Objective:

To present a case of locally advanced rectal cancer associated with Lynch syndrome during pregnancy and discuss the management approach, highlighting its significance in the context of existing literature.

Key Findings:

• The patient had a significant tumor regression (yT2N0M0) after neoadjuvant treatment, indicating the potential effectiveness of this approach.
• Medical termination of pregnancy was necessary due to fetal viability concerns and potential teratogenic risks, highlighting the ethical complexities involved.
• The patient experienced limited adverse effects during treatment, all resolving with supportive care, suggesting a manageable treatment profile.

Interpretation:

This case highlights the complexities of managing rectal cancer in pregnant patients with Lynch syndrome, emphasizing the need for individualized, multidisciplinary approaches.

Limitations:

• The rarity of the condition limits generalizability of findings and may introduce biases in the case study methodology.
• Limited evidence exists regarding standardized management protocols for colorectal cancer during pregnancy, necessitating further research.

Conclusion:

Individualized management involving medical termination followed by neoadjuvant immunochemoradiotherapy can optimize outcomes for mothers with LS-associated rectal cancer during pregnancy, emphasizing the need for multidisciplinary approaches.