Younger age as a risk factor for rash development in pemetrexed and carboplatin treatment with dexamethasone prophylaxis.

Purpose: Carboplatin (CBDCA) plus pemetrexed (PEM) is one of the most effective regimens for treating thoracic cancer. Rash, which is mainly caused by PEM, occurs in 15-30% of patients. Dexamethasone administration for 3 days is recommended to manage rash, chemotherapy-induced nausea, and vomiting in this regimen. However, the nature of the PEM-induced rashes is not fully understood. Consequently, we aimed to identify the risk factors associated with rash development under dexamethasone prophylaxis in CBDCA + PEM treatment.

Methods: Patients with thoracic cancer who underwent CBDCA + PEM treatment (n = 133) were retrospectively assessed. The primary endpoint of the present study was to identify the risk factor(s) for the incidence of all-grade rash in the first cycle. Factors affecting the incidence during all treatment cycles were also evaluated.

Results: The incidence of all-grade rash in the first cycle was 24.1%, including 16.5% for grade 1, 5.3% for grade 2, and 2.3% for grade 3, respectively. Moreover, that in all cycles, it was 27.1%, with 18.8% for grade 1, 6.0% for grade 2, and 2.3% for grade 3. Multivariate logistic regression analyses identified that age < 65 years was the singular independent risk factor for rash development in the first and all cycles (adjusted odds ratio, 2.79; 95% confidence interval, 1.17-6.67; p = 0.02 for the first cycle, 3.03, 1.29-7.09; p = 0.01 for all cycles).

Conclusion: Our study revealed that patients aged < 65 years were at a significantly higher risk of rash development during CBDCA + PEM chemotherapy with dexamethasone prophylaxis than patients ≥ 65 years of age.