SMALL INTESTINE CANCER

Cancer in the small intestine occurs when abnormal cells grow uncontrollably in this part of the digestive system. The small intestine, also known as the small bowel, plays a vital role in digestion along with organs like the liver, pancreas, and gallbladder. It’s a key component of the gastrointestinal (GI) tract, which is a series of organs including the esophagus, stomach, small intestine, and large intestine (colon), forming a pathway for digestion. Specifically, the small intestine links the stomach to the large intestine.

The small intestine comprises three main segments:

Duodenum: This is the initial part of the intestine, situated close to the stomach.
Jejunum: Positioned in the middle, this section follows the duodenum.
Ileum: Serving as the final and longest part, it connects to the large intestine.

The majority of small intestine cancers originate in either the duodenum or the ileum.

Prevalence of Small Intestine Cancer

Small intestine cancer is a rare occurrence, accounting for only 3% of all gastrointestinal cancers in the United States. Other types of cancer, such as colon, rectal, esophageal, and stomach cancers, are more prevalent than cancers affecting the small intestine.

Types of Small intestine cancer

Small intestine cancer manifests in various types, categorized according to the specific cells from which the cancer originates.

Carcinoid Tumors: These tumors develop in neuroendocrine cells, which play a role in hormone production and regulation of digestive juices within the small intestine. Carcinoid tumors account for just under half of all small intestine cancer cases.
Adenocarcinomas: Originating in glandular epithelial cells (glands) that line the small intestine, adenocarcinomas represent approximately one-third of small intestine cancer cases.
Sarcomas: These cancers arise in connective tissues such as cartilage or muscle. The most prevalent type of sarcoma affecting the small intestine is known as a gastrointestinal stromal tumor (GIST). Formerly referred to as leiomyosarcomas, GISTs are the most common subtype of sarcomas in this region.
Lymphoma: Lymphoma begins in lymphocytes, which are a type of white blood cell found in the lymphatic system. The lymphatic system is crucial for immune function, aiding in the body’s defense against abnormal cells and pathogens.

Symptoms of small intestine cancer

This can vary depending on the type of tumor and its location. In some cases, tumors may not cause any noticeable symptoms and may only be discovered incidentally during medical imaging for other conditions. For instance, carcinoid tumors often do not present symptoms.

Common symptoms may include:

Abdominal Pain or Cramps: Persistent or recurrent pain or cramping in the abdomen.
Abdominal Lump: A palpable mass or lump in the abdomen.
Nausea, Vomiting, and Diarrhea: Frequent episodes of nausea, vomiting, or diarrhea.
Unexplained Weight Loss: Significant and unexplained weight loss over a period of time.
Anemia: Low red blood cell count, leading to symptoms like fatigue and weakness.
Jaundice: Yellowing of the eyes or skin due to liver dysfunction or blockage of bile ducts.
Bloody Stool: Presence of blood in stool, which may appear red or black in color.
Flushed Skin: Flushing or reddening of the skin, particularly a purplish coloration on the arms and upper body.

Causes

Small intestine cancer develops when malignant tumors form in the small intestine due to rapid multiplication of cancer cells, resulting in the formation of a mass. Over time, these cancer cells may break away from the original tumor and spread to other parts of the body through the lymph nodes or bloodstream, leading to the formation of secondary tumors, a process known as metastasis.

The formation of cancer cells is attributed to genetic mutations, which are alterations in the DNA of cells causing them to proliferate uncontrollably. The exact causes of these genetic changes are still unknown to researchers.

Risk Factors for Small Intestine Cancer

Age: The risk of developing small intestine cancer increases with age, with the average age of diagnosis being 65 years.
Gender: Small intestine cancer is slightly more prevalent in individuals assigned male at birth (AMAB).
Race: In the United States, small intestine cancer is slightly more common among individuals who are Black, except for lymphoma, which is more common in those who are white.
Inherited Genetic Conditions: Having a family history of certain conditions such as familial adenomatous polyposis (FAP), Peutz-Jeghers syndrome, hereditary nonpolyposis colorectal cancer (HNPCC), and Lynch syndrome can increase the risk.
Inflammatory Conditions: Chronic inflammatory bowel diseases like Crohn’s disease and celiac disease may elevate the risk of small intestine cancer.
Autoimmune Disorders or Weakened Immune System: Conditions that compromise the immune system, such as HIV/AIDS, Crohn’s disease, and celiac disease, as well as treatments like radiation therapy and immunosuppressive drugs post-organ transplant, can increase susceptibility to small intestine cancer.

