Efficacy of S-1 in colorectal cancer

Oral drugs in the treatment of metastatic colorectal cancer

Colorectal cancer (CRC) is one of the most common forms of cancer, with an estimated 1.36 million new cases and almost 700,000 deaths annually. Approximately 21% of patients with CRC have metastatic disease at diagnosis. The objective of this article is to review the literature on the efficacy and safety of oral drugs available for the treatment of metastatic colorectal cancer (mCRC). Several such drugs have been developed, and fluoropyrimidines are the backbone of chemotherapy in this indication. They exert their antitumour activity by disrupting the synthesis and function of DNA and RNA. Oral fluoropyrimidines include prodrugs capecitabine, tegafur, eniluracil/5-fluorouracil, tegafur/uracil, tegafur/gimeracil/oteracil and trifluridine/tipiracil (FTD/TPI). Oral drugs offer several advantages over injectable formulations, including convenience, flexibility, avoidance of injection-related adverse events (AEs) and, in some circumstances, lower costs. However, oral drugs may not be suitable for patients with gastrointestinal obstruction or malabsorption, they may result in reduced treatment adherence and should not be co-administered with drugs that interfere with absorption or hepatic metabolism. Oral fluoropyrimidines such as capecitabine, as monotherapy or in combination with oxaliplatin, irinotecan or bevacizumab, are as effective as intravenous 5-fluorouracil (5-FU) in first-line treatment of mCRC. Other oral fluoropyrimidines, such as FTD/TPI, are effective in patients with mCRC who are refractory, intolerant or ineligible for 5-FU. In addition, oral fluoropyrimidines are used in adjuvant treatment of mCRC. Regorafenib is an oral multikinase inhibitor used in patients in whom several previous lines of therapy have failed. Frequent AEs associated with oral drugs used in the treatment of CRC include hand-foot syndrome and gastrointestinal and haematological toxicities.

5-fluorouracil and other fluoropyrimidines in colorectal cancer: Past, present and future

5-Fluorouracil (5-FU) is an essential component of systemic chemotherapy for colorectal cancer (CRC) in the palliative and adjuvant settings. Over the past four decades, several modulation strategies including the implementation of 5-FU-based combination regimens and 5-FU pro-drugs have been developed and tested to increase the anti-tumor activity of 5-FU and to overcome the clinical resistance. Despite the encouraging progress in CRC therapy to date, the patients' response rates to therapy continue to remain low and the patients' benefit from 5-FU-based therapy is frequently compromised by the development of chemoresistance. Inter-individual differences in the treatment response in CRC patients may originate in the unique genetic and epigenetic make-up of each individual. The critical element in the current trend of personalized medicine is the proper comprehension of causes and mechanisms contributing to the low or lack of sensitivity of tumor tissue to 5-FU-based therapy. The identification and validation of predictive biomarkers for existing 5-FU-based and new targeted therapies for CRC treatment will likely improve patients' outcomes in the future. Herein we present a comprehensive review summarizing options of CRC treatment and the mechanisms of 5-FU action at the molecular level, including both anabolic and catabolic ways. The main part of this review comprises the currently known molecular mechanisms underlying the chemoresistance in CRC patients. We also focus on various 5-FU pro-drugs developed to increase the amount of circulating 5-FU and to limit toxicity. Finally, we propose future directions of personalized CRC therapy according to the latest published evidence.

Phase II Study of S-1 plus Cisplatin as First-Line Therapy in Patients with Metastatic Esophageal Carcinoma

BACKGROUND

Patients with metastatic esophageal squamous cell cancer (ESCC) need safer and more efficacious treatments. The aim of this phase II study was to investigate the efficacy and safety of S-1 plus cisplatin as first-line therapy in metastatic ESCC.

PATIENTS AND METHODS

50 patients with metastatic ESCC who had not received prior systemic chemotherapy for metastatic disease were enrolled. Patients received S-1 at 40 mg/m2 divided into 2 daily doses for 14 days and cisplatin at 75 mg/m2 on day 1 or 25 mg/m2 on days 1-3 intravenously, repeated every 21 days with a maximum of 6 cycles.

