"key topic" is a correct phrase in written English
You can use it to refer to something that is important to the discussion or topic at hand. For example, "The key topic of discussion during the meeting was how to improve customer service."
For instance, stop and frisk, which on Monday was ruled unconstitutional, will likely be a key topic of Tuesday's debate.
The emphasis throughout is on getting children speaking and writing Chinese and each chapter introduces a new key topic.
The stability of the European financial system and the growth prospects for the Union are a key topic for today.
Moral standing is often a key topic in debates about animal rights and within bioethics, medical ethics, and environmental ethics.
Morrison will attend the G20 finance ministers meeting in China on Friday, where he expects Brexit will be a key topic of discussion.
Lombok was a particularly relevant choice, and itself a key topic, as it faces big development decisions, fuelled by an upturn in tourism.
"Politics was always a key topic at dinner parties," says Anne-Claire Taittinger, a cousin and former head of the family firm.
The projecting of status is a key topic among men who think that talking to women and having relationships demands technique.
The key topic: how television companies, book publishers and other children's brands can adapt to changing digital habits of their young audiences.
Except the panic continued into the key topic on last week's agenda, a long debate about the enlargement of the EU.
The very fact that government spending will be a key topic for the 2012 election creates a political hazard for the Democratic Party.
