Duodenal Cancers
~Introduction
Duodenal cancers are rare malignant tumors that arise from the duodenum, the first part of the small intestine. The duodenum plays a crucial role in digestion by receiving chyme from the stomach and mixing it with bile and pancreatic enzymes. Because of its short length and protected location, primary cancers of the duodenum are uncommon when compared to cancers of the stomach or colon.
Despite their rarity, duodenal cancers are clinically significant due to their late presentation, diagnostic difficulty, and close anatomical relationship with vital structures such as the pancreas, bile duct, and major blood vessels. Early diagnosis is often challenging, leading to advanced disease at the time of detection.
~Anatomy of the Duodenum
The duodenum is approximately 25–30 cm long and is divided into four parts:
First (Superior) part
Second (Descending) part – contains the ampulla of Vater
Third (Horizontal) part
Fourth (Ascending) part
The close association of the duodenum with the pancreas and biliary system plays an important role in both the clinical features and management of duodenal cancers.
~Epidemiology
Duodenal cancers account for less than 1% of all gastrointestinal malignancies
More common in older adults, usually after 50 years of age
Slight male predominance
Incidence is higher in individuals with:
Familial adenomatous polyposis (FAP)
Peutz–Jeghers syndrome
Celiac disease
Crohn’s disease
~Etiology and Risk Factors
The exact cause of duodenal cancer is not fully understood, but several predisposing factors have been identified.
Risk Factors
Genetic syndromes:
Familial adenomatous polyposis (FAP)
Lynch syndrome
Peutz–Jeghers syndrome
Chronic inflammatory conditions:
Celiac disease
Crohn’s disease
Dietary factors:
High fat diet
Low fiber intake
Smoking and alcohol consumption
Prior radiation exposure
~Types of Duodenal Cancers
Duodenal cancers are classified based on histological type.
1. Duodenal Adenocarcinoma
Most common type (about 60–70%)
Arises from glandular epithelium
Frequently occurs in the second part of the duodenum
Often associated with adenomatous polyps
2. Neuroendocrine Tumors (NETs)
Arise from neuroendocrine cells
May secrete hormones
Often slow-growing
Associated with Zollinger–Ellison syndrome
3. Gastrointestinal Stromal Tumors (GISTs)
Originate from interstitial cells of Cajal
Rare in the duodenum
May present with bleeding
4. Lymphoma
Usually non-Hodgkin’s lymphoma
Associated with immune disorders
May cause obstruction or perforation
5. Sarcoma and Other Rare Tumors
Very uncommon
Include leiomyosarcoma and carcinoma variants
~Pathogenesis
Most duodenal adenocarcinomas develop through an adenoma–carcinoma sequence, similar to colorectal cancer. Genetic mutations lead to dysplasia and malignant transformation.
Common molecular changes include:
APC gene mutation
KRAS mutation
TP53 mutation
Chronic inflammation and continuous epithelial injury promote carcinogenesis.
~Clinical Features
General Symptoms
Symptoms are often vague and nonspecific, leading to delayed diagnosis.
Abdominal pain or discomfort
Weight loss
Anorexia
Fatigue
Anemia
Local Symptoms
Depending on tumor location:
Upper gastrointestinal bleeding
Vomiting
Duodenal obstruction
Early satiety
~Symptoms Due to Obstruction of Adjacent Structures
Obstructive jaundice (tumors near ampulla of Vater)
Pancreatitis
Steatorrhea
~Diagnosis
1. Laboratory Investigations
Complete blood count (anemia)
Liver function tests (elevated bilirubin in biliary obstruction)
Tumor markers:
CEA
CA 19-9 (not specific but useful for follow-up)
2. Imaging Studies
CT scan – most useful initial imaging
MRI and MRCP for biliary involvement
Endoscopic ultrasound (EUS) for local staging
3. Endoscopy
Upper GI endoscopy allows:
Direct visualization
Biopsy confirmation
Side-viewing endoscope used for periampullary tumors
4. Histopathology
Microscopic features depend on tumor type. Adenocarcinoma shows:
Glandular formation
Cellular atypia
Invasion into surrounding tissue
~Staging
Duodenal cancers are staged using the TNM classification:
T – Depth of tumor invasion
N – Lymph node involvement
M – Distant metastasis
Common sites of metastasis:
Liver
Lymph nodes
Peritoneum
Lung
~Management
1. Surgical Treatment
Surgery is the only curative option.
a. Pancreaticoduodenectomy (Whipple Procedure)
Used for tumors in the second part of the duodenum
Involves removal of:
Duodenum
Head of pancreas
Common bile duct
Gallbladder
b. Segmental Duodenal Resection
Used for localized tumors
Preserves pancreas
2. Adjuvant Therapy
Chemotherapy
5-Fluorouracil based regimens
Used in advanced or high-risk cases
Radiotherapy
Limited role
Used in unresectable tumors or palliation
3. Palliative Care
Endoscopic stenting for obstruction
Pain control
Nutritional support
~Prognosis
Prognosis depends on:
Stage at diagnosis
Tumor size
Lymph node involvement
Histological type
5-Year Survival Rates
Early-stage disease: 50–70%
Advanced disease: 20–30%
Early detection significantly improves survival.
~Complications
Intestinal obstruction
Gastrointestinal bleeding
Perforation
Malnutrition
Metastatic spread
~Prevention and Surveillance
Regular endoscopic surveillance in high-risk individuals (FAP, genetic syndromes)
Early treatment of premalignant lesions
Healthy diet and lifestyle modifications
~Conclusion
Duodenal cancers are rare but serious gastrointestinal malignancies with diverse histological types and clinical presentations. Their close anatomical relationship with the pancreas and biliary system makes diagnosis and management challenging. Symptoms are often nonspecific, leading to delayed diagnosis and poor outcomes.
Surgical resection remains the cornerstone of treatment, while chemotherapy and radiotherapy have supportive roles. Early detection through surveillance in high-risk populations and advances in imaging and surgical techniques have improved prognosis. Continued research and awareness are essential for better management and improved survival in patients with duodenal cancers.
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