Overview: A 65-Year-Old Man with Metastatic Colorectal Cancer

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EP: 1.Overview: A 65-Year-Old Man with Metastatic Colorectal Cancer

EP: 2.First-Line Therapy Options for mCRC

EP: 3.Capecitabine/Bevacizumab and Signs of Progression/Recurrence for mCRC

EP: 4.Subsequent Lines of Therapy and Non-Chemotherapy Options for mCRC

EP: 5.Potential Case Outcomes for 65-Year-Old Man With mCRC

Tanios Bekaii-Saab, MD, FACP: This patient is a 65-year-old man with 2-month history of constipation, bloating, abdominal pain, and 10-pound unintentional weight loss who is pretty healthy otherwise. Past medical history includes mild hypertension, which seems to be well controlled with antihypertensives. The primary care physician proceeded with a CBC [complete blood count], which showed hemoglobin of 9.4 g/dL, and there was evidence of anemia but consistent with iron deficiency anemia. The CEA [carcinoembryonic antigen] was drawn and unfortunately was high. Because the patient was being prepped for a colonoscopy, this was concerning. The patient unfortunately never had another colonoscopy. He went for a colonoscopy, which showed a 5-cm mass in the sigmoid colon.

The patient was taken for left hemicolectomy and pathology came back as undifferentiated adenocarcinoma, invading through the vascularized property and extended into the pericolonic tissue.

The patient had 5 of 12 resected lymph nodes that proved to be positive. Testing of the tumor showed microsatellite stable, and the physician then decided to check for KRAS, BRAF, and others. The patient was found to have KRAS mutation in codon 12 of exon 2. A CT scan showed the patient had multiple lesions in both liver. The largest 1 was 1.5 cm, and there were also multiple lesions in the lung, mostly on the left lower pulmonary lobe. Unfortunately, these looked suspicious for metastatic disease, although they were too small to biopsy.

The diagnosis for this patient was stage IV colorectal cancer, and the patient recovered nicely from the surgery. At the time he was seen in clinic, his performance status was 1. When the patient comes to the oncology clinic, the decision was to proceed with FOLFOX [5-fluorouracil, leucovorin, oxaliplatin] and bevacizumab, he had 4 cycles of treatment. Unfortunately, the patient developed some meaningful neuropathy, and therefore was switched to maintenance capecitabine and bevacizumab for 6 cycles. Upon restaging, the patient was found to have progressive disease. At that time, he was switched to FOLFIRI [5-fluorouracil, leucovorin, irinotecan]–bevacizumab for 6 months with very low toxicities.

Six months later, there was clinical progression confirmed by scanning with new lung metastases and those that were there were growing significantly. The patient was feeling a little short of breath and had a cough. At that time, the patient was switched to regorafenib.

Unfortunately for this patient, he hadn’t had colonoscopies, which typically start at age 45. But at the time it was age 50. It’s difficult to say where the patient would have been if he had been screened previously, but screening is an important factor to prevent or to do early detection and sometimes prevent colon cancer. This patient had a left-sided tumor, which is relatively favorable, but unfortunately with a RAS mutation that’s a negative prognostic factor, in addition to the fact that it negatively predicts for the activity of EGFR inhibitors. The presentation otherwise is relatively typical for a patient who presents with colon cancer.

This transcript has been edited for clarity.

Case: A 65-Year-Old Man With Metastatic Colorectal Cancer

Initial presentation

• A 65-year-old man reported a 2-month history of constipation, bloating, abdominal pain, and 10-pound unintentional weight loss
• PMH: Mild hypertension controlled with calcium channel blockers

Clinical workup

• Labs: Hg 9.4 g/dL, LFTs elevated and CEA 80 ng/mL
• Colonoscopy revealed a 5-cm completely obstructing mass in sigmoid colon
• Patient underwent left hemicolectomy with diverting ostomy
• Pathology: undifferentiated adenocarcinoma tumor invading through muscularis propria and extending into the pericolorectal tissue with5 of 12 resected nodes positive
• CT scan showed several lesions in both lobes of the liver, measuring up to 15 mm in diameter, and 3 small lesions (<5 mm) in the left lower pulmonary lobe
• Molecular testing: KRAS mutation in codon 12 of exon 2; microsatellite stable
• Diagnosis: Stage 4 colorectal cancer
• ECOG PS is 1
  
  

Treatment

• The patient received systemic therapy with FOLFOX + bevacizumab in the first line for 4 cycles
• The patient developed neuropathy and was switched to capecitabine + bevacizumab for 4 months and then unfortunately progressed, residual neuropathy at G1
• At that time he was switched to FOLFIRI + bevacizumab
• 6 months later, clinical progression is confirmed when new lung metastases are seen on chest CT
• The patient was switched to regorafenib