Drugmaker AstraZeneca forecast a second straight year of sales growth on Thursday, driven by revenue from cancer medicines and other new treatments, lifting its shares.

Shares in AstraZeneca, which reported better than expected fourth-quarter results, were up 5.1 percent to 6,015 pence by 1040 GMT, on track for their best day in more than 18 months.

After a sharp sales fall following his appointment in 2012 due to the expiry of major patents, the results were the latest vindication of Chief Executive Officer Pascal Soriot's strategy for rebooting the British drugmaker.

Sales of cancer drugs Tagrisso, Imfinzi and Lynparza were central to the gains, with oncology sales rising 61 percent to $1.78 billion. Chinese sales, which have more than doubled since 2012, rose by 22 percent to almost $1 billion.

"What is happening in China is exciting... it is even better than what we expected," Soriot told a news conference, while cautioning that growth in the world's second biggest economy may be slower this year.

AstraZeneca has suffered the biggest loss of drug patents since 2012, wiping out more than half of its sales, but analysts believe it is poised for one of the fastest growth rates in the coming years.

"2018 feels like the year Astra turned the corner," Nicholas Hyett, equity analyst at Hargreaves Lansdown, said. "The Oncology portfolio is going from strength to strength... even after recent successes, the pipeline of new drugs looks rich."

Of the successful new treatments, Imfinzi and Tagrisso treat lung cancer, Lynparza ovarian cancer and Fasenra severe asthma. Sales for all of them beat analysts' forecast for the quarter.

Tagrisso, which brought in $1.86 billion in 2018 and accounts for 9 percent of total product sales, will likely become its top selling medicine in 2019, AstraZeneca said.

The company was also the latest big drug producer to say that it had made extensive preparations for Brexit, adding it assumed that Britain's departure from the European Union would be "orderly" even if it leaves without a deal with Brussels.

The highly regulated drugs sector is seen as one of the most vulnerable to a "no-deal" outcome due to its pan-European supply chains and need for regulatory oversight.

Overall product sales in the three months ended Dec. 31 rose 8 percent to $5.77 billion at constant currency ahead of a company provided analyst estimate of $5.66 billion.

The drugmaker expects a high single-digit percentage rise in sales in 2019 and core earnings of $3.50 to $3.70 per share.

(Reporting by Pushkala Aripaka and Ankur Banerjee in Bengaluru and Paul Sandle in London; editing by Patrick Graham and Alexander Smith) ((ankur.banerjee@thomsonreuters.com;; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 6132; Reuters Messaging: ankur.banerjee.thomsonreuters.com@reuters.net; Twitter: @AnkurBanerjee17))