Exhaustive Guide to GI Cancers: Oral, Esophageal, Gastric, and Colorectal

Oral Cancer Details

• Classifications and Types:     * Squamous cell carcinomas: These represent the most common type of oral cancers.     * Common sites: Lips, tongue, buccal mucosa, and oropharynx.     * Basal cell carcinoma: This type is usually asymptomatic.     * Kaposi sarcoma: Specifically associated with patients diagnosed with AIDS.

• Risk Factors and Etiologies:     * Advanced age.     * Tobacco use.     * Alcohol use.     * Excessive exposure to sunlight.     * Exposure to toxic chemicals.     * Gum disease.     * Poor nutrition.     * Poor oral hygiene.     * Infection with Human Papillomavirus (HPV).     * Infection with Human Immunodeficiency Virus (HIV).

• Clinical Manifestations:     * Earliest sign—Mucosal erythroplasia: Characterized by red, raised, eroded lesions.     * Leukoplakia: Defined as white patches that do not heal within a period of $2\,weeks$.

• Labs and Diagnostics:     * Needle or incisional biopsy.     * Imaging: MRI, CT scan, and PET scan.     * Procedures: Endoscopy and laryngoscopy.

• Management Strategies:     * Priority Goal: Maintenance of the airway to promote gas exchange, remove secretions, and prevent aspiration.     * Non-surgical Management:         * Chemotherapy, Radiation therapy, and Multimodal therapy (considered the most effective).         * Promotion of gas exchange: Assessment for respiratory obstruction and increased secretions; promoting deep breathing; oral suctioning; $O_2$ therapy; proper positioning; hydration; collaboration with a respiratory therapist; administration of steroids and/or antibiotics if necessary.         * Oral hygiene: Essential frequent care using a soft-bristle toothbrush. Apply topical analgesia as prescribed. Avoid alcohol-based mouthwashes and lemon-glycerin swabs due to acidity and contribution to dry mouth. Rinse frequently with sodium bicarbonate or warm saline.         * Aspiration precaution: Implementation of measures to prevent inhaling foreign material.         * Nutrition: Dietician consultation for hydration and food intake maintenance.     * Surgical management:         * Options: Glossectomy, mandibulectomy, microsurgery, neck dissection, and laryngectomy.         * Post-surgical care: Airway management (tracheostomy if present, $O_2$ therapy); Wound care (protect incision from infection, mouth care, positioning to decrease edema, suctioning, keeping incision free from secretions); Pain management; Communication management via speech therapist.

• Health Promotion and Prevention:     * Minimize exposure to the sun and tanning beds.     * Tobacco cessation.     * Minimize alcohol intake.     * HPV vaccination to decrease oral cancer risk.

Esophageal Cancer Details

• Classifications and Types:     * Squamous cell carcinomas: Primarily affect the upper $\frac{2}{3}$ of the esophagus.     * Adenocarcinomas: Currently the most common type; usually affect the distal third of the esophagus and the gastroesophageal (GE) junction.     * Tumor Proliferation: Tumors spread early to the lymph nodes.

• Risk Factors and Etiologies:     * Smoking and excessive alcohol consumption.     * Obesity.     * Malnutrition and a diet low in fresh fruits and vegetables.     * Untreated Gastroesophageal Reflux Disease (GERD) and Barrett's esophagus.     * Consumption of foods high in nitrate.

• Clinical Manifestations:     * Silent tumor: Symptoms typically do not manifest until the cancer has spread.     * Dysphagia: Persistent and progressive swallowing difficulty; the most common symptom. This is often accompanied by weight loss exceeding $20\,lbs$.     * High nutritional risk due to a fear of choking.

• Labs and Diagnostics:     * Esophagogastroduodenoscopy (EGD).     * Esophageal ultrasound (EUS).     * PET scan, bronchoscopy, and exploratory laparoscopy.