RESULTS

47 patients were assessable for response and 18 patients achieved a partial response, giving an overall response rate of 38.3%. Among those who had objective responses, a large percentage (72.2%) quickly showed remarkable tumor shrinkage during the first 2 cycles. 18 (38.3%) patients had stable disease. The median progression-free survival was 5.6 months, and the median overall survival was 12.0 months. Toxicity was mild to moderate and generally tolerable.

CONCLUSION

The combination of S-1 plus cisplatin was a well-tolerated and convenient chemotherapy regimen with promising efficacy.

A chemoselective strategy for late-stage functionalization of complex small molecules with polypeptides and proteins

Conjugates between proteins and small molecules enable access to a vast chemical space that is not achievable with either type of molecule alone; however, the paucity of specific reactions capable of functionalizing proteins and natural products presents a formidable challenge for preparing conjugates. Here we report a strategy for conjugating electron-rich (hetero)arenes to polypeptides and proteins. Our bioconjugation technique exploits the electrophilic reactivity of an oxidized selenocysteine residue in polypeptides and proteins, and the electron-rich character of certain small molecules to provide bioconjugates in excellent yields under mild conditions. This conjugation chemistry enabled the synthesis of peptide-vancomycin conjugates without the prefunctionalization of vancomycin. These conjugates have an enhanced in vitro potency for resistant Gram-positive and Gram-negative pathogens. Additionally, we show that a 6 kDa affibody protein and a 150 kDa immunoglobulin-G antibody could be modified without diminishing bioactivity.

Updated 5-year survival and exploratory T x N subset analyses of ACTS-CC trial: a randomised controlled trial of S-1 versus tegafur-uracil/leucovorin as adjuvant chemotherapy for stage III colon cancer

Objective

Adjuvant Chemotherapy Trial of TS-1 for Colon Cancer (ACTS-CC), a randomised phase III trial, demonstrated that adjuvant therapy with S-1 for stage III colon cancer was non-inferior in 3-year disease-free survival (DFS) to that of tegafur-uracil plus leucovorin (UFT/LV). We updated DFS and overall survival (OS) and performed T x N subset analysis.

Methods

A total of 1518 patients with curatively resected stage III colon cancer were randomly assigned to receive S-1 (80-120  mg/day on days 1-28 every 42 days, four courses) or UFT/LV (UFT: 300-600  mg/day and LV: 75  mg/day on days 1-28 every 35 days, five courses).

Results

The 5-year DFS rates of the S-1 and UFT/LV group were 70.2 % and 66.9 %, respectively (HR 0.88; 95%  CI 0.74 to 1.06; p=0.177), and non-inferiority of DFS was reconfirmed with a median of 63.5-month follow-up. The similarity of OS was also confirmed (HR 0.92; 95%  CI 0.72 to 1.17; p=0.488); 5-year OS rates of the S-1 and UFT/LV group were 86.0 % and 84.4 %, respectively. No significant interactions were identified between the major baseline characteristics and DFS of the S-1 and UFT/LV groups, except for histological type; S-1 was more favourable in patients with poorly differentiated adenocarcinoma. Patient outcomes were well separated by TNM-substages (IIIA/IIIB/IIIC). With the patients divided into 20 subsets by T and N factors, the DFS and OS rates of T3 and N1 subset, which accounted for 62 % of stage IIIB patients and 44 % of all studied subjects, were significantly better than those of the other subsets in stage IIIB and similar to those of stage IIIA.

Conclusions

Adjuvant therapy of S-1 for stage III colon cancer was reconfirmed to be non-inferior in DFS to those of UFT/LV after long follow-up. No difference in OS was also demonstrated. T3N1 patients might be considered separately from other patients included in stage IIIB because of its favourable outcome.

Trial registration number

NCT00660894.

Progress in neoadjuvant drug therapy of rectal cancer

Rectal cancer is one of the most common malignant tumors of the digestive system. A portion of patients have had locally advanced disease at the time of diagnosis and have lost the chance of radical surgery. How to increase the R0 resection rate has always been a major difficulty in clinical practice. Some studies have shown that for some patients, neoadjuvant drug therapy can achieve reduction of clinical stage, increase the R0 resection rate and anus-preserving rate, reduce the local recurrence and micro-metastasis, and prolong the survival time of patients. This article mainly reviews the progress in neoadjuvant drug therapy of rectal cancer.

