Effect of oxaliplatin-containing neoadjuvant chemotherapy on tumor volume in locally advanced rectal cancer and sensitivity of surviving tumor cells to radiotherapy.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3547-3547 ◽  
Author(s):  
Kjersti Flatmark ◽  
Knut Hakon Hole ◽  
Marie Gron Saelen ◽  
Torveig Weum Abrahamsen ◽  
Karianne Giller Fleten ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Tumor Volume ◽  
Locally Advanced ◽  
Neoadjuvant Treatment ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Volume Reduction ◽  
Median Volume ◽  
Tumor Volume Reduction ◽  
Additional Tumor

3547 Background: The use of oxaliplatin (OXA) is well established in adjuvant and palliative treatment of colorectal cancer (CRC), but its role in neoadjuvant treatment of locally advanced rectal cancer (LARC) is controversial. Data from the ACCORD 12/0405, STAR-01 and NSABBP R-04 trials suggest no additional clinical benefit of adding OXA to fluoropyrimidine-based preoperative chemoradiotherapy (CRT) in LARC. However, the possibility of reducing risk of systemic recurrence and the use of OXA-containing neoadjuvant chemotherapy (NACT) in liver metastasis warrant further clarification of the role of OXA in neoadjuvant treatment of LARC. Methods: We report results from a non-randomized phase II trial of neoadjuvant treatment of 72 LARC patients, receiving two courses of the Nordic FLOX regimen prior to CRT (25 x 2 Gy; weekly OXA; daily capecitabine). Tumor volumes were calculated from MRI scans taken before and after NACT and 4 weeks after CRT completion. Using OXA resistant human CRC cell lines, the impact of previous OXA exposure on radiosensitivity (1-5 Gy) was examined. Results: Median baseline tumor volume was 16.6 cm3 (1.1-293 cm3). All tumors, except one, responded to NACT, leaving a median tumor volume of 5.3 cm3 (0.2-157 cm3), representing a median volume reduction of 63%. In all but three patients, additional tumor volume reduction was observed following subsequent CRT (median tumor volume 5.3 cm3; 0.02-119 cm3; median volume reduction of 68%). Exposure of cell lines to increasing concentrations of OXA resulted in resistance towards the drug. OXA resistant models exhibited increased radiosensitivity compared to OXA sensitive counterparts. Conclusions: OXA-containing NACT led to substantial tumor volume reduction. Additional tumor volume reduction was observed in almost all cases, suggesting that pretreatment with OXA-containing NACT did not preclude tumor response to CRT. Results from experimental models rather suggest that pretreatment with OXA might enhance radiosensitivity of surviving OXA resistant cells. Taken together, our results are in favor of continued exploration of OXA-containing NACT in LARC. Clinical trial information: NCT00278694.

scholarly journals Molecular and Dynamic Evaluation of Proteins Related to Resistance to Neoadjuvant Treatment with Chemoradiotherapy in Circulating Tumor Cells of Patients with Locally Advanced Rectal Cancer

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1539
Author(s):  
Virgílio Souza e Silva ◽  
Emne Ali Abdallah ◽  
Bianca de Cássia Troncarelli Flores ◽  
Alexcia Camila Braun ◽  
Daniela de Jesus Ferreira Costa ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Transforming Growth Factor ◽  
Locally Advanced ◽  
Neoadjuvant Treatment ◽  
Neoadjuvant Chemoradiotherapy ◽  
Disease Free Survival ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer

