How Esophageal Cancer Is Diagnosed

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Tests used to diagnose esophageal cancer may include a barium swallow, endoscopy, and endoscopic ultrasound, and are often ordered for people who have difficulty swallowing, a persistent cough, or risk factors for the disease such as long-standing acid reflux. Other procedures and imaging tests such as CT, PET, and bronchoscopy can be helpful in determining the stage of the disease. Careful staging, in turn, is needed in order to choose the best treatment options.

esophageal cancer diagnosis
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Labs and Tests

There is no at-home test for esophageal cancer. It's helpful to be aware of both the risk factors for the disease and the potential warning signs and symptoms of esophageal cancer so that you can make an appointment with your doctor and pursue proper professional testing if needed.

Lab tests are fairly non-specific with esophageal cancer but are used along with imaging, a careful review of family and personal health history, and a physical exam to diagnose the disease. A complete blood count (CBC) may show evidence of anemia (a low red blood cell count) if a cancer is bleeding. Liver function tests may be elevated if the cancer has spread to the liver.

Procedures

Procedures are very important in making the diagnosis of esophageal cancer and include:

Endoscopy

Upper endoscopy (esophagoscopy or esophagus-gastric-duodenoscopy) is the primary method of diagnosing esophageal cancer today. In this procedure, a flexible, lighted tube is inserted through the mouth and down through the esophagus. The tube has a camera at the end that allows physicians to directly visualize the lining of the esophagus. If abnormalities are noted, a biopsy can be performed at the same time.

Before the procedure, people are given a sedative that causes sleepiness, and the procedure is usually well tolerated.

Endoscopic Ultrasound (EUS)

This is a procedure done to obtain helpful imaging. During a traditional upper endoscopy, an ultrasound probe at the end of the scope is used to bounce high-energy sound waves off of internal tissues of the esophagus. The echoes form a sonogram, a picture of those tissues. EUS is most helpful in determining the depth of the tumor, which is very important in staging it. It is also very helpful in evaluating nearby lymph nodes and guiding biopsies of any abnormalities. Other imaging tests may also be considered (see below), though this is the most invasive.

Biopsy

A biopsy is often taken during endoscopy, but may also be done via bronchoscopy or thoracoscopy. Pathologists look at this tissue under the microscope to figure out if the tissue is cancerous and, if so, whether it is a squamous cell carcinoma or adenocarcinoma. The sample is also given a tumor grade, a number that describes how aggressive the tumor appears.

Other tissue tests may be done that look at the molecular characteristics of the tumor, such as HER2 status (like breast cancers that can be HER2 positive, esophageal cancers may also be HER2 positive).

Bronchoscopy

bronchoscopy is usually done for esophageal tumors that are located in the middle to upper third of the esophagus. A bronchoscope (a thin, lighted tube) is inserted through the nose or mouth into the trachea (the tube that connects the mouth to the lungs) and bronchi (the large airways) of the lungs. The procedure allows a physician to directly observe any abnormalities in these areas and collect tissue samples of them (biopsy) if present.

Bronchoscopy is done under sedation, usually as an outpatient procedure. 

Thoracoscopy

During a thoracoscopy, an incision or cut is made between two ribs and a thoracoscope, which is a thin, lighted tube, is inserted into the chest. Doctors use this to look at the organs inside the chest and check abnormal areas for cancer. Tissue samples and lymph nodes may be removed for biopsy. In some cases, this procedure may be used to remove portions of the esophagus or lung.

Laparoscopy

In a laparoscopy, small incisions or cuts are made in the wall of the abdomen. A laparoscope, another thin, lighted tube, is inserted into the body through one of the incisions to look at the organs inside the abdomen and check for signs of disease. Other instruments may be inserted through the same or other incisions to perform procedures such as removing organs or taking tissue samples for biopsy.

Laryngoscopy

A small lighted tube is inserted down the throat to look at the larynx or voice box. This test can detect any evidence of spread of cancer to the larynx or pharynx (throat). 