A Convenient Synthesis of Gimeracil

A practical three-step synthetic approach to gimeracil in a 68% overall yield is described, using 2,4-dimethoxypyridine as the starting material with 3,5-dichloro-2,4-dimethoxypyridine and 3,5-dichloro-2,4-dihydroxypyridine as intermediates. The advantages of this procedure include short reaction steps, simple operation and good yield.

Treatment of advanced colorectal cancer in a patient with cardiotoxic reactions to 5-fluorouracil and capecitabine using suboptimal doses

A 32-year-old female with stage IV colorectal cancer and metastasis to the liver experienced cardiotoxic reactions after treatment with 5-fluorouracil and its oral prodrug capecitabine even at two-thirds the recommended dose. After careful considerations, the decision was made to attempt capecitabine retrial at a further suboptimal dose with combination chemotherapy where she no longer experienced cardiac events. As a result, the liver tumour shrank and rectal mass stabilised, tumour markers dropped and she underwent surgical resection of both masses. Later there was local recurrence of disease near the previous liver tumour, so the suboptimal capecitabine therapy was restarted without complaint. The patient became a candidate for a NanoKnife procedure, offering a potentially curative therapy. This case report summarises a novel treatment strategy for those patients with advanced colorectal cancer who experience cardiotoxic reactions to fluoropyrimidines, the active agent of gold standard treatment.

Oral versus intravenous fluoropyrimidines for colorectal cancer

BACKGROUND

Patients prefer oral to intravenous (IV) palliative chemotherapy, provided that oral therapy is not less effective. We compared the efficacy and safety of oral and IV fluoropyrimidines for treatment of colorectal cancer (CRC).

OBJECTIVES

To compare the effects of oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5), along with OVID MEDLINE, OVID Embase, and Web of Science databases, in June 2016. We also searched five clinical trials registers, several conference proceedings, and reference lists from study reports and systematic reviews. We contacted pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.

DATA COLLECTION AND ANALYSIS

Three review authors extracted data and assessed risk of bias independently. We assessed the seven domains in the Cochrane 'Risk of bias' tool and three additional domains: schedules of outcome assessment and/or follow-up; use of intention-to-treat analysis; and baseline comparability of treatment arms.

MAIN RESULTS

We included nine RCTs (total of 10,918 participants) that examined treatment with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy. We included 35 RCTs (total of 12,592 participants) that examined treatment with palliative intent for inoperable advanced or metastatic CRC with chemotherapy (31 first-line studies, two second-line studies, and two studies of first- or second-line chemotherapy). All studies included male and female participants, and no studies included participants younger than 18 years of age. Patients treated with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy • Disease-free survival (DFS): DFS did not differ between participants treated with oral versus IV fluoropyrimidines (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.87 to 1.00; seven studies, 8903 participants; moderate-quality evidence).• Overall survival (OS): OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 0.92, 95% CI 0.84 to 1.00; seven studies, 8902 participants analysed; high-quality evidence).• Grade ≥ 3 adverse events (AEs): Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (odds ratio (OR) 0.14, 95% CI 0.11 to 0.16; seven studies, 8087 participants; moderate-quality evidence), stomatitis (OR 0.21, 95% CI 0.14 to 0.30; five studies, 4212 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.82, 95% CI 0.74 to 0.90; five studies, 7741 participants; low-quality evidence). There was more grade ≥ 3 hand foot syndrome (OR 4.59, 95% CI 2.97 to 7.10; five studies, 5731 participants; low-quality evidence) in patients treated with oral fluoropyrimidines. There were no differences between participants treated with oral versus IV fluoropyrimidines in occurrence of grade ≥ 3 diarrhoea (OR 1.12, 95% CI 0.99 to 1.25; nine studies, 9551 participants; very low-quality evidence), febrile neutropenia (OR 0.59, 95% CI 0.18 to 1.90; four studies, 2925 participants; low-quality evidence), vomiting (OR 1.05, 95% CI 0.83 to 1.34; eight studies, 9385 participants; low-quality evidence), nausea (OR 1.21, 95% CI 0.97 to 1.51; seven studies, 9233 participants; low-quality evidence), mucositis (OR 0.64, 95% CI 0.25 to 1.62; four studies, 2233 participants; very low-quality evidence), and hyperbilirubinaemia (OR 1.67, 95% CI 0.52 to 5.38; three studies, 2757 participants; very low-quality evidence). Patients treated with palliative intent for inoperable advanced or metastatic CRC with chemotherapy • Progression-free survival (PFS): Overall, PFS was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.06, 95% CI 1.02 to 1.11; 23 studies, 9927 participants; moderate-quality evidence). Whilst PFS was worse in participants treated with oral compared with IV fluoropyrimidines when UFT/Ftorafur or eniluracil with oral 5-fluorouracil (5-FU) was used, PFS did not differ between individuals treated with oral versus IV fluoropyrimidines when capecitabine, doxifluridine, or S-1 was used.• OS: Overall, OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 1.02, 95% CI 0.99 to 1.05; 29 studies, 12,079 participants; high-quality evidence). OS was inferior in participants treated with oral versus IV fluoropyrimidines when eniluracil with oral 5-fluorouracil (5-FU) was used.• Time to progression (TTP): TTP was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.07, 95% CI 1.01 to 1.14; six studies, 1970 participants; moderate-quality evidence).• Objective response rate (ORR): ORR did not differ between participants treated with oral versus IV fluoropyrimidines (OR 0.98, 95% CI 0.90 to 1.06; 32 studies, 11,115 participants; moderate-quality evidence).• Grade ≥ 3 AEs: Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (OR 0.17, 95% CI 0.15 to 0.18; 29 studies, 11,794 participants; low-quality evidence), febrile neutropenia (OR 0.27, 95% CI 0.21 to 0.36; 19 studies, 9407 participants; moderate-quality evidence), stomatitis (OR 0.26, 95% CI 0.20 to 0.33; 21 studies, 8718 participants; low-quality evidence), mucositis (OR 0.17, 95% CI 0.12 to 0.24; 12 studies, 4962 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.83, 95% CI 0.74 to 0.94; 14 studies, 5436 participants; low-quality evidence). There was more grade ≥ 3 diarrhoea (OR 1.66, 95% CI 1.50 to 1.84; 30 studies, 11,997 participants; low-quality evidence) and hand foot syndrome (OR 3.92, 95% CI 2.84 to 5.43; 18 studies, 6481 participants; moderate-quality evidence) in the oral fluoropyrimidine arm. There were no differences between oral and IV fluoropyrimidine arms in terms of grade ≥ 3 vomiting (OR 1.18, 95% CI 1.00 to 1.40; 23 studies, 9528 participants; low-quality evidence), nausea (OR 1.16, 95% CI 0.99 to 1.36; 25 studies, 9796 participants; low-quality evidence), and hyperbilirubinaemia (OR 1.62, 95% CI 0.99 to 2.64; nine studies, 2699 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

Results of this review should provide confidence that treatment for CRC with most of the oral fluoropyrimidines commonly used in current clinical practice is similarly efficacious to treatment with IV fluoropyrimidines. Treatment with eniluracil with oral 5-FU was associated with inferior PFS and OS among participants treated with palliative intent for CRC, and eniluracil is no longer being developed. Oral and IV fluoropyrimidines have different patterns of side effects; future research may focus on determining the basis for these differences.

Experience with S-1 in older Caucasian patients with metastatic colorectal cancer (mCRC): Findings from an observational chart review

BACKGROUND

An aging population will increase the number of older patients with metastatic colorectal cancer (mCRC). However, there is limited knowledge about treatment in older patients as they are under-represented in clinical trials. The oral fluoropyrimidine S-1 is associated with a lower rate of adverse events than capecitabine and may therefore be a suitable drug for elderly. However, data on the use of S-1 in Caucasian mCRC patients are lacking/scarce.

