Phase I Trial of Neoadjuvant Preoperative Chemotherapy With S-1 and Irinotecan Plus Radiation in Patients With Locally Advanced Rectal Cancer

The "Watch and Wait" Method After Chemoradiotherapy for Rectal Cancer Requiring Abdominoperineal Resection

The present study examined the therapeutic effects of preoperative neoadjuvant chemoradiation therapy (NACRT) and predictive factors for complete clinical remission, compared the prognosis and costs of abdominoperineal resection (APR) and the "watch and wait" method (WW), and evaluated the usefulness of WW. In our department, patients with stage II-III lower rectal cancer requiring APR receive NACRT. NACRT was performed as a preoperative treatment (52 Gy + S-1: 80-120 mg/day × 25 days). Eight weeks after the completion of NACRT, rectal examination, endoscopic, computed tomography, and magnetic resonance imaging findings were evaluated to assess its therapeutic effects. APR was indicated for patients in whom endoscopic findings suggested a residual tumor in which a deep ulcer or marginal swelling remained or lymph node metastasis. However, WW was selected for patients who refused APR after informed consent was obtained. In the APR and WW groups, 5- and 20-year treatment costs after CRT were calculated using the Medical Fee Points of Japan in 2020. No significant differences were observed in 3-year disease-free survival rates for either parameter between the two groups. Regarding expenses, treatment costs were lower in the WW group than in the APR group. Organ preservation using active surveillance with CRT for rectal cancer requiring APR is feasible with the achievement of endoluminal complete remission.

Short-term outcomes of robot-assisted versus conventional laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy: a propensity score-matched analysis

The benefits of robot-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. Only a few studies have evaluated the safety and feasibility of RALS following neoadjuvant chemoradiotherapy (NCRT). This study aimed to compare the short-term outcomes of RALS versus conventional laparoscopic surgery (CLS) after NCRT for rectal cancer. Propensity score matching of 111 consecutive patients who underwent RALS or CLS after NCRT for rectal adenocarcinoma between February 2014 and February 2022 was performed. Among them, 60 matched patients were enrolled and their short-term outcomes were compared. Although operative time, conversion rate to open laparotomy and blood loss were comparable, the incidence of postoperative complications, including anastomotic leakage, was significantly lower, urinary retention tended to be lower, and the days to soft diet intake and postoperative hospital stay were significantly shorter in the RALS than the CLS group. No postoperative mortality was observed in either group, and there were no significant differences in terms of resection margins and number of lymph nodes dissected. RALS after NCRT for rectal cancer is safe and technically feasible, and has acceptable short-term outcomes. Further studies are required for validation of the long-term oncological outcomes.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study

INTRODUCTION

Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients.

METHODS

Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes.

RESULTS

Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%.

CONCLUSION

Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Comparison of short-term outcomes of robotic-assisted and conventional laparoscopic surgery for rectal cancer: A propensity score-matched analysis

INTRODUCTION

The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS).

METHODS

The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group.

RESULTS

After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested.

CONCLUSION

Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

Efficacy and tolerability of preoperative chemoradiotherapy with S-1 alone for locally advanced rectal cancer

Preoperative chemoradiotherapy with capecitabine or 5-fluorouracil is a standard treatment for locally advanced rectal cancer (LARC). S-1, a prodrug of 5-fluorouracil, is a candidate for this chemoradiotherapy regimen in Japan; however, treatment outcomes after S-1 treatment alone are not clear. This study aimed to assess the efficacy and tolerability of preoperative chemoradiotherapy with S-1 alone for LARC. We retrospectively evaluated 54 LARC patients who underwent preoperative chemoradiotherapy with S-1 alone in our institution between 2005 and 2017. The clinical tumor stage was cT2-3 in 31 patients and cT4 in 23 patients, and lymph node metastases were clinically evident in 31 patients. S-1, at a dose of 80 mg/m2/day, was orally administered during radiotherapy. A total dose of 45-50.4 Gy was delivered in 25-28 fractions (median: 50.4 Gy). Surgical resections were scheduled 6-10 weeks after chemoradiotherapy completion. The 3- and 5-year overall survival rates were 92.4 and 72.8%, respectively, with a median follow-up time of 51 months. The 3- and 5-year local control rates were 96.2 and 85.9%, respectively. A pathological complete response was observed in 7 patients (13.0%) at the time of surgery. Ten patients (18.5%) had grade 3 acute toxicities and 5 patients (9.3%) had grade 3 late toxicities. No grade 4 or 5 toxicities were observed. Preoperative chemoradiotherapy with S-1 alone followed by total mesorectal excision resulted in a low incidence of toxicities and comparable clinical results. Therefore, S-1 alone can be a treatment option for preoperative chemoradiotherapy in LARC patients.

