"focus on the topic" is a correct and usable phrase in written English.
It can be used to describe being attentive to, and discussing, a particular subject. For example, "Let's focus on the topic of the budget for the rest of the meeting."
Making the surprise announcement in St. Peter's Basilica on the second anniversary of his election, Francis said the Holy Year will focus on the topic of mercy, one of the most important themes of his papacy.
Take Denver Art Museum's Women of Abstract Expressionism, the first show to focus on the topic, which ran through the summer.
(Though they both focus on the topic of race in America, I Am Not Your Negro is quite the opposite of ESPN's justly celebrated OJ: Made In America).
The intense focus on the topic has caused anxiety among some Republicans working to win a Senate majority and keep control of the House next year.
Cuteness has not yet emerged as an independent scientific field – Dale estimates that only a few dozen academics worldwide focus on the topic – but he is hopeful that it is in the process of happening.
Asked what would most help to achieve this, respondents suggested the following: more pressure from funders of lab work; more focus on the topic by senior staff; and more cross collaboration between technical staff and facilities.
Their political interests may focus on the topics and debates in their homeland.
Today's list of "best of" are my choices of books published in 2014 that focus on the topics of human biology, psychology and medicine.
In this paper, we focus on the topic-aware influence maximization task.
In DNA sequence analysis, we focus on the topics of sequence comparison and gene recognition.
"Focus on the topics in your beat that are really changing our society".