MATERIAL AND METHODS

In the present study we evaluated safety and the efficacy of S-1 alone or in combination with oxaliplatin (SOx) or irinotecan (IRIS) in older mCRC patients. Patients who received at least one cycle of S-1 (first-line therapy), SOx (mainly first-line therapy) or IRIS (second-line therapy) were included.

RESULTS

From June 2012 to December 2014, 71 older patients received ≥1 cycle of either S-1 (n = 9), SOx (n = 44) or IRIS (n = 18) for mCRC. Median age was 76 years and most patients had a WHO performance status of 0 (32%) or 1 (56%). All patients were evaluable for response and safety. In the SOx group, 18 (41%) and 20 patients (45%) had partial response (PR) and stable disease (SD), respectively (disease control rate 86%). Median progression-free survival (PFS) was 8.5 months and median overall survival (OS) was 18.5 months. In the S-1 group (median age 82 years), PR was 22%, median PFS 6.4 months and median OS 15.8 months. In the IRIS group, PR was 28%, median PFS 7.8 months and the median OS 16.5 months. In general, therapy was well tolerated; main non-hematological toxicities were fatigue and diarrhea.

CONCLUSION

S-1 monotherapy, SOx and IRIS were well tolerated for older patients with mCRC and could become alternative regimens in older mCRC patients. These regimens are now further evaluated in the randomized ongoing NORDIC9 trial.

Effect of Metabolic Inhibitors on the Hepatic Disposition of 5-Fluorouracil after Application to the Rat Liver Surface

We evaluated the effects of 5-fluorouracil (5-FU) metabolic inhibitors, gimeracil or uridine, on the hepatic disposition of 5-FU after application to the liver surface in rats, aiming to enhance the availability of 5-FU in the liver. 5-FU solution with or without metabolic inhibitors was applied to the rat liver surface using a cylindrical diffusion cell. The liver, blood and the remaining solution in the diffusion cell were collected at specified times, and assayed for 5-FU content. 5-FU absorption properties were not altered by addition of gimeracil and uridine. The 5-FU concentration in the diffusion cell attachment site of the rat liver (site 1) at 0.1-0.4 M ratios of gimeracil to 5-FU was significantly higher than that of the control. On the contrary, the addition of uridine did not increase the 5-FU concentration at site 1. At a 0.1 M ratio of gimeracil to 5-FU, the maximum 5-FU plasma concentration was the lowest, and the area under the 5-FU concentration-time curve at site 1 was 3.4 times greater than that of the control. We demonstrated that applying 5-FU with gimeracil to the rat liver surface could increase the availability of 5-FU in the liver.

Concurrent radiotherapy with S-1 plus cisplatin versus concurrent radiotherapy with cisplatin alone for the treatment of locally advanced cervical carcinoma: a pilot randomised controlled trial

BACKGROUND

In the present study, we compared the efficacy and safety of concurrent radiotherapy with S-1 plus cisplatin (CRSC) versus concurrent radiotherapy with cisplatin alone (CRC) for the treatment of advanced cervical carcinoma (ACC).

METHODS

Between February 2006 and January 2009, 72 eligible patients with ACC were included and randomly divided into two groups. Thirty-six patients received CRSC with radiotherapy (60 Gy/30 fractions over 6 weeks) beginning on day 1, S-1 (according to body surface area) for 28 days repeated every 6 weeks, and cisplatin (50 mg/m(2), intravenously on day 1) every 4 weeks for two cycles. The other 36 received CRC at the same cisplatin and radiotherapy dosage as for CRSC. The primary outcome was overall survival, whereas the secondary outcomes included progression-free survival and toxicity.

RESULTS

The median overall survival was 75 months (range 4-86 months) for the CRSC group and 66 months (range 3-87 months) for the CRC group (P = 0.039). The median corresponding progression-free survival was 66 months (range 3-75 months) and 58 months (range 3-71 months), respectively (P = 0.042). The toxicity profile was similar in both the groups.

CONCLUSION

Our results suggested that CRSC might be more effective than CRC in patients with ACC with acceptable toxicity.