Some studies have suggested that dietary habits (such as consuming salty or smoked foods and red meat), tobacco use, and alcohol consumption may also influence the risk of developing small intestine cancer.

Consulting a healthcare provider is advisable if there are concerns about the risk of small intestine cancer.

Diagnosing small intestine cancer

This can be complex due to its rarity and the variability of symptoms depending on the tumor type. It often requires extensive procedures and tests for an accurate diagnosis.

1. Physical Exam and History:

During the physical examination, your healthcare provider will carefully palpate your abdomen, looking for any abnormal masses or tenderness that could indicate the presence of a tumor. They’ll also assess your overall health and inquire about any symptoms you may be experiencing. Gathering a comprehensive medical history is crucial, as it provides insights into potential risk factors and previous health conditions that may be relevant to the diagnosis.

2. Blood Tests:

Blood chemistry studies examine levels of various substances in the blood, such as liver enzymes, which can indicate abnormalities related to cancer. Additionally, a complete blood count (CBC) helps evaluate red and white blood cell counts, as well as platelet levels. Anemia, indicated by a low red blood cell count, can be a sign of gastrointestinal bleeding associated with small intestine tumors.

3. Imaging:

Endoscopy: This procedure involves the insertion of a thin, flexible tube equipped with a camera (endoscope) into the gastrointestinal tract. Upper endoscopy examines the esophagus, stomach, and duodenum, while double-balloon enteroscopy allows visualization deeper into the small intestine. Biopsies obtained during endoscopy can provide definitive diagnosis through microscopic examination of tissue samples.
Capsule Endoscopy: By swallowing a small capsule containing a camera, detailed images of the small intestine can be captured as the capsule passes through the digestive tract. This non-invasive procedure is particularly useful for detecting lesions or abnormalities in areas inaccessible by traditional endoscopy.
CT Scan and MRI: These imaging modalities utilize advanced technology to generate detailed cross-sectional images of the abdomen, allowing healthcare providers to visualize potential tumors and assess their size, location, and involvement of surrounding structures.
Abdominal X-ray and Barium X-ray: X-ray imaging, often combined with the administration of barium contrast material, provides a comprehensive view of the gastrointestinal tract. Barium coats the lining of the intestines, highlighting any abnormalities or obstructions that may be indicative of cancerous growths.

4. Surgery: In cases where imaging and endoscopic procedures are inconclusive, surgical intervention may be necessary to obtain tissue samples for definitive diagnosis. Laparoscopy involves inserting a thin tube with a camera through small incisions in the abdomen, allowing visualization and biopsy of suspicious lesions. Laparotomy, a more invasive procedure involving a larger abdominal incision, provides direct access to the small intestine for thorough examination and tissue sampling.

By employing a combination of these diagnostic approaches, healthcare providers can accurately diagnose small intestine cancer, determine its stage and extent, and develop an appropriate treatment plan tailored to each patient’s needs.

Cancer staging

This is a crucial aspect of diagnosing small intestine cancer as it helps determine the extent of the disease, including the size of the tumor, its location, and whether it has spread to other parts of the body (metastasized). During the diagnosis phase, healthcare providers typically conduct a series of tests and procedures to stage cancer.

The specific staging system utilized for small intestine cancer depends on the type of cancer present.

Carcinoid Tumors: Carcinoid tumors in the small intestine are often staged using the TNM system, which evaluates the size and extent of the primary tumor (T), the involvement of nearby lymph nodes (N), and the presence of distant metastases (M). This system provides detailed information about the tumor’s progression and helps guide treatment decisions.
Adenocarcinoma: Adenocarcinomas of the small intestine are also staged using the TNM system, similar to carcinoid tumors. The staging process involves assessing the size of the tumor, lymph node involvement, and the presence of metastases to other organs or tissues.
Sarcoma: The staging of sarcomas in the small intestine may vary depending on the specific subtype, such as gastrointestinal stromal tumors (GISTs). Staging typically involves evaluating the size and extent of the tumor, lymph node involvement, and the presence of metastases. Imaging studies, such as CT scans and MRI, play a crucial role in determining the stage of sarcomas.
Lymphoma: Lymphomas affecting the small intestine are staged based on the extent of disease involvement, including the size and location of the tumor, lymph node involvement, and the presence of distant metastases. Imaging studies and biopsies are essential for the accurate staging of lymphomas.

