From the Guidelines
The next step in managing a young patient with rectal cancer and multiple adenomas should include comprehensive genetic testing, particularly for Lynch syndrome and familial adenomatous polyposis (FAP), as well as neoadjuvant chemoradiation therapy and complete surgical resection of the rectal cancer with appropriate margins, typically through total mesorectal excision, along with removal of all accessible adenomas. The patient's age and the presence of multiple adenomas suggest a possible underlying genetic syndrome, which necessitates genetic testing and counseling 1. According to the guidelines, tumor testing for DNA mismatch repair (MMR) deficiency with immunohistochemistry for MMR proteins and/or MSI should be assessed in all CRC patients, especially those younger than 70 years 1. Neoadjuvant chemoradiation therapy may be indicated depending on cancer stage, commonly using 5-fluorouracil or capecitabine with radiation therapy for 5-6 weeks before surgery 1. Following treatment of the primary cancer, the patient requires lifelong surveillance with regular colonoscopies every 1-2 years to monitor for new adenomas and recurrent cancer 1. A multidisciplinary approach involving colorectal surgeons, oncologists, gastroenterologists, and genetic counselors is essential for optimal management 1. The aggressive approach is justified by the high risk of malignant transformation in remaining adenomas and the likelihood of an underlying genetic syndrome that predisposes to multiple cancers throughout the gastrointestinal tract and potentially other organ systems. Key considerations include:
- Comprehensive genetic testing for Lynch syndrome and FAP
- Neoadjuvant chemoradiation therapy and complete surgical resection of the rectal cancer
- Lifelong surveillance with regular colonoscopies
- Multidisciplinary approach to management
- Family members should be advised to undergo genetic counseling and screening, as these conditions often have a hereditary component 1.
From the Research
Next Steps in Managing a Young Patient with Rectal Cancer and Multiple Adenomas
The patient's presentation with rectal cancer and multiple adenomas at a young age raises suspicion for a hereditary cancer syndrome, such as Lynch syndrome. The next steps in her care should include:
- Genetic counseling and testing for Lynch syndrome, as the patient's age and family history (if available) may indicate an increased risk for this condition 2, 3, 4
- Testing for DNA mismatch repair deficiency, which is a hallmark of Lynch syndrome and can be detected through immunohistochemistry and PCR-based microsatellite instability analysis 5, 4, 6
- A comprehensive evaluation of the patient's tumor tissue, including analysis of microsatellite instability and mismatch repair protein expression, to aid in the diagnosis of Lynch syndrome and guide further management 5, 4, 6
- Consideration of a gynecologic evaluation, as women with Lynch syndrome are at increased risk for endometrial and ovarian cancers 2, 4
- Discussion of the potential benefits and limitations of genetic testing and counseling with the patient, as well as the implications for her family members 2, 3, 4
Importance of Mismatch Repair Deficiency Testing
Mismatch repair deficiency testing is crucial in the clinical management of patients with suspected Lynch syndrome, as it can help identify those at increased risk for cancer development and guide targeted screening and prevention strategies 5, 4, 6. The testing methods, including immunohistochemistry and PCR-based microsatellite instability analysis, can provide valuable information on the patient's risk for cancer and inform treatment decisions 5, 4, 6.