PREDICTIVE FACTORS FOR PATHOLOGICAL COMPLETE RESPONSE AFTER LONG-COURSE PREOPERATIVE CHEMORADIOTHERAPY FOR MIDDLE AND LOWER RECTAL CANCER
Main Article Content
Abstract
Objective: To identify factors associated with pathological complete response after long-course preoperative chemoradiotherapy in patients with middle and lower rectal cancer. Subjects and Methods: A retrospective descriptive and analytical study was conducted on 168 patients with stage II–III middle and lower rectal cancer who underwent long-course preoperative chemoradiotherapy followed by radical surgery. Pathological complete response was defined as the absence of viable tumor cells in the primary tumor bed in the surgical specimen, corresponding to Mandard TRG 1/ypT0. Clinical, laboratory, and imaging-related factors were analyzed using univariate tests and multivariable logistic regression.
Results: The pathological complete response rate was 22.0% (37/168). Patients with pathological complete response had a significantly smaller pretreatment tumor size than those without pathological complete response (4.78 ± 1.90 cm vs. 5.81 ± 2.25 cm; p = 0.006) and lower pretreatment CEA levels [2.37 (1.15–3.28) vs. 4.57 (2.55–7.94) ng/mL; p < 0.001]. In multivariable analysis, pretreatment CEA >5 ng/mL was an independent unfavorable factor for pathological complete response (OR = 0.33; 95%CI: 0.14–0.81; p = 0.015). After chemoradiotherapy, mrTRG 1–2 was strongly associated with pathological complete response.
Conclusion: Low pretreatment CEA, smaller baseline tumor size, and post-treatment mrTRG 1–2 were suggestive factors associated with a higher probability of pathological complete response after long-course preoperative chemoradiotherapy.
Results: The pathological complete response rate was 22.0% (37/168). Patients with pathological complete response had a significantly smaller pretreatment tumor size than those without pathological complete response (4.78 ± 1.90 cm vs. 5.81 ± 2.25 cm; p = 0.006) and lower pretreatment CEA levels [2.37 (1.15–3.28) vs. 4.57 (2.55–7.94) ng/mL; p < 0.001]. In multivariable analysis, pretreatment CEA >5 ng/mL was an independent unfavorable factor for pathological complete response (OR = 0.33; 95%CI: 0.14–0.81; p = 0.015). After chemoradiotherapy, mrTRG 1–2 was strongly associated with pathological complete response.
Conclusion: Low pretreatment CEA, smaller baseline tumor size, and post-treatment mrTRG 1–2 were suggestive factors associated with a higher probability of pathological complete response after long-course preoperative chemoradiotherapy.
Article Details
Keywords
rectal cancer, preoperative chemoradiotherapy, pathological complete response, pCR, CEA, mrTRG.
References
1. Benson AB, Venook AP, Al-Hawary MM, et al. Rectal Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2022;20(10):1139-1167. doi:10.6004/jnccn.2022.0051.
2. Sauer R, Becker H, Hohenberger W, et al. Preoperative versus postoperative chemoradiotherapy for rectal cancer. N Engl J Med. 2004;351(17):1731-1740. doi:10.1056/NEJMoa040694.
3. Gérard JP, Conroy T, Bonnetain F, et al. Preoperative radiotherapy with or without concurrent fluorouracil and leucovorin in T3–4 rectal cancers: results of FFCD 9203. J Clin Oncol. 2006;24(28):4620-4625. doi:10.1200/JCO.2006.06.7629.
4. Bosset JF, Collette L, Calais G, et al. Chemotherapy with preoperative radiotherapy in rectal cancer. N Engl J Med. 2006;355(11):1114-1123. doi:10.1056/NEJMoa060829.
5. Maas M, Nelemans PJ, Valentini V, et al. Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data. Lancet Oncol. 2010;11(9):835-844. doi:10.1016/S1470-2045(10)70172-8.
6. Rödel C, Martus P, Papadoupolos T, et al. Prognostic significance of tumor regression after preoperative chemoradiotherapy for rectal cancer. J Clin Oncol. 2005;23(34):8688-8696. doi:10.1200/JCO.2005.02.1329.
7. Al-Sukhni E, Attwood K, Mattson DM, Gabriel E, Nurkin SJ. Predictors of pathologic complete response following neoadjuvant chemoradiotherapy for rectal cancer. Ann Surg Oncol. 2016;23(4):1177-1186. doi:10.1245/s10434-015-5017-y.
8. Choi E, Kim JH, Kim OB, et al. Predictors of pathologic complete response after preoperative concurrent chemoradiotherapy of rectal cancer. Ann Surg Treat Res. 2016;90(3):163-169. doi:10.4174/astr.2016.90.3.163.
9. Petrelli F, Sgroi G, Sarti E, et al. Increasing the interval between neoadjuvant chemoradiotherapy and surgery in rectal cancer: a meta-analysis of published studies. Ann Surg. 2016;263(3):458-464. doi:10.1097/SLA.0000000000000368.
2. Sauer R, Becker H, Hohenberger W, et al. Preoperative versus postoperative chemoradiotherapy for rectal cancer. N Engl J Med. 2004;351(17):1731-1740. doi:10.1056/NEJMoa040694.
3. Gérard JP, Conroy T, Bonnetain F, et al. Preoperative radiotherapy with or without concurrent fluorouracil and leucovorin in T3–4 rectal cancers: results of FFCD 9203. J Clin Oncol. 2006;24(28):4620-4625. doi:10.1200/JCO.2006.06.7629.
4. Bosset JF, Collette L, Calais G, et al. Chemotherapy with preoperative radiotherapy in rectal cancer. N Engl J Med. 2006;355(11):1114-1123. doi:10.1056/NEJMoa060829.
5. Maas M, Nelemans PJ, Valentini V, et al. Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data. Lancet Oncol. 2010;11(9):835-844. doi:10.1016/S1470-2045(10)70172-8.
6. Rödel C, Martus P, Papadoupolos T, et al. Prognostic significance of tumor regression after preoperative chemoradiotherapy for rectal cancer. J Clin Oncol. 2005;23(34):8688-8696. doi:10.1200/JCO.2005.02.1329.
7. Al-Sukhni E, Attwood K, Mattson DM, Gabriel E, Nurkin SJ. Predictors of pathologic complete response following neoadjuvant chemoradiotherapy for rectal cancer. Ann Surg Oncol. 2016;23(4):1177-1186. doi:10.1245/s10434-015-5017-y.
8. Choi E, Kim JH, Kim OB, et al. Predictors of pathologic complete response after preoperative concurrent chemoradiotherapy of rectal cancer. Ann Surg Treat Res. 2016;90(3):163-169. doi:10.4174/astr.2016.90.3.163.
9. Petrelli F, Sgroi G, Sarti E, et al. Increasing the interval between neoadjuvant chemoradiotherapy and surgery in rectal cancer: a meta-analysis of published studies. Ann Surg. 2016;263(3):458-464. doi:10.1097/SLA.0000000000000368.