Planned Non-operative Management for Rectal Cancer

The investigators propose to conduct an observational study on consecutive patients with low-lying or mid rectal cancers smaller than 5 cm in length and less than 50% of rectal circumferential extent. The aim of this study is to test a hypothesis that escalation of either radiation or chemotherapy dose of the routine preoperative radio(chemo)therapy leads to an increase of clinical complete response rate. The planned sample size of 23 patients was calculated based on the assumption that clinical complete response rate after routine preoperative radio(chemo)therapy is 34% \[1\] and expected rate after radio(chemo)therapy dose escalation is 75% \[2-4\]. An endorectal high dose rate iridium brachytherapy boost (2 fractions of 10 Gy) will be added after the routine preoperative treatment consisted of external beam radiotherapy (5 × 5 Gy) combined with sequential 3 cycles of consolidation FOLFOX4. However, for patients with involvement of the anal canal, additional 3 cycles of consolidation FOLFOX4 (6 cycles in total) will be added instead of brachytherapy boost to avoid severe post-radiation toxicity.

Sex

All

Inclusion Criteria:

1. Adenocarcinoma of the rectum classified clinically as T2, T3a-c or T4b but only with superficial infiltration of the vagina or prostate; tumour accessible by digital rectal examination; tumour ≤5 cm in length and ≤50% of rectal circumferential extent; N0-N2, but mesorectal node \<7 mm and no lateral nodes enlargement); extramural vascular invasion but not larger than 7 mm in the largest dimension; M0.
2. Operable patient
3. Patient having read the information note and having signed the informed consent
4. Follow-up possible

Exclusion Criteria:

1. Inoperable patient
2. cT1, cT3d, large T4, tumour ≥5cm or ≥50 of rectal circumferential extent
3. Enlargement of lateral nodes or any node ≥8 mm in diameter
4. Patient presenting metastasis at diagnosis
5. Previous pelvic irradiation
6. Simultaneous progressive another cancer
7. Close follow-up uncertain.

• BACKGROUNDJankowski M, Pietrzak L, Rupinski M, Michalski W, Holdakowska A, Paciorek K, Rutkowski A, Olesinski T, Cencelewicz A, Szczepkowski M, Zegarski W, Reszke J, Richter P, Wawok P, Malecki K, Bebenek M, Szelachowska J, Mazurek M, Gisterek I, Polkowski W, Jankiewicz M, Stylinski R, Socha J, Bujko K; Polish Colorectal Study Group. Watch-and-wait strategy in rectal cancer: Is there a tumour size limit? Results from two pooled prospective studies. Radiother Oncol. 2021 Jul;160:229-235. doi: 10.1016/j.radonc.2021.05.014. Epub 2021 May 21. PMID 34023328
• BACKGROUNDGarant A, Magnan S, Devic S, Martin AG, Boutros M, Vasilevsky CA, Ferland S, Bujold A, DesGroseilliers S, Sebajang H, Richard C, Vuong T. Image Guided Adaptive Endorectal Brachytherapy in the Nonoperative Management of Patients With Rectal Cancer. Int J Radiat Oncol Biol Phys. 2019 Dec 1;105(5):1005-1011. doi: 10.1016/j.ijrobp.2019.08.042. Epub 2019 Aug 30. PMID 31476417
• BACKGROUNDRijkmans EC, Cats A, Nout RA, van den Bongard DHJG, Ketelaars M, Buijsen J, Rozema T, Franssen JH, Velema LA, van Triest B, Marijnen CAM. Endorectal Brachytherapy Boost After External Beam Radiation Therapy in Elderly or Medically Inoperable Patients With Rectal Cancer: Primary Outcomes of the Phase 1 HERBERT Study. Int J Radiat Oncol Biol Phys. 2017 Jul 15;98(4):908-917. doi: 10.1016/j.ijrobp.2017.01.033. Epub 2017 Jan 20. PMID 28366579
• BACKGROUND4. Garcia-Aguilar J, Patil S, Kim JK, et al. Preliminary results of the organ preservation of rectal adenocarcinoma (OPRA) trial. J Clin Oncol 38: 2020 (suppl; abstr 4008).