A randomised study of tailored toxicity-based dosage of fluorouracil-epirubicin-cyclophosphamide chemotherapy for early breast cancer (SBG 2000-1)

Reporting of tobacco use and tobacco-related analyses in cancer cooperative group clinical trials: a systematic scoping review

BACKGROUND

Continued smoking after a diagnosis of cancer negatively impacts cancer outcomes, but the impact of tobacco on newer treatments options is not well established. Collecting and evaluating tobacco use in clinical trials may advance understanding of the consequences of tobacco use on treatment modalities, but little is known about the frequency of reporting and analysis of tobacco use in cancer cooperative clinical trial groups.

PATIENTS AND METHODS

A comprehensive literature search was conducted to identify cancer cooperative group clinical trials published from January 2017-October 2019. Eligible studies evaluated either systemic and/or radiation therapies, included ≥100 adult patients, and reported on at least one of: overall survival, disease/progression-free survival, response rates, toxicities/adverse events, or quality-of-life.

RESULTS

A total of 91 studies representing 90 trials met inclusion criteria with trial start dates ranging from 1995 to 2015 with 14% involving lung and 5% head and neck cancer patients. A total of 19 studies reported baseline tobacco use; 2 reported collecting follow-up tobacco use. Seven studies reported analysis of the impact of baseline tobacco use on clinical outcomes. There was significant heterogeneity in the reporting of baseline tobacco use: 7 reported never/ever status, 10 reported never/ex-smoker/current smoker status, and 4 reported measuring smoking intensity. None reported verifying smoking status or second-hand smoke exposure. Trials of lung and head and neck cancers were more likely to report baseline tobacco use than other disease sites (83% versus 6%, P < 0.001).

CONCLUSIONS

Few cancer cooperative group clinical trials report and analyze trial participants' tobacco use. Significant heterogeneity exists in reporting tobacco use. Routine standardized collection and reporting of tobacco use at baseline and follow-up in clinical trials should be implemented to enable investigators to evaluate the impact of tobacco use on new cancer therapies.

The Influence of Wuzhi Capsule on the Pharmacokinetics of Cyclophosphamide

BACKGROUND

Cyclophosphamide is approved for the treatment of a variety of tumors, yet the use of cyclophosphamide is limited by kidney and liver toxicity. In the clinic, the Wuzhi capsule is approved to attenuate cyclophosphamide toxicity in the kidney and liver.

OBJECTIVE

We aimed to investigate the effects of the principal ingredients of Wuzhi capsule, schisandrin A (SIA) and schisantherin A (STA), on the pharmacokinetics of cyclophosphamide.

METHODS

The essential pharmacokinetic data and physicochemical parameters of SIA, STA, and cyclophosphamide were collected. Physiologically based pharmacokinetic (PBPK) models of SIA, STA, and cyclophosphamide were built in Simcyp Simulator and verified using published clinical pharmacokinetic data. The verified PBPK models were used to predict potential herb-drug interactions (HDIs) between cyclophosphamide and SIA and STA in cancer patients.

RESULTS

The area under the plasma concentration-time curve (AUC) of cyclophosphamide was increased by 18% and 1% when co-administered with STA and SIA at a single dose, respectively, and increased by 301% and 29% when co-administered with STA and SIA at multiple doses, respectively. The maximum concentration (Cmax) of cyclophosphamide was increased by 75% and 7% when co-administered with STA and SIA at multiple doses, respectively.

CONCLUSION

The AUC and Cmax of cyclophosphamide were increased when cyclophosphamide was combined with the Wuzhi capsule, compared to cyclophosphamide alone. Our study shows that the adverse drug reactions and toxicity of cyclophosphamide should be closely monitored and an effective dosage adjustment of cyclophosphamide may need to be considered when co-administered with the Wuzhi capsule.

Uridine Glucuronosyltransferase 2B7 Polymorphism-Based Pharmacogenetic Dosing of Epirubicin in FEC Chemotherapy for Early-Stage Breast Cancer

BACKGROUND

Epirubicin is metabolized by uridine glucuronosyltransferase 2B7 (UGT2B7). Patients homozygous for the minor allele (CC) in the UGT2B7 -161 promoter polymorphism have lower clearance and significantly higher rates of leukopenia compared to wild-type homozygote (TT) or heterozygote (CT) patients. This study was designed to determine if TT and CT genotype patients could tolerate a higher epirubicin dose compared to CC genotype patients.

PATIENTS AND METHODS

We studied women with histologically confirmed non-metastatic, invasive breast cancer who were scheduled to receive at least three cycles of FE₁₀₀C in the (neo)adjuvant setting. Patients received standard-dose FE₁₀₀C during the first 21-day cycle. Based on genotype, the epirubicin dose was escalated in the second and third cycles to 115 and 130 mg/m² or to 120 and 140 mg/m² for CT and TT genotype patients, respectively. The main outcome measurements were myelosuppression and dose-limiting toxicity. These were analyzed for relationships with the three genotypes.

RESULTS

Forty-five patients were enrolled (10 CC, 21 CT, and 14 TT genotypes) and received 100 mg/m² of epirubicin in the first cycle. Twelve and 10 TT patients were dose escalated at the second and third cycles, respectively; 16 CT patients were dose escalated at the second and third cycles. Leukopenia, but not febrile neutropenia, was genotype and dose dependent and increased in patients with CT and TT genotypes as their dose was increased. However, the third-cycle leukopenia rates were comparable to patients with the CC genotype receiving standard-dose epirubicin.

CONCLUSION

Pharmacogenetically guided epirubicin dosing is well tolerated and allowed dose escalation without increased toxicity.

Leukocyte nadir as a predictive factor for efficacy of adjuvant chemotherapy in breast cancer. Results from the prospective trial SBG 2000-1

Background: Retrospective studies have suggested that chemotherapy-induced leukopenia is associated with improved recurrence-free or overall survival. The SBG 2000-1 trial was designed to verify the favorable prognosis associated with chemotherapy-induced leukopenia in early breast cancer. Patients not experiencing chemotherapy-induced leukopenia were randomized into standard dosed or individually escalated chemotherapy doses based on the grade of leukopenia after a first standard dose.Patients and methods: 1452 women in Sweden and Denmark with operable node-positive or high-risk node-negative breast cancer aged 18-60 years were recruited to participate in this trial. Participants received a first FEC cycle at standard doses (600/60/600 mg/m²). Patients (n = 1052) with nadir leukopenia grade 0-2 after the first cycle were randomized between either 6 standard FEC or 6 tailored FEC courses with doses of epirubicin and cyclophosphamide escalated during courses 2 and 3 and thereafter aimed at achieving grade 3 leukopenia. Patients with nadir leukopenia grade 3-4 after the first course continued treatment with standard FEC. Results of the randomized comparison has been published previously. The present study focuses on chemotherapy-induced leukopenia as a covariable with outcome in randomized and non-randomized patients. The prognostic value of leukopenia after course 3, was studied in a Cox model adjusted for cumulative doses of epirubicin and cyclophosphamide. The association of chemotherapy-induced leukopenia with prognosis was a preplanned secondary endpoint for this trial.Results: The eight-year distant disease-free survival was 73%, 77%, 78% and 83% for patients with leucocyte nadir grade 0, 1, 2 and 3-4, respectively. Higher degree of leukopenia was highly significantly associated to improved distant disease-free survival (HR 0.84, 95% CI 0.74-0.96, p = .008) and overall survival (HR 0.87 (0.76-0.99, p = .032).Conclusion: This prospective study confirms that chemotherapy-induced leukopenia is a covariable with outcome in primary breast cancer, even after adjustment for chemotherapy doses.