Ron Denn lived in the awful space between hope and hell in 2013, as he watched his wife, Karen, fight for her life against late-stage metastatic breast cancer.

After her diagnosis in 2010, Karen pursued every option — a double-mastectomy, radiation, chemotherapy.

She died at age 50 after the cancer spread to her brain.

In her final months, there was no real benefit from treatment, Denn said pensively on Aug. 16, the second anniversary of Karen’s death.

“It took away from her physical health,” said Denn, a project manager who lives in White Bear Lake. “It affected her thinking. She was more tired.”

And yet.

“It’s a real fine line,” Denn said. “When do you give up?

“All we have to do is make it to the next treatment that works, the miracle drug,” he said. “But that’s not really the way it is.”

While tremendous progress has been made in cancer treatment, granting health and longevity to many, chemotherapy remains the norm in U.S. medicine — even for those least likely to survive. While the promise is of more days and better days, a new study reveals that, for patients with late-stage cancer, neither promise may be true.

The findings, though difficult, could be the salve needed to help doctors and patients have honest conversations that deliver the most humane care possible.

“Oncologists are of two minds,” said Holly Prigerson, author of the study published online in the July issue of JAMA Oncology.

“They sort of know this. And they don’t know what to do about it.”

The study followed 312 patients with life expectancies of six months or less. Most were male. The average age was 59. About half received end-stage chemotherapy.

Families and caregivers reported that treatment efforts in the final weeks of life were largely ineffective, or worse. Patients considered the healthiest, still able to enjoy walking, working, even eating out, were cheated most out of good days, presumably because of the drugs’ severe toxic effects.

Prigerson, an epidemiologist at Weill Cornell Medical College of New York, said further research is needed “to nail down which drugs are helpful and for how long.” But she sees a sea change coming.

“It almost seems like a movement,” said Prigerson, who is being approached by oncology groups asking her to speak about her findings and recommendations.

Oncologists do want to know how to navigate these difficult cases, she said. “They’re not denying it.”

Yet getting from theory to practice will be a formidable leap — for doctors and patients.

“The standard of care in most countries is that, if the doctor doesn’t think anything is going to work, the doctor tells the patient, and that’s the way it goes,” said Drew Rosielle, palliative medicine specialist with the University of Minnesota Health Systems. “In the United States, doctors would agree that this should be the standard, but they give treatments they know are futile because they don’t feel they have any other choice.”

While wary of generalizing, Rosielle said there are many situations in which the patient or family has unrealistic beliefs about the power of chemotherapy to prolong life. A small number of patients have been known to “fire” their doctor and seek treatment elsewhere.

“Most oncologists are caring, loving, dedicated doctors who sometimes have a hard time telling patients, ‘I don’t have any more tricks in my medicine bag,’ ” Rosielle said. “That’s where the breakdown happens.”

On the other hand, many patients are ready to stop the drugs but may have a doctor who wants to fight-fight-fight.

What’s to be done?

In light of the findings, the best scenario seems to be honesty from the get-go, based on the most accurate information possible.

“Patients, tell your doctor that you want to have a frank conversation,” Rosielle said. Doctors: Be willing to have it.

Dr. Ed Greeno, medical director of the U’s Cancer Care, agrees, adding that the best conversation is an ongoing one.

“I try to start off with, ‘OK, we’ve got multiple treatments to try over four, six, eight, 12 months,’  ” he said. “If you introduce that process gently, they know the options.

“Then, at some point, if the right choice is to not keep treating the cancer, they’ve heard that conversation already.”

The focus might then shift to emotional support, pain management, comfort care and, perhaps, hospice, with patients given space to answer other kinds of questions: What would you still like to accomplish in this life? How would you like your days to be? What worries you the most?

“Karen’s big thing was that she didn’t want to suffer, and I was right along with her,” Ron Denn said.

Allowing a loved one to get his or her affairs in order, to write a legacy to one’s children, and to feel as well as possible for as long as possible, should be seen as a win, not a loss.

“These are really hard conversations,” Greeno said. “But it’s our job to force that conversation.”