• Management Strategies:     * Priority Goal: Nutrition maintenance and aspiration precaution.     * Non-surgical Management:         * Chemotherapy, Radiation therapy, and Multimodal therapy (most effective).         * Esophageal dilation: Provides temporary but immediate relief for dysphagia using dilators or stents (Note: risk for perforation and bacteremia).         * Nutrition and swallowing therapy: Consultation with a dietitian for nutrition screening; positioning to prevent reflux; consumption of semi-soft foods or thickened liquids; liquid nutrition supplementation; enteral feeding for severe dysphagia.         * Therapies: Speech therapist for swallowing exercises; Occupational therapy for feeding exercises.     * Surgical management:         * Options: Esophagectomy, esophagogastrostomy.         * Post-surgical care: Tracheostomy management (if present); maintain semi-Fowler to high Fowler's position; supplemental $O_2$; prophylactic antibiotics; chest tube management; deep breathing exercises; splinting during coughing for pain and wound management.

• Postoperative Care and Complications:     * NGT (Nasogastric Tube) Management: Used for decompressing the stomach and preventing tension on suture lines. The tube must NOT be irrigated or repositioned without a specific order from the surgeon.     * Nutrition management: Enteral feeding typically initiated via J-tube on post-op day $2$; increased slowly and progressed to oral intake after a barium swallow test confirms the absence of anastomotic leaks.     * Aspiration precautions: Prevent aspiration pneumonia; high Fowler's position to prevent gastric secretion reflux; incentive spirometry; nebulizer treatment; monitoring temperature.     * Cardiac complications: Fluid volume overload during treatment for hypotension (caused by pressure on the posterior heart); Atrial fibrillation (A. fib) due to vagus nerve irritation during surgery.     * Infection: Typically occurs $4-5\,days$ post-surgery.     * Anastomosis Leakage: Usually occurring $2-10\,days$ post-surgery; can lead to mediastinitis and sepsis.     * Postoperative chylothorax: A rare but serious complication from injury to the thoracic duct or lymphatic vessels; characterized by milky or increasing pleural drainage, malnutrition, fluid loss, and respiratory compromise.

• Health Promotion and Prevention:     * Complete treatment for H. pylori infection for GERD.     * Smoking cessation.     * Weight loss to avoid obesity (linked to Barrett's esophagus).     * Monitoring for odynophagia and weight loss.

Gastric Cancer Details

• Classifications and Types:     * Adenocarcinomas: The most common type of gastric cancer.

• Risk Factors and Etiologies:     * H. pylori infection: The most significant risk factor.     * Pernicious anemia and gastric polyps.     * Chronic atrophic gastritis and achlorhydria.     * Dietary: Pickled foods and processed foods.     * History of gastric surgery.     * Barrett's esophagus and GERD.

• Clinical Manifestations:     * Often asymptomatic in early stages; disease is usually advanced upon detection.     * Early symptoms: Indigestion (dyspepsia) and abdominal discomfort (frequently ignored).     * Advanced cancer signs: Progressive weight loss, nausea/vomiting (N/V), weakness, fatigue, anemia, and jaundice due to hepatomegaly (indicating metastasis).

• Labs and Diagnostics:     * Low Hemoglobin and Hematocrit (H&H).     * Hypoproteinemia.     * Increased liver function tests (suggesting hepatic metastasis).     * High carcinoembryonic antigen (CEA).     * Stool positive for occult blood.     * Esophagogastroduodenoscopy (EGD) with biopsy: The definitive diagnostic tool.     * Imaging: CT scan, tomography, MRI.

• Management Strategies:     * Priority Goal: Dependent on the stage of the cancer and existing symptoms.     * Non-surgical Management: Chemotherapy and radiation (radiation is limited as cancer is often widespread at discovery).     * Surgical management: The preferred treatment method (laparoscopic surgery, partial or total gastrectomy). In advanced stages, resection is used for palliation rather than cure.

