A prospective feasibility study to evaluate neoadjuvant-synchronous S-1 with radiotherapy for locally advanced rectal cancer: A multicentre phase II trial

Tolerability and Safety Assessment of Adjuvant Chemoradiotherapy with S-1 after Limited Surgery for T1 or T2 Lower Rectal Cancer

BACKGROUND

The short-term outcomes of chemoradiotherapy (CRT) with S-1 (a combination of tegafur, gimeracil, and oteracil) following limited surgery for patients with T1 or T2 lower rectal cancer have shown encouraging results.

OBJECTIVES

This study was designed to delve deeper into the long-term outcomes of CRT with S-1 after limited surgery, with the goal of evaluating both the long-term efficacy and potential risks associated with this treatment approach in patients diagnosed with T1 or T2 lower rectal cancer.

METHODS

This was conducted as a multicenter, single-arm, prospective phase II trial. The patient population consisted of individuals clinically diagnosed with either T1 or T2 lower rectal or anal canal cancer, with a maximum tumor diameter of 30 mm and classified as N0 or M0. Patients underwent local excision or endoscopic resection. After surgery, CRT with S-1 was administered to patients meeting several criteria, including the confirmation of well-differentiated or moderately differentiated adenocarcinoma, negative surgical margins, submucosal invasion depth of ≥1000 µm, and high tumor-budding grade (2/3). The primary endpoint of this study was relapse-free survival, while secondary endpoints included local recurrence-free survival, overall survival, anal sphincter preservation rate, and safety.

RESULTS

A total of 52 patients were included, with pathological diagnoses revealing T1 in 36 patients and T2 in 16 patients. The 3-year and 5-year relapse-free survival rates were 90.17% and 85.87%, respectively. The 3-year and 5-year local recurrence-free survival rates were 90.17% and 88.07%, respectively, while the 3-year and 5-year overall survival rates were 94.03% and 91.94%, respectively.

CONCLUSIONS

CRT with S-1 after limited surgery for T1 lower rectal cancer demonstrated favorable outcomes in terms of recurrence, survival, and local control rates while effectively maintaining anal function in patients. However, further treatment approaches may be necessary to improve outcomes for patients diagnosed with stage T2 lower rectal cancer.

Efficacy and safety of preoperative chemoradiotherapy with S-1 for advanced rectal cancer: a phase II study

Background

Preoperative chemoradiotherapy (CRT) for patients with rectal cancer is not yet established in Japan. We aimed to evaluate the efficacy and safety of preoperative CRT with S-1, a fixed-dose combination of tegafur, gimeracil, and oteracil potassium.

Materials and methods

We conducted a prospective, interventional, non-randomized single-center study. Radiotherapy was administered at a total dose of 45 Gy (1.8 Gy in 25 fractions) for five weeks. S-1 was administered orally for nine weeks (five weeks during and four weeks after radiotherapy) at a dose of 80 mg/m²/day. The endpoint was the pathological complete response (pCR) rate.

Results

Twenty-eight patients were finally enrolled. The following patient characteristics were recorded: clinical Stage (II: n = 12, III: n = 16), median age (66 years, range 40-77 years), male/female ratio (20/8), and lesion site (Ra-Rb:3/Rb:23/Rb-P:2). Preoperative treatment was completed in 27 patients (96%). Treatment abandonment occurred because of diarrhea. Grade 3 or higher adverse events were observed in one (4%) patient with two events. No serious adverse events occurred in the ≥ 70 years group. The response rate was 68% in all patients and 68% among elderly patients. Radical resection was achieved in all patients, including 19 (68%) who underwent sphincter-preserving surgery. The pCR rate was 11% (three patients). The five-year disease-free survival rate was 68%, and the overall survival rate was 82%. Local recurrence occurred in only one patient five years after surgery.

Conclusion

Preoperative CRT with S-1 alone may be a safe and acceptable regimen from the perspective of adverse events and oncological outcomes.

Trial registration

UMIN Clinical Trial Registry: UMIN000013598. Registered 1 April 2014, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recpt-no=R000015887.

Tolerability and safety of adjuvant chemoradiotherapy with S-1 after limited surgery for T1 or T2 lower rectal cancer

BACKGROUND

Chemo-radiotherapy (CRT) after local excision for pT1 with high-risk features or pT2 rectal cancer is recommended as an optional treatment to achieve both curability and maintenance of quality of life. The aim of this study was to evaluate the short-term safety of combining limited surgery with adjuvant CRT for T1 or T2 lower rectal cancer.

METHODS

This was a multicenter, single-arm, prospective phase II trial. Patients diagnosed with lower rectal or anal canal cancer (clinical T1 or T2 with a maximum diameter of 30 mm and N0 and M0) underwent local excision or endoscopic resection. Patients received CRT with S-1 (tegafur/gimeracil/oteracil) after confirmation of well- or moderately differentiated adenocarcinoma, and negative margins, and/or depth of submucosal invasion ≥ 1000 µm or muscularis propria, and/or positive lymphovascular invasion, and/or tumor budding grade of 2/3. The primary endpoint was relapse-free survival. Secondary endpoints included overall and local relapse-free survival, safety, anal sphincter preservation rate, and anal function.

