The Saracens flyer broke into the top 10 England try scorers of all time last weekend with a close-range score in the 38-18 victory over Scotland.
Ashton aims to one day surpass legendary wing Rory Underwood's record of 49 tries from 85 Tests and top the list of England's all-time leading try scorers.
He said: "It is an honour to be on that list with them all. I hope to be on top of it one day and then sit back and reflect on it - but not now."
"I am only 25. I have been here for three years and hopefully I will be here for a lot longer."
England still have a chance of winning the Grand Slam this year.