Imaging

Imaging tests may be done initially as part of the diagnostic workup for esophageal cancer, but are more commonly done to stage cancer that has been found. Tests that may be done include: 

Barium Swallow

The first test done to evaluate a possible esophageal cancer is often a barium swallow or upper endoscopy, although proceeding directly to an endoscopy is preferred if an esophageal cancer is suspected.

In a barium swallow (also called an upper GI series), a person drinks a whitish liquid containing barium and then undergoes a series of X-rays. The barium lines the esophagus and stomach, allowing a radiologist to see abnormalities in the wall of the esophagus on the images taken.

A barium swallow may be helpful in diagnosing strictures (scar tissue within the esophagus), but is used less than in the past because a biopsy cannot be performed at the same time.

CT Scan

A CT scan (computerized tomography) uses a cross-section of X-rays to create a 3D picture of internal organs. With esophageal cancer, the test is not usually used as part of the diagnosis but is important in staging the disease. CT is particularly good at looking for evidence of any spread (metastasis) of the tumor to lymph nodes or other regions of the body, such as the lungs or liver. 

PET Scan

PET scans are very helpful in looking for evidence of spread with esophageal cancer. A PET scan differs from other imaging studies in that it measures metabolic activity in a region of the body. A small amount of radioactive sugar is injected into the bloodstream and allowed time to be taken up by cells. Cells that are more active, such as cancer cells, show up brighter than areas that are less active metabolically. 

X-Ray

In addition to the above tests for diagnosing and staging esophageal cancer, a chest X-ray to look for spread to the lung may be conducted.

Differential Diagnoses

There are a number of conditions that may cause symptoms similar to those of esophageal cancer, such as difficulty swallowing. Some of these include:

  • Esophageal stricture: A stricture is scar tissue that forms in the esophagus causing narrowing. It often occurs due to trauma, for example, due to complications of endoscopy for esophageal varices (varicose veins of the esophagus often associated with alcoholism), after a person has had a nasogastric tube (NG tube) in place for an extended period of time, or due to the accidental ingestion of drain cleaner as a child.
  • Stomach cancer (gastric cancer): Cancers in the stomach may cause symptoms similar to those of esophageal cancer.
  • Benign esophageal tumors (such as esophageal leiomyoma): Most tumors of the esophagus (around 99 percent) are cancerous. Benign tumors may, however, occur, and the majority of these are leiomyomas.
  • Achalasia: Achalasia is a rare condition in which the band of tissue between the lower esophagus and stomach (the lower esophageal sphincter) doesn't relax properly, making it difficult for food to pass from the esophagus into the stomach.

Staging

Determining the stage of a cancer is important in choosing the best treatment options, including deciding whether or not surgery is even an option. A combination of imaging tests and biopsy results are usually used to determine the stage.

Doctors use the TNM staging method to classify an esophageal tumor; this system is used for other cancers as well. With esophageal cancer, however, physicians add an additional letter to the acronym—G—to account for tumor grade. L is also added for squamous cell carcinomas.

The specifics of staging are complex, but learning about them can help you better understand your disease.

T stands for tumor: The number for T is based on how deep into the lining of the esophagus the tumor extends. The innermost layer (closest to food passing through the esophagus) is the lamina propria. The next two layers are known as the submucosa. Beyond that lies the lamina propria and, finally, the adventitia—the deepest layer of the esophagus.

  • Tis: This stands for carcinoma in situ, a tumor that involves only the very top layer of cells in the esophagus.
  • T1: The tumor extends through the lamina propria and muscularis musculae. (In T1a, the tumor has invaded the lamina propria or muscularis mucosae. In T1b, the tumor has invaded the submucosa).
  • T2: The tumor has invaded the muscle (the muscularis propria).
  • T3: The tumor has spread to the adventitia. It has now penetrated all the way through the muscle in into surrounding tissues.
  • T4: T4a means that the tumor has spread beyond the esophagus to involve adjacent structures such as the pleura (lining of the lungs), pericardium (lining of the heart), the azygous vein, the diaphragm, and the peritoneum (the lining of the abdomen). T4b means that the tumor has spread to the aorta, vertebrae, or the trachea.

