Betsy Marie Photography

Until February, Nathan and Elisa Bond were about as ordinary a 30-something couple as you could find in Brooklyn. Mr. Bond, 38, was a teacher and an artist; Ms. Bond, 36, worked for a real estate broker; their daughter, Sadie, had turned 1 in the fall. The last thing on their minds was cancer.

Stuart Bradford

Indeed, when Nathan Bond started having gastrointestinal problems last summer, he figured it might be lactose intolerance. Then an infectious-disease doctor diagnosed a parasitic infection, continuing to treat it even as the symptoms kept getting worse.

It wasn’t until Mr. Bond saw a gastrointestinal specialist, at his wife’s insistence, that he had a colonoscopy. On Valentine’s Day, he learned he had Stage 3 rectal cancer.

“It was very scary and overwhelming,” his wife said later. “But I thought: ‘I get to take care of him. I’m going to do whatever it takes.’ I thought this is a chance to show him now how much I love him.”

And then, nine days later, Elisa Bond was given a diagnosis of breast cancer.

Her doctor had only recently ordered a mammogram after Ms. Bond had found a lump in her breast, but it had to be delayed for a few weeks so she could wean Sadie from breast-feeding. Because she had a history of cysts, she wasn’t worried.

Yet within a week of the diagnosis she learned that the cancer was Stage 4, the most advanced: it had already spread to the liver, pelvic bones and spine.

Having a spouse with a life-threatening illness is hard enough. But what happens when both partners get sick?

Researchers have long been interested in the role that relationships play in cancer, and vice versa. In 2009, a report in the journal Cancer found that women who suffered a serious illness were seven times as likely to become separated or divorced as men with similar health problems. Other studies show that married cancer patients have higher survival rates than similar patients who are separated or widowed.

But there are no statistics on couples who must cope with illness at the same time. Neither Nathan nor Elisa Bond has a family history of cancer, and diagnoses of late-stage cancer before 40 are unusual for anyone — let alone two spouses at once.

Yet they are facing the challenges together. “We have always felt like a very united couple, very much a team,” Ms. Bond said in an interview. “We do everything together. Having cancer together was this odd, almost fitting description of us.”

To keep family members and friends up to date, Ms. Bond began a blog (familybondingtime.blogspot.com) about the couple’s diagnosis and treatment. Friends created a “Friends of Nathan and Elisa” Web site to raise money to offset the family’s health costs. Soon the couple’s story went viral, and they are inundated with e-mails of support.

“Our lives are not tragic,” Ms. Bond said. “We’ve always felt blessed and happy. It’s hard to take that away even in the face of something scary and seemingly insurmountable.”

Elisa and Nathan both had similar reactions to the dual diagnoses. They didn’t immediately worry about themselves, but both worried about how they could take care of each other.

For Nathan, a high priority “is being there for my wife and daughter when they need me,” and “I feel like a lot of that was taken away by my tumor.”

As the couple go through chemotherapy, they have relied on friends and family to take them to doctors, help manage their household in Bay Ridge and help take care of Sadie. But there are times when they must depend on each other.

The first week of Elisa’s chemotherapy treatment, she needed Nathan and called to him in another room. But he was exhausted from his own treatment.

“I couldn’t just jump up and run to her,” he said. “I had to slowly stand up and walk to the other side of the house. That was frustrating.”

Even so, they both say that having cancer together gives each of them unique insight into the other’s needs and challenges, and has surprisingly allowed them to spend more time with each other.

“If you’re going to be sick in bed, at least the person who is next to you is a person you enjoy being with,” Elisa said. “It’s a small thing, but it helps.”

The shared experience helps them focus on the importance of keeping life as normal as possible. They still have squabbles about silly things like laundry, and they still give Sadie time-outs when she misbehaves.

“If I leave this earth, I’m going to leave knowing that I have a well-behaved child,” Elisa said. “Life is going on; I’m trying to keep it as normal as possible. There’s plenty of time for love and plenty of time for discipline — I don’t have to give up one for the other just because we have cancer.”

Nathan says they are grateful to their friends, who have taken a practical and passionate approach to helping them, focusing on logistics in the short term and fund-raising for the long term. He has also been heartened by e-mails from friends who say the couple’s close relationship has inspired them.

“She’s a great person to have cancer with, which sounds like a weird statement now that I say it out loud,” he said. “She’s so strong and I admire the way she handles it, and it gives me the strength to handle it even better.

“I wouldn’t want to have cancer with anybody else but her.”

This article appeared in print on Tuesday, April 12, 2011 on page D5.