Analysis of Clinical characteristics to predict pathologic complete response for patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Abstract

To explore clinical characteristics which could be applied to predict pathologic complete response (pCR) for patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy (neo-CRT) and total mesorectal excision (TME). 297 patients with locally advanced rectal cancer (cT3-4 or cN+) who were treated with neo-CRT followed by TME were retrospectively reviewed. Clinical characteristics including age, gender, tumor distance from anus, serum CEA, hemoglobin levels before treatment and clinical TN stage were used to investigate the association with pCR after neo-CRT. Seventy-nine (26.6%) patients achieved pCR after neo-CRT. pCR were achieved in 42 (34.4%) patients in cT1-3 stage and 37 (21.1%) in cT4 stage. pCR rate was 36.4% and 16.4% for patients with pre-treatment serum CEA ≤5.33ng/ml and >5.33ng/ml, respectively. Uni- and multi-variate analyses revealed that pre-treatment serum CEA level ≤5.33ng/ml and clinical T stage, (i.e., cT1-3 versus cT4) were highly correlated with pCR (p < 0.05). Clinical T stage and pre-treatment serum CEA level were strongly associated with pCR for patients with locally advanced rectal cancer treated with neo-CRT followed by TME which could be applied as clinical predictors for pCR.

A Comprehensive Evaluation of Associations Between Routinely Collected Staging Information and The Response to (Chemo)Radiotherapy in Rectal Cancer

“…The material is not large enough to draw firm conclusions from, and it is also retrospectively collected. Nonetheless, similar results were seen in other studies investigating factors associated with pCR after preoperative CRT [13,19,21] or scRT [36]. Tumors in stage cT2 also constitute most patients with CR after CRT [37].…”

“…We have therefore used categorical variables in our analyses. Actually, most of the parameters we found associated with response rate have also correlated with pCR in other studies [12,19,34,35], although not universally. Many of the factors revealing significant associations with response have been reported after CRT before, but a comprehensive evaluation of all routinely available factors including high-quality MRI parameters has to our knowledge not been reported.…”

“…In a meta-analysis including 23 studies with almost 8500 patients, a low CEA level with cut-offs between 3.0 and 5.0 µg/L meant a doubling of the chance of reaching pCR than elevated levels [44], i.e., similar to our finding. Other studies have also found a correlation between elevated pre-treatment CEA level and pCR after CRT [19,21]. CEA is likely one of the most powerful predictors of response to preoperative RT/CRT and may be clinically relevant.…”

“…Numerous studies have explored what predicts a good response, or a pCR at surgery [4,[12][13][14][15][16][17][18][19][20][21]. However, these studies have thus far been unsuccessful in detecting any clinically useful marker for response prediction.…”

Association Between Pathological Complete Response and Tumor Location in Patients with Rectal Cancer After Neoadjuvant Chemoradiotherapy, a Prospective Cohort Study

“…Contributing factors for pCR include CEA level, anal verge distance, peripheral extension, smoking status, lymph node status, grade, size less than 5 cm, and time interval to surgery (21,22). Despite various studies in this era, there are few studies on the location of tumors (21,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36).…”