The scars of childhood cancer may go beyond the physical: Adults who survived cancer as children may have lower-than-average likelihood of getting married, a new study suggests.

Childhood cancer survivors are known to be at risk of long-term health effects from their cancer treatment — including hormone deficiencies, learning impairments and elevated risks of a second cancer or heart disease in adulthood.

The new findings suggest that some of these effects may also influence survivors' odds of getting married, researchers report in the journal Cancer Epidemiology, Biomarkers & Prevention.

Using data from a U.S. study of nearly 9,000 childhood cancer survivors, the investigators found that these adults were about one-quarter more likely than either the general population or their own siblings to have never been married.

Radiation for childhood brain cancer was the treatment most closely linked to marriage rates. The researchers also found that certain lingering effects of radiation — including problems with thinking and memory, impaired growth and poorer physical functioning — seemed to be involved.

"Many childhood cancer survivors still struggle to fully participate in our society because of the lasting cognitive and physical effects of their past cancer therapy," senior researcher Dr. Nina S. Kadan- Lottick, of Yale University in New Haven, Connecticut, said in a written statement.

"Our study," she added, "pinpointed what aspects of the survivor experience likely contribute to altered marriage patterns: short stature, poor physical functioning and cognitive problems."

The findings are based on almost 9,000 survivors of childhood cancers between the ages of 18 and 54, plus close to 3,000 of their siblings. Compared with those siblings, cancer survivors were 21 percent more likely to have never married.

Based on U.S. census data, survivors were also 25 percent more likely to have never married than other Americans their age, race and gender.

Across the study group, 46 percent of survivors had never married, versus about 32 percent of both siblings and the general population.

Men and women who had survived cancer of the brain or spine had the lowest marriage rate, with 62 percent having never married.

On the other hand, survivors of certain other cancers were about as likely as their siblings to marry — including those who'd had lymphoma, Hodgkin's disease, bone cancer or kidney cancer.

And when it came to divorce, childhood cancer survivors were no more likely than siblings or other U.S. adults to see their marriages end.

It is debatable, Kadan-Lottick and her colleagues write, whether marriage should be seen as a "desirable outcome." However, they note, marriage and divorce patterns can help indicate how well childhood cancer survivors are faring in their intimate relationships.

"Our results suggest that survivors of childhood cancer need ongoing support even as they enter adulthood," Kadan-Lottick said.