Clinical predictive factors of pathologic tumor response after preoperative chemoradiotherapy in rectal cancer

Abstract

PurposeThe aim of this study was to identify clinical predictive factors for tumor response after preoperative chemoradiotherapy (CRT) in rectal cancer.Materials and MethodsThe study involved 51 patients who underwent preoperative CRT followed by surgery between January 2005 and February 2012. Radiotherapy was delivered to the whole pelvis at a dose of 45 Gy in 25 fractions, followed by a boost of 5.4 Gy in 3 fractions to the primary tumor with 5 fractions per week. Three different chemotherapy regimens were used (5-fluorouracil and leucovorin, capecitabine, or tegafur/uracil). Tumor responses to preoperative CRT were assessed in terms of tumor downstaging and pathologic complete response (ypCR). Statistical analyses were performed to identify clinical factors associated with pathologic tumor response.ResultsTumor downstaging was observed in 28 patients (54.9%), whereas ypCR was observed in 6 patients (11.8%). Multivariate analysis found that predictors of downstaging was pretreatment relative lymphocyte count (p = 0.023) and that none of clinical factors was significantly associated with ypCR.ConclusionPretreatment relative lymphocyte count (%) has a significant impact on the pathologic tumor response (tumor downstaging) after preoperative CRT for locally advanced rectal cancer. Enhancement of lymphocyte-mediated immune reactions may improve the effect of preoperative CRT for rectal cancer.

Circulating Lymphocytes as Predictors of Sensitivity to Preoperative Chemoradiotherapy in Rectal Cancer Cases

“…Recent studies have suggested that the radiosensitivity was not only depend on the biological characteristics of tumor cells, but also being affected by tumor microenvironment (Barcellos-Hoff et al, 2005), which gave us the inspiration that the blood cells, as part of the microenvironment, might play a critically important role for tumor regression after nCRT in patients with LARC. In fact, some results have clearly shown that circulating lymphocyte levels were significantly different in CR patients and non-CR patients (Kitayama et al, 2011;Choi et al, 2012). But to our knowledge, the report that circulating lymphocyte can predict TRG to nCRT in rectal cancer was rare.…”

Negative influence of programmed death‐1‐ligands on the survival of esophageal cancer patients treated with chemotherapy

“…Recently, multiple studies have shown the association between the conventional treatment using certain anticancer agents and immune responses against cancer cells . Based on these results, significant numbers of researchers now appear to believe that chemotherapeutic agents can induce anti‐tumor immune responses that significantly contribute to the overall anti‐tumor effects of the chemotherapeutic agents .…”

“…Recently, multiple studies have shown the association between the conventional treatment using certain anticancer agents and immune responses against cancer cells. (18)(19)(20)(21)(22)(23) Based on these results, significant numbers of researchers now appear to believe that chemotherapeutic agents can induce anti-tumor immune responses that significantly contribute to the overall anti-tumor effects of the chemotherapeutic agents. (24) Our results presented here appear to support this notion and suggest that the PD-1 system might be one of the key players in determining the chemotherapy-related immune responses.…”

Clinical significance of preoperative carcinoembryonic antigen level in patients with clinical stage IA non-small cell lung cancer

“…Carcinoembryonic antigen (CEA) is an established tumor marker and has demonstrated its prognostic value in colorectal cancer (4). CEA is also overexpressed in approximately 35-60% of patients with NSCLC (5), and the clinical usefulness of the serum CEA level in lung cancer has recently been vigorously explored.…”