Overview
Definition:
Transverse colon cancer refers to malignant neoplasms originating in the middle section of the large intestine, situated between the ascending colon and the descending colon
An extended right hemicolectomy is a surgical procedure involving the removal of the ascending colon, cecum, terminal ileum, and the transverse colon, along with its associated mesentery and lymph nodes, to achieve oncologic clearance for tumors in the transverse colon.
Epidemiology:
Colorectal cancer is a significant global health issue
While tumors can occur anywhere in the colon, transverse colon cancers constitute approximately 10-15% of all colon malignancies
Incidence varies geographically and is influenced by diet, lifestyle, and genetic factors
Age is a primary risk factor, with most cases diagnosed in individuals over 50 years.
Clinical Significance:
Transverse colon cancers can present insidiously, often leading to delayed diagnosis
The anatomical location and the lumen size of the transverse colon can influence presentation, with larger tumors more likely to cause obstruction or perforation
Extended right hemicolectomy is a technically demanding procedure that requires careful oncologic principles to ensure adequate resection margins and lymphadenectomy, critical for patient outcomes and disease control.
Clinical Presentation
Symptoms:
Change in bowel habits, such as constipation or diarrhea
Abdominal pain or cramping, often colicky
Rectal bleeding or blood in stool, which may appear as bright red or dark and tarry
Unexplained weight loss
Fatigue and weakness due to anemia
Abdominal mass, palpable in some cases
Nausea and vomiting, especially if obstruction is present.
Signs:
Palpable abdominal mass
Signs of anemia, such as pallor
Cachexia in advanced stages
Abdominal distension
Tenderness on palpation, especially if perforated or inflamed
Ascites in cases of peritoneal spread.
Diagnostic Criteria:
Diagnosis is typically based on a combination of clinical suspicion, imaging, and histological confirmation
Colonoscopy with biopsy is the gold standard for diagnosis
Staging is performed using TNM classification based on imaging and pathological findings after surgical resection.
Diagnostic Approach
History Taking:
Detailed history of bowel habit changes, duration of symptoms, presence of blood in stool, unexplained weight loss, and family history of colorectal cancer or polyposis syndromes
Prior history of inflammatory bowel disease or abdominal radiation therapy are important risk factors.
Physical Examination:
Thorough abdominal examination to assess for masses, tenderness, guarding, rigidity, and signs of obstruction or peritonitis
Digital rectal examination to rule out distal pathology and assess for stool in the rectum
General physical examination to assess for anemia or cachexia.
Investigations:
Complete blood count (CBC) to assess for anemia and leukocytosis
Liver function tests (LFTs) and renal function tests
Tumor markers: Carcinoembryonic antigen (CEA) is useful for monitoring treatment response and recurrence, though not for initial diagnosis
Imaging: Colonoscopy with biopsy is essential for diagnosis and assessment of the lesion
CT scan of the abdomen and pelvis with intravenous contrast is crucial for staging, assessing local extent, lymph node involvement, and detecting distant metastases
Chest X-ray or CT chest for staging
Barium enema may be useful in select cases or if colonoscopy is incomplete.
Differential Diagnosis:
Appendiceal tumors
Cecal tumors
Other colonic malignancies (e.g., descending or sigmoid colon)
Benign colonic polyps
Diverticulitis
Inflammatory bowel disease (Crohn's disease, Ulcerative colitis)
Mesenteric ischemia
Colonic strictures of non-malignant etiology.
Management
Initial Management:
Depends on presentation
For stable patients, diagnostic workup (colonoscopy, CT scan) is prioritized
For obstructed or perforated patients, initial management involves fluid resuscitation, nasogastric decompression, and broad-spectrum antibiotics
Urgent surgical intervention may be required.
Surgical Management:
The standard surgical procedure for transverse colon cancer requiring resection is an extended right hemicolectomy
This involves removal of the cecum, ascending colon, hepatic flexure, and the proximal two-thirds to three-quarters of the transverse colon
The terminal ileum is resected to ensure adequate proximal margin and lymph node clearance
Lymphadenectomy includes removal of the ileocolic, right colic, and middle colic lymph node basins
Reconstruction is typically achieved via an ileocolic anastomosis, often a side-to-side stapled anastomosis, or a hand-sewn functional end-to-end anastomosis
The appendiceal stump is usually inverted or ligated
Indications for surgery include confirmed malignancy, resectable disease, and symptomatic obstruction or perforation
Adequate surgical margins (at least 5 cm proximal and distal to the tumor) are crucial
Total colectomy may be considered for synchronous polyposis or multifocal disease.