Prognostic impact of the number of lateral pelvic lymph node metastases on rectal cancer

BACKGROUND

This study aimed to clarify the number of lateral pelvic lymph node metastases of colorectal cancer for which prognosis could be improved by dissection.

METHODS

We analysed the data of 30 patients with lateral pelvic lymph node metastases of rectal cancer that underwent a total mesorectal excision with lateral pelvic lymph node dissection at our institute from 1986 to 2016. We performed survival analysis on the number of lateral pelvic lymph node metastases in each of these patients and identified an optimal cut-off point of the number of lateral pelvic lymph node metastases that would predict recurrence-free survival using the receiver operating characteristic curves and an Akaike information criterion value.

RESULTS

The 5-year recurrence-free survival and overall survival of patients with one or two lateral pelvic lymph node metastases were significantly better than that of those with three or more (5-year recurrence-free survival, 63.3 vs. 0.0%, respectively; hazard ratio, 0.23; 95% CI, 0.07-0.72; P = 0.0124) (5-year overall survival, 68.2 vs. 15.6%, respectively; hazard ratio, 0.29; 95% CI, 0.09-0.92; P = 0.0300). All of the metastatic lateral pelvic lymph nodes in the group with one or two lateral pelvic lymph node metastases were restricted to the internal iliac artery or obturator nerve regions.

CONCLUSIONS

The cut-off number of lateral pelvic lymph node metastases in the internal iliac artery or obturator nerve regions of colorectal cancer cases in whom prognosis was improved by lateral pelvic lymph node dissection was 2; patients who had <3 lateral pelvic lymph node metastases had better prognoses than those with ≥3 lateral pelvic lymph node metastases.

Retrospective study of preoperative chemoradiotherapy with capecitabine versus capecitabine plus oxaliplatin for locally advanced rectal cancer

This study aimed to evaluate whether the addition of oxaliplatin to a neoadjuvant chemoradiotherapy (CRT) regimen could improve survival benefit in locally advanced rectal cancer (LARC) patients. We retrospectively analysed 73 LARC patients (cT2-4 and/or cN1-2) who received preoperative CRT with capecitabine followed by surgery (arm A, 43 patients) or capecitabine plus oxaliplatin followed by surgery (arm B, 30 patients). The main endpoints of the study were pathologic complete response (pCR) rate, overall survival (OS) and disease-free survival (DFS). The secondary endpoints included the sphincter preservation rate and safety. The pCR for arms A and B were 28% and 17% (P = 0.267). In arms A and B, the mean OS was 84.287 months (95% CI 68.413-100.160) and 106.333 months (95% CI 99.281-113.386) (P = 0.185); the mean DFS was 72.812 months (95% CI 56.271-89.353) and 95.073 months (95% CI 83.392-106.754) (P = 0.310); and the sphincter preservation rates were 72% and 67%, respectively (P = 0.619). The incidence of grade 3 toxicity was much higher in arm B than in arm A (57% vs. 21%, P = 0.002). Adding oxaliplatin to a preoperative CRT regimen for LARC did not improve the survival benefits of patients or increase toxicity.

Strategy to avoid local recurrence in patients with locally advanced rectal cancer

Background

To clarify the short- and long-term outcomes of radical surgery after neoadjuvant chemoradiotherapy (NCRT) with TS-1 and irinotecan, which enhances radiosensitivity, in patients with locally advanced rectal cancer.

Methods

The study group comprised 105 patients with locally advanced rectal cancer who received NCRT followed by radical surgery. NCRT consisted of pelvic radiotherapy (45 Gy in 25 fractions over a period of 5 weeks), S-1 (80 mg/m²) given concurrently for 25 days, and irinotecan (60 mg/m²), given once a week as a continuous intravenous infusion. Radical surgery was performed 8 weeks after treatment.

