Case Report: Integration of intratumoral oncolytic adenovirus with total neoadjuvant therapy in metachronous locally advanced rectal cancer

Background: Recent landmark randomized controlled trials have established total neoadjuvant therapy (TNT) as a standard treatment option for selected patients with locally advanced rectal cancer (LARC), offering improved tumor response and opportunities for organ preservation. In parallel, the integration of oncolytic virotherapy (OVT) into neoadjuvant regimens has shown potential benefits in various solid tumors. However, to date, no clinical reports have demonstrated the therapeutic efficacy of combining OVT with TNT specifically in LARC. Case presentation: We report a case of a 50-year-old patient diagnosed with metachronous LARC harboring TP53 mutation. We treated this patient with intratumoral injection of the recombinant human adenovirus H101 in combination with TNT, resulting in a pathologic complete response (pCR) and successful preservation of anal sphincter function. At the most recent follow-up, there was no evidence of local recurrence or distant metastasis. Conclusion: This case highlights the potential of oncolytic virotherapy to enhance chemotherapy and radiotherapy effects in LARC patients.