What are the National Comprehensive Cancer Network (NCCN) guidelines for hepatic metastasectomy in a 68‑year‑old man who had a stage IB sigmoid adenocarcinoma resected with open sigmoidectomy and primary anastomosis one year ago and now has an ovoid hypo‑enhancing lesion in liver segments 5‑6 consistent with possible colorectal liver metastasis?

NCCN Guidelines for Hepatic Metastasectomy in Stage IB Sigmoid Adenocarcinoma with Metachronous Liver Metastases

This patient should be referred immediately to a specialized hepatobiliary multidisciplinary team for evaluation of liver resection or ablation, as metachronous colorectal liver metastases discovered one year after curative primary resection are potentially curable with surgical intervention. 1

Immediate Next Steps

Confirm Diagnosis and Complete Staging

• Do not biopsy the liver lesion without first discussing with the regional hepatobiliary unit, as this is unnecessary and may cause complications 2, 1
• Obtain CT chest to evaluate for pulmonary metastases, as limited pulmonary disease does not preclude liver resection 2, 1
• Check CEA levels for baseline prognostic information 2
• Consider PET-CT scan if there is concern for additional extrahepatic disease, particularly given the original stage IB primary (though this represents relatively low-risk disease) 2

Multidisciplinary Team Referral

• All treatment decisions must be made by a hepatobiliary multidisciplinary team that includes hepatobiliary surgeons, colorectal surgeons, medical oncologists, and radiologists with expertise in liver imaging 2, 3, 1
• This referral should occur before initiating any chemotherapy, as resectable disease may warrant surgery-first approach 2

Resectability Criteria (NCCN/EORTC Standards)

The hepatobiliary team will determine resectability based on these technical criteria:

Core Requirements for R0 Resection

• Complete removal of all macroscopic disease with negative margins is achievable 1
• Adequate remnant liver volume of approximately one-third of standard liver volume (minimum two segments) can be preserved 2, 1
• Primary tumor has been resected with curative intent (✓ already achieved in this patient) 1
• No unresectable extrahepatic disease is present 1
• Patient is medically fit for major hepatic surgery as determined by the hepatobiliary surgeon and anesthesiologist 2, 1

Favorable Features in This Case

• Metachronous presentation (one year after primary resection) generally carries better prognosis than synchronous disease 2
• Segments 5-6 location is technically favorable, as these are in the right lobe and amenable to anatomic resection 3
• Solitary lesion (based on description of "ovoid hypoenhancing lesion") is ideal for resection 2

Treatment Algorithm Based on Resectability Assessment

If Deemed Resectable (Most Likely Scenario)

Option 1: Surgery-First Approach

• Proceed directly to hepatic resection without neoadjuvant chemotherapy 2
• This is appropriate for clearly resectable disease with favorable biology (stage IB primary, one-year disease-free interval) 2
• Followed by adjuvant chemotherapy for 6 months postoperatively 3

Option 2: Neoadjuvant Chemotherapy Followed by Surgery

• 2-3 months of systemic chemotherapy (FOLFOX or FOLFIRI) to assess tumor biology and treat micrometastatic disease 3, 4
• Re-evaluation after 2 months of chemotherapy 1, 4
• Hepatic resection if disease remains resectable or responds 3
• Complete 6 months total perioperative chemotherapy (neoadjuvant + adjuvant) 3, 4

The choice between these approaches should be made by the hepatobiliary MDT based on:

• Certainty of resectability on imaging 1
• Concern for occult micrometastatic disease 3
• Patient's performance status and ability to tolerate sequential treatments 4

If Borderline Resectable

• Initiate neoadjuvant chemotherapy with FOLFOX or FOLFIRI ± biologics (based on RAS/BRAF status and tumor sidedness) 2, 1, 4
• Re-evaluate every 2 months for conversion to resectable disease 1, 4
• Consider portal vein embolization or two-stage hepatectomy to increase functional liver reserve 2
• Consider combination of resection and ablation for bilobar or multiple lesions 2, 1

If Unresectable

• Systemic palliative chemotherapy with high-response regimens (FOLFOX/FOLFIRI ± biologics) 4
• Re-evaluate for resection every 2 months, as conversion to resectable disease occurs in a subset of patients 1, 4
• Consider ablative therapy alone if patient is medically unfit for resection but disease is amenable to ablation 2

Expected Surgical Approach for Resectable Disease

Hepatic Resection Technique

• Right hepatectomy or segmentectomy of segments 5-6 depending on lesion size and location 3
• Goal: R0 resection with 1 cm margins 3
• Operative mortality: 0-6.6% in experienced centers 2
• Five-year survival: 25-44% for resected colorectal liver metastases 2

Pathology Requirements

The resection specimen must be evaluated for: 2

• Number, size, and location of metastases
• Resection margin clearance from tumor
• Capsular invasion
• Degree of differentiation
• Presence of necrosis
• Vascular and lymphatic invasion
• Lymph node status if sampled

Critical Pitfalls to Avoid

• Never perform debulking (R1/R2) resection – all macroscopic disease must be removable for surgery to be indicated 4
• Do not biopsy liver lesions before hepatobiliary consultation, as this is unnecessary and may cause complications 2, 1
• Do not delay referral to hepatobiliary MDT while initiating chemotherapy, as this may compromise surgical options 2
• Limited extrahepatic disease is not an absolute contraindication – resectable pulmonary metastases or isolated extrahepatic sites can still be addressed 2, 1
• Number of metastases alone does not preclude resection – patients with multiple and bilobar disease can be candidates if technical criteria are met 1, 5

Post-Resection Surveillance

• Five years of follow-up with CT chest and liver plus CEA monitoring 2, 3
• Recurrent liver metastases should be treated the same as initial metastases – re-resection or ablation should be offered based on operative risk and resectability 2
• Re-resection for recurrence can achieve similar outcomes to initial hepatectomy 3