RESULTS

Pathological diagnosis was T1 in 36 patients and T2 in 16 patients. Serious complications after surgery were not reported. The CRT completion rate per protocol was 86.5% (45/52). Thirty-two patients developed 54 events of CRT-related adverse events, including only one patient with a grade 3 event (stomatitis). The most common CRT-related adverse event was diarrhea (n = 14). No patients showed deterioration of anal function at 3 years postoperatively.

CONCLUSION

CRT with S-1 after limited surgery for T1 or T2 lower rectal cancer resulted in a low incidence of toxicities and maintenance of anal function.

p62 is a useful predictive marker for tumour regression after chemoradiation therapy in patients with advanced rectal cancer: an immunohistochemical study

AIM

This study aimed to evaluate the relationship between p62 expression status and tumour regression grade in advanced rectal cancer.

METHODS

We enrolled 47 consecutive patients with advanced rectal cancer who underwent chemoradiation therapy (CRT) before surgery. p62 expression in the biopsy specimens was immunohistochemically evaluated, and p62 expression score (staining intensity × positive tumour cells, %) was calculated (range 0-300). The relationship between p62 expression score and CRT effect was analysed.

RESULTS

The staining intensity was +2 and +3 in 29 and 18 patients, respectively. The median proportion of positive neoplastic cells was 87.8%, and that of the p62 expression score was 200. Stronger staining intensity and a higher proportion of p62-positive neoplastic cells were significantly associated with CRT non-effectiveness (P = 0.0002 and P = 0.0116, respectively), and a higher p62 expression score was significantly associated with CRT non-effectiveness (P < 0.0001). The optimal cut-off value for predicting the CRT effect was 240.

CONCLUSIONS

A higher p62 expression score was significantly associated with less CRT effectiveness in patients with advanced rectal cancer. Analysis of p62 expression score using biopsy specimens is a useful and easily assessable prediction marker for CRT effect and might help select patients who can undergo a 'watch-and-wait' strategy after CRT.

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.

Effect of S-1 on blood levels of phenobarbital and phenytoin: A case report

Drug-drug interaction of fluorinated pyrimidine anticancer agents with phenytoin is well known, but interaction with phenobarbital is limited. We describe a case showing increases in plasma phenobarbital as well as phenytoin concentrations during preoperative S-1 (tegafur/gimeracil/oteracil) and radiation therapy for rectal cancer.

A multicenter phase II trial of preoperative chemoradiotherapy with S-1 plus oxaliplatin and bevacizumab for locally advanced rectal cancer

BACKGROUND

We clarified the safety and efficacy of preoperative chemoradiotherapy for locally advanced rectal cancer using a multidrug regimen (S-1 + oxaliplatin + bevacizumab).

METHODS

This multicenter phase II trial involved 47 patients with locally advanced rectal cancer. All patients received S-1 orally (80 mg/m²/day on days 1-5, 8-12, 15-19, and 22-26) and infusions of oxaliplatin (50 mg/m² on days 1, 8, 15, and 22) and bevacizumab (5 mg/kg on days 1 and 15). The total radiation dose was 40 Gy delivered in daily fractions of 2 Gy via the four-field technique. The primary endpoint was the pathological complete response rate. The secondary endpoints were safety (incidence of adverse events) and clinical response, relapse-free survival, overall survival, local recurrence, R0 resection, downstaging, and treatment completion rates.

RESULTS

All 47 patients received chemoradiotherapy, and 44 patients underwent curative resection. Two patients refused surgery and selected a watch-and-wait strategy. The pathological complete response rate was 18.2% in patients who underwent curative resection. The clinical response rate was 91.3% in 46 patients. Concerning hematotoxicity, there was one grade 4 adverse event (2.1%) and seven grade 3 events (14.9%). Diarrhea was the most frequent non-hematotoxic event, and the grade 3 event rate was 25.5%.

CONCLUSIONS

Although preoperative chemoradiotherapy for patients with locally advanced rectal cancer using the S-1 + oxaliplatin + bevacizumab regimen did not achieve the expected pathological complete response rate, this regimen led to an improved clinical response rate.

Short-term outcomes of preoperative chemoradiotherapy with S-1 for locally advanced rectal cancer

The purpose of the present study was to evaluate the short-term results of preoperative chemoradiation therapy with S-1 for locally advanced rectal cancer. A total of 32 patients with advanced rectal cancer who had been treated with preoperative chemoradiotherapy with S-1 and underwent surgical resection between May 2012 and December 2019 were analyzed. Advanced rectal cancer of clinical stage II and III was diagnosed in 13 (41%) and 19 (59%) patients, respectively. Therapeutic toxicities of anemia (24 patients; 75%), anal pain (22 patients; 69%) and skin and subcutaneous tissue disorders (19 patients; 59%) were frequently observed in all grades. Grade ≥3 leukopenia, anemia, neutrophil count reduction, platelet count reduction and diarrhea were identified in 2 (6%), 1 (3%), 1 (3%), 1 (3%) and 1 (3%) patients, respectively. A total of 29 patients (91%) completed this therapy without any change to the protocol or dosage. R0 resection was performed in 100% of the patients, and no postoperative mortality was observed. Pathological complete response was observed in 9 cases (28.1%). This therapy can be considered for cases of locally advanced rectal cancer due to its acceptable toxicity and relatively high antitumor effect.

