I am of two minds about this.
1. People have made the most amazing recoveries when they finally hit on a drug combination that works for their myeloma. Truly. Someone can look as if they are on death's door, and then when the myeloma is controlled, they bounce back. Probably not to where they were before, but enough to have a meaningful quality of life. It can be quite shocking and unexpected! So I guess the primary issue here is the following: how far down the treatment algorithm have they gone? What are the side effects, and how risky are the future options? Because at some point the side effects and risks outweigh the benefits. And a lot of this depends on his state of health and function before all this started - ie how much can he reasonably tolerate? This is something that only the primary oncologist can answer. How much does he WANT to tolerate? This is something only he can answer.
2. On the other hand, it is difficult for doctors to have "end-of-life" conversations with patients. No doubt. Doctors are humans first, and it's tough to look mortality in the face all day long. So there are natural barriers to the conversation that goes "there's nothing else we can do", which doctor must strive to overcome in the appropriate circumstances. It's possible that they are getting false hope. Your loved one's problems sound formidable at this point. I HIGHLY recommend a palliative consultation. Palliative care is a specific specialty in medicine, just like pediatrics or neurosurgery. Palliative care doctors are experts in helping patients sort through EXACTLY these issues. They are not hospice doctors. They certainly help hospice patients at the end of life, but they do much much more than that, long before end of life. Don't wait until hospice is on the horizon to get their help. They can help clarify for the patient what their goals are, how far down the treatment line they have come, what to expect from the treatment options in the future, etc. As an ER doctor, I find that patients and families typically have a very sterilized version of what aggressive treatment would be like and what it implies. The most aggressive treatments at the end of life are brutal, traumatic, messy and painful. And frankly, at the very end of life, they are Hail Mary passes - typically unsuccessful. When I have these sorts of conversations with families, it's usually in very chaotic, time-pressured, high-anxiety situations. When there is a misconception, it's virtually always that treatment will be simpler and easier than it really would be. For example, in someone his age with his fragile bones, CPR WILL break ribs and sternum. If it doesn't, it's not being done properly. That will make healing after CPR very very difficult and painful. In 2009, in-hospital cardiac arrest had only a 22% survival rate.
http://www.nejm.org/doi/full/10.1056/NEJMoa1109148#t=article Patients often think doctors are being callous when we say things like that, but if you witnessed the aftermath of such resuscitation efforts and the emotional and physical pain involved, you'd see it's callous NOT to inform people of what it's really like. Otherwise, how are people supposed to make wise decisions?! So the ER, with all of its chaos and pressures, is definitely not the place to have this sort of conversation. Palliative care experts do this in a relaxed atmosphere, usually over more than one visit, so people have time to talk and think about it. They answer questions you've come up with in the meantime. They get to know you. Importantly, they are also experts in helping the patient cope with the current circumstances, both through referring to resources and prescribing medication. I think they are the most underutilized specialty around.
It's complicated.
Hope this helps some.