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What is metastatic colorectal cancer (mCRC)?
Cancers that start in the colon or rectum, which make up the large intestine, are called colorectal cancers.3
When colorectal cancer spreads to other organs, it is called metastatic colorectal cancer, which is abbreviated as mCRC.5
~30-40% of people with colorectal cancer will eventually develop metastases6
Different types of metastatic colorectal cancer
There are two main factors that physicians may use to establish a personalized first treatment plan for mCRC:1-3
- Biomarker status, or tumor genetics
- Location of the original tumor within the colon/rectum
Both factors can influence treatment choices.1-3
Knowing your biomarker status is a crucial first step toward targeted treatment
Learning about biomarkers in your cancer cells is important for selecting the treatment that may work best for you. When you find out you have metastatic colorectal cancer, it is important for you to have biomarker testing right away.
Biomarker tests reveal the genetic characteristics of your cancer, which can help your doctor choose the best therapy for you.5,7,8
4 other biomakers to know when
you have mCRC1,5,8
Microsatellite instability BRAF gene
HER2 protein NTRK gene KRAS G12c gene
Talk to your doctor for more information
Treatment guidelines for oncologists recommend all patients with metastatic colorectal cancer should have tumor tissue tested for biomarkers.13
Tumor location, or “sidedness,” may also inform treatment2,14,15
Doctors separate the colon into right and left sides when describing where a tumor is located because each side has distinct features.2,14,15 The left side (shown in orange) includes the following regions of the colon:14
- Splenic flexure
- Descending colon
- Sigmoid colon
- Rectum
The side of the colon that a tumor is on, or sidedness, may influence how well people respond to certain treatments, and can impact potential treatment choices.2,14,15
Most people with colorectal cancer (up to 70%) have tumors on the left side.2
Talk to your doctor about your biomarker status and tumor sidedness.
References: 1. Ciardiello F, Ciardiello D, Martini G, Napolitano S, Tabernero J, Cervantes A. Clinical management of metastatic colorectal cancer in the era of precision medicine. CA Cancer J Clin. 2022;72:372-401. 2. Baran B, Mert Ozupek N, Yerli Tetik N, Acar E, Bekcioglu O, Baskin Y. Difference between left-sided and right-sided colorectal cancer: a focused review of literature. Gastroenterology Res. 2018;11:264-273. 3. American Cancer Society. About colorectal cancer. https://www.cancer.org/content/dam/CRC/PDF/Public/8604.00.pdf. Accessed December 12, 2023. 4. Boeckx N, Koukakis R, Op de Beeck K, et al. Primary tumor sidedness has an impact on prognosis and treatment outcome in metastatic colorectal cancer: results from two randomized first-line panitumumab studies. Ann Oncol. 2017;28:1862-1868. 5. NCCN Guidelines for Patients®. Colon cancer, 2022. https://www.nccn.org/patients/guidelines/content/PDF/colon-patient.pdf. Accessed November 15, 2023. 6. Duineveld LA, van Asselt KM, Bemelman WA, et al. Symptomatic and asymptomatic colon cancer recurrence: a multicenter cohort study. Ann Fam Med. 2016;14:215-220. 7. National Cancer Institute. Biomarker testing for cancer treatment. https://www.cancer.gov/about-cancer/treatment/types/biomarker-testing-cancer-treatment. Updated December 14, 2021. Accessed November 15, 2023. 8. American Cancer Society. Colorectal cancer early detection, diagnosis, and staging. https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/how-diagnosed.html. Accessed November 15, 2023. 9. Allegra CJ, Rumble RB, Hamilton SR, et al. Extended RAS gene mutation testing in metastatic colorectal carcinoma to predict response to anti–epidermal growth factor receptor monoclonal antibody therapy: American Society of Clinical Oncology provisional clinical opinion update 2015. J Clin Oncol. 2016;34:179-185. 10. National Cancer Institute. NCI Dictionary of Cancer terms. https://www.cancer.gov/publications/dictionaries/cancer-terms/expand/. Accessed January 29, 2024. 11. Zhao B, Wang L, Qiu H, et al. Mechanisms of resistance to anti-EGFR therapy in colorectal cancer. Oncotarget. 2016;8(3):3980-4000. 12. Vectibix® (panitumumab) prescribing information, Amgen. 13. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Colon Cancer, V.4.2023. https://www.nccn.org/professionals/physician_gls/pdf/colon.pdf. November 16, 2023. Accessed December 12, 2023. 14. Stintzing S, Tejpar S, Gibbs P, Thiebach L, Lenz HJ. Understanding the role of primary tumour localisation in colorectal cancer treatment and outcomes. Eur J Cancer. 2017;84:69-80. 15. Bahl A, Talwar V, Sirohi B, et al. Primary tumor location as a prognostic and predictive marker in metastatic colorectal cancer (mCRC). Front Oncol. 2020;10:964.