Phase II study of S-1 on alternate days plus bevacizumab in patients aged ≥ 75 years with metastatic colorectal cancer (J-SAVER)
BackgroundAlternate-day administration of S-1 is thought to reduce toxicities. This phase II study evaluated S-1 on alternate days combined with bevacizumab as first-line treatment for elderly patients with metastatic colorectal cancer.Patients and methodsEligible patients had histologically proven colorectal adenocarcinoma, measurable metastatic lesions, age ≥ 75 years, Eastern Cooperative Oncology Group performance status ≤ 1, no previous chemotherapy, and refused oxaliplatin- or irinotecan-containing regimens. Patients received 40 mg, 50 mg, or 60 mg (body surface area ≤ 1.25 m2, > 1.25 to ≤ 1.50 m2, or > 1.50 m2, respectively) of S-1 twice orally on Sunday, Monday, Wednesday, and Friday every week. Bevacizumab (7.5 mg/kg) was administered every 3 weeks. The primary endpoint was progression-free survival.ResultsOf 54 enrolled patients, 50 patients were evaluated for efficacy and 53 for safety. The median age was 79 years (range 75–88 years). The median progression-free survival was 8.1 months (95% confidence interval (CI) 6.7–9.5 months). The median overall survival was 23.1 months (95% CI 17.4–28.8 months). The response rate was 44% (95% CI 30.2–57.8%), and the disease control rate was 88% (95% CI 79.0–97.0%). Grade 3 or higher hematologic, non-hematologic, and bevacizumab-related adverse events occurred in 9%, 11%, and 25% of patients, respectively. The most common grade 3 and 4 treatment-related adverse events were hypertension (11%), nausea (6%), fatigue (6%), anemia (6%), and proteinuria (6%). Only 6 patients discontinued treatment due to adverse events.ConclusionS-1 on alternate days combined with bevacizumab showed better tolerability and comparable survival compared with the results of similar studies.
Alternate-day oral therapy with TS-1 for advanced gastric cancer
BackgroundTS-1 (1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyrimidine-1 M potassium oxonate) has a high single-agent response rate, of more than 40%, for gastric cancer; however, the recommended regimen of 4 weeks of administration interrupted by 2 weeks of drug withdrawal frequently causes adverse effects. The alternate-day dosage of pyrimidine fluoride anticancer drugs could reduce their adverse effects without compromising their effects. We attempted an alternate-day therapy with TS-1 aiming at the avoidance of adverse effects and significantly longer duration of administration.MethodsWe observed patients for clinical effects and adverse effects under alternate-day dosage of TS-1, and determined blood 5-fluorouracil (FU) levels. The judgment of clinical effects was based on the New Guidelines to Evaluate the Response to Treatment in Solid Tumors (RECIST), whereas the evaluation of adverse effects was based on the National Cancer Institute NCI-common toxicity criteria (CTC).ResultsIn 72 (78%) of 92 patients, the TS-1 regimen was converted to the alternate-day dosage because of adverse effects. Twenty patients were treated with the alternate-day dosage regimen from the start because of the fear of adverse effects. The alternate-day dosage was clinically effective, as 28 of 34 patients after relatively curative resection remained alive and free from recurrence. The median survival time of 58 patients after noncurative resection or with unresectable or recurrent cancer was 332 days. Fifty-three percent of these 58 patients achieved partial response and stable disease of more than 12 weeks’ duration. We followed time-dependent changes in blood 5-FU levels in 36 of the patients on alternate-day therapy, in whom TS-1 had been administered daily before being administered every other day. The trough level was significantly lower when TS-1 was administered on alternate days, and blood 5-FU reached a peak at sufficiently effective levels at 2 h even after administration on the alternate-day basis.ConclusionThis study demonstrated that, compared with daily administration, alternate-day administration of TS-1 reduces adverse effects, and simultaneously ensures effective blood levels and provides sufficient clinical effects.
Blood gases, electrolytes and interpretation 1. Blood gases
Blood gas analysis can give the clinician essential information on the respiratory and metabolic status of a patient. Although often considered difficult or confusing to interpret due to the abundance of chemistry, with a little practice blood gases become easy and quick to interpret. In addition, they provide a vital insight into a patient's status that will ultimately influence how a case is managed. This article discusses the approach to blood gas interpretation and focuses on the interpretation of acid-base and oxygenation status in small animal patients. A second article, to be published in the March issue of In Practice, will discuss the role that electrolytes play in blood gas interpretation along with interpretation of ionised calcium and lactate results.