The efficiency of 18F-FDG-PET/CT in the assessment of tumor response to preoperative chemoradiation therapy for locally recurrent rectal cancer

Background Locally recurrent rectal cancer (LRRC) remains a major problem after curative resection of primary rectal cancer. A noninvasive, prognostic biomarker with which to accurately evaluate disease status and assess the treatment response is critically needed to optimize treatment plans. This study assesses the effectiveness of PET/CT evaluation of preoperative chemoradiation therapy (CRT) in patients with LRRC. Methods Since 2004, we have been performing preoperative CRT to improve local tumor control and survival. Between 2004 and 2013, 40 patients with LRRC underwent preoperative CRT (radiation: 50 Gy/25 fractions; chemotherapy: irinotecan plus UFT [tegafur and uracil]/leucovorin) and radical surgery, and underwent 18F-FDG-PET/CT before and 3 weeks after the completion of CRT. The maximum standardized uptake values (SUVmax) of the pre-CRT scan (Pre-SUV) and the post-CRT scan (Post-SUV) were measured. The predictive value of the 18F-FDG-PET and CT/MRI response assessments was evaluated. Results The mean Pre-SUV was significantly higher than the Post-SUV (8.2 ± 6.1, vs. 3.8 ± 4.0; P < 0.0001). Following CRT, 17/40 patients (42.5%) were classified as responders according to the Mandard tumor regression grade (TRG1–2). The mean Post-SUV was significantly lower in responders than in nonresponders (2.0 ± 1.7 vs. 5.1 ± 3.9; P = 0.0038). Pathological response was not correlated with the response as evaluated by CT (P > 0.9999) or MRI (P > 0.9999). Multivariate regression analysis identified Post-SUV as an independent predictor of local re-recurrence-free survival (P = 0.0383) and for overall survival (P = 0.0195). Conclusions PET/CT is useful in assessing tumor response to preoperative CRT for LRRC and predicting prognosis after surgery.

Genetic prognostic factors for neoadjuvant chemoradiotherapy for colorectal cancer

Introduction. There has been a recent trend toward a gradual increase in the incidence of rectal cancer and a decrease in the average age of patients. These changes interpret the need to personalize treatment in each case.Objective – to evaluate the association of polymorphic variants of some genes with the results of neoadjuvant chemoradiotherapy of rectal cancer.Materials and methods. We analyzed polymorphic variants of MTHFR, XPD, XRCC1, XRCC1, P53, VEGF, EGFR, TNF, CHEK2 and MMP1 genes in 76 patients with rectal cancer who underwent preoperative chemoradiation therapy followed by surgical treatment. Genotyping was performed by DNA isolation from venous blood leukocytes of the subjects followed by polymerase chain reaction with electrophoretic detection of the result.Results. Statistical analysis of the association of polymorphic variants of the studied genes with the treatment pathomorphosis revealed significance in relation to the MMP1-1607 gene (1G >2G) (p = 0.033). There was also an association of co-carrying polymorphic variants of TNF (G / A) + MMP1 (2G / 2G) genes with grade III–IV therapeutic pathomorphosis (p = 0.007).Conclusion. Carriage of recessive allele of MMP1 gene can be a predictor of favorable prognosis of preoperative chemoradiotherapy in patients with rectal cancer.

Review of Intersphincteric Resections for Rectal Cancer Treatment

Colorectal cancer is the third most common cancer, second most common cancer in women, and the fourth leading cause of death in the world. Radical surgical treatment with Total Mesorectal Excision (TME) is considered the best treatment for cancer found in the lower third of the rectum and has benefits of complete tumor removal to reduce risk of recurrence and to improve survival. Advances in preoperative chemoradiation therapy have increased chances of achieving a 1 cm distal margin and allowed successful sphincter-preserving surgery by intersphincteric resection (ISR) and Coloanal Anastomosis (CAA) that allows normal defecation. MRI is particularly useful in evaluating localization of the tumor, involvement of anal sphincter (internal and external sphincters), levator ani muscles, and adjacent structures to the anus, with an accuracy of 85%, sensitivity of 87%, and specificity of 75%. Performing ISR with TME oncologic principles achieves similar results to Low Anterior Resection (LAR), but depends on the presence of sufficient Distal Rectal Margin (DRM); if a sufficient DRM cannot be achieved, then patients are offered an Abdominoperineal Resection (APR) with permanent colostomy and poor quality-of-life results.

