Last June, Alyssa Dyal and Sumit Kashyap were fooling around on her bed when Kashyap felt her breast and suddenly pulled away.

“He was like, ‘You need to get that checked out. That could be a problem,’ ” says Dyal, 24. “I was surprised he noticed, and I was surprised at the amount of concern in his voice.”

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The grad students, who live in Boston, had met on an app and had been dating for about two months at that point. As for the lump, Dyal had noticed it before, but shrugged it off as likely harmless: Her mother and sister had both had lumps in their breasts that were found to be benign cysts. She hadn’t been to the doctor.

“I was in school full time, I was working,” Dyal says. But Kashyap’s worry stuck with her.

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Dyal went to the doctor the following week. After various tests, the diagnosis came in: She had stage four metastatic cancer.

While breast cancer diagnoses are typically made in doctors’ offices, it’s not unusual for a sexual partner to make the catch. Dyal says she’s met several women in her cancer support group that have had experiences similar to hers.

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“They notice the lump but they don’t think anything of it,” she says. “It’s usually at the insistence of a lover that they get it checked out.”

In 2002, Eric Fields diagnosed a woman shortly after meeting her at a club on a summer night. They ended up back at his place and things were heating up when he noticed that something was off.

“I kind of felt a mass right under the breast, right up against her sternum,” says Fields, a 46-year-old communications company manager living in Dallas. “I mentioned it to her, as casual as it could be in that moment.”

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When she didn’t understand what he was talking about, he says, he took her hand in his and placed it on the lump.

“She looked at me like I had a monster mask on my face,” he says.

His date wanted to continue hooking up, but Fields stopped her: He’d lost his mother the year before, to colon cancer, and couldn’t continue. A few days later, he followed up with the woman.

“I called her [and said], ‘You gotta make that appointment,’ and she was like, ‘I went yesterday.’ ”

The woman, who was in her early 20s at the time, underwent chemotherapy and had the mass removed. She’s been in remission since 2004, and she and Fields have stayed in touch. She even introduced him to the man she married in 2011.

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