N stands for lymph nodes:

  • N0: There are no lymph nodes involved.
  • N1: The tumor has spread to one or two nearby (regional) lymph nodes.
  • N2: The tumor has spread to three to six nearby lymph nodes.
  • N3: The tumor has spread to seven or more nearby lymph nodes.

M stands for metastasis (distant spread) of cancer:

  • M0: Metastases are not present.
  • M1: Metastases are present.

G stands for grade:

This is different for adenocarcinoma and squamous cell carcinoma.

For adenocarcinoma:

  • G1: The cells look like normal cells (well differentiated), and at least 95 percent of the tumor has well-formed glands.
  • G2: The cells look a little different from normal cells (moderately differentiated), and 5 percent to 95 percent of the tumor exhibits gland formation.
  • G3: The cells look very abnormal (poorly differentiated) with less than 50 percent of the tumor showing gland formation.

For squamous cell carcinoma:

  • G1: The cells look like normal cells (well differentiated) and are arranged in sheets.
  • G2: The cells look a little different than normal cells (somewhat differentiated).
  • G3: The cells look much different from healthy cells (poorly differentiated) and are arranged in nests.

L stands for location (squamous cell carcinoma only):

  • Upper: The tumor is present in the cervical esophagus to the lower border of the azygous vein.
  • Middle: The tumor is present from the lower border of the azygous vein to the lower border of the inferior pulmonary vein.
  • Lower: The tumor is found between the lower border of the inferior pulmonary vein and the stomach (including tumors that involve the esophagogastric junction).

Using the above, oncologists then assign a stage. This is considered a pathological stage, rather than a clinical one, which is more accurate in terms of prognosis.

Esophageal Adenocarcinoma Stages

Stage 0: The cancer is found only in the innermost layer of cells lining the esophagus (Tis, N0, M0). This is also known as carcinoma in situ

Stage I: Stage I tumors can be found in any location and are broken down into stage IA, stage IB, and stage IC.

  • Stage IA: Stage IA tumors involve the innermost layers but have not spread to the submucosa (T1a, N0, M0, G1).
  • Stage IB: These tumors may be similar to stage IA but more abnormal appearing (T1a, N0, M0, G2), or have invaded the submucosa (T1b, N0, M0, G1-2).
  • Stage IC: These tumors may involve only the innermost layers but appear very abnormal (T1, N0, M0, G3), or have spread into the muscle (T2, N0, M0, G1-2).

Stage II: Depending on where the cancer has spread, stage II esophageal cancer is divided into stage IIA and stage IIB.

  • Stage IIA: In stage IIA, the tumor has spread to the muscle and has a higher grade (T2, N0, M0, G3).
  • Stage IIB: In stage IIB there are also two basic situations. In one, the tumor involves only the innermost layers of tissue, but has spread to one or two nearby lymph nodes (T1, N1, M0, any G). In the other, the tumor has spread to the adventitia but no lymph nodes (T3, N0, M0, any G).

Stage III: There are two substages of stage III.

  • Stage IIIA: This includes tumors that only involve the innermost layers but have spread to three to six lymph nodes (T1, N2, M0, any G, any location), or tumors that have spread to the muscle as well as one to two lymph nodes (T2, N1, M0, any G, any location).
  • Stage IIIB: There are three different types of tumors that may be classified as stage IIIB. In one, the tumor has spread beyond the esophagus to adjacent structures and may or may not have spread to lymph nodes (T4a, N0-1, M0, any G). In another, the tumor has spread to one or two lymph nodes and extends to the adventitia (T3, N1, M0, any G). In the third, the tumor has spread past the inner layers to some degree and involve three to six lymph nodes (T2-3, N2, M0, any G).

Stage IV: Only adenocarcinoma has a stage IVA (squamous cell carcinoma is divided into stage IVA and IVB). There are four situations where a tumor is classified stage IV. These include tumors that have spread to adjacent structures but not to the aorta, vertebrae, or trachea (T4A, N2, M0, any G); tumors that have spread to the aorta, vertebrae, or trachea (T4b, N0-2, M0, any G); tumors that have spread to seven or more lymph nodes (T1-4, N0-3, M1, any G); and tumors that have spread beyond the esophagus and adjacent structures to distant regions of the body (T1-4, N0-3, M1, any G).

