Precision fluoropyrimidines dosing in a compound heterozygous variant carrier of the DPYD gene: a case report.

BACKGROUND: Fluoropyrimidines (FPs) form still nowadays the backbone of chemotherapic schemes in colorectal cancer (CRC). Inter-patient variability of the toxicity profile of FPs may be partially accounted for by variable expression of dihydropyrimidine dehydrogenase (DPD). DPD rate activity is genetically determined by its extremely polymorphic coding gene DPYD. In spite of pharmacogenetic guideline-directed-dosing of FPs based regimens treating carrier of multiple variants of DPYD gene remains still challenging. CASE PRESENTATION: We present a case of a 48-year-old Caucasian man, compound heterozygous variant carrier of the DPYD gene (HapB3 and c.2194G>A) who had a diagnosis of adenocarcinoma of the left colon and was safely treated with a pharmacogenetic-guided 25% dose reduction of the standard CAP adjuvant treatment. Compound heterozygosis may have been responsible for an earlier over exposure to CAP resulting into low-grade toxicity with an anticipated median time to toxicity of the c.2194G>A variant to the 4th vs. 6th cycles. Some haplotypes of DPYD variants may have an advantage in terms of survival compared to wild-type patients. Our patient may also have benefitted from compound heterozygosis, as shown by no evidence of disease (NED) at 6-month follow-up. CONCLUSION: Pharmacogenetic-guided dosing of DPYD intermediate metabolizer compound heterozygous HapB3 and c.2194G>A variant carries should be managed by a multidisciplinary team with a dose reduction ranging from 25 to 50% to maintain effectiveness and close clinical monitoring for early detection of ADRs.

Dose-dense adjuvant chemotherapy in premenopausal breast cancer patients: A pooled analysis of the MIG1 and GIM2 phase III studies.

BACKGROUND: No evidence exists to recommend a specific chemotherapy regimen in young breast cancer patients. We performed a pooled analysis of two randomised clinical trials to evaluate the efficacy of adjuvant dose-dense chemotherapy in premenopausal breast cancer patients and its impact on the risk of treatment-induced amenorrhoea. PATIENTS AND METHODS: In the MIG1 study, node-positive or high-risk node-negative patients were randomised to 6 cycles of fluorouracil/epirubicin/cyclophosphamide every 2 (dose-dense) or 3 (standard-interval) weeks. In the GIM2 study, node-positive patients were randomised to 4 cycles of dose-dense or standard-interval EC or FEC followed by 4 cycles of dose-dense or standard-interval paclitaxel. Using individual patient data, the hazard ratio (HR) for overall survival by means of a Cox proportional hazards model and the odds ratio for treatment-induced amenorrhoea through a logistic regression model were calculated for each study. A meta-analysis of the two studies was performed using the random effect model to compute the parameter estimates. RESULTS: A total of 1,549 patients were included. Dose-dense chemotherapy was associated with a significant improved overall survival as compared to standard-interval chemotherapy (HR, 0.71; 95% confidence intervals [CI], 0.54-0.95; p = 0.021). The pooled HRs were 0.78 (95% CI, 0.54-1.12) and 0.65 (95% CI, 0.40-1.06) for patients with hormone receptor-positive and -negative tumours, respectively (interaction p = 0.330). No increased risk of treatment-induced amenorrhoea was observed with dose-dense chemotherapy (odds ratio, 1.00; 95% CI, 0.80-1.25; p = 0.989). CONCLUSION: Dose-dense adjuvant chemotherapy may be considered the preferred treatment option in high-risk premenopausal breast cancer patients.

Antioxidant supplement and long-term reduction of recurrent adenomas of the large bowel. A double-blind randomized trial.

BACKGROUND: Patients who undergo polypectomy are at increased risk of adenoma recurrence. The preventive potential of vitamins (A, C and E) and selenium supplementation represent an interesting opportunity for colorectal cancer prevention. METHODS: To assess the efficacy of a combination of these micronutrients in reducing the incidence of recurrent adenomas in subjects on post-polypectomy endoscopic follow-up, a double-blind placebo-controlled randomized trial was started in Italy in 1988. A total of 411 patients were randomized to receive either an active compound (200 µg selenium, 30 mg zinc, 2 mg vitamin A, 180 mg vitamin C, 30 mg vitamin E) or a placebo daily for 5 years. Of them, 330 had follow-up colonoscopy (164 in the intervention and 166 in the placebo group). RESULTS: After a median follow-up of 4 years (range 1-15 years), 100 patients had recurrence: 38 in the intervention and 62 in the placebo arm. The 15-year cumulative incidence of recurrence was 48.3% in the intervention and 64.5% in the placebo arm (HR = 0.59; log-rank P = 0.009). A 39% reduction of the risk of recurrence was observed in the intervention compared to the placebo group (adjusted HR = 0.61; 95% CI 0.41-0.92): the risk reduction was similar for small tubular (adjusted HR = 0.61; 95% CI 0.37-0.99) and advanced adenomas (adjusted HR = 0.50; 95% CI 0.24-1.01). CONCLUSIONS: Our study showed a statistically significant effect of antioxidant supplementation on adenoma recurrence. Further clinical trials are needed to address the role of antioxidants in subgroups of subjects at increased risk for colorectal cancer.