SORU: aşağıdaki parçaya göre cevaplayınız
It is clear from the passage that more research into the relationship between morphine and tumour growth----.
Morphine, which is given as a painkiller to many
people with cancer, might stimulate the growth of
tumours, say researchers in the US. Their worrying
findings have been questioned by others in the
field, but all agree that further studies are urgently
needed to settle the issue. In test-tube experiments
and in mice, Kalpna Gupta and her colleagues
found that morphine encourages the growth of
blood vessels, known as angiogenesis. The
increased blood supply accelerated the growth of
breast tumours in mice. Although the researchers
have not yet looked for this effect in people, Gupta
warns that morphine could be harmful for patients
with any form of solid tumour that depends on a
healthy blood supply. She stresses that nobody
should yet consider altering their use of morphine
because of her findings. "But clinical studies must
be done," she says.