From the Guidelines
The best treatment approach for a patient with metastatic rectal cancer is a multidisciplinary approach that prioritizes systemic therapy, with consideration of the tumor's molecular profile and the patient's overall health status, as recommended by the NCCN clinical practice guidelines in oncology 1.
Key Considerations
- A multidisciplinary team approach is necessary for managing metastatic colorectal cancer (mCRC) 1.
- Systemic therapy options include fluoropyrimidine-, oxaliplatin-, and/or irinotecan-containing chemotherapy regimens, as well as immunotherapy and targeted therapy regimens 1.
- The choice of therapy depends on the tumor's molecular profile, including biomarker status, and the patient's overall health status 1.
- Combination of a biologic agent, such as bevacizumab, cetuximab, or panitumumab, with chemotherapy regimens may be considered, depending on available data 1.
Treatment Options
- First-line treatment may include combination chemotherapy with FOLFOX or FOLFIRI, often combined with a targeted agent based on the tumor's molecular profile 1.
- For RAS wild-type tumors, anti-EGFR antibodies like cetuximab or panitumumab may be added to chemotherapy regimens 1.
- For RAS-mutated tumors, bevacizumab may be preferred 1.
- Immunotherapy with pembrolizumab may be recommended for microsatellite instability-high (MSI-H) tumors.
Local Treatments
- Local treatments, such as radiation therapy, may be used for symptom control 1.
- Surgical resection of metastases may be considered in select patients with limited metastatic disease 1.
Ongoing Care
- Treatment cycles typically continue for 3-6 months, followed by maintenance therapy or observation based on response 1.
- Ongoing care should prioritize both systemic disease control and symptom management, with therapy selection guided by the tumor's molecular characteristics to maximize efficacy while managing toxicity.
From the FDA Drug Label
Irinotecan has been studied in clinical trials in combination with 5-fluorouracil (5-FU) and leucovorin (LV) and as a single agent [see Dosage and Administration (2)]. When given as a component of combination-agent treatment, irinotecan was either given with a weekly schedule of bolus 5-FU/LV or with an every-2-week schedule of infusional 5-FU/LV Clinical studies of combination and single-agent use are described below. 14.1 Metastatic Colorectal Cancer First-Line Therapy in Combination with 5-FU/LV: Studies 1 and 2 Two phase 3, randomized, controlled, multinational clinical trials support the use of irinotecan hydrochloride injection as first-line treatment of patients with metastatic carcinoma of the colon or rectum.
The best treatment approach for a patient with metastatic rectal (colon) cancer is combination therapy with irinotecan, 5-fluorouracil (5-FU), and leucovorin (LV), as it has been shown to result in significant improvements in objective tumor response rates, time to tumor progression, and survival compared to 5-FU/LV alone 2.
- Key points:
- Combination therapy with irinotecan, 5-FU, and LV is a supported treatment approach.
- This approach has been shown to improve tumor response rates, time to tumor progression, and survival.
- The treatment regimen may involve a weekly schedule of bolus 5-FU/LV or an every-2-week schedule of infusional 5-FU/LV.
From the Research
Treatment Approaches for Metastatic Rectal (Colon) Cancer
The treatment approach for metastatic rectal (colon) cancer depends on various factors, including tumor and patient-related factors, as well as molecular information 3. The primary treatment for most patients is palliative systemic chemotherapy, with the goal of prolonging survival, controlling disease progression, and improving quality of life 4, 5.
First-Line Treatment Options
First-line treatment options for metastatic colorectal cancer include:
- Combination chemotherapy regimens, such as FOLFOXIRI or FOLFIRI, which have been shown to prolong survival and improve quality of life 4, 6
- Targeted therapies, such as bevacizumab or cetuximab, which can be used in combination with chemotherapy to improve outcomes 5, 7
- Immunotherapy, which may be recommended for patients with microsatellite instability (MSI) high/mismatch repair (MMR) deficient tumors 5
Selection of Optimal Treatment
The selection of optimal treatment for first-line metastatic colorectal cancer is based on tumor and patient-related factors, as well as molecular information 3. Factors to consider include:
- Tumor location (left-sided or right-sided) 5
- KRAS/NRAS/BRAF mutation status 5
- Presence of microsatellite instability (MSI) or mismatch repair (MMR) deficiency 5
- Patient performance status and comorbidities 4
Targeted Therapies
Targeted therapies, such as bevacizumab or cetuximab, can be used to treat metastatic colorectal cancer, particularly in patients with specific genetic mutations 5, 7. These therapies can improve outcomes, but may also increase the risk of adverse events 6.
Ongoing Research and Future Developments
Ongoing research and future developments in the treatment of metastatic colorectal cancer are focused on: