Breast cancer can be dormant for years

Breast cancer can return 20 years after a woman is first diagnosed, women might be told to continue taking hormonal drugs for longer than the current five years, in a bid to stop tumours returning. Scientists analysed data from clinical trials involving different women, all of whom had the most common form of breast cancer caused by the hormone oestrogen.

Breast cancet patient received pill treatments such as tamoxifen or aromatase inhibitors which block the effects of oestrogen or shut off the hormone's supply. After five years of therapy, their cancers had gone and they stopped taking the drugs. But monitoring the women's progress revealed recurrences of the disease up to 15 years later – 20 years after initial diagnosis.

Women who started off with large tumours and cancer that had spread to four or more lymph nodes faced the highest risk of recurrence, they had a 40 per cent risk of cancer returning in a different part of the body over a period of 15 years after treatment. For patients diagnosed with small, low-grade cancers that had not spread the risk was 10 per cent.

Recent research has suggested that extending hormone therapy to 10 years may be more effective at preventing breast cancer recurrence and death, five years of tamoxifen reduces the risk of recurrence after treatment. Aromatase inhibitors, which only work for post-menopausal women are more effective.

However, some patients choose to stop the hormone treatments early because of side effects such as menopausal symptoms, osteoporosis, joint pain or carpal tunnel syndrome.This research shows that stopping hormone treatment at five years leaves women with an ongoing risk of breast cancer coming back in future.
            haleplushearty.blogspot.com

Activation of immune T cells changes behavior

Researchers have discovered that T cells immune cells that protect the body from infections and cancer change the body's metabolism when they are activated, and that this activation leads to changes in behavior.

It is currently known that individual T cells change their metabolism to meet their energy needs after being activated, but the systemic metabolic effect of sustained activation of the immune system has remained unexplored.

 To understand the systemic effects, the group looked at T cell activation in mice designed to lack a surface receptor called PD-1, which is necessary for inhibiting the activity of T cells. T cells remain activated in mice without the receptor, similar to those in the immune systems of people with certain types of autoimmune disease.

In these mice, they found that amino acids molecules that are used to build proteins were depleted in the blood, and that they were increased in the T cells themselves, implicating the T cells in the change. The team tracked and imaged amino acids in many organs, and found that the depletion of amino acids from the blood was taking place due to the accumulation of amino acids in activated T cells in the lymph nodes, showing that strong or long lasting immune responses can cause metabolic changes elsewhere in the body.

Researchers analyzed the biochemistry of the brain, they found that the systemic decrease in the amino acids tryptophan and tyrosine in blood led to lower amounts available in the brain, limiting production of the neurotransmitters serotonin and dopamine. These neurotransmitters affect emotions, motivation and fear.

Serotonin is often a target of drugs that combat depression. The researchers found that their depletion in mice without PD-1 resulted in behavioral changes dominated by anxiety and exacerbated fear responses, which could be remedied by providing a diet rich in an essential amino acid.
          haleplushearty.blogspot.com