{"id":"a3f8cf97-814c-5deb-8c37-e4f0436f20e6","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:nia-clin-ontrac-skin","predicate":"reduces_during_tested_intervention","statement":"During ONTRAC treatment, new nonmelanoma skin cancers were 23% lower with nicotinamide than placebo (95% CI 4–38%); there was no evidence of benefit after discontinuation.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"b4a9f980-0961-59c7-a39d-4d723000fa3f","mechanism_event_label":"Nicotinamide reduced new skin cancers during treatment in this selected high-risk group; protection was not shown to persist after stopping.","subject":{"id":"08c27a3f-552e-5c92-8688-321a9b64a0d6","slug":"nicotinamide","display_name":"Nicotinamide","entity_type_key":"small_molecule"},"object":{"id":"dba69dcc-f75e-5775-8132-a9735e5d821f","slug":"nonmelanoma-skin-cancer-incidence","display_name":"New keratinocyte skin cancer incidence","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"b4a9f980-0961-59c7-a39d-4d723000fa3f","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:nia-clin-ontrac-skin-event","event_type":"observed_intervention","label":"Nicotinamide reduced new skin cancers during treatment in this selected high-risk group; protection was not shown to persist after stopping.","description":"During ONTRAC treatment, new nonmelanoma skin cancers were 23% lower with nicotinamide than placebo (95% CI 4–38%); there was no evidence of benefit after discontinuation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"08c27a3f-552e-5c92-8688-321a9b64a0d6","slug":"nicotinamide","display_name":"Nicotinamide","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"dba69dcc-f75e-5775-8132-a9735e5d821f","slug":"nonmelanoma-skin-cancer-incidence","display_name":"New keratinocyte skin cancer incidence","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Niacin precursor form and the measured endpoint are separate graph entities.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/niacin-clinical-sources/chen2015.abstract.txt\", \"locator\": \"Indexed primary abstract\", \"file_sha256\": \"7a305aa1d363f375f8cb640b5ddc5f77517f0229a6041558e392d7a07e198aa8\", \"start_char\": 0, \"end_char\": 2368, \"text_sha256\": \"7a305aa1d363f375f8cb640b5ddc5f77517f0229a6041558e392d7a07e198aa8\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"ONTRAC double-blind randomized trial; 386 high-risk participants with at least two recent nonmelanoma skin cancers","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Nicotinamide 500 mg twice daily for 12 months; observation for a further six months","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Selected high-risk population; this is pharmacological prevention, not proof of deficiency. Combined endpoint differs from subtype effects. Results do not establish efficacy in every population or after treatment stops.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Niacin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"niacin","display_name":"Niacin (vitamin B3)","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Nicotinamide reduced new skin cancers during treatment in this selected high-risk group; protection was not shown to persist after stopping.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[nia-clin-chen2015] A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention. (2015). https://pubmed.ncbi.nlm.nih.gov/26488693/ DOI: 10.1056/nejmoa1506197","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Skin cancer counts","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"6894a87f-a412-51a6-8f33-ecdfd809fbb6","evidence_kind":"source_excerpt","locator":"Lines 1431-1443","start_line":1431,"end_line":1443,"excerpt":"### nia-clin-ontrac-skin\nDuring ONTRAC treatment, new nonmelanoma skin cancers were 23% lower with nicotinamide than placebo (95% CI 4–38%); there was no evidence of benefit after discontinuation.\nCondition category: normal\nnutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Nicotinamide reduced new skin cancers during treatment in this selected high-risk group; protection was not shown to persist after stopping.\norganism: Homo sapiens\ntissue_or_cell_type: Skin cancer counts\nexperimental_model: ONTRAC double-blind randomized trial; 386 high-risk participants with at least two recent nonmelanoma skin cancers\nlimitations: Selected high-risk population; this is pharmacological prevention, not proof of deficiency. Combined endpoint differs from subtype effects. Results do not establish efficacy in every population or after treatment stops.\nexposure: Nicotinamide 500 mg twice daily for 12 months; observation for a further six months\ncross_nutrient: Niacin precursor form and the measured endpoint are separate graph entities.\nevidence_span: {\"source_cache\": \"artifacts/niacin-clinical-sources/chen2015.abstract.txt\", \"locator\": \"Indexed primary abstract\", \"file_sha256\": \"7a305aa1d363f375f8cb640b5ddc5f77517f0229a6041558e392d7a07e198aa8\", \"start_char\": 0, \"end_char\": 2368, \"text_sha256\": \"7a305aa1d363f375f8cb640b5ddc5f77517f0229a6041558e392d7a07e198aa8\"}\n[nia-clin-chen2015] A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention. 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