Results

A pathological complete response was confirmed in 23.8%. The 5-year recurrence-free survival rate was 79.3%, and the 5-year overall survival rate was 87.1%. Multivariate analysis showed that the following 4 variables were independent predictors of recurrence-free survival: Sex (male: p = 0.0172), Pre-treatment tumor diameter (< 40 mm: p = 0.0223), Histopathological treatment response (grade 0,1: p = 0.0169), and ypN (ypN1: p = 0.1995; ypN2: p = 0.0007). Only ypN was an independent predictor of overall survival (ypN1: p = 0.0009; ypN2: p = 0.0012).

Conclusions

Our treatment strategy combining TS-1 with irinotecan to increase radiosensitivity had a high response rate.

Optimal treatment strategy for rectal cancer based on the risk factors for recurrence patterns

BACKGROUND

For rectal cancer, multimodality therapeutic approach is necessary to prevent local recurrence and distant metastasis. However, the efficacy of additional treatments, such as neoadjuvant chemoradiotherapy (nCRT), neoadjuvant chemotherapy (NAC), and lateral pelvic lymph node dissection (LPLND), has not been scrutinized.

METHODS

Recurrence patterns were categorized into local recurrence and distant metastasis. Local recurrence was classified into two types: (1) pelvic cavity recurrence and (2) LPLN recurrence. First, we analyzed the risk factors for each recurrence pattern. Second, based on the status of clinically suspected involvement of circumferential resection margin (cCRM), the efficacy of additional treatments was investigated.

RESULTS

A total of 240 patients was enrolled. nCRT was performed for 25 (10%), NAC was for 46 (19%), and LPLND was for 35 patients (15%). As the recurrence patterns, pelvic cavity recurrence occurred in 15 (6%), LPLN recurrence in 8 (3%), and distant metastasis in 42 patients (18%). Five-year overall survival and relapse-free survival were 87% and 70%, respectively. Multivariate analysis indicated that pelvic cavity recurrence was associated with cCRM status and tumor histology, that LPLN recurrence was with serum carcinoembryonic antigen level and LPLN swelling, and that distant metastasis was with clinical N category. In the cCRM-positive subgroup (n = 66), cumulative rate of pelvic cavity recurrence was lower in the nCRT group than in the NAC or non-NAC/nCRT group (P = 0.02 and 0.09, respectively).

CONCLUSION

cCRM status was associated with pelvic cavity recurrence, and LPLN swelling was with LPLN recurrence. nCRT could reduce pelvic cavity recurrence in cCRM-positive subgroup.

Clinicopathological outcomes of preoperative chemoradiotherapy using S-1 plus Irinotecan for T4 lower rectal cancer

PURPOSE

To investigate the clinicopathological outcomes of patients with T4 lower rectal cancer treated using preoperative chemoradiotherapy with S-1 plus Irinotecan.

METHODS

Between 2005 and 2011, 35 patients with T4M0 lower rectal cancer, diagnosed initially as T4a in 12 and as T4b in 23, were treated with 45 Gy of radiotherapy concomitantly with S-1 plus Irinotecan. The median follow-up period was 50.6 months (range 2-123 months).

RESULTS

A total of 32 patients (91.4 %) completed the radiotherapy and 26 (74.3 %) completed the full chemotherapy regimen. Radical surgery was then performed in 33 (94.3 %) of the 35 patients after the exclusion of two patients, who had macroscopic residual disease. The pathological diagnosis was downstaged from T4a to ypT0-3 in all 12 of those patients (100 %) and from T4b to ypT0-4a in 20 of those 23 patients (87.0 %). The tumor regression grade of 1a/1b/2/3 (complete response) was 10/8/15/2, respectively. In terms of long-term survival, the 5-year local relapse-free survival rate was 74.8 % and the recurrence-free survival rate was 52.0 %.

CONCLUSIONS

This regimen may result in favorable downstaging. Moreover, in this series, pathological evidence of involvement of adjacent organs was rare following preoperative chemoradiotherapy, in the patients with disease diagnosed as T4b at the initial staging.

Comparison of the pathological response of the mesorectal positive nodes between short-course chemoradiotherapy with delayed surgery and long-course chemoradiotherapy in patients with rectal cancer

BACKGROUND

The aim of this study was to compare the pathological response of mesorectal positive nodes between short-course chemoradiotherapy with delayed surgery (SCRT-delay) and long-course chemoradiotherapy (LC-CRT) in patients with rectal cancer.

METHOD

The resected primary tumor specimens following the two different approaches were assessed utilizing the tumor regression grade (TRG 0-4), and each positive lymph node was assessed according to the lymph node regression grade (LRG 1-3), with TRG 4 and LRG 3 indicating total regression. The lymph node sizes were measured to elucidate any correlation with LRG scores.

RESULTS

Seventy-four patients with ypN-positive rectal cancer had 220 positive lymph nodes following the SCRT-delay, and 48 patients had 141 positive lymph nodes following the LC-CRT. The distribution of LRG 1/2/3 in the two groups was 123/72/25 and 60/31/50 (p < 0.001), respectively, and the distribution of TRG 0/1/2/3/4 in the two groups was 36/19/19/0 and 12/15/20/1 (p = 0.005), respectively. The requirements of total regression of positive lymph nodes were a primary tumor degenerated to TRG 3 with a size less than 6 mm in SCRT-delay (sensitivity, 60.9 %) or a primary tumor degenerated to TRG 2-4 with a size less than 5 mm at TRG 2 (sensitivity, 57.6 %) or 6 mm at TRG 3 and 4 (sensitivity, 84.2 %) in LC-CRT as indicated by the receiver operating characteristic curve analysis.

CONCLUSION

The tumor regression effect of LC-CRT on the primary tumor and positive nodes was more favorable than SCRT-delay, and LC-CRT is able to predict the LRG 3 response with a high sensitivity.

Short-course radiotherapy with delayed surgery versus conventional chemoradiotherapy: A comparison of the short- and long-term outcomes in patients with T3 rectal cancer

INTRODUCTION

The aim of this study was to compare the short- and long-term outcomes between short-course radiotherapy with delayed surgery (SRT-delay) and a standard conventional chemoradiotherapy (CRT) regimen.

METHODS

Two collaborating institutions adopted different regimens; the SRT-delay regimen was selected by Meiwa Hospital and the CRT regimen was selected by Hyogo College of Medicine. The inclusion criteria were T3 middle and low rectal cancer patients treated with radical surgery after preoperative therapy. The median follow-up period was 44 months (range, 12-85).

RESULTS

From 2007 to 2013, 104 patients were treated using the SRT-delay regimen and 61 patients were treated using the CRT regimen. The pretreatment characteristics of the 2 groups were not significantly different. The sphincter-preserving rate (93.3%, 85.2%), T downstaging (37.5%, 37.7%), ypN(-) (74.0%, 67.2%), postoperative complications and the bowel, and urinary and sexual functioning of the SRT-delay regimen were noninferior to those of the CRT regimen. The 3-year local recurrence-free survival, recurrence-free survival, and overall survival in the SRT-delay and CRT groups were 90.6% and 90.6% (P = .764), 83.8% and 78.3% (P = .687) and 96.0% and 92.8% (P = .833), respectively.

CONCLUSION

The SRT-delay regimen was noninferior in terms of the downstaging effect, and oncologic and functional outcomes compared with the CRT regimen for T3 middle and low rectal cancer.

Phase I trial of neoadjuvant preoperative chemotherapy with S-1, oxaliplatin, and bevacizumab plus radiation in patients with locally advanced rectal cancer

BACKGROUND

This phase I study was performed to determine the maximum tolerated dose (MTD), recommended dose (RD), and dose-limiting toxicities (DLTs) of oxaliplatin combined with preoperative chemoradiotherapy with S-1, oxaliplatin, and bevacizumab in locally advanced rectal cancer.

METHODS

Eligible patients had a newly diagnosed clinical stage T1-4 N0-3 M0 rectal adenocarcinoma within 12 cm of the anal verge suitable for curative resection. Conformal radiation therapy was given (4 fields, 2 Gy daily fractions, 5 days/week, total dose 40 Gy) with concurrent S-1 (80 mg/m(2)/day orally, days 1-5, 8-12, 15-19, and 22-26), bevacizumab (90 min continuous intravenous infusion at 5 mg/kg, days 1 and 15), and oxaliplatin (120 min continuous intravenous infusion, days 1, 8, 15, and 22). The initial oxaliplatin dose (40 mg/m(2)/day) was gradually increased to determine the MTD and RD. Surgery was performed 6 weeks after completion of preoperative chemoradiotherapy.

