A new immunotherapy treatment for aggressive stomach cancer has been approved by the NHS spending watchdog. The National Institute for Health and Care Excellence (Nice) has given the green light for the immunotherapy drug durvalumab, also known as Imfinzi and made by AstraZeneca, to be used by the NHS for adults whose stomach cancer has not spread extensively and can be surgically removed. An estimated 1,500 people annually could benefit following the ruling. Immunotherapy helps harness the body’s immune system to fight cancer. Trials have shown that durvalumab plus chemotherapy can increase the amount of time people have before their cancer progresses, and has also been shown to increase survival. The decision was hailed as the "first major advance" in stomach cancer treatment for nearly a decade.…