Adjuvant Therapy:
Adjuvant chemotherapy is typically recommended for stage III and high-risk stage II colon cancers based on pathological findings (e.g., lymph node involvement, T4 tumors, poor differentiation)
Chemotherapy regimens often include fluoropyrimidines (e.g., 5-FU, capecitabine) in combination with oxaliplatin (FOLFOX).
Neoadjuvant Therapy:
Neoadjuvant chemotherapy is generally not standard for resectable colon cancer but may be considered in select cases with locally advanced disease or bulky nodal involvement, aiming to downstage the tumor prior to surgery
Radiation therapy is typically reserved for rectal cancer and not routinely used for colon cancer unless for palliation of metastatic disease.
Complications
Early Complications:
Anastomotic leak, manifesting as peritonitis, sepsis, or abscess formation
Intra-abdominal abscess
Bleeding from the surgical site or anastomosis
Ileus
Wound infection
Stricture of the anastomosis
Injury to adjacent organs (e.g., ureter, duodenum)
Deep vein thrombosis (DVT) and pulmonary embolism (PE).
Late Complications:
Anastomotic stricture leading to symptoms of obstruction
Incisional hernia
Adhesions causing bowel obstruction
Recurrence of cancer (local or distant)
Nutritional deficiencies due to altered bowel transit or malabsorption
Chronic pain.
Prevention Strategies:
Meticulous surgical technique, ensuring adequate blood supply to the bowel ends for anastomosis
Careful handling of tissues to minimize trauma
Prophylactic antibiotics
Deep vein thrombosis prophylaxis (e.g., heparin, compression stockings)
Early mobilization of patients post-operatively
Close monitoring for signs of anastomotic leak or infection
Patient education on warning signs.
Prognosis
Factors Affecting Prognosis:
Stage of the cancer at diagnosis (most important factor)
Histological grade of the tumor
Presence of lymph node metastases
Presence of distant metastases
Tumor differentiation
Lymphovascular invasion
Microsatellite instability (MSI) status
Patient's overall health status and comorbidities
Completeness of surgical resection (R0 resection).
Outcomes:
Prognosis is highly dependent on the stage
Stage I cancers have a >90% 5-year survival rate
Stage II cancers have a 5-year survival rate of approximately 70-85%
Stage III cancers have a 5-year survival rate of around 50-70%
Stage IV cancers (metastatic) have a significantly poorer prognosis, with a 5-year survival rate typically less than 15%
Extended right hemicolectomy with adequate oncologic principles offers a chance for cure in early-stage disease.
Follow Up:
Post-operative follow-up typically includes regular clinical examinations, serum CEA level monitoring every 3-6 months for the first 2 years, and periodic imaging (CT scans) and colonoscopies as per established guidelines to detect recurrence or new primary lesions
Follow-up schedules are guided by the stage of the disease.
Key Points
Exam Focus:
Extended right hemicolectomy involves resection of cecum, ascending colon, hepatic flexure, and proximal transverse colon
Adequate lymphadenectomy (ileocolic, right colic, middle colic nodes) is essential
Anastomosis is usually ileocolic
Tumor stage is the most critical prognostic factor.
Clinical Pearls:
Consider transverse colon tumors when patients present with vague abdominal symptoms, anemia, or change in bowel habits, especially if colonoscopy is not the initial investigation
Always assess for synchronous lesions
The management of a perforated tumor requires urgent surgical control
Ensure adequate proximal bowel length for anastomosis after resecting a significant portion of the transverse colon.
Common Mistakes:
Inadequate lymphadenectomy, leading to incomplete staging and potential for recurrence
Insufficient margin clearance
Performing a simple right hemicolectomy for a tumor extending beyond the hepatic flexure
Misinterpreting imaging findings, leading to delayed diagnosis or incorrect staging
Not considering synchronous lesions during colonoscopy
Premature cessation of follow-up after seemingly successful treatment.