Esophageal Cancer

What is esophageal cancer?

Esophageal cancer refers to any malignancy of the esophagus, a hollow tube that carries swallowed food from the mouth to the stomach. Two specific cancers, esophageal adenocarcinoma and esophageal squamous cell carcinoma, account for the vast majority of all esophageal cancers.

Symptoms include difficulty swallowing, unexplained weight loss, and throat pain.

However, most esophageal cancers are not detected until they are fairly advanced, which makes achieving a complete cure rare. Even when esophageal cancer is detected early, long-term survival is uncommon. According to a study published in the Asian Journal of Surgery, the 5-year survival rate is very low, hovering around 10–15% of those diagnosed. In many cases, treatment is focused primarily on palliative measures to reduce discomfort and disability. The National Cancer Institute estimates there will be 19,260 new cases of esophageal cancer in the U.S. in 2021, and 15,530 deaths.

Recommended care

You should visit your primary care physician who will coordinate your care with a cancer specialist (oncologist). Treatment for esophageal cancer usually involves surgery, chemo- and radiation therapy.

Esophageal cancer symptoms

The two forms, esophageal adenocarcinoma and squamous cell carcinoma, have some important differences including risk factors and localization. Esophageal adenocarcinoma is more common in the U.S. and Europe. Its main associated risk factors are obesity and gastroesophageal reflux disease (GERD), and it most often arises in the lower esophagus. In contrast, esophageal squamous cell carcinoma is more common worldwide, particularly in developing nations. It is more commonly associated with smoking and heavy alcohol use, and more likely to arise in the upper esophagus. Despite these differences, both are very serious conditions which carry a poor prognosis.

In its early stages esophageal cancer rarely causes any symptoms and the cancer usually goes undetected until it is has progressed significantly. In some cases, the first sign may be metastatic spread to organs such as the lung or liver, sometimes picked up incidentally during workup for other conditions.

Main symptoms

When symptoms are present, they may include the following.

• Difficulty swallowing (dysphagia): This can cause food to get stuck, leading to regurgitation.
• Unexplained weight loss: This can be a direct result of energy consumption by the growing cancer or a consequence of decreased food intake from swallowing difficulties.
• Throat pain (odynophagia): This typically occurs when swallowing.
• Hoarse voice or cough: This can result from compression of the voice box (larynx) which sits alongside the esophagus.
• Internal bleeding: This is uncommon but can present as dark or tarry stools (melena). If slow and chronic, esophageal bleeding can be sufficient to cause low blood counts (anemia) which leads to fatigue and weakness.

Esophageal cancer causes

Like all cancers, esophageal cancer results from uncontrolled growth of specific groups of cells. Normally an elaborate system of molecular checkpoints and protections prevent any cell line from growing too fast or too much. Tumors occur when certain cells find a way to bypass those safety mechanisms, usually as a result of random mutation. Cancer, or malignancy, occurs when those rogue cell lines have the ability to spread and invade other tissues.

Like most cancers, esophageal cancer results from a diverse and complicated series of mutations. We rarely know what causes a specific mutation, but most cancers are associated with certain risk factors which make those mutations more likely. Tissue damage kills off healthy cells which then need to be replaced by new cells. This replication process is the most common time for mutations and other genetic mistakes to occur, making tissue damage and cell turnover a common feature predisposing to many cancers.

Adenocarcinoma

Risk factors for developing this form include the following.

• Gastroesophageal reflux disease (GERD)
• Obesity (BMI >30)
• Smoking: However, this creates a smaller risk than for squamous cell carcinoma.
• Male sex
• White race

Squamous cell carcinoma

Risk factors for developing this form include the following.

• Smoking
• Alcohol use: This risk is greater with more than three drinks per day.
• Poor diet: This includes a diet high in starch and low in fruits/vegetables.
• Achalasia: This is an uncommon disorder of esophageal muscle function.
• African-American race

Treatment options and prevention for esophageal cancer

Prevention

Prevention of esophageal cancer consists primarily of avoiding the risk factors listed above. Many of the steps to decrease esophageal cancer risk are recommended healthy lifestyle changes. Quitting smoking, losing excess weight, and limiting alcohol consumption can together decrease the risk of esophageal cancer by more than tenfold.

Staging

According to a 2017 study published in the American Family Physician, esophageal cancer typically has no signs or symptoms in the earlier stages, but in more advanced stages, the most common symptoms are difficulty swallowing and unintentional weight loss (10% or more weight loss in 3 to 6 months).

By the time symptoms are detected, the disease has usually progressed far enough to make a complete cure impossible [2]. This is why the first step in the management of newly diagnosed esophageal cancer is a very thorough workup to better understand how far the disease has spread. This information defines the "stage" of cancer, which is the single most important predictor of a person's prognosis.

Typically the staging workup will include endoscopies with ultrasound, where a camera is inserted into the throat and sound waves are used to look inside the tissue for local invasion. It will also likely involve full-body scans such as computed tomography (CT) and positron emission tomography (PET) which can detect cancer that has spread (or metastasized) to other areas. In some cases, exploratory surgery may be needed if imaging is unable to clearly determine the staging.

Treatment

If esophageal cancer is detected early enough that it has not metastasized to other parts of the body, surgery may still have a chance of achieving a cure.

• Esophagectomy: This involves complete removal of the esophagus.
• Lymphadenectomy: If there has been spread to the local lymph nodes, this more extensive procedure is also performed.

Unfortunately, even cancers caught in these earlier stages are unlikely to be fully cured. The five-year survival rate for localized disease without lymph node involvement is less than 50 percent and decreases significantly with each stage thereafter.

Prognosis

Given the poor prognosis of most esophageal cancer, significant efforts have been made to improve treatment outcomes. However, the hope of improving cure rates must be balanced against the undeniable harms caused by aggressive treatments. While it remains a highly controversial topic, there has been a shift in recent decades in favor of performing chemoradiation in addition to surgery.

Palliative care

Once cancer has metastasized, or spread to distant organs, there is no likelihood of achieving a cure through surgery. Survival rates in this group are extremely low, so the focus is largely on palliative efforts to reduce discomfort and disability.

• Systemic chemotherapy: This is the mainstay of treatment at this stage and has been shown to improve both survival and quality of life.
• Esophageal stenting: This is a procedure designed to maintain the ability to eat and digest food.
• Radiation: This may also be used in conjunction with chemotherapy with similar goals.

Unfortunately, most of these interventions carry significant side effects. For someone with very advanced esophageal cancer, or who is otherwise severely ill, these interventions may do more harm than good. Supportive care emphasising the quality of life over interventions that are known to cause discomfort with little chance of improving survival may be recommended late in the course of the disease.

When to seek further consultation for esophageal cancer

Though esophageal cancer is very serious and moderately common among cancers, it is quite rare compared to the other causes of a sore throat and trouble swallowing. These common symptoms are far more likely to be caused by a simple infection or irritation. That said, early detection provides the best chance at effective treatment, so anyone who is concerned they may have symptoms of esophageal cancer should see their physician promptly. This is particularly true for those with known risk factors such as smoking, heavy drinking, obesity and GERD. It is also true for anyone with symptoms that linger significantly longer than expected.

Organizing a medical team

Anyone diagnosed with esophageal cancer would be well served to follow with a team of medical professionals who have experience treating the disease. This team will often include oncologists (cancer doctors), radiologists and surgeons. Given the severity of esophageal cancer, it is usually helpful to have a palliative care team involved. Their involvement has been repeatedly shown to improve quality of life for people with cancer, and even prolong survival in some cases.