RESULTS

11 patients were enrolled. The MTD of oxaliplatin was considered to be 60 mg/m(2), because three of five patients developed DLTs such as diarrhea and hives. The recommended dose of oxaliplatin was set at 50 mg/m(2). Of the patients who received oxaliplatin at ≤ RD, 5 (83.3%) had a clinical response [four pathological responses and one pathological complete response (Grade 3)].

CONCLUSIONS

With this new regimen, the MTD of oxaliplatin was 60 mg/m(2), and the RD for phase II studies was 50 mg/m(2). This new regimen appears to provide worthwhile outcomes for locally advanced rectal cancer and merits a phase II study.

Neoadjuvant chemoradiation therapy using concurrent S-1 and irinotecan in rectal cancer: impact on long-term clinical outcomes and prognostic factors

PURPOSE

To assess the long-term outcomes of patients with rectal cancer who received neoadjuvant chemoradiation therapy (NCRT) with concurrent S-1 and irinotecan (S-1/irinotecan) therapy.

METHODS AND MATERIALS

The study group consisted of 115 patients with clinical stage T3 or T4 rectal cancer. Patients received pelvic radiation therapy (45 Gy) plus concurrent oral S-1/irinotecan. The median follow-up was 60 months.

RESULTS

Grade 3 adverse effects occurred in 7 patients (6%), and the completion rate of NCRT was 87%. All 115 patients (100%) were able to undergo R0 surgical resection. Twenty-eight patients (24%) had a pathological complete response (ypCR). At 60 months, the local recurrence-free survival was 93%, disease-free survival (DFS) was 79%, and overall survival (OS) was 80%. On multivariate analysis with a proportional hazards model, ypN2 was the only independent prognostic factor for DFS (P=.0019) and OS (P=.0064) in the study group as a whole. Multivariate analysis was additionally performed for the subgroup of 106 patients with ypN0/1 disease, who had a DFS rate of 85.3%. Both ypT (P=.0065) and tumor location (P=.003) were independent predictors of DFS. A combination of these factors was very strongly related to high risk of recurrence (P<.0001), which occurred most commonly in the lung.

CONCLUSIONS

NCRT with concurrent S-1/irinotecan produced high response rates and excellent long-term survival, with acceptable adverse effects in patients with rectal cancer. ypN2 is a strong predictor of dismal outcomes, and a combination of ypT and tumor location can identify high-risk patients among those with ypN0/1 disease.

A phase I trial of S-1 with concurrent radiotherapy in patients with locally recurrent rectal cancer

BACKGROUND

The purpose of this phase I trial of S-1 chemotherapy in combination with pelvic radiotherapy for locally recurrent rectal cancer was to determine the maximum tolerated dose (MTD), recommended dose (RD), and dose-limiting toxicity (DLT) of S-1.

METHODS

We enrolled 9 patients between April 2005 and March 2009. Radiotherapy (total dose, 60 Gy in 30 fractions) was given to the gross local recurrent tumor and pelvic nodal metastases using three-dimensional radiotherapy planning. We administered oral S-1 twice a day on days 1-14 and 22-35 during radiotherapy. The dose of S-1 was initially 60 mg/m(2)/day and was increased to determine the MTD and RD for this regimen.

RESULTS

DLT appeared at dose level 2 (70 mg/m(2)/day) in 2 patients, who experienced grade 3 enterocolitis and consequently required suspension of S-1 administration for longer than 2 weeks. Hematological toxicity was mild and reversible. At the initial evaluation, complete regression and partial regression were seen in 1 patient (11%) and 2 patients (22%), respectively.

CONCLUSION

This phase I trial of S-1 chemotherapy with pelvic radiotherapy for locally recurrent rectal cancer revealed that the MTD for S-1 was 70 mg/m(2)/day and the RD was 60 mg/m(2)/day.

The prospective role of plant products in radiotherapy of cancer: a current overview

Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Efforts are going on to find chemical compounds which would effectively offer protection to the normal tissues after radiation exposure during radiotherapy of cancer. In this regard, plant-derived compounds might serve as “leads” to design ideal radioprotectors/radiosensitizers. This article reviews some of the recent findings on prospective medicinal plants, phytochemicals, and their analogs, based on both in vitro and in vivo tumor models especially focused with relevance to cancer radiotherapy. Also, pertinent discussion has been presented on the molecular mechanism of apoptotic death in relation to the oxidative stress in cancer cells induced by some of these plant samples and their active constituents.