Preoperative chemoradiotherapy using S-1 combined with celecoxib for advanced lower rectal cancer: Phase I/II study

OBJECTIVES

To clarify the safety and efficacy of celecoxib combined with chemoradiotherapy using S-1 for lower rectal cancer.

METHODS

Twenty-one patients with pathologically proven lower rectal adenocarcinoma (cT3-T4, Tx N+, M0) were included in this study. A total dose of 45 Gy was administered in daily fractions of 1.8 Gy. Celecoxib was given orally twice daily with S-1 on the day of irradiation. The dose of celecoxib was set at 400 mg/day. In Phase I, the S-1 dose was started at 80 mg/m²/day; in Phase II, S-1 was administered in the same dose as Phase I. Patients underwent surgery six to eight weeks after completing chemoradiotherapy, followed by six months of postoperative adjuvant chemotherapy.

RESULTS

The S-1 recommended dose was 80 mg/m²/day. The pathological complete remission rate was 15.8%, the rate of protocol completion was 14.3%, and the rate of adverse events exceeding Grade 3 was 19.0%. Surgery was performed in 19 cases, with a sphincter-sparing rate of 31.6%. Postoperative complications exceeding Grade 3 occurred in 52.4% of cases. The three year overall survival and relapse-free survival rates were 89.3% and 67.0%, respectively.

CONCLUSIONS

We failed to show a synergistic or additive therapeutic effect of preoperative CRT using S-1, combined with celecoxib, for lower advanced rectal cancer beyond CRT using 5 FU or capecitabine alone. The incidence of complications, evidently involving intestinal ischemia, was relatively high. This treatment strategy is not recommended at present.

Long-term outcomes of neoadjuvant-synchronous S-1 plus radiotherapy for locally advanced rectal cancer: a multi-institutional prospective phase II study

Objectives: This study aimed to evaluate the long-term outcomes of neoadjuvant chemoradiotherapy with S-1 in patients with locally advanced rectal cancer. Methods: A multi-institutional, prospective, phase II trial was conducted between April 2009 and August 2011. The study enrolled 37 patients with histologically proven rectal carcinoma (T3-4 N0-3 M0) who underwent neoadjuvant chemoradiotherapy with S-1. Total mesorectal excision with D3 lymphadenectomy was performed 4-8 weeks after completion of neoadjuvant chemoradiotherapy with S-1 in 36 patients. We then analyzed late adverse events, overall survival, and disease-free survival. Results: The median patient age was 59 years (range: 32-79 years); there were 24 men and 13 women. Ten patients had Stage II disease, and 27 had Stage III disease. Severe late adverse events occurred in 7 patients (18.9%). The 5-year disease-free survival was 66.7%, and the 5-year overall survival was 74.7%. The median follow-up period was 57 months. Local recurrences developed in 5 patients (13.5%), and distant metastases developed in 8 (21.6%). Conclusion: Neoadjuvant-synchronous chemoradiotherapy with S-1 for locally advanced rectal cancer is feasible in terms of adverse events and long-term outcomes. (UMIN Clinical Trial Registry: UMIN000003396)

An 80-gene set to predict response to preoperative chemoradiotherapy for rectal cancer by principle component analysis

Preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer not only improves the postoperative local control rate, but also induces downstaging. However, it has not been established how to individually select patients who receive effective preoperative CRT. The aim of this study was to identify a predictor of response to preoperative CRT for locally advanced rectal cancer. This study is additional to our multicenter phase II study evaluating the safety and efficacy of preoperative CRT using oral fluorouracil (UMIN ID: 03396). From April, 2009 to August, 2011, 26 biopsy specimens obtained prior to CRT were analyzed by cyclopedic microarray analysis. Response to CRT was evaluated according to a histological grading system using surgically resected specimens. To decide on the number of genes for dividing into responder and non-responder groups, we statistically analyzed the data using a dimension reduction method, a principle component analysis. Of the 26 cases, 11 were responders and 15 non-responders. No significant difference was found in clinical background data between the two groups. We determined that the optimal number of genes for the prediction of response was 80 of 40,000 and the functions of these genes were analyzed. When comparing non-responders with responders, genes expressed at a high level functioned in alternative splicing, whereas those expressed at a low level functioned in the septin complex. Thus, an 80-gene expression set that predicts response to preoperative CRT for locally advanced rectal cancer was identified using a novel statistical method.