Morphine, which is given as a painkiller to many people with cancer, might stimulate the growth of tumors, 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 tumors 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 tumor 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.
According to the passage, some recent research findings concerning morphine ___.
suggest that morphine may cause tumors to grow at an increased rate
have resulted in widespread disuse of morphine in the treatment of cancer patients
have failed to find any link between it and tumor growth
and tumor growth have been discounted by the medical profession at large
have shown conclusively that morphine shouldn't be administered to cancer patients
We conclude from the passage that there is some strong evidence to suggest that ___.
Gupta’s clinical studies did not correlate with her laboratory ones
the rate of all tumor growth depends largely on the richness of the blood supply
morphine is being used less than formerly in the treatment of cancer patients
morphine caused breast cancer to develop in the mice Gupta was experimenting on
morphine assists the growth of blood vessels
It is clear from the passage that more research into the relationship between morphine and tumor growth ___.
needs to be carried out as soon as possible
is presently being carried out in a new series of clinical studies
has already been embarked on by Gupta and her colleagues