The Efficiency of 18F-FDG-PET/CT in Assessment of Tumor Response to Preoperative Chemoradiation Therapy for Locally Recurrent Rectal Cancer

Background:Locally recurrent rectal cancer (LRRC) remains a major problem after curative resection of primary rectal cancer. A noninvasive biomarker that accurately evaluates the disease status and assesses the treatment response with prognostic value is critically needed to optimize the treatment plan. This study assesses the effectiveness of PET/CT evaluation of preoperative chemoradiation therapy (CRT) in patients with LRRC.Patients and Methods:Since 2004, we have been performing preoperative CRT to improve local tumor control and survival. Between 2004 and 2013, 40 patients with LRRC underwent preoperative CRT (radiation; 50 Gy/25 fractions, chemotherapy; irinotecan plus UFT/leucovorin ) and radical surgery, and underwent 18F-FDG-PET/CT before and 3 weeks after the completion of CRT. The maximum standardized uptake value (SUVmax) of the pre-CRT scan (Pre-SUV) and the post-CRT scan (Post-SUV) were measured. The predictive ability of 18F-FDG-PET and CT/MRI response assessment were evaluated.Results:The mean Pre-SUV was significantly higher than Post-SUV (8.2±6.1, vs 3.8±4.0; P < 0.0001). Following CRT, 17/40 patients (42.5%) were classified as responders according to Mandard tumor regression grade (TRG1-2). The mean Post-SUV was significantly lower in responders than in nonresponders (2.0±1.7 vs 5.1±3.9; P = 0.0038). Pathological response was not correlated with the response as evaluated by CT (P > 0.9999) or MRI (P > 0.9999). Multivariate regression analysis identified Post-SUV as an independent predictor of local re-recurrence-free survival (P = 0.0383) and for overall survival (P = 0.0195). Conclusions:PET/CT is useful in assessing tumor response to preoperative CRT for LRRC and predicting prognosis after surgery.

Clinical significance of neutrophil-lymphocyte ratio to the patients with locally advanced rectal cancer who received preoperative chemoradiation therapy.

138 Background: Preoperative chemoradiation therapy (CRT) and total mesorectal excision have been the standard care of the patients with locally advanced rectal cancer. Response to the preop CRT varied from patient to patient, approximately 10-15% of the patients achieved complete response, on the contrary, nearly 40% of the patients still showed ypT4 disease. The aim of this study is to assess the prognostic value of NLR and suggest the optimal cut-off value to predict tumor response to the preoperative chemoradiation therapy in the patients with locally advanced rectal cancer. Methods: We analyzed the medical records of 1134 patients who diagnosed with locally advanced rectal cancer and treated with preop CRT followed by radical surgery at St. Vincent hospital, Seoul St. Mary’s hospital, Chonnam National University Hwasun Hospital, Gyeongsang National University Hospital and Dongsan Medical Center from 1998 to 2015. All patients had histologically confirmed rectal adenocarcinoma within 10 cm from anal verge. All patients received preoperative CRT to the pelvis followed by TME. Complete blood count was performed at initial workup before treatment and NLR was calculated with differential count. Results: An optimal cut-off value of the NLR was revealed as 1.98. The NLR showed average value for predicting death (AUC 0.516, p < 0.001). According to the cut-off value, patients were divided into two groups; high NLR (NLR≥2.0, n = 530) and low NLR (NLR < 2.0, n = 604). The patients with low NLR achieved pathologic complete response more frequently. 105 patients of total 604 patients (17.4%) with low NLR showed no remnant tumor cells, compared to 63 patients of the 530 patients (11.9%) with high NLR did (p = 0.012). The proportion of the patients who were downstaged to T1-2N0 was evaluated. In the low NLR group, 258 patients (42.7%) were downstaged, while 199 patients (37.5%) in the high NLR group were, which showed a tendency but did not reach statistical significance (p = 0.087). Conclusions: In this large-scale multi-center analysis, NLR was once again identified as a predictor of treatment response of preop CRT in patients with locally advanced rectal cancer.