• Postoperative Care and Complications:     * Prevention of atelectasis, paralytic ileus, peritonitis, and wound infection through incentive spirometry, bowel regimens, and ambulation.     * NGT management: Maintain patency to prevent gastric dilation post-surgery.     * Dumping Syndrome: Vasomotor symptoms resulting from rapid food emptying into the small intestine, causing fluid shifts and abdominal distention.         * Early signs (within $30\,minutes$ of eating): Vertigo, tachycardia, syncope, sweating, pallor, palpitations, and the desire to lie down.         * Late signs ($90\,minutes$ to $3\,hours$ after eating): Rapid entry of high-carb food release large amounts of insulin, causing hypoglycemia (dizziness, lightheadedness, palpitations, diaphoresis, confusion).         * Nutritional management of Dumping Syndrome: Six small daily feedings; low carbohydrate and sugar; moderate fat; protein-rich food with fiber; fluids given between meals rather than with meals; lying down after meals.     * Delayed gastric emptying: Usually resolves in one week; can be caused by edema at the anastomosis, adhesions, or metabolic causes (hypokalemia, hypoproteinemia, hyponatremia). Managed with NGT suction and electrolyte maintenance.     * Gastric dilation: Symptoms include epigastric pain, hiccups, fullness, tachycardia, and hypotension. Requires immediate notification of HCP for NGT irrigation or replacement.     * Bile Reflux: Leads to gastritis, esophagitis, or Peptic Ulcer Disease (PUD) due to pylorus manipulation. Treated with Proton Pump Inhibitors (PPI) and ursodiol.     * Nutrition-related problems: Vitamin $B_{12}$, folic acid, and iron deficiencies due to decreased intrinsic factors (pernicious anemia); requires Vitamin $B_{12}$ injections for life. Impaired calcium metabolism due to decreased Vitamin D absorption (hypocalcemia rare but checked if neurological symptoms occur).

Colorectal Cancer Details

• Classifications and General Facts:     * The $3^{rd}$ most common malignancy in the United States.     * Adenocarcinomas: The most common type.     * Can affect any area of the colon and rectum.

• Risk Factors and Etiologies:     * Age older than $50\,years$.     * Genetic predisposition and personal/family history.     * Crohn's disease and ulcerative colitis.     * Lifestyle: Smoking, obesity, heavy alcohol consumption, physical inactivity.     * Diet: High-fat and refined carbohydrates.

• Clinical Manifestations:     * Most common signs: Rectal bleeding, anemia, and changes in stool consistency or shape.     * Obstructive symptoms: Dependent on tumor location; include gas pains, cramping, incomplete evacuation, and hyperactive or absent bowel sounds.     * Complications: Perforation with peritonitis, bowel obstruction, abscess formation, and fistula formation.

• Labs and Diagnostics:     * Low H&H and increased liver tests.     * Positive fecal occult blood test (FOBT) and elevated CEA.     * Colonoscopy: The definitive diagnostic tool.     * Imaging: CT, MRI, and double-contrast barium enema.

• Management Strategies:     * Priority Goal: Removal of the tumor to prevent or slow metastatic spread.     * Non-surgical Management: Chemotherapy and Radiation therapy.     * Surgical management: Preferred method. Options include colectomy with colostomy/ileostomy and abdominoperineal (AP) resection for distal tumors (removes anus, rectum, and sigmoid colon).

• Postoperative Care and Colostomy Management:     * Pain management: IV Patient-Controlled Analgesia (PCA) for the first $24-36\,hours$.     * Wound Care: Monitor Jackson-Pratt (JP) drains and watch for infection/abscess; note that rectal phantom pain and itching may occur.     * NGT management: Used selectively for stomach decompression in cases of persistent vomiting, high aspiration risk, ileus, or distention.     * Colostomy details: Surgical creation of an opening on the abdominal wall. Can be temporary or permanent.         * Stool consistency: Ascending colon (liquid/fluid); Transverse colon (unformed/pasty); Descending colon (semi-formed); Sigmoid colon (formed).         * Functional timeline: Functional $3-6\,days$ after colectomy; $1-2\,days$ after ileostomy.         * Stoma assessment: Should be reddish pink and protrude about $\frac{3}{4}\,inch$ from the abdominal wall. May be edematous with slight bleeding immediately post-op. Keep moist with petrolatum gauze.     * Colostomy Care: Empty bag when $\frac{1}{3}$ to $\frac{1}{2}$ full. Change appliance every $5-10\,days$. Avoid gas-causing and odor-causing foods. Do not use aspirin tablets in the pouch (causes stomal ulceration). Irrigation used to empty colon of gas, stool, and mucus.

• Health Promotion and Screening:     * Screening (starting at $45\,years\,old$): Yearly FOBT; colonoscopy every $10\,years$; flexible sigmoidoscopy or CT colonography every $5\,years$.     * Dietary modification: Reduce fat and refined carbs; increase fiber.     * Report complications: Dermatitis, diarrhea, stomal stenosis, urinary calculi, and cholelithiasis.