Family and friends say it's out of character for Daniel Bouchard, 20, to disappear without telling anyone. (Bouchard family)

Concern and frustration are mounting among the families whose loved ones — all young, athletic men — have mysteriously vanished in B.C.'s Lower Mainland in the last year.

"Your heart surely goes out for all these people who have lost their children and haven't heard from them. It's only been four days for me and I don't know how they do it," said Dan Bouchard.

Bouchard's son, Daniel, 20, is the latest in a growing list of young men who have disappeared without a trace in the Lower Mainland.

Daniel Bouchard of White Rock went missing Monday night on the way back to his basement suite from a local pub.

Dan Bouchard hopes the public will help police find his missing son, Daniel. (CBC)

His parents said it's completely out of character for Bouchard to take off without a reason and miss work.

"[Police] have been in constant contact with me. Unfortunately, they haven't been able to tell me much because they're not finding out a lot but I'm confident this is a top priority especially with what's happened recently," Dan Bouchard told CBC News on Friday.

Police have not drawn any link in these six missing cases but John Kahler's sister, Lori, said they bear striking similarities because the men all were relatively young, athletic and good looking.

Lori Kahler, whose brother John disappeared in November of last year, says the six most recent disappearances are strikingly similar because the men all were young, athletic and good looking. (CBC)

"Between a lot of them, yes, I do see somewhat of a link," she told CBC News on Friday.

"The fact that none of these men have been found is very frustrating to me, because the closure point after seven, eight months is really what we need," she said.

Paula McElwee's son, Kellen, disappeared after a dinner out with friends three months ago. She said she couldn't help but think about different theories that may link the missing cases.

"Is someone kidnapping them and taking them to some kind of fight club and they have to fight their way out?" she said on Friday.

RCMP Cpl. Karen Boreham, who heads up the force's provincial missing persons unit, said there's no evidence of a connection in these cases.

"The least likely reason that you would go missing in British Columbia — whether you are a man or woman — would be as a result of foul play," Boreham said.

"The most likely reason that a person would go missing would be accident," she said.