New research suggests that social interaction may have a positive effect on a person's chance of survival after being treated for cancer.

Although cancer remains one of the leading causes of death both in the United States and across the globe, cancer survival rates have improved significantly in recent years.

Little is known, however, about social interaction and whether it has any bearing on the effectiveness of common cancer therapies, such as chemotherapy.

This is why a team of researchers from the National Human Genome Research Institute (NHGRI), in collaboration with the University of Oxford in the United Kingdom, set out to examine the impact of social interaction during chemotherapy on the patients' survival rates.

The new research was published in the journal Network Science.

First author Jeff Lienert, of the NHGRI's Social and Behavioral Research Branch, led the study, which examined whether patients' 5-year chances of survival were affected by interacting with peers who also underwent chemotherapy and survived.

Studying social interaction in chemotherapy

Lienert and colleagues accessed the medical records of 4,691 cancer patients who were undergoing chemotherapy treatment in medical facilities in Oxfordshire, U.K.

The patients were around 60 years old on average, and 44 percent of them were male.

The researchers were interested in investigating "co-presence in a chemotherapy ward," so they created a network of patients that could co-inhabit in such a ward.

Lienert and team considered the total amount of time that the patients spent in each other's company.

To determine social influence, the scientists weighted the co-presence of "immediate neighbours," while also considering their 5-year mortality rate.

Lienert explains the methodology of the study, saying, "We had information on when patients checked in and out of the chemotherapy ward, a small intimate space where people could see and interact for a long period of time."

"We used 'time spent getting chemotherapy in a room with others' as a proxy for social connection," Lienert adds.

Social interaction may increase survival rates

The study found that being in the company of, and interacting with, patients who survived cancer for at least 5 years after completing the treatment led to an increase in survival rate.

Conversely, interacting with peers who were less likely to survive for at least 5 years also led to a decrease in the patients' chances of surviving.

More specifically, when the cancer patients spent time with peers who did not survive for at least 5 years, their odds of dying within the first 5 years after receiving the chemotherapy treatment were 72 percent.

However, when they interacted with patients who survived for at least 5 years, their odds of dying dropped to 68 percent.

The scientists compared these outcomes against what they determined to be the survival chances of a cancer patient in isolation, and they concluded that social interaction made up for a 2 percent increase in survival odds.

"A 2 percent difference in survival - between being isolated during treatment and being with other patients - might not sound like a lot, but it's pretty substantial [...] If you saw 5,000 patients in 9 years, that 2 percent improvement would affect 100 people." said Lienert

Although the study is observational, and the scientists cannot explain causality, they speculate that human response to stress may play a key role.

An excessive buildup of stress hormones such as adrenaline may lower one's chances of survival, Lienert hypothesises, and social interaction may help to relieve that stress.

The author also emphasises the importance of providing social support for people undergoing chemotherapy, saying that the impact of social interaction with hospital visitors would most likely prove to be just as beneficial as interacting with fellow patients.

"Positive social support during the exact moments of greatest stress is crucial. If you have a friend with cancer, keeping him or her company during chemotherapy probably will help reduce their stress. The impact is likely to be as effective, and possibly more effective, than cancer patients interacting with other cancer patients," he concludes.

Source: National Human Genome Research Institute