Adverse drug reactions are appreciably harmful or unpleasant reactions resulting from an intervention related to the use of medical products, which predicts hazard from future administration and warrants prevention or specific treatment, or alteration of the dosage regimen, or withdrawal of the product. Given medical case reports extracted from MEDLINE, the task is to classify whether the case report mentions the presence of any adverse drug reaction. Classify your answers into non-adverse drug event and adverse drug event.

[EX Q]: Spontaneous regression of the lesions was noted after discontinuation of the treatment.
[EX A]: non-adverse drug event

[EX Q]: The patient began her prescribed radiation therapy and 5-fluorouracil radio-sensitizing chemotherapy.
[EX A]: non-adverse drug event

[EX Q]: The reported case represents an unusual association between medication with the proton pump inhibitor lansoprazole and the development of collagenous colitis suggesting the importance of evaluation of drug use in patients with microscopic colitis.
[EX A]:
adverse drug event

