[Relapse of chronic inflammatory demyelinating polyneuropathy following treatment with zoledronic acid]. / Reactivatie van chronische inflammatoire demyeliniserende polyneuropathie na zoledroninezuur.

BACKGROUND: Zoledronic acid is a nitrogen-containing bisphosphonate that is frequently used in the treatment of osteoporosis. Many patients experience a so-called acute-phase reaction during initial treatment; this is characterized by flu-like symptoms and fever. CASE DESCRIPTION: We describe a 61-year-old woman who suffered from chronic inflammatory demyelinating polyneuropathy (CIDP), and who was started on intravenous zoledronic acid treatment as adjuvant therapy for breast cancer. Within 24 hours of the initial treatment she developed cold shivers, extreme fatigue, muscle pain and headache. These symptoms resolved spontaneously in the course of the following days. At the same time, she also experienced a CIDP relapse, with a tingling sensation in her arms and legs and deterioration in her ability to walk. Considering the course of the symptoms and the absence of any other cause, CIDP relapse was very probably the result of the acute-phase reaction induced by zoledronic acid. CONCLUSION: Caution is warranted when using nitrogen-containing bisphosphonates such as zoledronic acid, particularly in patients with known neuromuscular disorders.

St. Gallen endocrine response classes predict recurrence rates over time.

BACKGROUND: In 2007 the St. Gallen consensus panel defined three endocrine response classes: highly endocrine responsive (ER-H), incomplete endocrine responsive (ER-I) and non-endocrine responsive tumours (ER-N). However, it is uncertain whether ER-I tumours are less responsive than ER-H tumours. We investigated whether recurrence rates vary over time between response classes. Additionally, we investigated the most predictive response class definition for tamoxifen benefit. PATIENTS AND METHODS: We recollected tumours from 646 patients who participated in a randomized trial of adjuvant tamoxifen vs. OBSERVATION: Estrogen receptor (ER), progesterone receptor (PgR), HER2 status and tumour grade were revised centrally. St. Gallen classes were evaluated for recurrence free interval (RFI). Change in hazards over time was assessed. Subsequently, 6 alternative response class definitions were compared to optimize the cut-off for PgR and ER. RESULTS: Schoenfeld residuals indicate a failure of proportional hazards between the endocrine response groups (p = 0.0001). The HR for recurrence risk shifted over time with the ER-H group initially being at lower risk (HR ER-H vs. ER-I 0.5), but after six years the recurrence risk increased (HR 1.9). The cut-off values for ER and PgR that statistically best discriminated RFI in the first 4 years for lymph node positive patients were ER ≥ 50% and PgR ≥ 75%. CONCLUSION: We demonstrated a marked variability in endocrine therapy benefit. Patients with ER-H tumours have a larger benefit during adjuvant tamoxifen and in the first years after accomplishing of the therapy, but suffer from late recurrences. This might have implications for optimal treatment duration.