Once healthcare providers determine the staging of small intestine cancer, they can develop a tailored treatment plan suited to the specific characteristics of the disease. Staging also provides valuable prognostic information, helping patients and healthcare teams understand the expected course of the illness and the potential outcomes of treatment.

Treatments

Here’s a comprehensive overview of the treatments available for small intestine cancer:

1. Surgery:

Resection: The most common treatment, involves removing part or all of the affected small intestine and nearby organs if necessary. Lymph nodes may also be removed to check for cancer spread.
Bypass: If the tumor is blocking the intestine and cannot be removed, surgery may be performed to create a bypass, allowing food to pass around the obstruction.

2. Chemotherapy:

Adjuvant Therapy: Administered after surgery to eliminate any remaining cancer cells.
Systemic Chemotherapy: Used when cancer has spread beyond the small intestine. Chemotherapy drugs may target cancer cells regionally or throughout the body to inhibit growth or induce cell death.

3. Radiation Therapy:

Primary Treatment: High-energy X-rays or radiation are employed to kill cancer cells or prevent their growth, particularly when surgical removal is not feasible.
Adjuvant or Palliative Care: Radiation therapy may be utilized after surgery to eradicate residual cancer cells or to alleviate symptoms, respectively.

4. Somatostatin Analogs:

These medications, such as lanreotide and octreotide, are employed to manage carcinoid tumors by regulating hormone production, thus alleviating symptoms and controlling disease progression.

5. Targeted Therapy:

Targeted therapies exploit specific vulnerabilities in cancer cells to destroy them. Current research focuses on treatments tailored to adenocarcinomas, gastrointestinal stromal tumors (GISTs), and lymphomas.

6. Immunotherapy:

Immunotherapy enhances the body’s immune response against cancer cells by aiding the immune system in recognizing and attacking them. This approach is particularly effective in cases where specific gene mutations are present in the tumor.

It’s important to note that individual treatment decisions are based on factors such as cancer type, stage, and patient preferences. Healthcare workers need to employ Multidisciplinary care involving oncologists, surgeons, radiation therapists, and other specialists to develop comprehensive treatment plans that optimize outcomes while minimizing side effects. Ongoing research continues to explore new therapies and combinations to improve the management of small intestine cancer.

Clinical Trials

Clinical trials play a crucial role in advancing cancer treatment by evaluating the safety and effectiveness of new therapies compared to standard treatments. Ongoing research in clinical trials focuses on various treatment modalities, including adjuvant chemotherapy, targeted therapy, immunotherapy, and others. If you’re considering participation in a clinical trial, it’s essential to discuss with your healthcare provider whether you meet the criteria and if it’s a suitable option for you.

Outlook/Prognosis:

The survival rate for small intestine cancer varies significantly depending on several factors, including the type of cancer, its stage, and the location within the small intestine.

Adenocarcinomas: The five-year survival rate for early-stage adenocarcinomas is around 65%, indicating that approximately 65% of individuals diagnosed at this stage are alive five years after diagnosis. However, the survival rate decreases significantly to 4% for those diagnosed at later stages.
Carcinoid Tumors: Early-stage carcinoid tumors have a considerably higher five-year survival rate of 95%. However, for later-stage carcinoid tumors, the survival rate drops to 42%.

It’s important to note that these survival rates are general estimates and may vary for each individual based on factors such as overall health, response to treatment, and other medical considerations. Additionally, advancements in treatment options and supportive care may influence outcomes.

To understand how the specific characteristics of your cancer impact your prognosis, it’s crucial to have a thorough discussion with your healthcare provider. They can provide personalized information based on your unique situation and guide you through treatment decisions tailored to your needs and preferences.

Sources

National Cancer Institute. (n.d.). Clinical Trials Information
Medical University of South Carolina: “Intestinal Lymphoma.”
Cleveland Clinic: “Small Intestine Cancer.”
Merck Manuals: Overview of Immunodeficiency Disorders.
American Cancer Society: “Small Intestine Cancer.”
Mayo Clinic: “Small Intestine Cancer: What Is Small Intestine Cancer?”
National Institute of Diabetes and Digestive and Kidney Diseases. (n.d.). Small Intestine Cancer.