Genetic alterations of K-ras may reflect prognosis in stage III colon cancer patients below 60 years of age

PURPOSE

Genetic alterations that are closely associated with patient prognosis can be landmarks of definitive therapeutic targets as well as useful biomarkers in human cancer clinics.

METHODS

Three hundred seventy-eight colorectal cancer (CRC) patients were examined for K-ras mutations by single-strand conformation polymorphism (SSCP), with a subsequent 144 young colon cancer (YCC) patients added to validate its prognostic significance.

RESULTS

K-ras mutations were identified in 161 (43%) of the 378 CRC patients and were significantly associated with tumor location (colon vs. rectum; 80/218 = 37% vs. 81/160 = 51%; P = 0.0068) and age (≥60 vs. <60; 103/220 = 47% vs. 58/158 = 37%; P = 0.049). The incidence of K-ras mutations was 30% in YCC patients as compared to 55% in elderly rectal cancer patients (P = 0.0004). K-ras mutations significantly correlated with a worse prognosis (P = 0.0014) only in 73 curatively resected YCC with stages I-III, but not in other CRCs, which was further validated in the independent set of the corresponding 144 YCC patients (P = 0.024). Both univariate and multivariate analyses identified K-ras mutations as an independent prognostic factor (HR = 5.5, P = 0.029; HR = 3.6, P = 0.011) in both learning and validation sets of the curatively resected YCC with stages I-III, respectively, and the prognostic relevance was marked in stage III YCC patients (P = 0.002), but not in stages I, II, and IV.

CONCLUSION

In curative YCC, K-ras mutations could have excellent prognostic value. Hence, the K-ras mutation status could be a good indicator to predict the clinical outcome in curatively resected stage III YCC patients, and K-ras pathway inhibition may be a relevant therapeutic target in CRC, excluding YCC patients with no K-ras mutation.

A Phase II trial of neoadjuvant preoperative chemoradiotherapy with S-1 plus irinotecan and radiation in patients with locally advanced rectal cancer: clinical feasibility and response rate

PURPOSE

We aimed to validate our hypothesis that a preoperative chemoradiotherapy regimen with S-1 plus irinotecan is feasible, safe, and active for the management of locally advanced rectal cancer in a single-arm Phase II setting.

METHODS AND MATERIALS

Eligible patients had previously untreated, locally advanced rectal adenocarcinoma. Radiotherapy was administered in fractions of 1.8 Gy/d for 25 days. S-1 was administered orally in a fixed daily dose of 80 mg/m2 on Days 1 to 5, 8 to 12, 22 to 26, and 29 to 33. Irinotecan (80 mg/m2) was infused on Days 1, 8, 22, and 29. Four or more weeks after the completion of the treatment, total mesorectal excision with lateral lymph node dissection was performed. The primary endpoint was the rate of completing treatment in terms of feasibility. The secondary endpoints were the response rate and safety.

RESULTS

We enrolled 43 men and 24 women in the study. The number of patients who completed treatment was 58 (86.6%). Overall, 46 patients (68.7%) responded to treatment and 24 (34.7%) had a complete histopathologic response. Three patients had Grade 3 leukopenia, and another three patients had Grade 3 neutropenia. Diarrhea was the most common type of nonhematologic toxicity: 3 patients had Grade 3 diarrhea.

CONCLUSIONS

A preoperative regimen of S-1, irinotecan, and radiotherapy to the rectum was feasible, and it appeared safe and effective in this nonrandomized Phase II setting. It exhibited a low incidence of adverse events, a high rate of completion of treatment, and an extremely high rate of pathologic complete response.

Phase I study of preoperative chemoradiation with s-1 and oxaliplatin in patients with locally advanced resectable rectal cancer

PURPOSE

To perform a Phase I study of preoperative chemoradiation (CRT) with S-1, a novel oral fluoropyrimidine, plus oxaliplatin in patients with locally advanced rectal cancer, to determine the maximum tolerated dose and the recommended dose.

METHODS AND MATERIALS

Radiotherapy was delivered to a total of 45 Gy in 25 fractions and followed by a coned-down boost of 5.4 Gy in 3 fractions. Concurrent chemotherapy consisted of a fixed dose of oxaliplatin (50 mg/m2/week) on Days 1, 8, 22, and 29 and escalated doses of S-1 on Days 1-14 and 22-35. The initial dose of S-1 was 50 mg/m2/day, gradually increasing to 60, 70, and 80 mg/m2/day. Surgery was performed within 6±2 weeks.

