of this.
Nevertheless, the American College of Gastroenterology recommends:
- Treatment of GERD symptoms, in the hope of preventing esophageal cancer;
- Upper endoscopy in those with chronic GERD symptoms, and
- Periodic upper endoscopy in those with Barrett's esophagus.
However, the National Cancer Institute recommends againstscreening the general population. Endoscopy can cause complications, and esophageal cancer is relatively rare. Screening everybody, they say, would probably create more problems than cures.