I was recently grousing about the individualized nature of multiple mye­lo­ma. In this modern day, we have some cancers that are curable, and many that are so predictable in their course that treatment is standardized.

Multiple myeloma is not either of those types of cancers. What works for you will not work for me and vice versa. Some of you started with MGUS or smoldering myeloma. Some of you may never advance beyond that. Others, and I am in this category, started right out of the gate with full-blown multiple myeloma. Mine came on quickly out of nowhere and never left, regardless of the treatment regimen.

The best phrase I could come up with to describe the nature of multiple myeloma was sui generis, which means "of its own kind," or "unique to itself." In the law, you will come across sui generis in an opinion where the facts of the case are so peculiar and specific that the court (usually an appellate one) recognizes that the holding will only apply to this case and no other.

I like the phrase, but it wasn’t exactly what I was looking for in describing multiple myeloma.

It was my husband Warren who came up with the best analogy.

“It’s the difference between steam and diesel locomotives.”

Note: You need to know that Warren is one of those train guys. You know, the kind that slow down so they will be stopped by the descending railroad gates so they can watch the train roll by and identify which type of engine is pulling the cars. The one who can tell you the status of the restoration of Big Boy No. 4014 in Cheyenne, Wyoming. That kind of guy.

I’m not a train girl, so my response was “What?”

Warren then proceeded to explain why multiple myeloma, when compared to more “conventional” (that is, curable or standardized treatable cancers) was the steam locomotive of the oncology world.

Per my train guy, there were two major shifts in the rail industry with the transition from steam to diesel engines in the twentieth century.

The first shift was external. In this country, the railroad companies began retiring the steam locomotives and replacing them with diesel engines in post-war America. For the most part, the steam locomotives were gone by the late 1950s and early 1960s. Today we look back upon the steam age as part of a romantic and now long vanished past. Fewer and fewer of us have seen a live steam locomotive, except as part of a special excursion or private line.

The second shift was internal within the industry. Steam engines were built one by one. While there was industrial standardization (such as the track width and rail size), each steam locomotive was custom built for the railroad line ordering it. Each line had its own shops and its own unique engines for maximum impact for the road’s needs. As a result, every single steam locomotive was unique, even within its own class with the same railroad.

In contrast, diesel locomotives were quickly standardized and mass-produced. A railroad could decide to add 500 diesel engines, contact an outside manufacturer such as GE, and soon there would be 500 identical diesel locomotives en route to the rail yard.

Oh, now I get it.

Some cancers, and their treatment, are like those diesel engines. When a friend of mine was diagnosed with an aggressive breast cancer, she had her treatment plan at the first oncology appointment. For the most part, breast cancer today is a diesel locomotive. Once the cancer is typed, the treatment plan follows swiftly.

Twelve years into my out-of-the gate multiple myeloma, with the disease progressing and the responsive treatment changing, sometimes quickly, especially over the last five years, I know what I have. I’ve got the steam locomotive, with my oncologists configuring and reconfiguring the specs of their response with every relapse. Like the steam locomotive, each single case of multiple myeloma, including mine, is unique, even at the same stage.

I know, of course, that any cancer, even the ones the oncology world seems to have solved, always have the potential to rebel and not fit the mold. Sometimes even diesels blow up. Trust me, I am not making light of nor envying those with diesels.

I am, however, stuck on the steam engine, looking at the firebox, wondering what’s burning in there. I am counting the wheel arrangement, trying to guesstimate how fast this baby is capable of running with the throttle wide open. My oncologists and I have not seen the multiple myeloma run full throttle yet, but we know that capacity is there.

And I already have my ticket punched.