RESULTS

Twelve patients were enrolled and tolerated up to Dose Level 4 (3 patients at each dose level) without dose-limiting toxicity. An additional 3 patients were enrolled at Dose Level 4, with 1 experiencing a dose-limiting toxicity of Grade 3 diarrhea. Although maximum tolerated dose was not attained, Dose Level 4 (S-1 80 mg/m2/day) was chosen as the recommended dose for further Phase II studies. No Grade 4 toxicity was observed, and Grade 3 toxicities of leukopenia and diarrhea occurred in the same patient (1 of 15, 6.7%). Pathologic complete responses were observed in 2 of 15 patients (13.3%).

CONCLUSIONS

The recommended dose of S-1 was determined to be 80 mg/m2/day when combined with oxaliplatin in preoperative CRT, and a Phase II trial is now ongoing.

Phase II study of preoperative chemoradiotherapy (CRT) with irinotecan plus S-1 in locally advanced rectal cancer

BACKGROUND AND PURPOSE

The aim of this study is to evaluate the efficacy and safety of preoperative radiation therapy combined with S-1 and irinotecan (SI) in LARC.

MATERIALS AND METHODS

Patients were considered LARC if they had a T3/T4 lesion or node positive. Weekly doses of 40 mg/m(2) irinotecan were intravenously administered once per week during weeks 1-5 of radiotherapy. S-1 (70 mg/m(2)) was given from Monday to Friday in all weeks of radiotherapy. 3-D conformal radiotherapy was given at daily fractions of 1.8Gy for 5days for a total dose of 50.4 (45+5.4)Gy. Surgery was performed 4-6 weeks following the completion of chemoradiation.

RESULTS

Between June 2006 and November 2007, 43 pts were enrolled. The stage was: cT3 24 patients, cT4 6 patients; 28 patients were cN+. Forty-one patients completed the chemoradiation and 42 patients underwent operation: a low anterior resection was performed in 36 patients, a total colectomy in 1 patient, and an abdominal perineal resection in 5 patients. T downstaging was observed in 50%; 23 N+ patients became N- (55%). The complete pathological response was observed in 9 patients (21%). The 3-year locoregional failure rate, distant failure rate, disease-free survival, and overall survival were 9.5%, 18.6%, 72.1%, and 94.3%, respectively. Only three patients experienced G3 diarrhea; one had G3 sepsis and two had septic shock. Hematological toxicity (G3-G4) was observed in five patients.

CONCLUSIONS

This study demonstrated the efficacy of preoperative CRT with S-1 and irinotecan with 21% of complete response. However, prompt recognition and management of infection is needed to use it in patients with locally advanced rectal cancer.

High Ki67, Bax, and thymidylate synthase expression well correlates with response to chemoradiation therapy in locally advanced rectal cancers: proposal of a logistic model for prediction

Background:

Recently, preoperative chemoradiation therapy (CRT) for rectal cancer has been increasingly used as a neoadjuvant treatment. In the present study, the relation between histological response to CRT and immunohistochemical markers in biopsy specimens was investigated.

Methods:

Biopsy specimens from a total of 60 patients were collected before preoperative CRT with S-1 and irinotecan, and liniac 45 Gy. Immunohistochemical staining for Ki67, Mcm3, Bax, Bcl-2, ssDNA, Grp78, thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), CD34, vascular endothelial growth factor, nestin, and L-type amino-acid transporter 1 was performed to allow comparison of the Ki67 labelling index (LI), Bax score, TS score, DPD score, microvessel density by CD34, and Grp78 score with cancer regression.

Results:

When the cases were divided into responders (Dworak grades 3 and 4) and non-responders (grades 1 and 2) groups, good correlations were evident with Ki67 LI, Bax, Grp78, and TS expression. On multiple logistic regression analysis, Ki67 LI, Bax, and TS scores were found to be independent factors. With their use in a logistic model, P-values could predict responder cases with a sensitivity of 82.8% and a specificity of 83.9%.

Conclusion

Using this system, treatment strategy for locally advanced rectal cancers can be determined before chemoradiation.