The heterogeneity of response to neoadjuvant chemoradiotherapy (NCRT) is still a challenge in locally advanced rectal cancer (LARC). The evaluation of thymidylate synthase (TYMS) and RAD23 homolog B (RAD23B) expression in circulating tumor cells (CTCs) provides complementary clinical information. CTCs were prospectively evaluated in 166 blood samples (63 patients) with LARC undergoing NCRT. The primary objective was to verify if the absence of RAD23B/TYMS in CTCs would correlate with pathological complete response (pCR). Secondary objectives were to correlate CTC kinetics before (C1)/after NCRT (C2), in addition to the expression of transforming growth factor-β receptor I (TGF-βRI) with survival rates. CTCs were isolated by ISET and evaluated by immunocytochemistry (protein expression). At C1, RAD23B was detected in 54.1% of patients with no pCR and its absence in 91.7% of patients with pCR (p = 0.014); TYMS− was observed in 90% of patients with pCR and TYMS+ in 51.7% without pCR (p = 0.057). Patients with CTC2 > CTC1 had worse disease-free survival (DFS) (p = 0.00025) and overall survival (OS) (p = 0.0036) compared with those with CTC2 ≤ CTC1. TGF-βRI expression in any time correlated with worse DFS (p = 0.059). To conclude, RAD23B/TYMS and CTC kinetics may facilitate the personalized treatment of LARC.

A multicenter phase Ib/II study of DNA-PK inhibitor peposertib (M3814) in combination with capecitabine and radiotherapy in patients with locally advanced rectal cancer.

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. TPS144-TPS144
Author(s):  
Paul Bernard Romesser ◽  
Emma B. Holliday ◽  
Tony Philip ◽  
Rocio Garcia-Carbonero ◽  
Jaume Capdevila ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Colon Cancer ◽  
Phase Ii ◽  
Locally Advanced ◽  
Neoadjuvant Treatment ◽  
Rectal Adenocarcinoma ◽  
Complete Response ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Phase Ib

TPS144 Background: Perioperative radiotherapy and chemotherapy, followed by total mesorectal excision, is the standard of care for patients with locally advanced rectal cancer (LARC). However, 1/3 of these patients still develop distant metastases, indicating the need for more effective therapies. In addition, strategies that increase pathological complete response rates are needed to enable non-surgical management of LARC. DNA-dependent protein kinase (DNA-PK) regulates a key DNA damage repair pathway for double-strand break repair. Peposertib (M3814), a potent, selective, orally administered DNA-PK inhibitor, has been shown to potentiate the effect of ionizing radiation in a human colon cancer xenograft model and several colon cancer cell lines. Peposertib is being investigated in several different trials across multiple indications. This Phase Ib/II study (NCT03770689) aims to evaluate the safety, tolerability, pharmacokinetics (PK), and efficacy of the neoadjuvant treatment combination of peposertib, capecitabine, and radiotherapy (RT) in patients with LARC. Methods: Patients aged ≥18 years with histologically confirmed and resectable Stage II/III rectal adenocarcinoma are eligible. Induction chemotherapy is permitted, but residual disease must first be documented by MRI, digital rectal examination and endoscopy. Patients who received other anticancer therapies or those with prior pelvic RT are excluded. At open-label Phase Ib (open), 18–30 patients (n = 3 per cohort) will receive peposertib + capecitabine (orally, 825 mg/m2 twice daily [BID]) + RT (45–50.4 Gy), 5 days/week. Peposertib 50 mg once daily (QD) was the starting dose. Additional dose levels will range between 100─800 mg QD. Dose escalation is determined by the safety monitoring committee and guided by a Bayesian 2-parameter logistic regression model. At Phase II (planned), 150 patients will be randomized (1:1) to receive oral capecitabine (825 mg/m2 BID) + RT (45–50 Gy), with either oral peposertib (recommended phase II dose [RP2D] or placebo, QD for 5 days/week. Primary objectives are to define a maximum tolerated dose and RP2D (Phase Ib), and to evaluate the efficacy of peposertib + capecitabine + RT in terms of pathological/clinical complete response (Phase II). Secondary objectives include assessment of antitumor activity (Phase Ib), quality of life outcomes (Phase II), and PK of peposertib, and the safety and tolerability of the combination therapy (both phases). To date, one patient has received peposertib 50 mg QD, six patients peposertib 100 mg QD, three patients peposertib 150 mg QD, and three patients peposertib 250 mg QD. Clinical trial information: NCT03770689.

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