Melena - Cancer Science

What is Melena?

Melena is a medical term used to describe black, tarry stools that are typically indicative of gastrointestinal bleeding. The dark color and tarry consistency are due to the presence of digested blood, which has usually originated from the upper gastrointestinal tract, such as the esophagus, stomach, or duodenum.

How is Melena Related to Cancer?

Melena can be a symptom of various types of cancer, particularly those affecting the gastrointestinal tract. These cancers include but are not limited to esophageal cancer, gastric (stomach) cancer, and colorectal cancer. The presence of melena often signifies that the cancer has caused bleeding within the digestive system.

What Causes Melena in Cancer Patients?

Several mechanisms can lead to melena in cancer patients:

Tumor ulceration: Tumors can erode blood vessels, leading to bleeding.
Tumor invasion: Cancerous growths can invade the lining of the gastrointestinal tract, causing bleeding.
Complications from treatment: Certain cancer treatments, such as chemotherapy or radiation therapy, can sometimes cause gastrointestinal bleeding.

How is Melena Diagnosed?

Melena is usually diagnosed based on the appearance of the stool. However, additional diagnostic tests may be required to determine the underlying cause:

Endoscopy: A procedure where a flexible tube with a camera is inserted through the mouth to visualize the upper gastrointestinal tract.
Colonoscopy: A similar procedure to endoscopy, but it visualizes the lower gastrointestinal tract.
Imaging tests: Such as CT scans or MRIs, may be used to identify tumors or other abnormalities.

What are the Treatment Options for Melena in Cancer Patients?

Treatment for melena in cancer patients focuses on addressing both the bleeding and the underlying cancer:

Endoscopic treatment: Techniques such as clipping, cauterization, or injection therapy can be used to stop bleeding during an endoscopy.
Medication: Proton pump inhibitors (PPIs) can reduce stomach acid and help control bleeding. In some cases, blood transfusions may be necessary.
Cancer treatment: Treating the underlying cancer through surgery, chemotherapy, or radiation therapy can help prevent further bleeding.

When Should You Seek Medical Attention?

Melena is a serious symptom that warrants immediate medical attention. If you experience black, tarry stools, especially if accompanied by symptoms such as abdominal pain, fatigue, or unintentional weight loss, it is crucial to seek medical care promptly.

What is the Prognosis for Cancer Patients with Melena?

The prognosis for cancer patients who present with melena depends on several factors, including:

Stage of cancer: Early-stage cancers generally have a better prognosis compared to advanced stages.
Overall health: Patients in good health may have better outcomes and a higher tolerance for treatment.
Response to treatment: How well the cancer responds to treatment can significantly influence prognosis.

Early detection and treatment of gastrointestinal bleeding and the underlying cancer can improve the prognosis and quality of life for affected individuals.