Opioid-Induced Constipation in Oncological Patients: New Strategies of Management.

OPINION STATEMENT: Cancer-associated pain has traditionally been treated with opioid analgesics, often in escalating doses. Opioid-induced constipation (OIC) is a common problem associated with chronic use of opioid analgesics. Typical treatment strategies to alleviate constipation are based on dietary changes, exercise, and laxatives. However, laxatives have a nonspecific action and do not target underlying mechanisms of OIC. This article will review prevalent, clinical presentation and recommendations for the treatment of OIC. An independent literature search was carried out by the authors. We reviewed the literature for randomized controlled trials that studied the efficacy of laxatives, naloxone, and naloxegol in treating OIC. Newer strategies addressing the causal pathophysiology of OIC are needed for a more effective assessment and management of OIC. Finally, traditional recommended therapies are appraised and compared with the latest pharmacological developments. Future research should address whether naloxegol is more efficacious by its comparison directly with first-line treatments, including laxatives.

Multicenter phase II study of fixed sequences of capecitabine combined with oxaliplatin or irinotecan in patients with previously untreated metastatic colorectal cancer.

PURPOSE: The purpose of this study was to evaluate the antitumor activity and toxicity of fixed sequences of capecitabine/oxaliplatin followed by capecitabine/irinotecan in patients with previously untreated metastatic colorectal cancer. PATIENTS AND METHODS: Adult patients with histologically confirmed, previously untreated, nonresectable, locally advanced or metastatic colorectal adenocarcinoma were enrolled in the study. Patients were treated as follows: capecitabine (1000 mg/m2 orally twice daily) on days 1-14 and oxaliplatin (130 mg/m2 2-hour intravenous infusion) on day 1, followed by capecitabine (1000 mg/m2 twice daily) on days 1-14 and irinotecan (240 mg/m2 1.5-hour intravenous infusion) on day 1. Each combination was administered every 21 days during 4 consecutive cycles followed by the alternating sequence to a maximum of 16 cycles. RESULTS: A total of 35 eligible patients have been included in this ongoing study. Response rate (complete responses plus partial responses) was 37.1%. With a median follow-up of 9.5 months, the median time to disease progression and overall survival were 7.4 months and 16.4 months, respectively. Treatment was well tolerated, with only 6% of the patients developing grade 3/4 neurotoxicity. However, the low number of patients treated beyond 4 cycles limits the interpretation of the data. CONCLUSION: The preliminary results from this ongoing study suggest the feasibility of this strategy, which resulted in promising antitumor activity with less neurotoxicity.

Activity and safety of oxaliplatin with weekly 5-fluorouracil bolus and low-dose leucovorin as first-line treatment for advanced colorectal cancer.

This study was designed to evaluate the safety and tolerability of oxaliplatin combined with weekly boluses of 5-fluorouracil (5-FU) and low doses of leucovorin (LV) and to determine objective response, progression-free survival, and overall survival of patients with previously untreated advanced colorectal cancer. Seventy-nine patients enrolled in an observational, multicenter, prospective, open-label phase II study received intravenous (I.V.) infusions of oxaliplatin 85 mg/m2 over the course of 2 hours on days 1 and 14 and LV 20 mg/m2 over the course of 2 hours and 5-FU 500 mg/m2 as a bolus on days 1, 7, and 14 every 4 weeks until disease progression or unacceptable toxicity occurred. Seventy-nine patients were evaluable for safety, and data from 70 patients were used for efficacy analysis. The objective response rate was 51.4%. Complete responses occurred in 7 patients (10%), and partial responses occurred in 29 patients (41.4%). Disease control, defined as response or stable disease, was obtained in 56 of 70 patients (80%). The median duration of response was 8.34 weeks (range, 7.3-11.5 weeks). The median time to progression was 7.13 months (range, 6.28-7.72 months), and median overall survival time was 15 months (range, 12.32-18.37 months). Acute dose-limiting toxicities were grade 3/4 diarrhea and neutropenia, which occurred in 10.5% and 3.9% of patients, respectively. Among the 70 patients who experienced neurosensory toxicity, it was estimated that only 1.3% had grade 3 symptoms. Preliminary data showed that the regimen is at least as active as other regimens combining oxaliplatin and infusional schedules of 5-FU and might be more convenient for patients because it avoids the need for I.V. catheter implantation.

Biweekly docetaxel and vinorelbine in anthracycline-resistant metastatic breast cancer: a multicenter phase II study.

The aim of this study was to determine the efficacy and toxicity of a biweekly combination of docetaxel and vinorelbine in patients with metastatic breast cancer (MBC) previously treated with anthracyclines. Eligible patients (n = 49) with MBC received vinorelbine, 25 mg/m2, followed by docetaxel, 60 mg/m2. Cycles were repeated every 14 days for a total of 8 planned cycles. Response rate was evaluated every 4 cycles. All 49 patients were evaluable for safety and 44 for efficacy. Vinorelbine plus docetaxel resulted in an overall response rate of 45% (CI 95%: 31-60) with 2 (4%) complete responses and 18 (41%) partial responses. Patients with visceral metastasis achieved a lower response rate than those without (33% versus 60%, p = 0.044). Time to progression was 11.0 months (CI 95%: 8.6-13.5), and median overall survival was 12.7 months (CI 95%: 9.0-16.4). The most common grade III to IV hematologic adverse events was neutropenia (65% of patients). Febrile neutropenia was observed in 9 cycles (3%) and in 7 patients (14%). Grade III to IV nonhematologic toxicity was rare. Biweekly combination of docetaxel and vinorelbine is an effective and well-tolerated regimen in anthracycline-resistant MBC.

A multicenter phase II study of irinotecan in patients with advanced colorectal cancer previously treated with 5-fluorouracil.

This multicenter, open-label, phase II study was performed to assess the efficacy and toxicity of irinotecan 350 mg/m2 intravenously every 3 weeks in patients with advanced colorectal cancer (CRC) previously treated with 5-fluorouracil (5-FU). The study enrolled 115 patients and a total of 558 cycles (median, 6 per patient) were administered. The overall objective response rate on an intent-to-treat basis was 18% (with 1 complete response and 20 partial responses), whereas 42 patients (37%) showed stable disease. Median time to progression was 4.8 months and median survival was 13.6 months. Grade 3/4 toxicities included delayed diarrhea (19.1%), nausea/vomiting (10.4%), and neutropenia (8.7%). There were 2 toxic deaths, 1 from delayed diarrhea and 1 from hemorrhage and grade 4 mucositis. In conclusion, the present study confirms the antitumor efficacy of irinotecan monotherapy in patients with CRC pretreated with 5-FU.