Squamous Cell Carcinoma of the Esophagus Stages

Unlike adenocarcinoma, the staging for and prognosis of squamous cell carcinoma also includes the location of the tumor.

Stage 0: The cancer is found only in the innermost layer of cells lining the esophagus (Tis, N0, M0). This is also known as carcinoma in situ. Stage 0 tumors may be found in any location.

Stage I: This stage can be broken down into stage IA and IB, and these tumors may be located anywhere in the esophagus.

  • Stage IA: The tumor involves only the innermost layers of tissue, but has not yet reached the submucosa. The cells are very normal appearing (T1a, N0, M0, G1).
  • Stage IB: There are three situations in which a tumor could be stage IB. One is similar to stage IA, except the cells extend to the submucosa (T1b, N0, M0, G1). In another, the tumor remains in the innermost tissues, but the cells are more abnormal appearing (T1, N0, M0, G2-3). In the third, a tumor has spread to involve the muscle, but the cells are very normal appearing and have not spread to lymph nodes (T2, N0, M0, G1). 

Stage II: Depending on where cancer has spread, stage II esophageal cancer is divided into stage IIA and stage IIB.

  • Stage IIA: There are three different ways in which a tumor can be classified as stage IIA. This includes tumors that have extended to the muscle (similar to stage IB), but the cells are very abnormal appearing (T2, N0, M0, G2-3). This stage also includes tumors that have invaded the adventitia and are either in the lower esophagus (T3, N0, M0, any G, lower), or mid to upper esophagus (T3, N0, M0, G1, upper middle).
  • Stage IIB: Three are four different ways in which a tumor may be considered stage IIB. These include tumors that have spread to the adventitia and have abnormal appearing cells in any location (T3, N0, M0, G2-3); tumors that involve the adventitia and have an undefined grade in any location (T3, N0, M0, X) or have any grade but a location that is not defined (T3, N0, M0, any X), or those that only involved the innermost tissues but have spread to one or two lymph nodes (T1, N1, M0, any G, any location).

Stage III: Stage III tumors may be of any grade and found in any location.

  • Stage IIIA: Stage IIIA includes tumors that only involve the innermost layers but have spread to three to six lymph nodes (T1, N2, M0, any G, any location), or tumors that have spread to the muscle as well as one to two lymph nodes (T2, N1, M0, any G, any location).
  • Stage IIIB: These tumors comprise tumors that have spread beyond the innermost tissues and involve nodes, including tumors that are T4a, N0-1, M0, T3, N1, M0, and T2-3, N2, M0. 

Stage IV:  Unlike adenocarcinoma, squamous cell carcinomas are broken down into stage IVA and stage IVB. These tumors can be of any grade and in any location.

  • Stage IVA: Stage IVA tumors may involve many lymph nodes and have spread to structures nearby the esophagus, but not to distant regions. These include tumors defined as T4a, N2, M0, any G, any location; T4b, N0-2, M0, any G, any location; and T1-4, N3, M), any G, any location.
  • Stage IVB: These tumors, unlike earlier stages, have spread to distant regions of the body (T1-4, N0-3, M1, any G, any location).

Screening

Cancer screening tests are those that are done on people who do not have any symptoms of a disease. (If symptoms are present, diagnostic tests are performed.) At present, there is no screening test for esophageal cancer that's available to the general public.

Since the risk of esophageal cancer is elevated in people with Barrett's esophagus, some physicians have recommended periodic screening with endoscopy. The thought behind this is that finding dysplasia (abnormal cells), especially catching severe cases early, could allow for treatments to remove the abnormal cells in the precancerous stage.

That said, thus far, there is minimal to no evidence that this screening reduces the death rate from esophageal cancer. At the same time, screening has the potential for harm, such as bleeding, esophageal perforation, or other problems. There's hope that the future will bring evidence that will help determine if screening high-risk people is advisable.

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