IMPROVE-pT1: Accurate Allocation of Completion Resection in Early Colorectal Cancer

After introducing a nationwide screening program for colorectal cancer (CRC) in Denmark, more cases of early-stage CRC are being detected. Cancers in the earliest stages are often removed locally, either during the diagnostic colonoscopy or through planned minimally invasive surgery. This early detection of cancer, and thereby an improved prognosis, is a positive feature but has also introduced a new clinical dilemma. Is the patient fully cured by the local resection, or do they need further surgery? Whether further surgery is recommended at the Multi-Disciplinary Team (MDT) board meeting depends on the outcome of specific criteria from the histopathological assessment of the locally removed specimen. The presence of these criteria does not, however, translate directly into the presence of residual disease - merely into a theoretically increased risk. In Denmark, after surgery, the fraction of cases with residual disease has been around 15% for many years. In the remaining 85% of cases, local removal alone was curative - and the surgery appears excessive. Investigating blood samples for the presence of circulating tumor DNA (ctDNA) is a new and promising method for cancer detection. The method utilizes that cancer cells release ctDNA into the circulation. ctDNA detected in blood drawn from a patient a few days after local removal of a tumor indicates that residual disease is present and further treatment, such as surgery, is needed. The purpose of this study is to investigate, whether analyses of ctDNA can correctly identify patients with residual disease after local removal of early CRC. If this identification proves accurate, many patients can be spared further surgery.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Patients having undergone local resection of pT1 colorectal cancer and with planned completion resection, as recommended by the local MDT board

  * The reason for the planning of completion resection may be non-micro radical tumor removal, piece-meal resection making assessment of resection margin impossible or the presence of one or more histological risk factors

Exclusion Criteria:

* Patients not able to understand information about the study and/or give informed consent
* Patients not accepting blood samples stored in biobank
* Cases with non-obtainable primary tumor tissue, required for the conduction of mutational analyses
* Other recent (within 5 years) or current malignant disease, except basocellular carcinoma of the skin
* Planned completion resection due to other factors, such as patient's wish or hereditary disposition for CRC, and with the absence of risk factors mentioned above
* Withdrawal of consent

• BACKGROUNDZviran A, Schulman RC, Shah M, Hill STK, Deochand S, Khamnei CC, Maloney D, Patel K, Liao W, Widman AJ, Wong P, Callahan MK, Ha G, Reed S, Rotem D, Frederick D, Sharova T, Miao B, Kim T, Gydush G, Rhoades J, Huang KY, Omans ND, Bolan PO, Lipsky AH, Ang C, Malbari M, Spinelli CF, Kazancioglu S, Runnels AM, Fennessey S, Stolte C, Gaiti F, Inghirami GG, Adalsteinsson V, Houck-Loomis B, Ishii J, Wolchok JD, Boland G, Robine N, Altorki NK, Landau DA. Genome-wide cell-free DNA mutational integration enables ultra-sensitive cancer monitoring. Nat Med. 2020 Jul;26(7):1114-1124. doi: 10.1038/s41591-020-0915-3. Epub 2020 Jun 1. PMID 32483360