From the Guidelines
The choice between Total Mesorectal Excision (TME) alone versus preoperative chemoradiation/Total Neoadjuvant Therapy (TNT) for rectal cancer depends primarily on the stage and location of the tumor, with TNT being recommended for locally advanced rectal cancers (T3-T4 or node-positive disease) and TME alone for early-stage rectal cancers (T1-T2, N0) without high-risk features, as supported by the most recent guidelines 1. When deciding between TME and TNT for rectal cancer, several factors must be considered, including the stage and location of the tumor, as well as the patient's overall health and preferences.
- For early-stage rectal cancers (T1-T2, N0) without high-risk features, TME alone is typically recommended as the primary treatment approach, due to its ability to achieve high rates of local control and survival with minimal morbidity 1.
- However, for locally advanced rectal cancers (T3-T4 or node-positive disease), preoperative chemoradiation therapy followed by TME is the standard of care, as it has been shown to improve local control and survival rates compared to TME alone 1.
- TNT, which includes both chemotherapy and radiation before surgery, is particularly beneficial for mid to low rectal tumors (within 12 cm from the anal verge) with threatened circumferential resection margins or extensive nodal disease, as it can downstage tumors, increase the likelihood of R0 resection, and improve sphincter preservation rates 1.
- The standard TNT regimen typically includes long-course radiation (45-50.4 Gy over 5-6 weeks) with concurrent 5-fluorouracil or capecitabine, followed by 2-4 months of systemic chemotherapy (typically FOLFOX or CAPOX), and then surgery 8-12 weeks after completion of therapy, as supported by recent studies 1.
- Additionally, TNT allows for assessment of tumor response before surgery, which can guide further treatment decisions and potentially identify patients who might benefit from a watch-and-wait approach if complete clinical response is achieved, highlighting the importance of a multidisciplinary approach to rectal cancer management 1.
From the Research
Choosing Between Total Mesorectal Excision (TME) and Total Neoadjuvant Therapy (TNT) for Rectal Cancer
- The decision to choose TME or TNT for rectal cancer depends on various factors, including the location and stage of the tumor, as well as the patient's overall health and preferences.
- Studies have shown that TME can be effective for upper rectal cancer, with low local recurrence rates and good disease-free survival rates 2.
- However, for more advanced or lower rectal cancers, TNT may be a better option, as it can reduce the risk of local recurrence and improve disease-free survival rates 3, 4.
- A randomized trial found that TME with or without preoperative chemoradiotherapy had similar long-term outcomes for resectable mid/low rectal cancer, suggesting that a selective policy towards preoperative chemoradiotherapy may be recommended 5.
Factors to Consider When Choosing Between TME and TNT
- Tumor location: Upper rectal cancers may be treated with TME alone, while lower rectal cancers may require TNT.
- Tumor stage: More advanced tumors may require TNT to reduce the risk of local recurrence.
- Patient health: Patients with certain medical conditions or poor overall health may not be candidates for TNT.
- Patient preferences: Patients may have preferences for one treatment option over the other, which should be taken into account when making a decision.
Evolution of TME Technique
- The TME technique has evolved over time, with improvements in preoperative staging, pathologic assessment, and surgical technique 6.
- The standardization and widespread implementation of TME have significantly impacted outcomes for rectal cancer surgery, with reductions in local recurrence and improvements in disease-free and overall survival.
- Continued advances in TME technique and multimodal therapies are expected to further improve outcomes for rectal cancer patients.