Pre-emptive oral clarithromycin reduces the skin toxicity of panitumumab treatment for metastatic colorectal cancer

Evaluation of the additional prophylactic effect of topical steroid ointment to systemic minocycline against anti-epidermal growth factor antibody-induced skin toxicities in metastatic colorectal cancer treatment

BACKGROUND

Anti-epidermal growth factor receptor (EGFR) antibodies often cause skin toxicities. Preemptive skin treatments using systemic antibiotics with or without topical steroid are reportedly effective although the most suitable method remains unclear. This study aimed to determine whether combination prophylaxis using systemic minocycline and topical steroid is superior to minocycline alone in a real-world metastatic colorectal cancer (mCRC) treatment.

METHODS

Patients with mCRC (n = 87) who received anti-EGFR monoclonal antibodies were retrospectively assessed. The primary objective was to compare the incidence of grade ≥ 2 overall skin toxicities during all treatment periods between the control group receiving prophylactic minocycline 100 mg/day, and the combination prophylaxis group receiving minocycline 100 mg/day + topical steroid. The incidence of each skin symptom was also evaluated.

RESULTS

The incidence of grade ≥ 2 overall skin toxicities was 63.6% in the control and 56.9% in the combination groups, with no significant difference (P = 0.63). Similarly, the incidence of grade ≥ 2 dry skin, fissures, paronychia, and pruritus did not significantly differ. In addition, incidence of all-grade skin toxicities was not different. However, the incidence of grade ≥ 2 papulopustular rashes was significantly lower in the combination group (23.1% vs. 50.0%, P = 0.03). Propensity score-matched analysis supported these results. Multivariate logistic regression analysis showed no significant association between combination prophylaxis and grade ≥ 2 overall skin toxicities, but it did show a reduction in grade ≥ 2 papulopustular rashes.

CONCLUSION

Adding topical steroids to systemic minocycline did not mitigate grade ≥ 2 overall skin toxicities induced by anti-EGFR antibodies; however, it significantly improved papulopustular rashes.

Role of ErbB1 in the Underlying Mechanism of Lapatinib-Induced Diarrhoea: A Review

Lapatinib, an orally administered small-molecule tyrosine kinase inhibitor (SM-TKI), is an effective treatment for ErbB2-positive breast cancer. However, its efficacy as one of the targeted cancer therapies has been hampered by several adverse effects, especially gastrointestinal toxicity, commonly manifested as diarrhoea. Although it can be generally tolerated, diarrhoea is reported as the most common and most impactful on a patient's quality of life and associated with treatment interruption. Severe diarrhoea can result in malabsorption, leading to dehydration, fatigue, and even death. ErbB1 is an epidermal growth factor profoundly expressed in normal gut epithelium while lapatinib is a dual ErbB1/ErbB2 tyrosine kinase inhibitor. Thus, ErbB1 inhibition by lapatinib may affect gut homeostasis leading to diarrhoea. Nevertheless, the underlying mechanisms remain unclear. This review article provides evidence of the possible mechanisms of lapatinib-induced diarrhoea that may be related to/or modulated by ErbB1. Insight regarding the involvement of ErbB1 in the pathophysiological changes such as inflammation and intestinal permeability as the underlying cause of diarrhoea is covered in this article.